From df851d59441d8dec12456dc6aad1099cb8c77b69 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 20 Dec 2022 21:29:39 -0800
Subject: [PATCH 01/87] Rename generator class to Adapter

---
 packages/pigeon/lib/pigeon_lib.dart | 143 ++++++++++++++--------------
 1 file changed, 72 insertions(+), 71 deletions(-)

diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 5da91c4a7c5..a8348ea7474 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -355,18 +355,19 @@ IOSink? _openSink(String? output) {
   return sink;
 }
 
-/// A generator that will write code to a sink based on the contents of [PigeonOptions].
-abstract class Generator {
-  /// Returns an [IOSink] instance to be written to if the [Generator] should
-  /// generate.  If it returns `null`, the [Generator] will be skipped.
+/// An adapter that will call a generator to write code to a sink
+/// based on the contents of [PigeonOptions].
+abstract class Adapter {
+  /// Returns an [IOSink] instance to be written to if the [Adapter] should
+  /// generate.  If it returns `null`, the [Adapter] will be skipped.
   IOSink? shouldGenerate(PigeonOptions options);
 
   /// Write the generated code described in [root] to [sink] using the
   /// [options].
   void generate(StringSink sink, PigeonOptions options, Root root);
 
-  /// Generates errors that would only be appropriate for this [Generator]. For
-  /// example, maybe a certain feature isn't implemented in a [Generator] yet.
+  /// Generates errors that would only be appropriate for this [Adapter]. For
+  /// example, maybe a certain feature isn't implemented in a [Adapter] yet.
   List<Error> validate(PigeonOptions options, Root root);
 }
 
@@ -378,10 +379,10 @@ DartOptions _dartOptionsWithCopyrightHeader(
           copyrightHeader != null ? _lineReader(copyrightHeader) : null));
 }
 
-/// A [Generator] that generates the AST.
-class AstGenerator implements Generator {
-  /// Constructor for [AstGenerator].
-  const AstGenerator();
+/// A [Adapter] that generates the AST.
+class AstAdapter implements Adapter {
+  /// Constructor for [AstAdapter].
+  const AstAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -395,10 +396,10 @@ class AstGenerator implements Generator {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Generator] that generates Dart source code.
-class DartGenerator implements Generator {
-  /// Constructor for [DartGenerator].
-  const DartGenerator();
+/// A [Adapter] that generates Dart source code.
+class DartAdapter implements Adapter {
+  /// Constructor for [DartAdapter].
+  const DartAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -414,10 +415,10 @@ class DartGenerator implements Generator {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Generator] that generates Dart test source code.
-class DartTestGenerator implements Generator {
-  /// Constructor for [DartTestGenerator].
-  const DartTestGenerator();
+/// A [Adapter] that generates Dart test source code.
+class DartTestAdapter implements Adapter {
+  /// Constructor for [DartTestAdapter].
+  const DartTestAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -445,10 +446,10 @@ class DartTestGenerator implements Generator {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Generator] that generates Objective-C header code.
-class ObjcHeaderGenerator implements Generator {
-  /// Constructor for [ObjcHeaderGenerator].
-  const ObjcHeaderGenerator();
+/// A [Adapter] that generates Objective-C header code.
+class ObjcHeaderAdapter implements Adapter {
+  /// Constructor for [ObjcHeaderAdapter].
+  const ObjcHeaderAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -469,10 +470,10 @@ class ObjcHeaderGenerator implements Generator {
       validateObjc(options.objcOptions!, root);
 }
 
-/// A [Generator] that generates Objective-C source code.
-class ObjcSourceGenerator implements Generator {
-  /// Constructor for [ObjcSourceGenerator].
-  const ObjcSourceGenerator();
+/// A [Adapter] that generates Objective-C source code.
+class ObjcSourceAdapter implements Adapter {
+  /// Constructor for [ObjcSourceAdapter].
+  const ObjcSourceAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -492,10 +493,10 @@ class ObjcSourceGenerator implements Generator {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Generator] that generates Java source code.
-class JavaGenerator implements Generator {
-  /// Constructor for [JavaGenerator].
-  const JavaGenerator();
+/// A [Adapter] that generates Java source code.
+class JavaAdapter implements Adapter {
+  /// Constructor for [JavaAdapter].
+  const JavaAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -516,10 +517,10 @@ class JavaGenerator implements Generator {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Generator] that generates Swift source code.
-class SwiftGenerator implements Generator {
-  /// Constructor for [SwiftGenerator].
-  const SwiftGenerator();
+/// A [Adapter] that generates Swift source code.
+class SwiftAdapter implements Adapter {
+  /// Constructor for [SwiftAdapter].
+  const SwiftAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -538,10 +539,10 @@ class SwiftGenerator implements Generator {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Generator] that generates C++ header code.
-class CppHeaderGenerator implements Generator {
-  /// Constructor for [CppHeaderGenerator].
-  const CppHeaderGenerator();
+/// A [Adapter] that generates C++ header code.
+class CppHeaderAdapter implements Adapter {
+  /// Constructor for [CppHeaderAdapter].
+  const CppHeaderAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -563,10 +564,10 @@ class CppHeaderGenerator implements Generator {
       validateCpp(options.cppOptions!, root);
 }
 
-/// A [Generator] that generates C++ source code.
-class CppSourceGenerator implements Generator {
-  /// Constructor for [CppSourceGenerator].
-  const CppSourceGenerator();
+/// A [Adapter] that generates C++ source code.
+class CppSourceAdapter implements Adapter {
+  /// Constructor for [CppSourceAdapter].
+  const CppSourceAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -586,10 +587,10 @@ class CppSourceGenerator implements Generator {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Generator] that generates Kotlin source code.
-class KotlinGenerator implements Generator {
-  /// Constructor for [KotlinGenerator].
-  const KotlinGenerator();
+/// A [Adapter] that generates Kotlin source code.
+class KotlinAdapter implements Adapter {
+  /// Constructor for [KotlinAdapter].
+  const KotlinAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -1331,37 +1332,37 @@ ${_argParser.usage}''';
   }
 
   /// The 'main' entrypoint used by the command-line tool.  [args] are the
-  /// command-line arguments.  The optional parameter [generators] allows you to
+  /// command-line arguments.  The optional parameter [adapters] allows you to
   /// customize the generators that pigeon will use. The optional parameter
   /// [sdkPath] allows you to specify the Dart SDK path.
   static Future<int> run(List<String> args,
-      {List<Generator>? generators, String? sdkPath}) {
+      {List<Adapter>? adapters, String? sdkPath}) {
     final PigeonOptions options = Pigeon.parseArgs(args);
-    return runWithOptions(options, generators: generators, sdkPath: sdkPath);
+    return runWithOptions(options, adapters: adapters, sdkPath: sdkPath);
   }
 
   /// The 'main' entrypoint used by external packages.  [options] is
-  /// used when running the code generator.  The optional parameter [generators] allows you to
+  /// used when running the code generator.  The optional parameter [adapters] allows you to
   /// customize the generators that pigeon will use. The optional parameter
   /// [sdkPath] allows you to specify the Dart SDK path.
   static Future<int> runWithOptions(PigeonOptions options,
-      {List<Generator>? generators, String? sdkPath}) async {
+      {List<Adapter>? adapters, String? sdkPath}) async {
     final Pigeon pigeon = Pigeon.setup();
     if (options.debugGenerators ?? false) {
       generator_tools.debugGenerators = true;
     }
-    final List<Generator> safeGenerators = generators ??
-        <Generator>[
-          const DartGenerator(),
-          const JavaGenerator(),
-          const SwiftGenerator(),
-          const KotlinGenerator(),
-          const CppHeaderGenerator(),
-          const CppSourceGenerator(),
-          const DartTestGenerator(),
-          const ObjcHeaderGenerator(),
-          const ObjcSourceGenerator(),
-          const AstGenerator(),
+    final List<Adapter> safeAdapters = adapters ??
+        <Adapter>[
+          const DartAdapter(),
+          const JavaAdapter(),
+          const SwiftAdapter(),
+          const KotlinAdapter(),
+          const CppHeaderAdapter(),
+          const CppSourceAdapter(),
+          const DartTestAdapter(),
+          const ObjcHeaderAdapter(),
+          const ObjcSourceAdapter(),
+          const AstAdapter(),
         ];
     _executeConfigurePigeon(options);
 
@@ -1383,12 +1384,12 @@ ${_argParser.usage}''';
       }
     }
 
-    for (final Generator generator in safeGenerators) {
-      final IOSink? sink = generator.shouldGenerate(options);
+    for (final Adapter adapter in safeAdapters) {
+      final IOSink? sink = adapter.shouldGenerate(options);
       if (sink != null) {
-        final List<Error> generatorErrors =
-            generator.validate(options, parseResults.root);
-        errors.addAll(generatorErrors);
+        final List<Error> adapterErrors =
+            adapter.validate(options, parseResults.root);
+        errors.addAll(adapterErrors);
         await releaseSink(sink);
       }
     }
@@ -1425,10 +1426,10 @@ ${_argParser.usage}''';
               CppOptions(header: path.basename(options.cppHeaderOut!)))));
     }
 
-    for (final Generator generator in safeGenerators) {
-      final IOSink? sink = generator.shouldGenerate(options);
+    for (final Adapter adapter in safeAdapters) {
+      final IOSink? sink = adapter.shouldGenerate(options);
       if (sink != null) {
-        generator.generate(sink, options, parseResults.root);
+        adapter.generate(sink, options, parseResults.root);
         await sink.flush();
         await releaseSink(sink);
       }

From e40d679b8bacd7af8b6d913d3c5e5d96462be2da Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 20 Dec 2022 21:30:01 -0800
Subject: [PATCH 02/87] create new generator class and dart subclass

---
 packages/pigeon/lib/dart_generator.dart | 17 +++++++++++++++
 packages/pigeon/lib/generator.dart      | 29 +++++++++++++++++++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 packages/pigeon/lib/generator.dart

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 85956ced69e..c9c672a661d 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -9,6 +9,7 @@ import 'package:yaml/yaml.dart' as yaml;
 
 import 'ast.dart';
 import 'functional.dart';
+import 'generator.dart';
 import 'generator_tools.dart';
 
 /// Documentation comment open symbol.
@@ -55,6 +56,22 @@ class DartOptions {
   }
 }
 
+/// Class that manages all coe generation.
+class DartGenerator extends Generator<DartOptions> {
+  /// Instantiates a Generator.
+  DartGenerator({
+    required DartOptions languageOptions,
+    required Root root,
+    required StringSink sink,
+  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+
+  /// Generates files for specified language with specified [languageOptions]
+  @override
+  void generate() {
+    //
+  }
+}
+
 String _escapeForDartSingleQuotedString(String raw) {
   return raw
       .replaceAll(r'\', r'\\')
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
new file mode 100644
index 00000000000..f45c113a7b6
--- /dev/null
+++ b/packages/pigeon/lib/generator.dart
@@ -0,0 +1,29 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'ast.dart';
+
+/// A Super class of generator classes.
+///
+/// This is meant to provide structure and direction for future generator work.
+abstract class Generator<T> {
+  /// Instantiates a Generator.
+  const Generator({
+    required this.languageOptions,
+    required this.root,
+    required this.sink,
+  });
+
+  ///
+  final T languageOptions;
+
+  ///
+  final Root root;
+
+  ///
+  final StringSink sink;
+
+  /// Generates files for specified language with specified [languageOptions]
+  void generate();
+}

From 8c4e2a0a2b888f924638ba65d6e0a581836ee604 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 21 Dec 2022 11:57:23 -0800
Subject: [PATCH 03/87] cpp and dart test gen

---
 packages/pigeon/lib/dart_generator.dart | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index c9c672a661d..f9042b148ac 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -56,16 +56,16 @@ class DartOptions {
   }
 }
 
-/// Class that manages all coe generation.
+/// Class that manages all Dart code generation.
 class DartGenerator extends Generator<DartOptions> {
-  /// Instantiates a Generator.
+  /// Instantiates a Dart Generator.
   DartGenerator({
     required DartOptions languageOptions,
     required Root root,
     required StringSink sink,
   }) : super(languageOptions: languageOptions, root: root, sink: sink);
 
-  /// Generates files for specified language with specified [languageOptions]
+  /// Generates Dart files with specified [DartOptions]
   @override
   void generate() {
     //

From bcdbdbcaf089550dac5c14b1c66e6ef5b6838b69 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 21 Dec 2022 11:58:03 -0800
Subject: [PATCH 04/87] added files

---
 packages/pigeon/lib/cpp_generator.dart  | 33 +++++++++++++++++++++++++
 packages/pigeon/lib/dart_generator.dart | 16 ++++++++++++
 packages/pigeon/lib/pigeon_lib.dart     | 20 +++++++--------
 3 files changed, 59 insertions(+), 10 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 744f6e9ffce..584d4792ff2 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -4,6 +4,7 @@
 
 import 'ast.dart';
 import 'functional.dart';
+import 'generator.dart';
 import 'generator_tools.dart';
 import 'pigeon_lib.dart' show Error;
 
@@ -64,6 +65,38 @@ class CppOptions {
   }
 }
 
+/// Class that manages all Cpp header code generation.
+class CppHeaderGenerator extends Generator<CppOptions> {
+  /// Instantiates a Cpp Generator.
+  CppHeaderGenerator({
+    required CppOptions languageOptions,
+    required Root root,
+    required StringSink sink,
+  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+
+  /// Generates Cpp header files with specified [CppOptions]
+  @override
+  void generate() {
+    //
+  }
+}
+
+/// Class that manages all Cpp code generation.
+class CppSourceGenerator extends Generator<CppOptions> {
+  /// Instantiates a Cpp Generator.
+  CppSourceGenerator({
+    required CppOptions languageOptions,
+    required Root root,
+    required StringSink sink,
+  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+
+  /// Generates Cpp files with specified [CppOptions]
+  @override
+  void generate() {
+    //
+  }
+}
+
 String _getCodecSerializerName(Api api) => '${api.name}CodecSerializer';
 
 const String _pointerPrefix = 'pointer';
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index f9042b148ac..4ddbe9056ef 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -72,6 +72,22 @@ class DartGenerator extends Generator<DartOptions> {
   }
 }
 
+/// Class that manages all Dart code generation.
+class DartTestGenerator extends Generator<DartOptions> {
+  /// Instantiates a Dart Generator.
+  DartTestGenerator({
+    required DartOptions languageOptions,
+    required Root root,
+    required StringSink sink,
+  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+
+  /// Generates Dart files with specified [DartOptions]
+  @override
+  void generate() {
+    //
+  }
+}
+
 String _escapeForDartSingleQuotedString(String raw) {
   return raw
       .replaceAll(r'\', r'\\')
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index a8348ea7474..5bab11a01bb 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -379,7 +379,7 @@ DartOptions _dartOptionsWithCopyrightHeader(
           copyrightHeader != null ? _lineReader(copyrightHeader) : null));
 }
 
-/// A [Adapter] that generates the AST.
+/// An [Adapter] that generates the AST.
 class AstAdapter implements Adapter {
   /// Constructor for [AstAdapter].
   const AstAdapter();
@@ -396,7 +396,7 @@ class AstAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Adapter] that generates Dart source code.
+/// An [Adapter] that generates Dart source code.
 class DartAdapter implements Adapter {
   /// Constructor for [DartAdapter].
   const DartAdapter();
@@ -415,7 +415,7 @@ class DartAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Adapter] that generates Dart test source code.
+/// An [Adapter] that generates Dart test source code.
 class DartTestAdapter implements Adapter {
   /// Constructor for [DartTestAdapter].
   const DartTestAdapter();
@@ -446,7 +446,7 @@ class DartTestAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Adapter] that generates Objective-C header code.
+/// An [Adapter] that generates Objective-C header code.
 class ObjcHeaderAdapter implements Adapter {
   /// Constructor for [ObjcHeaderAdapter].
   const ObjcHeaderAdapter();
@@ -470,7 +470,7 @@ class ObjcHeaderAdapter implements Adapter {
       validateObjc(options.objcOptions!, root);
 }
 
-/// A [Adapter] that generates Objective-C source code.
+/// An [Adapter] that generates Objective-C source code.
 class ObjcSourceAdapter implements Adapter {
   /// Constructor for [ObjcSourceAdapter].
   const ObjcSourceAdapter();
@@ -493,7 +493,7 @@ class ObjcSourceAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Adapter] that generates Java source code.
+/// An [Adapter] that generates Java source code.
 class JavaAdapter implements Adapter {
   /// Constructor for [JavaAdapter].
   const JavaAdapter();
@@ -517,7 +517,7 @@ class JavaAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Adapter] that generates Swift source code.
+/// An [Adapter] that generates Swift source code.
 class SwiftAdapter implements Adapter {
   /// Constructor for [SwiftAdapter].
   const SwiftAdapter();
@@ -539,7 +539,7 @@ class SwiftAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Adapter] that generates C++ header code.
+/// An [Adapter] that generates C++ header code.
 class CppHeaderAdapter implements Adapter {
   /// Constructor for [CppHeaderAdapter].
   const CppHeaderAdapter();
@@ -564,7 +564,7 @@ class CppHeaderAdapter implements Adapter {
       validateCpp(options.cppOptions!, root);
 }
 
-/// A [Adapter] that generates C++ source code.
+/// An [Adapter] that generates C++ source code.
 class CppSourceAdapter implements Adapter {
   /// Constructor for [CppSourceAdapter].
   const CppSourceAdapter();
@@ -587,7 +587,7 @@ class CppSourceAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [Adapter] that generates Kotlin source code.
+/// An [Adapter] that generates Kotlin source code.
 class KotlinAdapter implements Adapter {
   /// Constructor for [KotlinAdapter].
   const KotlinAdapter();

From 31bb7019a1065d505ee4ab34dca147cf2c7e0df7 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 21 Dec 2022 12:09:44 -0800
Subject: [PATCH 05/87] Adds Generator class to all generators

---
 packages/pigeon/lib/java_generator.dart   | 17 ++++++++++++
 packages/pigeon/lib/kotlin_generator.dart | 17 ++++++++++++
 packages/pigeon/lib/objc_generator.dart   | 33 +++++++++++++++++++++++
 3 files changed, 67 insertions(+)

diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index c52d976cfdf..e77c11da941 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -4,6 +4,7 @@
 
 import 'ast.dart';
 import 'functional.dart';
+import 'generator.dart';
 import 'generator_tools.dart';
 import 'pigeon_lib.dart' show TaskQueueType;
 
@@ -84,6 +85,22 @@ class JavaOptions {
   }
 }
 
+/// Class that manages all Java code generation.
+class JavaGenerator extends Generator<JavaOptions> {
+  /// Instantiates a Java Generator.
+  JavaGenerator({
+    required JavaOptions languageOptions,
+    required Root root,
+    required StringSink sink,
+  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+
+  /// Generates Java files with specified [JavaOptions]
+  @override
+  void generate() {
+    //
+  }
+}
+
 /// Calculates the name of the codec that will be generated for [api].
 String _getCodecName(Api api) => '${api.name}Codec';
 
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 1f52d3d22c3..371987d70af 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -4,6 +4,7 @@
 
 import 'ast.dart';
 import 'functional.dart';
+import 'generator.dart';
 import 'generator_tools.dart';
 import 'pigeon_lib.dart' show TaskQueueType;
 
@@ -64,6 +65,22 @@ class KotlinOptions {
   }
 }
 
+/// Class that manages all Kotlin code generation.
+class KotlinGenerator extends Generator<KotlinOptions> {
+  /// Instantiates a Kotlin Generator.
+  KotlinGenerator({
+    required KotlinOptions languageOptions,
+    required Root root,
+    required StringSink sink,
+  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+
+  /// Generates Kotlin files with specified [KotlinOptions]
+  @override
+  void generate() {
+    //
+  }
+}
+
 /// Calculates the name of the codec that will be generated for [api].
 String _getCodecName(Api api) => '${api.name}Codec';
 
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index e8de7c1154c..e1e5815bcaa 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -4,6 +4,7 @@
 
 import 'ast.dart';
 import 'functional.dart';
+import 'generator.dart';
 import 'generator_tools.dart';
 import 'pigeon_lib.dart' show Error, TaskQueueType;
 
@@ -63,6 +64,38 @@ class ObjcOptions {
   }
 }
 
+/// Class that manages all Objc header code generation.
+class ObjcHeaderGenerator extends Generator<ObjcOptions> {
+  /// Instantiates a Objc Generator.
+  ObjcHeaderGenerator({
+    required ObjcOptions languageOptions,
+    required Root root,
+    required StringSink sink,
+  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+
+  /// Generates Objc header files with specified [ObjcOptions]
+  @override
+  void generate() {
+    //
+  }
+}
+
+/// Class that manages all Objc code generation.
+class ObjcSourceGenerator extends Generator<ObjcOptions> {
+  /// Instantiates a Objc Generator.
+  ObjcSourceGenerator({
+    required ObjcOptions languageOptions,
+    required Root root,
+    required StringSink sink,
+  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+
+  /// Generates Objc files with specified [ObjcOptions]
+  @override
+  void generate() {
+    //
+  }
+}
+
 /// Calculates the ObjC class name, possibly prefixed.
 String _className(String? prefix, String className) {
   if (prefix != null) {

From 06315ce0c5c32aa4a9ae948014669e06c040c1e6 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 21 Dec 2022 12:16:34 -0800
Subject: [PATCH 06/87] adds swift

---
 packages/pigeon/lib/swift_generator.dart | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 3736506c1e7..8db09cf96bc 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -4,6 +4,7 @@
 
 import 'ast.dart';
 import 'functional.dart';
+import 'generator.dart';
 import 'generator_tools.dart';
 
 /// Documentation comment open symbol.
@@ -47,6 +48,22 @@ class SwiftOptions {
   }
 }
 
+/// Class that manages all Swift code generation.
+class SwiftGenerator extends Generator<SwiftOptions> {
+  /// Instantiates a Swift Generator.
+  SwiftGenerator({
+    required SwiftOptions languageOptions,
+    required Root root,
+    required StringSink sink,
+  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+
+  /// Generates Swift files with specified [SwiftOptions]
+  @override
+  void generate() {
+    //
+  }
+}
+
 /// Calculates the name of the codec that will be generated for [api].
 String _getCodecName(Api api) => '${api.name}Codec';
 

From 5675c646717296c9a0444f8714c5fb258ce39d06 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 21 Dec 2022 12:25:11 -0800
Subject: [PATCH 07/87] Updates tests to use new Adapter naming scheme

---
 packages/pigeon/test/pigeon_lib_test.dart | 48 +++++++++++------------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/packages/pigeon/test/pigeon_lib_test.dart b/packages/pigeon/test/pigeon_lib_test.dart
index 4a121e7e9e0..411643f679f 100644
--- a/packages/pigeon/test/pigeon_lib_test.dart
+++ b/packages/pigeon/test/pigeon_lib_test.dart
@@ -9,8 +9,8 @@ import 'package:pigeon/ast.dart';
 import 'package:pigeon/pigeon_lib.dart';
 import 'package:test/test.dart';
 
-class _ValidatorGenerator implements Generator {
-  _ValidatorGenerator(this.sink);
+class _ValidatorAdapter implements Adapter {
+  _ValidatorAdapter(this.sink);
   bool didCallValidate = false;
 
   final IOSink? sink;
@@ -397,9 +397,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const DartGenerator dartGenerator = DartGenerator();
+    const DartAdapter dartAdapter = DartAdapter();
     final StringBuffer buffer = StringBuffer();
-    dartGenerator.generate(buffer, options, root);
+    dartAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -407,9 +407,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options = PigeonOptions(
         javaOut: 'Foo.java', copyrightHeader: './copyright_header.txt');
-    const JavaGenerator javaGenerator = JavaGenerator();
+    const JavaAdapter javaAdapter = JavaAdapter();
     final StringBuffer buffer = StringBuffer();
-    javaGenerator.generate(buffer, options, root);
+    javaAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -417,9 +417,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const ObjcHeaderGenerator objcHeaderGenerator = ObjcHeaderGenerator();
+    const ObjcHeaderAdapter objcHeaderAdapter = ObjcHeaderAdapter();
     final StringBuffer buffer = StringBuffer();
-    objcHeaderGenerator.generate(buffer, options, root);
+    objcHeaderAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -427,9 +427,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const ObjcSourceGenerator objcSourceGenerator = ObjcSourceGenerator();
+    const ObjcSourceAdapter objcSourceAdapter = ObjcSourceAdapter();
     final StringBuffer buffer = StringBuffer();
-    objcSourceGenerator.generate(buffer, options, root);
+    objcSourceAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -437,9 +437,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options = PigeonOptions(
         swiftOut: 'Foo.swift', copyrightHeader: './copyright_header.txt');
-    const SwiftGenerator swiftGenerator = SwiftGenerator();
+    const SwiftAdapter swiftAdapter = SwiftAdapter();
     final StringBuffer buffer = StringBuffer();
-    swiftGenerator.generate(buffer, options, root);
+    swiftAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -447,9 +447,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options = PigeonOptions(
         cppHeaderOut: 'Foo.h', copyrightHeader: './copyright_header.txt');
-    const CppHeaderGenerator cppHeaderGenerator = CppHeaderGenerator();
+    const CppHeaderAdapter cppHeaderAdapter = CppHeaderAdapter();
     final StringBuffer buffer = StringBuffer();
-    cppHeaderGenerator.generate(buffer, options, root);
+    cppHeaderAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -457,9 +457,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const CppSourceGenerator cppSourceGenerator = CppSourceGenerator();
+    const CppSourceAdapter cppSourceAdapter = CppSourceAdapter();
     final StringBuffer buffer = StringBuffer();
-    cppSourceGenerator.generate(buffer, options, root);
+    cppSourceAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -929,9 +929,9 @@ abstract class Api {
       dartTestOut: 'stdout',
       dartOut: 'stdout',
     );
-    const DartTestGenerator dartGenerator = DartTestGenerator();
+    const DartTestAdapter dartAdapter = DartTestAdapter();
     final StringBuffer buffer = StringBuffer();
-    dartGenerator.generate(buffer, options, root);
+    dartAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -1187,9 +1187,9 @@ abstract class Api {
   test('generator validation', () async {
     final Completer<void> completer = Completer<void>();
     withTempFile('foo.dart', (File input) async {
-      final _ValidatorGenerator generator = _ValidatorGenerator(stdout);
+      final _ValidatorAdapter generator = _ValidatorAdapter(stdout);
       final int result = await Pigeon.run(<String>['--input', input.path],
-          generators: <Generator>[generator]);
+          adapters: <Adapter>[generator]);
       expect(generator.didCallValidate, isTrue);
       expect(result, isNot(0));
       completer.complete();
@@ -1200,10 +1200,10 @@ abstract class Api {
   test('generator validation skipped', () async {
     final Completer<void> completer = Completer<void>();
     withTempFile('foo.dart', (File input) async {
-      final _ValidatorGenerator generator = _ValidatorGenerator(null);
+      final _ValidatorAdapter generator = _ValidatorAdapter(null);
       final int result = await Pigeon.run(
           <String>['--input', input.path, '--dart_out', 'foo.dart'],
-          generators: <Generator>[generator]);
+          adapters: <Adapter>[generator]);
       expect(generator.didCallValidate, isFalse);
       expect(result, equals(0));
       completer.complete();
@@ -1214,10 +1214,10 @@ abstract class Api {
   test('run with PigeonOptions', () async {
     final Completer<void> completer = Completer<void>();
     withTempFile('foo.dart', (File input) async {
-      final _ValidatorGenerator generator = _ValidatorGenerator(null);
+      final _ValidatorAdapter generator = _ValidatorAdapter(null);
       final int result = await Pigeon.runWithOptions(
           PigeonOptions(input: input.path, dartOut: 'foo.dart'),
-          generators: <Generator>[generator]);
+          adapters: <Adapter>[generator]);
       expect(generator.didCallValidate, isFalse);
       expect(result, equals(0));
       completer.complete();

From a319b481ddd797f22e49ac04f434e3153cf36627 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 21 Dec 2022 12:55:30 -0800
Subject: [PATCH 08/87] Dart generate methods

---
 packages/pigeon/lib/dart_generator.dart | 18 ++++++++++++++++--
 packages/pigeon/lib/pigeon_lib.dart     | 18 ++++++++++--------
 2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 4ddbe9056ef..0a5f310d233 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -68,7 +68,7 @@ class DartGenerator extends Generator<DartOptions> {
   /// Generates Dart files with specified [DartOptions]
   @override
   void generate() {
-    //
+    generateDart(languageOptions, root, sink);
   }
 }
 
@@ -79,12 +79,26 @@ class DartTestGenerator extends Generator<DartOptions> {
     required DartOptions languageOptions,
     required Root root,
     required StringSink sink,
+    required this.dartOutPath,
+    required this.testOutPath,
   }) : super(languageOptions: languageOptions, root: root, sink: sink);
 
+  /// Path to output generated Dart file.
+  String dartOutPath;
+
+  /// Path to output generated Test file.
+  String testOutPath;
+
   /// Generates Dart files with specified [DartOptions]
   @override
   void generate() {
-    //
+    generateTestDart(
+      languageOptions,
+      root,
+      sink,
+      dartOutPath: dartOutPath,
+      testOutPath: testOutPath,
+    );
   }
 }
 
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 5bab11a01bb..0bb11c18d43 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -405,7 +405,9 @@ class DartAdapter implements Adapter {
   void generate(StringSink sink, PigeonOptions options, Root root) {
     final DartOptions dartOptionsWithHeader = _dartOptionsWithCopyrightHeader(
         options.dartOptions, options.copyrightHeader);
-    generateDart(dartOptionsWithHeader, root, sink);
+    final DartGenerator generator = DartGenerator(
+        languageOptions: dartOptionsWithHeader, root: root, sink: sink);
+    generator.generate();
   }
 
   @override
@@ -424,13 +426,13 @@ class DartTestAdapter implements Adapter {
   void generate(StringSink sink, PigeonOptions options, Root root) {
     final DartOptions dartOptionsWithHeader = _dartOptionsWithCopyrightHeader(
         options.dartOptions, options.copyrightHeader);
-    generateTestDart(
-      dartOptionsWithHeader,
-      root,
-      sink,
-      dartOutPath: options.dartOut!,
-      testOutPath: options.dartTestOut!,
-    );
+    final DartTestGenerator testGenerator = DartTestGenerator(
+        languageOptions: dartOptionsWithHeader,
+        root: root,
+        sink: sink,
+        dartOutPath: options.dartOut!,
+        testOutPath: options.dartTestOut!);
+    testGenerator.generate();
   }
 
   @override

From 6d7405d7a118bb687bcf02ce7cbc9b83488a3226 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 21 Dec 2022 13:07:37 -0800
Subject: [PATCH 09/87] convert all generate functions to use new method

---
 packages/pigeon/lib/cpp_generator.dart    |  8 ++++--
 packages/pigeon/lib/java_generator.dart   |  2 +-
 packages/pigeon/lib/kotlin_generator.dart |  2 +-
 packages/pigeon/lib/objc_generator.dart   |  4 +--
 packages/pigeon/lib/pigeon_lib.dart       | 32 +++++++++++++++++------
 packages/pigeon/lib/swift_generator.dart  |  2 +-
 6 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 584d4792ff2..dccb6d8602d 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -72,12 +72,16 @@ class CppHeaderGenerator extends Generator<CppOptions> {
     required CppOptions languageOptions,
     required Root root,
     required StringSink sink,
+    required this.path,
   }) : super(languageOptions: languageOptions, root: root, sink: sink);
 
+  /// Path to output generated Cpp Header file.
+  String path;
+
   /// Generates Cpp header files with specified [CppOptions]
   @override
   void generate() {
-    //
+    generateCppHeader(path, languageOptions, root, sink);
   }
 }
 
@@ -93,7 +97,7 @@ class CppSourceGenerator extends Generator<CppOptions> {
   /// Generates Cpp files with specified [CppOptions]
   @override
   void generate() {
-    //
+    generateCppSource(languageOptions, root, sink);
   }
 }
 
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index e77c11da941..5bc65d32a8a 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -97,7 +97,7 @@ class JavaGenerator extends Generator<JavaOptions> {
   /// Generates Java files with specified [JavaOptions]
   @override
   void generate() {
-    //
+    generateJava(languageOptions, root, sink);
   }
 }
 
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 371987d70af..584b45a8535 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -77,7 +77,7 @@ class KotlinGenerator extends Generator<KotlinOptions> {
   /// Generates Kotlin files with specified [KotlinOptions]
   @override
   void generate() {
-    //
+    generateKotlin(languageOptions, root, sink);
   }
 }
 
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index e1e5815bcaa..417189d7a60 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -76,7 +76,7 @@ class ObjcHeaderGenerator extends Generator<ObjcOptions> {
   /// Generates Objc header files with specified [ObjcOptions]
   @override
   void generate() {
-    //
+    generateObjcHeader(languageOptions, root, sink);
   }
 }
 
@@ -92,7 +92,7 @@ class ObjcSourceGenerator extends Generator<ObjcOptions> {
   /// Generates Objc files with specified [ObjcOptions]
   @override
   void generate() {
-    //
+    generateObjcSource(languageOptions, root, sink);
   }
 }
 
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 0bb11c18d43..45bb47009c5 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -460,7 +460,9 @@ class ObjcHeaderAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    generateObjcHeader(objcOptionsWithHeader, root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator(
+        languageOptions: objcOptionsWithHeader, root: root, sink: sink);
+    generator.generate();
   }
 
   @override
@@ -484,7 +486,9 @@ class ObjcSourceAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    generateObjcSource(objcOptionsWithHeader, root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator(
+        languageOptions: objcOptionsWithHeader, root: root, sink: sink);
+    generator.generate();
   }
 
   @override
@@ -509,7 +513,9 @@ class JavaAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator =
+        JavaGenerator(languageOptions: javaOptions, root: root, sink: sink);
+    generator.generate();
   }
 
   @override
@@ -531,7 +537,9 @@ class SwiftAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator =
+        SwiftGenerator(languageOptions: swiftOptions, root: root, sink: sink);
+    generator.generate();
   }
 
   @override
@@ -553,8 +561,12 @@ class CppHeaderAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    generateCppHeader(path.basenameWithoutExtension(options.cppHeaderOut!),
-        cppOptionsWithHeader, root, sink);
+    final CppHeaderGenerator generator = CppHeaderGenerator(
+        languageOptions: cppOptionsWithHeader,
+        root: root,
+        sink: sink,
+        path: path.basenameWithoutExtension(options.cppHeaderOut!));
+    generator.generate();
   }
 
   @override
@@ -578,7 +590,9 @@ class CppSourceAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    generateCppSource(cppOptionsWithHeader, root, sink);
+    final CppSourceGenerator generator = CppSourceGenerator(
+        languageOptions: cppOptionsWithHeader, root: root, sink: sink);
+    generator.generate();
   }
 
   @override
@@ -602,7 +616,9 @@ class KotlinAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator =
+        KotlinGenerator(languageOptions: kotlinOptions, root: root, sink: sink);
+    generator.generate();
   }
 
   @override
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 8db09cf96bc..3853d87b686 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -60,7 +60,7 @@ class SwiftGenerator extends Generator<SwiftOptions> {
   /// Generates Swift files with specified [SwiftOptions]
   @override
   void generate() {
-    //
+    generateSwift(languageOptions, root, sink);
   }
 }
 

From 1e59fef259017c0e4f113cd8adbd63511febff89 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 21 Dec 2022 13:14:45 -0800
Subject: [PATCH 10/87] chagngelog

---
 packages/pigeon/CHANGELOG.md             | 4 ++++
 packages/pigeon/lib/generator_tools.dart | 2 +-
 packages/pigeon/pubspec.yaml             | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index e0278c5731d..6e6688e0d85 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 4.2.16
+
+* Creates new Generator classes for each language.
+
 ## 4.2.15
 
 * Relocates generator classes. (Reverted)
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 6624a1dc8ec..ea522eaa04d 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -9,7 +9,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon. This must match the version in pubspec.yaml.
-const String pigeonVersion = '4.2.15';
+const String pigeonVersion = '4.2.16';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index e9c9d6b4901..886f56a6ea0 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 4.2.15 # This must match the version in lib/generator_tools.dart
+version: 4.2.16 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

From 0964cd32dedc3b3208f5280e64658d635215936e Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 21 Dec 2022 14:23:38 -0800
Subject: [PATCH 11/87] remove Generator class fields

---
 packages/pigeon/lib/cpp_generator.dart    | 15 ++-----
 packages/pigeon/lib/dart_generator.dart   | 15 ++-----
 packages/pigeon/lib/generator.dart        | 17 +-------
 packages/pigeon/lib/java_generator.dart   |  8 +---
 packages/pigeon/lib/kotlin_generator.dart |  8 +---
 packages/pigeon/lib/objc_generator.dart   | 16 ++-----
 packages/pigeon/lib/pigeon_lib.dart       | 52 +++++++++--------------
 packages/pigeon/lib/swift_generator.dart  |  8 +---
 8 files changed, 41 insertions(+), 98 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index d46028a279c..cb3c23e21bc 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -69,18 +69,15 @@ class CppOptions {
 class CppHeaderGenerator extends Generator<CppOptions> {
   /// Instantiates a Cpp Generator.
   CppHeaderGenerator({
-    required CppOptions languageOptions,
-    required Root root,
-    required StringSink sink,
     required this.path,
-  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+  });
 
   /// Path to output generated Cpp Header file.
   String path;
 
   /// Generates Cpp header files with specified [CppOptions]
   @override
-  void generate() {
+  void generate(CppOptions languageOptions, Root root, StringSink sink) {
     generateCppHeader(path, languageOptions, root, sink);
   }
 }
@@ -88,15 +85,11 @@ class CppHeaderGenerator extends Generator<CppOptions> {
 /// Class that manages all Cpp code generation.
 class CppSourceGenerator extends Generator<CppOptions> {
   /// Instantiates a Cpp Generator.
-  CppSourceGenerator({
-    required CppOptions languageOptions,
-    required Root root,
-    required StringSink sink,
-  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+  CppSourceGenerator();
 
   /// Generates Cpp files with specified [CppOptions]
   @override
-  void generate() {
+  void generate(CppOptions languageOptions, Root root, StringSink sink) {
     generateCppSource(languageOptions, root, sink);
   }
 }
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 0a5f310d233..13cfb1ecff2 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -59,15 +59,11 @@ class DartOptions {
 /// Class that manages all Dart code generation.
 class DartGenerator extends Generator<DartOptions> {
   /// Instantiates a Dart Generator.
-  DartGenerator({
-    required DartOptions languageOptions,
-    required Root root,
-    required StringSink sink,
-  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+  DartGenerator();
 
   /// Generates Dart files with specified [DartOptions]
   @override
-  void generate() {
+  void generate(DartOptions languageOptions, Root root, StringSink sink) {
     generateDart(languageOptions, root, sink);
   }
 }
@@ -76,12 +72,9 @@ class DartGenerator extends Generator<DartOptions> {
 class DartTestGenerator extends Generator<DartOptions> {
   /// Instantiates a Dart Generator.
   DartTestGenerator({
-    required DartOptions languageOptions,
-    required Root root,
-    required StringSink sink,
     required this.dartOutPath,
     required this.testOutPath,
-  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+  });
 
   /// Path to output generated Dart file.
   String dartOutPath;
@@ -91,7 +84,7 @@ class DartTestGenerator extends Generator<DartOptions> {
 
   /// Generates Dart files with specified [DartOptions]
   @override
-  void generate() {
+  void generate(DartOptions languageOptions, Root root, StringSink sink) {
     generateTestDart(
       languageOptions,
       root,
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index f45c113a7b6..0979627b3ac 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -9,21 +9,8 @@ import 'ast.dart';
 /// This is meant to provide structure and direction for future generator work.
 abstract class Generator<T> {
   /// Instantiates a Generator.
-  const Generator({
-    required this.languageOptions,
-    required this.root,
-    required this.sink,
-  });
-
-  ///
-  final T languageOptions;
-
-  ///
-  final Root root;
-
-  ///
-  final StringSink sink;
+  const Generator();
 
   /// Generates files for specified language with specified [languageOptions]
-  void generate();
+  void generate(T languageOptions, Root root, StringSink sink);
 }
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 5bc65d32a8a..00293bfc0e8 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -88,15 +88,11 @@ class JavaOptions {
 /// Class that manages all Java code generation.
 class JavaGenerator extends Generator<JavaOptions> {
   /// Instantiates a Java Generator.
-  JavaGenerator({
-    required JavaOptions languageOptions,
-    required Root root,
-    required StringSink sink,
-  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+  JavaGenerator();
 
   /// Generates Java files with specified [JavaOptions]
   @override
-  void generate() {
+  void generate(JavaOptions languageOptions, Root root, StringSink sink) {
     generateJava(languageOptions, root, sink);
   }
 }
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 584b45a8535..99690a4ac92 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -68,15 +68,11 @@ class KotlinOptions {
 /// Class that manages all Kotlin code generation.
 class KotlinGenerator extends Generator<KotlinOptions> {
   /// Instantiates a Kotlin Generator.
-  KotlinGenerator({
-    required KotlinOptions languageOptions,
-    required Root root,
-    required StringSink sink,
-  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+  KotlinGenerator();
 
   /// Generates Kotlin files with specified [KotlinOptions]
   @override
-  void generate() {
+  void generate(KotlinOptions languageOptions, Root root, StringSink sink) {
     generateKotlin(languageOptions, root, sink);
   }
 }
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 417189d7a60..0d376e1a582 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -67,15 +67,11 @@ class ObjcOptions {
 /// Class that manages all Objc header code generation.
 class ObjcHeaderGenerator extends Generator<ObjcOptions> {
   /// Instantiates a Objc Generator.
-  ObjcHeaderGenerator({
-    required ObjcOptions languageOptions,
-    required Root root,
-    required StringSink sink,
-  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+  ObjcHeaderGenerator();
 
   /// Generates Objc header files with specified [ObjcOptions]
   @override
-  void generate() {
+  void generate(ObjcOptions languageOptions, Root root, StringSink sink) {
     generateObjcHeader(languageOptions, root, sink);
   }
 }
@@ -83,15 +79,11 @@ class ObjcHeaderGenerator extends Generator<ObjcOptions> {
 /// Class that manages all Objc code generation.
 class ObjcSourceGenerator extends Generator<ObjcOptions> {
   /// Instantiates a Objc Generator.
-  ObjcSourceGenerator({
-    required ObjcOptions languageOptions,
-    required Root root,
-    required StringSink sink,
-  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+  ObjcSourceGenerator();
 
   /// Generates Objc files with specified [ObjcOptions]
   @override
-  void generate() {
+  void generate(ObjcOptions languageOptions, Root root, StringSink sink) {
     generateObjcSource(languageOptions, root, sink);
   }
 }
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 45bb47009c5..65718a4ff46 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -405,9 +405,8 @@ class DartAdapter implements Adapter {
   void generate(StringSink sink, PigeonOptions options, Root root) {
     final DartOptions dartOptionsWithHeader = _dartOptionsWithCopyrightHeader(
         options.dartOptions, options.copyrightHeader);
-    final DartGenerator generator = DartGenerator(
-        languageOptions: dartOptionsWithHeader, root: root, sink: sink);
-    generator.generate();
+    final DartGenerator generator = DartGenerator();
+    generator.generate(dartOptionsWithHeader, root, sink);
   }
 
   @override
@@ -427,12 +426,12 @@ class DartTestAdapter implements Adapter {
     final DartOptions dartOptionsWithHeader = _dartOptionsWithCopyrightHeader(
         options.dartOptions, options.copyrightHeader);
     final DartTestGenerator testGenerator = DartTestGenerator(
-        languageOptions: dartOptionsWithHeader,
-        root: root,
-        sink: sink,
-        dartOutPath: options.dartOut!,
-        testOutPath: options.dartTestOut!);
-    testGenerator.generate();
+        dartOutPath: options.dartOut!, testOutPath: options.dartTestOut!);
+    testGenerator.generate(
+      dartOptionsWithHeader,
+      root,
+      sink,
+    );
   }
 
   @override
@@ -460,9 +459,8 @@ class ObjcHeaderAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator(
-        languageOptions: objcOptionsWithHeader, root: root, sink: sink);
-    generator.generate();
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(objcOptionsWithHeader, root, sink);
   }
 
   @override
@@ -486,9 +484,8 @@ class ObjcSourceAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final ObjcSourceGenerator generator = ObjcSourceGenerator(
-        languageOptions: objcOptionsWithHeader, root: root, sink: sink);
-    generator.generate();
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(objcOptionsWithHeader, root, sink);
   }
 
   @override
@@ -513,9 +510,8 @@ class JavaAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final JavaGenerator generator =
-        JavaGenerator(languageOptions: javaOptions, root: root, sink: sink);
-    generator.generate();
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
   }
 
   @override
@@ -537,9 +533,8 @@ class SwiftAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final SwiftGenerator generator =
-        SwiftGenerator(languageOptions: swiftOptions, root: root, sink: sink);
-    generator.generate();
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
   }
 
   @override
@@ -562,11 +557,8 @@ class CppHeaderAdapter implements Adapter {
             ? _lineReader(options.copyrightHeader!)
             : null));
     final CppHeaderGenerator generator = CppHeaderGenerator(
-        languageOptions: cppOptionsWithHeader,
-        root: root,
-        sink: sink,
         path: path.basenameWithoutExtension(options.cppHeaderOut!));
-    generator.generate();
+    generator.generate(cppOptionsWithHeader, root, sink);
   }
 
   @override
@@ -590,9 +582,8 @@ class CppSourceAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final CppSourceGenerator generator = CppSourceGenerator(
-        languageOptions: cppOptionsWithHeader, root: root, sink: sink);
-    generator.generate();
+    final CppSourceGenerator generator = CppSourceGenerator();
+    generator.generate(cppOptionsWithHeader, root, sink);
   }
 
   @override
@@ -616,9 +607,8 @@ class KotlinAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final KotlinGenerator generator =
-        KotlinGenerator(languageOptions: kotlinOptions, root: root, sink: sink);
-    generator.generate();
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
   }
 
   @override
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 3853d87b686..b25931c03e3 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -51,15 +51,11 @@ class SwiftOptions {
 /// Class that manages all Swift code generation.
 class SwiftGenerator extends Generator<SwiftOptions> {
   /// Instantiates a Swift Generator.
-  SwiftGenerator({
-    required SwiftOptions languageOptions,
-    required Root root,
-    required StringSink sink,
-  }) : super(languageOptions: languageOptions, root: root, sink: sink);
+  SwiftGenerator();
 
   /// Generates Swift files with specified [SwiftOptions]
   @override
-  void generate() {
+  void generate(SwiftOptions languageOptions, Root root, StringSink sink) {
     generateSwift(languageOptions, root, sink);
   }
 }

From f589da4c3f875040a59713e2e86b6955ab3c06a1 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 21 Dec 2022 23:01:58 -0800
Subject: [PATCH 12/87] move paths to options

---
 packages/pigeon/lib/cpp_generator.dart  | 28 ++++------
 packages/pigeon/lib/dart_generator.dart | 73 ++++++++++++++++++++-----
 packages/pigeon/lib/pigeon_lib.dart     | 29 ++++++++--
 3 files changed, 93 insertions(+), 37 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index cb3c23e21bc..6bc120bc2d3 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -21,11 +21,8 @@ const String _defaultCodecSerializer = 'flutter::StandardCodecSerializer';
 /// Options that control how C++ code will be generated.
 class CppOptions {
   /// Creates a [CppOptions] object
-  const CppOptions({
-    this.header,
-    this.namespace,
-    this.copyrightHeader,
-  });
+  const CppOptions(
+      {this.header, this.namespace, this.copyrightHeader, this.cppHeaderOut});
 
   /// The path to the header that will get placed in the source filed (example:
   /// "foo.h").
@@ -37,14 +34,17 @@ class CppOptions {
   /// A copyright header that will get prepended to generated code.
   final Iterable<String>? copyrightHeader;
 
+  ///
+  final String? cppHeaderOut;
+
   /// Creates a [CppOptions] from a Map representation where:
   /// `x = CppOptions.fromMap(x.toMap())`.
   static CppOptions fromMap(Map<String, Object> map) {
     return CppOptions(
-      header: map['header'] as String?,
-      namespace: map['namespace'] as String?,
-      copyrightHeader: map['copyrightHeader'] as Iterable<String>?,
-    );
+        header: map['header'] as String?,
+        namespace: map['namespace'] as String?,
+        copyrightHeader: map['copyrightHeader'] as Iterable<String>?,
+        cppHeaderOut: map['cppHeaderOut'] as String?);
   }
 
   /// Converts a [CppOptions] to a Map representation where:
@@ -68,17 +68,13 @@ class CppOptions {
 /// Class that manages all Cpp header code generation.
 class CppHeaderGenerator extends Generator<CppOptions> {
   /// Instantiates a Cpp Generator.
-  CppHeaderGenerator({
-    required this.path,
-  });
-
-  /// Path to output generated Cpp Header file.
-  String path;
+  CppHeaderGenerator();
 
   /// Generates Cpp header files with specified [CppOptions]
   @override
   void generate(CppOptions languageOptions, Root root, StringSink sink) {
-    generateCppHeader(path, languageOptions, root, sink);
+    generateCppHeader(
+        languageOptions.cppHeaderOut, languageOptions, root, sink);
   }
 }
 
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 13cfb1ecff2..64ef93b2f21 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -56,6 +56,57 @@ class DartOptions {
   }
 }
 
+/// Options that control how Dart test code will be generated.
+class DartTestOptions {
+  /// Constructor for DartOptions.
+  DartTestOptions({
+    this.copyrightHeader,
+    required this.dartOutPath,
+    required this.testOutPath,
+  });
+
+  /// A copyright header that will get prepended to generated code.
+  final Iterable<String>? copyrightHeader;
+
+  /// Path to output generated Dart file.
+  String dartOutPath;
+
+  /// Path to output generated Test file.
+  String testOutPath;
+
+  /// Creates a [DartOptions] from a Map representation where:
+  /// `x = DartOptions.fromMap(x.toMap())`.
+  static DartTestOptions fromMap(Map<String, Object> map) {
+    final Iterable<dynamic>? copyrightHeader =
+        map['copyrightHeader'] as Iterable<dynamic>?;
+    return DartTestOptions(
+      dartOutPath: map['dartOutPath']! as String,
+      testOutPath: map['testOutPath']! as String,
+      copyrightHeader: copyrightHeader?.cast<String>(),
+    );
+  }
+
+  /// Converts a [DartOptions] to a Map representation where:
+  /// `x = DartOptions.fromMap(x.toMap())`.
+  Map<String, Object> toMap() {
+    final Map<String, Object> result = <String, Object>{
+      if (copyrightHeader != null) 'copyrightHeader': copyrightHeader!,
+    };
+    return result;
+  }
+
+  /// Overrides any non-null parameters from [options] into this to make a new
+  /// [DartOptions].
+  DartTestOptions merge(DartTestOptions options) {
+    return DartTestOptions.fromMap(mergeMaps(toMap(), options.toMap()));
+  }
+
+  /// Converts DartTestOptions to DartOptions and returns it.
+  DartOptions toDartOptions() {
+    return DartOptions(copyrightHeader: copyrightHeader);
+  }
+}
+
 /// Class that manages all Dart code generation.
 class DartGenerator extends Generator<DartOptions> {
   /// Instantiates a Dart Generator.
@@ -69,28 +120,20 @@ class DartGenerator extends Generator<DartOptions> {
 }
 
 /// Class that manages all Dart code generation.
-class DartTestGenerator extends Generator<DartOptions> {
+class DartTestGenerator extends Generator<DartTestOptions> {
   /// Instantiates a Dart Generator.
-  DartTestGenerator({
-    required this.dartOutPath,
-    required this.testOutPath,
-  });
-
-  /// Path to output generated Dart file.
-  String dartOutPath;
-
-  /// Path to output generated Test file.
-  String testOutPath;
+  DartTestGenerator();
 
   /// Generates Dart files with specified [DartOptions]
   @override
-  void generate(DartOptions languageOptions, Root root, StringSink sink) {
+  void generate(DartTestOptions languageOptions, Root root, StringSink sink) {
+    final DartOptions dartOptions = languageOptions.toDartOptions();
     generateTestDart(
-      languageOptions,
+      dartOptions,
       root,
       sink,
-      dartOutPath: dartOutPath,
-      testOutPath: testOutPath,
+      dartOutPath: languageOptions.dartOutPath,
+      testOutPath: languageOptions.testOutPath,
     );
   }
 }
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 65718a4ff46..94cfd55f2ff 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -379,6 +379,19 @@ DartOptions _dartOptionsWithCopyrightHeader(
           copyrightHeader != null ? _lineReader(copyrightHeader) : null));
 }
 
+DartTestOptions _dartTestOptionsWithCopyrightHeader(DartOptions? dartOptions,
+    String? copyrightHeader, String dartOutPath, String testOutPath) {
+  final Iterable<String>? parsedCopyrightHeader = dartOptions != null
+      ? dartOptions.copyrightHeader
+      : copyrightHeader != null
+          ? _lineReader(copyrightHeader)
+          : null;
+  return DartTestOptions(
+      dartOutPath: dartOutPath,
+      testOutPath: testOutPath,
+      copyrightHeader: parsedCopyrightHeader);
+}
+
 /// An [Adapter] that generates the AST.
 class AstAdapter implements Adapter {
   /// Constructor for [AstAdapter].
@@ -423,10 +436,14 @@ class DartTestAdapter implements Adapter {
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
-    final DartOptions dartOptionsWithHeader = _dartOptionsWithCopyrightHeader(
-        options.dartOptions, options.copyrightHeader);
-    final DartTestGenerator testGenerator = DartTestGenerator(
-        dartOutPath: options.dartOut!, testOutPath: options.dartTestOut!);
+    final DartTestOptions dartOptionsWithHeader =
+        _dartTestOptionsWithCopyrightHeader(
+      options.dartOptions,
+      options.copyrightHeader,
+      options.dartOut!,
+      options.dartTestOut!,
+    );
+    final DartTestGenerator testGenerator = DartTestGenerator();
     testGenerator.generate(
       dartOptionsWithHeader,
       root,
@@ -553,11 +570,11 @@ class CppHeaderAdapter implements Adapter {
   void generate(StringSink sink, PigeonOptions options, Root root) {
     final CppOptions cppOptions = options.cppOptions ?? const CppOptions();
     final CppOptions cppOptionsWithHeader = cppOptions.merge(CppOptions(
+        cppHeaderOut: path.basenameWithoutExtension(options.cppHeaderOut!),
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final CppHeaderGenerator generator = CppHeaderGenerator(
-        path: path.basenameWithoutExtension(options.cppHeaderOut!));
+    final CppHeaderGenerator generator = CppHeaderGenerator();
     generator.generate(cppOptionsWithHeader, root, sink);
   }
 

From 637679dc0c02c7078deee8d5ce9ff2a58713efcd Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 22 Dec 2022 08:24:58 -0800
Subject: [PATCH 13/87] remove dartTestOptions

---
 packages/pigeon/lib/dart_generator.dart       | 80 +++++--------------
 packages/pigeon/lib/pigeon_lib.dart           | 20 ++---
 packages/pigeon/test/dart_generator_test.dart | 80 +++++++++----------
 packages/pigeon/tool/shared/generation.dart   |  2 +-
 4 files changed, 69 insertions(+), 113 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 64ef93b2f21..604becc9c30 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -25,64 +25,30 @@ const String _standardMessageCodec = 'StandardMessageCodec';
 /// Options that control how Dart code will be generated.
 class DartOptions {
   /// Constructor for DartOptions.
-  const DartOptions({this.copyrightHeader});
-
-  /// A copyright header that will get prepended to generated code.
-  final Iterable<String>? copyrightHeader;
-
-  /// Creates a [DartOptions] from a Map representation where:
-  /// `x = DartOptions.fromMap(x.toMap())`.
-  static DartOptions fromMap(Map<String, Object> map) {
-    final Iterable<dynamic>? copyrightHeader =
-        map['copyrightHeader'] as Iterable<dynamic>?;
-    return DartOptions(
-      copyrightHeader: copyrightHeader?.cast<String>(),
-    );
-  }
-
-  /// Converts a [DartOptions] to a Map representation where:
-  /// `x = DartOptions.fromMap(x.toMap())`.
-  Map<String, Object> toMap() {
-    final Map<String, Object> result = <String, Object>{
-      if (copyrightHeader != null) 'copyrightHeader': copyrightHeader!,
-    };
-    return result;
-  }
-
-  /// Overrides any non-null parameters from [options] into this to make a new
-  /// [DartOptions].
-  DartOptions merge(DartOptions options) {
-    return DartOptions.fromMap(mergeMaps(toMap(), options.toMap()));
-  }
-}
-
-/// Options that control how Dart test code will be generated.
-class DartTestOptions {
-  /// Constructor for DartOptions.
-  DartTestOptions({
+  DartOptions({
     this.copyrightHeader,
-    required this.dartOutPath,
-    required this.testOutPath,
+    this.dartOutPath,
+    this.testOutPath,
   });
 
   /// A copyright header that will get prepended to generated code.
   final Iterable<String>? copyrightHeader;
 
-  /// Path to output generated Dart file.
-  String dartOutPath;
+  /// Path to output generated Dart file for tests.
+  String? dartOutPath;
 
-  /// Path to output generated Test file.
-  String testOutPath;
+  /// Path to output generated Test file for tests.
+  String? testOutPath;
 
   /// Creates a [DartOptions] from a Map representation where:
   /// `x = DartOptions.fromMap(x.toMap())`.
-  static DartTestOptions fromMap(Map<String, Object> map) {
+  static DartOptions fromMap(Map<String, Object> map) {
     final Iterable<dynamic>? copyrightHeader =
         map['copyrightHeader'] as Iterable<dynamic>?;
-    return DartTestOptions(
-      dartOutPath: map['dartOutPath']! as String,
-      testOutPath: map['testOutPath']! as String,
+    return DartOptions(
       copyrightHeader: copyrightHeader?.cast<String>(),
+      dartOutPath: map['dartOutPath'] as String?,
+      testOutPath: map['testOutPath'] as String?,
     );
   }
 
@@ -91,19 +57,16 @@ class DartTestOptions {
   Map<String, Object> toMap() {
     final Map<String, Object> result = <String, Object>{
       if (copyrightHeader != null) 'copyrightHeader': copyrightHeader!,
+      if (dartOutPath != null) 'dartOutPath': dartOutPath!,
+      if (testOutPath != null) 'testOutPath': testOutPath!,
     };
     return result;
   }
 
   /// Overrides any non-null parameters from [options] into this to make a new
   /// [DartOptions].
-  DartTestOptions merge(DartTestOptions options) {
-    return DartTestOptions.fromMap(mergeMaps(toMap(), options.toMap()));
-  }
-
-  /// Converts DartTestOptions to DartOptions and returns it.
-  DartOptions toDartOptions() {
-    return DartOptions(copyrightHeader: copyrightHeader);
+  DartOptions merge(DartOptions options) {
+    return DartOptions.fromMap(mergeMaps(toMap(), options.toMap()));
   }
 }
 
@@ -120,20 +83,21 @@ class DartGenerator extends Generator<DartOptions> {
 }
 
 /// Class that manages all Dart code generation.
-class DartTestGenerator extends Generator<DartTestOptions> {
+class DartTestGenerator extends Generator<DartOptions> {
   /// Instantiates a Dart Generator.
   DartTestGenerator();
 
   /// Generates Dart files with specified [DartOptions]
   @override
-  void generate(DartTestOptions languageOptions, Root root, StringSink sink) {
-    final DartOptions dartOptions = languageOptions.toDartOptions();
+  void generate(DartOptions languageOptions, Root root, StringSink sink) {
+    final String dartOutPath = languageOptions.dartOutPath ?? '';
+    final String testOutPath = languageOptions.testOutPath ?? '';
     generateTestDart(
-      dartOptions,
+      languageOptions,
       root,
       sink,
-      dartOutPath: languageOptions.dartOutPath,
-      testOutPath: languageOptions.testOutPath,
+      dartOutPath: dartOutPath,
+      testOutPath: testOutPath,
     );
   }
 }
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 94cfd55f2ff..e630a09c438 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -372,21 +372,14 @@ abstract class Adapter {
 }
 
 DartOptions _dartOptionsWithCopyrightHeader(
-    DartOptions? dartOptions, String? copyrightHeader) {
-  dartOptions = dartOptions ?? const DartOptions();
-  return dartOptions.merge(DartOptions(
-      copyrightHeader:
-          copyrightHeader != null ? _lineReader(copyrightHeader) : null));
-}
-
-DartTestOptions _dartTestOptionsWithCopyrightHeader(DartOptions? dartOptions,
-    String? copyrightHeader, String dartOutPath, String testOutPath) {
+    DartOptions? dartOptions, String? copyrightHeader,
+    [String? dartOutPath, String? testOutPath]) {
   final Iterable<String>? parsedCopyrightHeader = dartOptions != null
       ? dartOptions.copyrightHeader
       : copyrightHeader != null
           ? _lineReader(copyrightHeader)
           : null;
-  return DartTestOptions(
+  return DartOptions(
       dartOutPath: dartOutPath,
       testOutPath: testOutPath,
       copyrightHeader: parsedCopyrightHeader);
@@ -436,12 +429,11 @@ class DartTestAdapter implements Adapter {
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
-    final DartTestOptions dartOptionsWithHeader =
-        _dartTestOptionsWithCopyrightHeader(
+    final DartOptions dartOptionsWithHeader = _dartOptionsWithCopyrightHeader(
       options.dartOptions,
       options.copyrightHeader,
-      options.dartOut!,
-      options.dartTestOut!,
+      options.dartOut,
+      options.dartTestOut,
     );
     final DartTestGenerator testGenerator = DartTestGenerator();
     testGenerator.generate(
diff --git a/packages/pigeon/test/dart_generator_test.dart b/packages/pigeon/test/dart_generator_test.dart
index bf359ddfe43..38442ccd358 100644
--- a/packages/pigeon/test/dart_generator_test.dart
+++ b/packages/pigeon/test/dart_generator_test.dart
@@ -29,7 +29,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('  dataType1? field1;'));
@@ -49,7 +49,7 @@ void main() {
       enums: <Enum>[anEnum],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foobar'));
     expect(code, contains('  one,'));
@@ -92,7 +92,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, contains('Future<Output> doSomething(Input arg_input)'));
@@ -118,7 +118,7 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, contains('Future<int> add(int arg_x, int arg_y)'));
@@ -145,7 +145,7 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, contains('int add(int x, int y)'));
@@ -182,7 +182,7 @@ void main() {
       )
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
       code,
@@ -224,7 +224,7 @@ void main() {
       )
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
       code,
@@ -276,7 +276,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('abstract class Api'));
     expect(code, contains('static void setup(Api'));
@@ -310,7 +310,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<void> doSomething'));
     expect(code, contains('return;'));
@@ -343,7 +343,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     // The next line verifies that we're not setting a variable to the value of "doSomething", but
     // ignores the line where we assert the value of the argument isn't null, since on that line
@@ -373,7 +373,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('output.*=.*doSomething[(][)]'));
     expect(code, contains('Output doSomething();'));
@@ -415,7 +415,7 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum1?.index,'));
     expect(code, contains('? Enum.values[result[0]! as int]'));
@@ -442,7 +442,7 @@ void main() {
       ])
     ]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foo {'));
     expect(code, contains('Future<void> bar(Foo? arg_foo) async'));
@@ -485,7 +485,7 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum1.index,'));
     expect(code, contains('enum1: Enum.values[result[0]! as int]'));
@@ -512,7 +512,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('channel.send[(]null[)]'));
   });
@@ -570,7 +570,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer mainCodeSink = StringBuffer();
     final StringBuffer testCodeSink = StringBuffer();
-    generateDart(const DartOptions(), root, mainCodeSink);
+    generateDart(DartOptions(), root, mainCodeSink);
     final String mainCode = mainCodeSink.toString();
     expect(mainCode, isNot(contains(r"import 'fo\'o.dart';")));
     expect(mainCode, contains('class Api {'));
@@ -579,7 +579,7 @@ void main() {
     expect(mainCode, isNot(contains("'${Keys.result}': output")));
     expect(mainCode, isNot(contains('return <Object>[];')));
     generateTestDart(
-      const DartOptions(),
+      DartOptions(),
       root,
       testCodeSink,
       dartOutPath: "fo'o.dart",
@@ -631,7 +631,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('abstract class Api'));
     expect(code, contains('Future<Output> doSomething(Input arg0);'));
@@ -675,7 +675,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('=.s*doSomething')));
     expect(code, contains('await api.doSomething('));
@@ -719,7 +719,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, matches('Output.*doSomething.*Input'));
@@ -747,7 +747,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('channel.send[(]null[)]'));
   });
@@ -788,7 +788,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('  List<int?>? field1;'));
@@ -815,7 +815,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('  Map<String?, int?>? field1;'));
@@ -844,7 +844,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(List<int?> arg'));
   });
@@ -872,7 +872,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(List<int?> arg'));
   });
@@ -896,7 +896,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<List<int?>> doit('));
     expect(code,
@@ -931,7 +931,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('List<int?> doit('));
     expect(
@@ -958,7 +958,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit()'));
     expect(code, contains('return (replyList[0] as int?);'));
@@ -983,7 +983,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<List<int?>?> doit()'));
     expect(code,
@@ -1008,7 +1008,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit()'));
     expect(code, contains('return (replyList[0] as int?);'));
@@ -1031,7 +1031,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('int? doit();'));
     expect(code, contains('final int? output = api.doit();'));
@@ -1055,7 +1055,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit();'));
     expect(code, contains('final int? output = await api.doit();'));
@@ -1078,7 +1078,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1107,7 +1107,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<void> doit(int? arg_foo) async {'));
   });
@@ -1133,7 +1133,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('void doit(int? foo);'));
   });
@@ -1151,7 +1151,7 @@ name: foobar
           Root(classes: <Class>[], apis: <Api>[], enums: <Enum>[]);
       final StringBuffer sink = StringBuffer();
       generateTestDart(
-        const DartOptions(),
+        DartOptions(),
         root,
         sink,
         dartOutPath: path.join(foo.path, 'bar.dart'),
@@ -1238,7 +1238,7 @@ name: foobar
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       expect(code, contains('///$comment'));
@@ -1273,7 +1273,7 @@ name: foobar
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains('extends StandardMessageCodec')));
     expect(code, contains('StandardMessageCodec'));
@@ -1316,7 +1316,7 @@ name: foobar
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(const DartOptions(), root, sink);
+    generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('extends StandardMessageCodec'));
   });
@@ -1355,7 +1355,7 @@ name: foobar
     );
     final StringBuffer sink = StringBuffer();
     generateTestDart(
-      const DartOptions(),
+      DartOptions(),
       root,
       sink,
       dartOutPath: 'code.dart',
diff --git a/packages/pigeon/tool/shared/generation.dart b/packages/pigeon/tool/shared/generation.dart
index 01efa09c8f5..3e6ced166f8 100644
--- a/packages/pigeon/tool/shared/generation.dart
+++ b/packages/pigeon/tool/shared/generation.dart
@@ -168,7 +168,7 @@ Future<int> runPigeon({
     copyrightHeader: './copyright_header.txt',
     dartOut: dartOut,
     dartTestOut: dartTestOut,
-    dartOptions: const DartOptions(),
+    dartOptions: DartOptions(),
     cppHeaderOut: cppHeaderOut,
     cppSourceOut: cppSourceOut,
     cppOptions: CppOptions(namespace: cppNamespace),

From af5e0e63da9f2e8e39d2a0a6873fb467e1d9dfde Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 22 Dec 2022 09:56:36 -0800
Subject: [PATCH 14/87] Moves write header to generator class method

---
 packages/pigeon/lib/cpp_generator.dart    | 49 ++++++++++++----
 packages/pigeon/lib/dart_generator.dart   | 53 +++++++++++------
 packages/pigeon/lib/generator.dart        | 20 ++++++-
 packages/pigeon/lib/java_generator.dart   | 34 +++++++----
 packages/pigeon/lib/kotlin_generator.dart | 34 +++++++----
 packages/pigeon/lib/objc_generator.dart   | 69 +++++++++++++++--------
 packages/pigeon/lib/swift_generator.dart  | 33 +++++++----
 7 files changed, 202 insertions(+), 90 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 6bc120bc2d3..689dbfed950 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -73,8 +73,17 @@ class CppHeaderGenerator extends Generator<CppOptions> {
   /// Generates Cpp header files with specified [CppOptions]
   @override
   void generate(CppOptions languageOptions, Root root, StringSink sink) {
+    final Indent indent = Indent(sink);
+
+    writeFileHeaders(languageOptions, root, sink, indent);
     generateCppHeader(
-        languageOptions.cppHeaderOut, languageOptions, root, sink);
+        languageOptions.cppHeaderOut, languageOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(
+      CppOptions languageOptions, Root root, StringSink sink, Indent indent) {
+    writeCppHeaderHeader(languageOptions, root, sink, indent);
   }
 }
 
@@ -86,7 +95,16 @@ class CppSourceGenerator extends Generator<CppOptions> {
   /// Generates Cpp files with specified [CppOptions]
   @override
   void generate(CppOptions languageOptions, Root root, StringSink sink) {
-    generateCppSource(languageOptions, root, sink);
+    final Indent indent = Indent(sink);
+
+    writeFileHeaders(languageOptions, root, sink, indent);
+    generateCppSource(languageOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(
+      CppOptions languageOptions, Root root, StringSink sink, Indent indent) {
+    writeCppSourceHeader(languageOptions, root, sink, indent);
   }
 }
 
@@ -1035,14 +1053,18 @@ void _writeSystemHeaderIncludeBlock(Indent indent, List<String> headers) {
   }
 }
 
-/// Generates the ".h" file for the AST represented by [root] to [sink] with the
-/// provided [options] and [headerFileName].
-void generateCppHeader(
-    String? headerFileName, CppOptions options, Root root, StringSink sink) {
-  final Indent indent = Indent(sink);
+/// Writes Cpp header file header to sink.
+void writeCppHeaderHeader(
+    CppOptions options, Root root, StringSink sink, Indent indent) {
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
   }
+}
+
+/// Generates the ".h" file for the AST represented by [root] to [sink] with the
+/// provided [options] and [headerFileName].
+void generateCppHeader(String? headerFileName, CppOptions options, Root root,
+    StringSink sink, Indent indent) {
   indent.writeln('$_commentPrefix $generatedCodeWarning');
   indent.writeln('$_commentPrefix $seeAlsoWarning');
   indent.addln('');
@@ -1126,13 +1148,18 @@ void generateCppHeader(
   indent.writeln('#endif  // $guardName');
 }
 
-/// Generates the ".cpp" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateCppSource(CppOptions options, Root root, StringSink sink) {
-  final Indent indent = Indent(sink);
+/// Writes Cpp source file header to sink.
+void writeCppSourceHeader(
+    CppOptions options, Root root, StringSink sink, Indent indent) {
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
   }
+}
+
+/// Generates the ".cpp" file for the AST represented by [root] to [sink] with the
+/// provided [options].
+void generateCppSource(
+    CppOptions options, Root root, StringSink sink, Indent indent) {
   indent.writeln('$_commentPrefix $generatedCodeWarning');
   indent.writeln('$_commentPrefix $seeAlsoWarning');
   indent.addln('');
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 604becc9c30..90b31c7b419 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -78,7 +78,16 @@ class DartGenerator extends Generator<DartOptions> {
   /// Generates Dart files with specified [DartOptions]
   @override
   void generate(DartOptions languageOptions, Root root, StringSink sink) {
-    generateDart(languageOptions, root, sink);
+    final Indent indent = Indent(sink);
+
+    writeFileHeaders(languageOptions, root, sink, indent);
+    generateDart(languageOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(
+      DartOptions languageOptions, Root root, StringSink sink, Indent indent) {
+    writeHeader(languageOptions, root, sink, indent);
   }
 }
 
@@ -90,16 +99,27 @@ class DartTestGenerator extends Generator<DartOptions> {
   /// Generates Dart files with specified [DartOptions]
   @override
   void generate(DartOptions languageOptions, Root root, StringSink sink) {
+    final Indent indent = Indent(sink);
+
     final String dartOutPath = languageOptions.dartOutPath ?? '';
     final String testOutPath = languageOptions.testOutPath ?? '';
+
+    writeFileHeaders(languageOptions, root, sink, indent);
     generateTestDart(
       languageOptions,
       root,
       sink,
+      indent,
       dartOutPath: dartOutPath,
       testOutPath: testOutPath,
     );
   }
+
+  @override
+  void writeFileHeaders(
+      DartOptions languageOptions, Root root, StringSink sink, Indent indent) {
+    writeHeader(languageOptions, root, sink, indent);
+  }
 }
 
 String _escapeForDartSingleQuotedString(String raw) {
@@ -502,25 +522,25 @@ String _addGenericTypesNullable(TypeDeclaration type) {
   return type.isNullable ? '$genericdType?' : genericdType;
 }
 
+/// Writes file header to sink.
+void writeHeader(DartOptions opt, Root root, StringSink sink, Indent indent) {
+  if (opt.copyrightHeader != null) {
+    addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
+  }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+  indent.writeln(
+    '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import',
+  );
+}
+
 /// Generates Dart source code for the given AST represented by [root],
 /// outputting the code to [sink].
-void generateDart(DartOptions opt, Root root, StringSink sink) {
+void generateDart(DartOptions opt, Root root, StringSink sink, Indent indent) {
   final List<String> customClassNames =
       root.classes.map((Class x) => x.name).toList();
   final List<String> customEnumNames =
       root.enums.map((Enum x) => x.name).toList();
-  final Indent indent = Indent(sink);
-
-  void writeHeader() {
-    if (opt.copyrightHeader != null) {
-      addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-    indent.writeln(
-      '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import',
-    );
-  }
 
   void writeEnums() {
     for (final Enum anEnum in root.enums) {
@@ -679,7 +699,6 @@ $resultAt != null
     }
   }
 
-  writeHeader();
   writeImports();
   writeEnums();
   for (final Class klass in root.classes) {
@@ -748,11 +767,11 @@ String _posixify(String inputPath) {
 void generateTestDart(
   DartOptions opt,
   Root root,
-  StringSink sink, {
+  StringSink sink,
+  Indent indent, {
   required String dartOutPath,
   required String testOutPath,
 }) {
-  final Indent indent = Indent(sink);
   if (opt.copyrightHeader != null) {
     addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
   }
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 0979627b3ac..61b3587c3cf 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'ast.dart';
+import 'generator_tools.dart';
 
 /// A Super class of generator classes.
 ///
@@ -12,5 +13,22 @@ abstract class Generator<T> {
   const Generator();
 
   /// Generates files for specified language with specified [languageOptions]
-  void generate(T languageOptions, Root root, StringSink sink);
+  ///
+  /// This method, when overridden, should follow a generic structure that is currently:
+  /// 1. Create Indent
+  /// 2. Write File Headers
+  /// 3. Generate File
+  void generate(
+    T languageOptions,
+    Root root,
+    StringSink sink,
+  );
+
+  /// Adds specified file headers.
+  void writeFileHeaders(
+    T languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+  );
 }
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 00293bfc0e8..310125937da 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -93,7 +93,16 @@ class JavaGenerator extends Generator<JavaOptions> {
   /// Generates Java files with specified [JavaOptions]
   @override
   void generate(JavaOptions languageOptions, Root root, StringSink sink) {
-    generateJava(languageOptions, root, sink);
+    final Indent indent = Indent(sink);
+
+    writeFileHeaders(languageOptions, root, sink, indent);
+    generateJava(languageOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(
+      JavaOptions languageOptions, Root root, StringSink sink, Indent indent) {
+    writeHeader(languageOptions, root, sink, indent);
   }
 }
 
@@ -534,22 +543,24 @@ String _castObject(
   }
 }
 
+/// Writes file header to sink.
+void writeHeader(
+    JavaOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.copyrightHeader != null) {
+    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+  }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+}
+
 /// Generates the ".java" file for the AST represented by [root] to [sink] with the
 /// provided [options].
-void generateJava(JavaOptions options, Root root, StringSink sink) {
+void generateJava(
+    JavaOptions options, Root root, StringSink sink, Indent indent) {
   final Set<String> rootClassNameSet =
       root.classes.map((Class x) => x.name).toSet();
   final Set<String> rootEnumNameSet =
       root.enums.map((Enum x) => x.name).toSet();
-  final Indent indent = Indent(sink);
-
-  void writeHeader() {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-  }
 
   void writeImports() {
     indent.writeln('import android.util.Log;');
@@ -764,7 +775,6 @@ void generateJava(JavaOptions options, Root root, StringSink sink) {
 }''');
   }
 
-  writeHeader();
   indent.addln('');
   if (options.package != null) {
     indent.writeln('package ${options.package};');
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 99690a4ac92..abdf83aa74f 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -73,7 +73,16 @@ class KotlinGenerator extends Generator<KotlinOptions> {
   /// Generates Kotlin files with specified [KotlinOptions]
   @override
   void generate(KotlinOptions languageOptions, Root root, StringSink sink) {
-    generateKotlin(languageOptions, root, sink);
+    final Indent indent = Indent(sink);
+
+    writeFileHeaders(languageOptions, root, sink, indent);
+    generateKotlin(languageOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(KotlinOptions languageOptions, Root root,
+      StringSink sink, Indent indent) {
+    writeHeader(languageOptions, root, sink, indent);
   }
 }
 
@@ -447,28 +456,30 @@ String _nullsafeKotlinTypeForDartType(TypeDeclaration type) {
   return '${_kotlinTypeForDartType(type)}$nullSafe';
 }
 
+/// Writes file header to sink.
+void writeHeader(
+    KotlinOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.copyrightHeader != null) {
+    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+  }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+}
+
 /// Generates the ".kotlin" file for the AST represented by [root] to [sink] with the
 /// provided [options].
-void generateKotlin(KotlinOptions options, Root root, StringSink sink) {
+void generateKotlin(
+    KotlinOptions options, Root root, StringSink sink, Indent indent) {
   final Set<String> rootClassNameSet =
       root.classes.map((Class x) => x.name).toSet();
   final Set<String> rootEnumNameSet =
       root.enums.map((Enum x) => x.name).toSet();
-  final Indent indent = Indent(sink);
 
   HostDatatype getHostDatatype(NamedType field) {
     return getFieldHostDatatype(field, root.classes, root.enums,
         (TypeDeclaration x) => _kotlinTypeForBuiltinDartType(x));
   }
 
-  void writeHeader() {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-  }
-
   void writeImports() {
     indent.writeln('import android.util.Log');
     indent.writeln('import io.flutter.plugin.common.BasicMessageChannel');
@@ -663,7 +674,6 @@ void generateKotlin(KotlinOptions options, Root root, StringSink sink) {
     });
   }
 
-  writeHeader();
   indent.addln('');
   if (options.package != null) {
     indent.writeln('package ${options.package}');
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 0d376e1a582..5b59377a8dd 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -72,7 +72,16 @@ class ObjcHeaderGenerator extends Generator<ObjcOptions> {
   /// Generates Objc header files with specified [ObjcOptions]
   @override
   void generate(ObjcOptions languageOptions, Root root, StringSink sink) {
-    generateObjcHeader(languageOptions, root, sink);
+    final Indent indent = Indent(sink);
+
+    writeFileHeaders(languageOptions, root, sink, indent);
+    generateObjcHeader(languageOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(
+      ObjcOptions languageOptions, Root root, StringSink sink, Indent indent) {
+    writeObjcHeaderHeader(languageOptions, root, sink, indent);
   }
 }
 
@@ -84,7 +93,16 @@ class ObjcSourceGenerator extends Generator<ObjcOptions> {
   /// Generates Objc files with specified [ObjcOptions]
   @override
   void generate(ObjcOptions languageOptions, Root root, StringSink sink) {
-    generateObjcSource(languageOptions, root, sink);
+    final Indent indent = Indent(sink);
+
+    writeObjcSourceHeader(languageOptions, root, sink, indent);
+    generateObjcSource(languageOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(
+      ObjcOptions languageOptions, Root root, StringSink sink, Indent indent) {
+    writeObjcSourceHeader(languageOptions, root, sink, indent);
   }
 }
 
@@ -555,19 +573,20 @@ void _writeFlutterApiDeclaration(
   indent.writeln('@end');
 }
 
-/// Generates the ".h" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateObjcHeader(ObjcOptions options, Root root, StringSink sink) {
-  final Indent indent = Indent(sink);
-
-  void writeHeader() {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
+/// Writes Objc header file header to sink.
+void writeObjcHeaderHeader(
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.copyrightHeader != null) {
+    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
   }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+}
 
+/// Generates the ".h" file for the AST represented by [root] to [sink] with the
+/// provided [options].
+void generateObjcHeader(
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {
   void writeImports() {
     indent.writeln('#import <Foundation/Foundation.h>');
   }
@@ -596,7 +615,6 @@ void generateObjcHeader(ObjcOptions options, Root root, StringSink sink) {
     });
   }
 
-  writeHeader();
   writeImports();
   writeForwardDeclarations();
   indent.writeln('');
@@ -898,22 +916,24 @@ void _writeFlutterApiSource(
   indent.writeln('@end');
 }
 
+/// Writes Objc Source file header to sink.
+void writeObjcSourceHeader(
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.copyrightHeader != null) {
+    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+  }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+}
+
 /// Generates the ".m" file for the AST represented by [root] to [sink] with the
 /// provided [options].
-void generateObjcSource(ObjcOptions options, Root root, StringSink sink) {
-  final Indent indent = Indent(sink);
+void generateObjcSource(
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {
   final List<String> classNames =
       root.classes.map((Class x) => x.name).toList();
   final List<String> enumNames = root.enums.map((Enum x) => x.name).toList();
 
-  void writeHeader() {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-  }
-
   void writeImports() {
     indent.writeln('#import "${options.header}"');
     indent.writeln('#import <Flutter/Flutter.h>');
@@ -1030,7 +1050,6 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
     }
   }
 
-  writeHeader();
   writeImports();
   indent.writeln('');
   writeArcEnforcer();
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index b25931c03e3..8ea5ed88065 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -56,7 +56,15 @@ class SwiftGenerator extends Generator<SwiftOptions> {
   /// Generates Swift files with specified [SwiftOptions]
   @override
   void generate(SwiftOptions languageOptions, Root root, StringSink sink) {
-    generateSwift(languageOptions, root, sink);
+    final Indent indent = Indent(sink);
+    writeFileHeaders(languageOptions, root, sink, indent);
+    generateSwift(languageOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(
+      SwiftOptions languageOptions, Root root, StringSink sink, Indent indent) {
+    writeHeader(languageOptions, root, sink, indent);
   }
 }
 
@@ -442,28 +450,30 @@ String _nullsafeSwiftTypeForDartType(TypeDeclaration type) {
   return '${_swiftTypeForDartType(type)}$nullSafe';
 }
 
+/// Writes file header to sink.
+void writeHeader(
+    SwiftOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.copyrightHeader != null) {
+    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+  }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+}
+
 /// Generates the ".swift" file for the AST represented by [root] to [sink] with the
 /// provided [options].
-void generateSwift(SwiftOptions options, Root root, StringSink sink) {
+void generateSwift(
+    SwiftOptions options, Root root, StringSink sink, Indent indent) {
   final Set<String> rootClassNameSet =
       root.classes.map((Class x) => x.name).toSet();
   final Set<String> rootEnumNameSet =
       root.enums.map((Enum x) => x.name).toSet();
-  final Indent indent = Indent(sink);
 
   HostDatatype getHostDatatype(NamedType field) {
     return getFieldHostDatatype(field, root.classes, root.enums,
         (TypeDeclaration x) => _swiftTypeForBuiltinDartType(x));
   }
 
-  void writeHeader() {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-  }
-
   void writeImports() {
     indent.writeln('import Foundation');
     indent.format('''
@@ -632,7 +642,6 @@ import FlutterMacOS
     });
   }
 
-  writeHeader();
   indent.addln('');
   writeImports();
   indent.addln('');

From ae817ad221d8f05293e97536904ae24816466cf8 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 22 Dec 2022 09:56:48 -0800
Subject: [PATCH 15/87] Updates tests to use new generator class

---
 packages/pigeon/test/cpp_generator_test.dart  |  81 ++++--
 packages/pigeon/test/dart_generator_test.dart | 153 ++++++----
 packages/pigeon/test/java_generator_test.dart | 117 +++++---
 .../pigeon/test/kotlin_generator_test.dart    |  99 ++++---
 packages/pigeon/test/objc_generator_test.dart | 261 +++++++++++-------
 .../pigeon/test/swift_generator_test.dart     |  99 ++++---
 6 files changed, 528 insertions(+), 282 deletions(-)

diff --git a/packages/pigeon/test/cpp_generator_test.dart b/packages/pigeon/test/cpp_generator_test.dart
index d089b0a4480..4e4a3a1a354 100644
--- a/packages/pigeon/test/cpp_generator_test.dart
+++ b/packages/pigeon/test/cpp_generator_test.dart
@@ -45,7 +45,8 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('class Input'));
       expect(code, contains('class Output'));
@@ -53,7 +54,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppSourceGenerator generator = CppSourceGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('Input::Input()'));
       expect(code, contains('Output::Output'));
@@ -101,7 +103,8 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Method name and argument names should be adjusted.
       expect(code, contains(' DoSomething(const Input& some_input)'));
@@ -116,7 +119,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppSourceGenerator generator = CppSourceGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('pointer_input_field'));
       expect(code, contains('Output::output_field()'));
@@ -144,7 +148,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
 
       expect(
@@ -184,7 +189,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
 
       expect(
@@ -238,14 +244,16 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, isNot(contains('){')));
       expect(code, isNot(contains('const{')));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppSourceGenerator generator = CppSourceGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, isNot(contains('){')));
       expect(code, isNot(contains('const{')));
@@ -271,7 +279,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('''
 #include <flutter/basic_message_channel.h>
@@ -286,7 +295,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(header: 'a_header.h'), root, sink);
+      final CppSourceGenerator generator = CppSourceGenerator();
+      generator.generate(const CppOptions(header: 'a_header.h'), root, sink);
       final String code = sink.toString();
       expect(code, contains('''
 #include "a_header.h"
@@ -322,14 +332,16 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(namespace: 'foo'), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(namespace: 'foo'), root, sink);
       final String code = sink.toString();
       expect(code, contains('namespace foo {'));
       expect(code, contains('}  // namespace foo'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(namespace: 'foo'), root, sink);
+      final CppSourceGenerator generator = CppSourceGenerator();
+      generator.generate(const CppOptions(namespace: 'foo'), root, sink);
       final String code = sink.toString();
       expect(code, contains('namespace foo {'));
       expect(code, contains('}  // namespace foo'));
@@ -390,7 +402,8 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Getters should return const pointers.
       expect(code, contains('const bool* nullable_bool()'));
@@ -422,7 +435,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppSourceGenerator generator = CppSourceGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Getters extract optionals.
       expect(code,
@@ -521,7 +535,8 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // POD getters should return copies references.
       expect(code, contains('bool non_nullable_bool()'));
@@ -546,7 +561,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppSourceGenerator generator = CppSourceGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Getters just return the value.
       expect(code, contains('return non_nullable_bool_;'));
@@ -644,7 +660,8 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(
           code, contains('ErrorOr<std::optional<bool>> ReturnNullableBool()'));
@@ -749,7 +766,8 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('ErrorOr<bool> ReturnBool()'));
       expect(code, contains('ErrorOr<int64_t> ReturnInt()'));
@@ -825,7 +843,8 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -838,7 +857,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppSourceGenerator generator = CppSourceGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Most types should just use get_if, since the parameter is a pointer,
       // and get_if will automatically handle null values (since a null
@@ -943,7 +963,8 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      final CppHeaderGenerator generator = CppHeaderGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -956,7 +977,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppSourceGenerator generator = CppSourceGenerator();
+      generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Most types should extract references. Since the type is non-nullable,
       // there's only one possible type.
@@ -1010,7 +1032,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    generateCppSource(const CppOptions(), root, sink);
+    final CppSourceGenerator generator = CppSourceGenerator();
+    generator.generate(const CppOptions(), root, sink);
     final String code = sink.toString();
     // A bare 'auto' here would create a copy, not a reference, which is
     // ineffecient.
@@ -1122,7 +1145,8 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateCppHeader('foo', const CppOptions(), root, sink);
+    final CppHeaderGenerator generator = CppHeaderGenerator();
+    generator.generate(const CppOptions(cppHeaderOut: 'foo'), root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       expect(code, contains('//$comment'));
@@ -1157,7 +1181,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateCppHeader('', const CppOptions(), root, sink);
+    final CppHeaderGenerator generator = CppHeaderGenerator();
+    generator.generate(const CppOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' : public flutter::StandardCodecSerializer')));
   });
@@ -1199,7 +1224,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateCppHeader('', const CppOptions(), root, sink);
+    final CppHeaderGenerator generator = CppHeaderGenerator();
+    generator.generate(const CppOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains(' : public flutter::StandardCodecSerializer'));
   });
@@ -1268,7 +1294,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateCppSource(const CppOptions(), root, sink);
+    final CppSourceGenerator generator = CppSourceGenerator();
+    generator.generate(const CppOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains('reply(wrap')));
     expect(code, contains('reply(flutter::EncodableValue('));
diff --git a/packages/pigeon/test/dart_generator_test.dart b/packages/pigeon/test/dart_generator_test.dart
index 38442ccd358..5eb9bdd9fc6 100644
--- a/packages/pigeon/test/dart_generator_test.dart
+++ b/packages/pigeon/test/dart_generator_test.dart
@@ -29,7 +29,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('  dataType1? field1;'));
@@ -49,7 +50,8 @@ void main() {
       enums: <Enum>[anEnum],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foobar'));
     expect(code, contains('  one,'));
@@ -92,7 +94,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, contains('Future<Output> doSomething(Input arg_input)'));
@@ -118,7 +121,8 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, contains('Future<int> add(int arg_x, int arg_y)'));
@@ -145,7 +149,8 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, contains('int add(int x, int y)'));
@@ -182,7 +187,8 @@ void main() {
       )
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
       code,
@@ -224,7 +230,8 @@ void main() {
       )
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
       code,
@@ -276,7 +283,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('abstract class Api'));
     expect(code, contains('static void setup(Api'));
@@ -310,7 +318,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<void> doSomething'));
     expect(code, contains('return;'));
@@ -343,7 +352,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     // The next line verifies that we're not setting a variable to the value of "doSomething", but
     // ignores the line where we assert the value of the argument isn't null, since on that line
@@ -373,7 +383,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('output.*=.*doSomething[(][)]'));
     expect(code, contains('Output doSomething();'));
@@ -415,7 +426,8 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum1?.index,'));
     expect(code, contains('? Enum.values[result[0]! as int]'));
@@ -442,7 +454,8 @@ void main() {
       ])
     ]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foo {'));
     expect(code, contains('Future<void> bar(Foo? arg_foo) async'));
@@ -485,7 +498,8 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum1.index,'));
     expect(code, contains('enum1: Enum.values[result[0]! as int]'));
@@ -512,7 +526,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('channel.send[(]null[)]'));
   });
@@ -570,7 +585,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer mainCodeSink = StringBuffer();
     final StringBuffer testCodeSink = StringBuffer();
-    generateDart(DartOptions(), root, mainCodeSink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, mainCodeSink);
     final String mainCode = mainCodeSink.toString();
     expect(mainCode, isNot(contains(r"import 'fo\'o.dart';")));
     expect(mainCode, contains('class Api {'));
@@ -578,12 +594,15 @@ void main() {
     expect(mainCode, isNot(contains('.ApiMock.doSomething')));
     expect(mainCode, isNot(contains("'${Keys.result}': output")));
     expect(mainCode, isNot(contains('return <Object>[];')));
-    generateTestDart(
-      DartOptions(),
+
+    final DartTestGenerator testGenerator = DartTestGenerator();
+    testGenerator.generate(
+      DartOptions(
+        dartOutPath: "fo'o.dart",
+        testOutPath: 'test.dart',
+      ),
       root,
       testCodeSink,
-      dartOutPath: "fo'o.dart",
-      testOutPath: 'test.dart',
     );
     final String testCode = testCodeSink.toString();
     expect(testCode, contains(r"import 'fo\'o.dart';"));
@@ -631,7 +650,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('abstract class Api'));
     expect(code, contains('Future<Output> doSomething(Input arg0);'));
@@ -675,7 +695,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('=.s*doSomething')));
     expect(code, contains('await api.doSomething('));
@@ -719,7 +740,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, matches('Output.*doSomething.*Input'));
@@ -747,7 +769,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('channel.send[(]null[)]'));
   });
@@ -759,11 +782,10 @@ void main() {
   test('header', () {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(
-      DartOptions(copyrightHeader: makeIterable('hello world')),
-      root,
-      sink,
-    );
+
+    final DartGenerator generator = DartGenerator();
+    generator.generate(
+        DartOptions(copyrightHeader: makeIterable('hello world')), root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
   });
@@ -788,7 +810,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('  List<int?>? field1;'));
@@ -815,7 +838,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('  Map<String?, int?>? field1;'));
@@ -844,7 +868,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(List<int?> arg'));
   });
@@ -872,7 +897,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(List<int?> arg'));
   });
@@ -896,7 +922,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<List<int?>> doit('));
     expect(code,
@@ -931,7 +958,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('List<int?> doit('));
     expect(
@@ -958,7 +986,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit()'));
     expect(code, contains('return (replyList[0] as int?);'));
@@ -983,7 +1012,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<List<int?>?> doit()'));
     expect(code,
@@ -1008,7 +1038,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit()'));
     expect(code, contains('return (replyList[0] as int?);'));
@@ -1031,7 +1062,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('int? doit();'));
     expect(code, contains('final int? output = api.doit();'));
@@ -1055,7 +1087,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit();'));
     expect(code, contains('final int? output = await api.doit();'));
@@ -1078,7 +1111,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1107,7 +1141,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<void> doit(int? arg_foo) async {'));
   });
@@ -1133,7 +1168,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('void doit(int? foo);'));
   });
@@ -1150,12 +1186,14 @@ name: foobar
       final Root root =
           Root(classes: <Class>[], apis: <Api>[], enums: <Enum>[]);
       final StringBuffer sink = StringBuffer();
-      generateTestDart(
-        DartOptions(),
+      final DartTestGenerator testGenerator = DartTestGenerator();
+      testGenerator.generate(
+        DartOptions(
+          dartOutPath: path.join(foo.path, 'bar.dart'),
+          testOutPath: path.join(tempDir.path, 'test', 'bar_test.dart'),
+        ),
         root,
         sink,
-        dartOutPath: path.join(foo.path, 'bar.dart'),
-        testOutPath: path.join(tempDir.path, 'test', 'bar_test.dart'),
       );
       final String code = sink.toString();
       expect(code, contains("import 'package:foobar/foo/bar.dart';"));
@@ -1238,7 +1276,8 @@ name: foobar
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       expect(code, contains('///$comment'));
@@ -1273,7 +1312,8 @@ name: foobar
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains('extends StandardMessageCodec')));
     expect(code, contains('StandardMessageCodec'));
@@ -1316,7 +1356,8 @@ name: foobar
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('extends StandardMessageCodec'));
   });
@@ -1354,13 +1395,17 @@ name: foobar
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateTestDart(
-      DartOptions(),
+
+    final DartTestGenerator testGenerator = DartTestGenerator();
+    testGenerator.generate(
+      DartOptions(
+        dartOutPath: 'code.dart',
+        testOutPath: 'test.dart',
+      ),
       root,
       sink,
-      dartOutPath: 'code.dart',
-      testOutPath: 'test.dart',
     );
+
     final String testCode = sink.toString();
     expect(
         testCode,
diff --git a/packages/pigeon/test/java_generator_test.dart b/packages/pigeon/test/java_generator_test.dart
index bfcea98cfe2..f2a25288754 100644
--- a/packages/pigeon/test/java_generator_test.dart
+++ b/packages/pigeon/test/java_generator_test.dart
@@ -27,7 +27,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public class Messages'));
     expect(code, contains('public static class Foobar'));
@@ -55,7 +56,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public enum Foobar'));
     expect(code, contains('    ONE(0),'));
@@ -86,7 +88,8 @@ void main() {
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions =
         JavaOptions(className: 'Messages', package: 'com.google.foobar');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('package com.google.foobar;'));
     expect(code, contains('ArrayList<Object> toList()'));
@@ -129,7 +132,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public interface Api'));
     expect(code, matches('Output.*doSomething.*Input'));
@@ -200,7 +204,8 @@ void main() {
 
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('private @Nullable Boolean aBool;'));
     expect(code, contains('private @Nullable Long aInt;'));
@@ -249,7 +254,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Api'));
     expect(code, matches('doSomething.*Input.*Output'));
@@ -283,7 +289,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('=.*doSomething')));
     expect(code, contains('doSomething('));
@@ -317,7 +324,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('Reply<Void>'));
     expect(code, contains('callback.reply(null)'));
@@ -345,7 +353,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('Output doSomething()'));
     expect(code, contains('api.doSomething()'));
@@ -373,7 +382,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doSomething(Reply<Output>'));
     expect(code, contains('channel.send(null'));
@@ -392,7 +402,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Foobar'));
     expect(code, contains('private @Nullable List<Object> field1;'));
@@ -411,7 +422,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Foobar'));
     expect(code, contains('private @Nullable Map<Object, Object> field1;'));
@@ -447,7 +459,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public class Messages'));
     expect(code, contains('public static class Outer'));
@@ -498,7 +511,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public interface Api'));
     expect(code, contains('public interface Result<T> {'));
@@ -549,7 +563,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Api'));
     expect(code, matches('doSomething.*Input.*Output'));
@@ -582,7 +597,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public enum Enum1'));
     expect(code, contains('    ONE(0),'));
@@ -621,7 +637,8 @@ void main() {
     ]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public enum Foo'));
     expect(
@@ -641,7 +658,8 @@ void main() {
       className: 'Messages',
       copyrightHeader: makeIterable('hello world'),
     );
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
   });
@@ -667,7 +685,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('List<Long> field1;'));
@@ -695,7 +714,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('Map<String, String> field1;'));
@@ -725,7 +745,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(@NonNull List<Long> arg'));
   });
@@ -754,7 +775,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(@NonNull List<Long> arg'));
   });
@@ -779,7 +801,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('List<Long> doit('));
     expect(code, contains('List<Long> output ='));
@@ -805,7 +828,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(Reply<List<Long>> callback)'));
     expect(code, contains('List<Long> output ='));
@@ -828,7 +852,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(Reply<Long> callback)'));
     expect(
@@ -858,7 +883,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Messages'));
     expect(code, contains('Long add(@NonNull Long x, @NonNull Long y)'));
@@ -889,7 +915,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Api');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('Object xArg = args.get(0)'));
   });
@@ -915,7 +942,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Messages'));
     expect(code, contains('BasicMessageChannel<Object> channel'));
@@ -947,7 +975,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -973,7 +1002,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@Nullable Long doit();'));
   });
@@ -997,7 +1027,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     // Java doesn't accept nullability annotations in type arguments.
     expect(code, contains('Result<Long>'));
@@ -1025,7 +1056,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('  void doit(@Nullable Long foo);'));
   });
@@ -1052,7 +1084,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1083,7 +1116,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1108,7 +1142,8 @@ void main() {
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions =
         JavaOptions(className: 'Messages', useGeneratedAnnotation: true);
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@javax.annotation.Generated("dev.flutter.pigeon")'));
   });
@@ -1125,7 +1160,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code,
         isNot(contains('@javax.annotation.Generated("dev.flutter.pigeon")')));
@@ -1207,7 +1243,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       // This regex finds the comment only between the open and close comment block
@@ -1247,7 +1284,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' extends StandardMessageCodec')));
     expect(code, contains('StandardMessageCodec'));
@@ -1291,7 +1329,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains(' extends StandardMessageCodec'));
   });
diff --git a/packages/pigeon/test/kotlin_generator_test.dart b/packages/pigeon/test/kotlin_generator_test.dart
index 4653410837e..96056c1b1b1 100644
--- a/packages/pigeon/test/kotlin_generator_test.dart
+++ b/packages/pigeon/test/kotlin_generator_test.dart
@@ -27,7 +27,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar ('));
     expect(code, contains('val field1: Long? = null'));
@@ -50,7 +51,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum class Foobar(val raw: Int) {'));
     expect(code, contains('ONE(0)'));
@@ -78,7 +80,8 @@ void main() {
     ]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum class Foo(val raw: Int) {'));
     expect(code, contains('val fooArg = Foo.ofRaw(args[0] as Int)'));
@@ -124,7 +127,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('interface Api'));
     expect(code, contains('fun doSomething(input: Input): Output'));
@@ -213,7 +217,8 @@ void main() {
     final StringBuffer sink = StringBuffer();
 
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('val aBool: Boolean? = null'));
     expect(code, contains('val aInt: Long? = null'));
@@ -265,7 +270,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code,
         contains('class Api(private val binaryMessenger: BinaryMessenger)'));
@@ -302,7 +308,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('.*doSomething(.*) ->')));
     expect(code, matches('doSomething(.*)'));
@@ -338,7 +345,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('callback: () -> Unit'));
     expect(code, contains('callback()'));
@@ -367,7 +375,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doSomething(): Output'));
     expect(code, contains('wrapped = listOf<Any?>(api.doSomething())'));
@@ -398,7 +407,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doSomething(callback: (Output) -> Unit)'));
     expect(code, contains('channel.send(null)'));
@@ -418,7 +428,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
     expect(code, contains('val field1: List<Any?>? = null'));
@@ -438,7 +449,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
     expect(code, contains('val field1: Map<Any, Any?>? = null'));
@@ -476,7 +488,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Outer'));
     expect(code, contains('data class Nested'));
@@ -529,7 +542,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('interface Api'));
     expect(code, contains('api.doSomething(argArg) {'));
@@ -577,7 +591,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, matches('fun doSomething.*Input.*callback.*Output.*Unit'));
@@ -610,7 +625,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum class Enum1(val raw: Int)'));
     expect(code, contains('ONE(0)'));
@@ -627,7 +643,8 @@ void main() {
     final KotlinOptions kotlinOptions = KotlinOptions(
       copyrightHeader: makeIterable('hello world'),
     );
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
   });
@@ -654,7 +671,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
     expect(code, contains('val field1: List<Long?>'));
@@ -683,7 +701,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
     expect(code, contains('val field1: Map<String?, String?>'));
@@ -714,7 +733,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(arg: List<Long?>'));
   });
@@ -744,7 +764,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(argArg: List<Long?>'));
   });
@@ -769,7 +790,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(): List<Long?>'));
     expect(code, contains('wrapped = listOf<Any?>(api.doit())'));
@@ -796,7 +818,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(callback: (List<Long?>) -> Unit'));
     expect(code, contains('val result = it as List<Long?>'));
@@ -824,7 +847,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun add(x: Long, y: Long): Long'));
     expect(code, contains('val args = message as List<Any?>'));
@@ -861,7 +885,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('val channel = BasicMessageChannel'));
     expect(code, contains('val result = it as Long'));
@@ -889,7 +914,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(): Long?'));
   });
@@ -913,7 +939,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(callback: (Long?) -> Unit'));
   });
@@ -940,7 +967,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -970,7 +998,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(fooArg: Long?, callback: () -> Unit'));
   });
@@ -1005,7 +1034,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('val input: String\n'));
   });
@@ -1086,7 +1116,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       // This regex finds the comment only between the open and close comment block
@@ -1126,7 +1157,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' : StandardMessageCodec() ')));
     expect(code, contains('StandardMessageCodec'));
@@ -1170,7 +1202,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains(' : StandardMessageCodec() '));
   });
diff --git a/packages/pigeon/test/objc_generator_test.dart b/packages/pigeon/test/objc_generator_test.dart
index cf83029338e..cc33903df77 100644
--- a/packages/pigeon/test/objc_generator_test.dart
+++ b/packages/pigeon/test/objc_generator_test.dart
@@ -17,7 +17,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(code, matches('@property.*NSString.*field1'));
@@ -32,7 +33,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
     expect(code, contains('@implementation Foobar'));
@@ -49,7 +51,8 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('typedef NS_ENUM(NSUInteger, Enum1) {'));
     expect(code, contains('  Enum1One = 0,'));
@@ -67,7 +70,8 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(prefix: 'PREFIX'), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(header: 'PREFIX'), root, sink);
     final String code = sink.toString();
     expect(code, contains('typedef NS_ENUM(NSUInteger, PREFIXEnum1) {'));
     expect(code, contains('  PREFIXEnum1One = 0,'));
@@ -103,7 +107,8 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
     expect(code, contains('@implementation Foobar'));
@@ -135,13 +140,15 @@ void main() {
     final StringBuffer sink = StringBuffer();
     const ObjcOptions options = ObjcOptions(header: 'foo.h', prefix: 'AC');
     {
-      generateObjcHeader(options, root, sink);
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(options, root, sink);
       final String code = sink.toString();
       expect(code, contains('typedef NS_ENUM(NSUInteger, ACFoo)'));
       expect(code, contains(':(ACFoo)foo error:'));
     }
     {
-      generateObjcSource(options, root, sink);
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(const ObjcOptions(), root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -204,7 +211,8 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(header: 'foo.h'), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@property(nonatomic, assign) Enum1 enum1'));
   });
@@ -236,7 +244,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Input'));
     expect(code, contains('@interface Output'));
@@ -275,7 +284,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
     expect(code, contains('@implementation Input'));
@@ -322,7 +332,8 @@ void main() {
     ], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(header: 'foo.h'), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(code, contains('@class FlutterStandardTypedData;'));
@@ -350,7 +361,8 @@ void main() {
     ], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation Foobar'));
     expect(code,
@@ -371,7 +383,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(header: 'foo.h'), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code,
         contains('@property(nonatomic, strong, nullable) Input * nested;'));
@@ -391,7 +404,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -410,7 +424,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(prefix: 'ABC'), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface ABCFoobar'));
   });
@@ -424,7 +439,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(prefix: 'ABC'), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation ABCFoobar'));
   });
@@ -458,7 +474,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(prefix: 'ABC'), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, matches('property.*ABCInput'));
     expect(code, matches('ABCNested.*doSomething.*ABCInput'));
@@ -494,7 +511,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(prefix: 'ABC'), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, contains('ABCInput fromList'));
     expect(code, matches(r'ABCInput.*=.*args.*0.*\;'));
@@ -530,7 +548,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(header: 'foo.h'), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Api : NSObject'));
     expect(
@@ -569,7 +588,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation Api'));
     expect(code, matches('void.*doSomething.*Input.*Output.*{'));
@@ -598,8 +618,10 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+
     final String code = sink.toString();
     expect(code, contains('(void)doSomething:'));
   });
@@ -627,7 +649,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('=.*doSomething')));
@@ -658,7 +681,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, contains('completion:(void(^)(NSError *_Nullable))'));
@@ -687,7 +711,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, contains('completion:(void(^)(NSError *_Nullable))'));
@@ -711,7 +736,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, matches('ABCOutput.*doSomethingWithError:[(]FlutterError'));
@@ -734,7 +760,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, matches('output.*=.*api doSomethingWithError:&error'));
@@ -757,7 +784,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(
@@ -783,7 +811,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(
@@ -802,7 +831,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(code, matches('@property.*NSArray.*field1'));
@@ -817,7 +847,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(code, matches('@property.*NSDictionary.*field1'));
@@ -838,7 +869,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(
@@ -867,7 +899,8 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('(NSDictionary<NSString *, id> *)foo'));
   });
@@ -901,7 +934,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(
@@ -940,7 +974,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(
@@ -967,7 +1002,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(
@@ -987,7 +1023,8 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(
@@ -1026,7 +1063,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(
@@ -1064,7 +1102,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(
@@ -1084,7 +1123,8 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(
@@ -1111,7 +1151,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(
@@ -1127,14 +1168,14 @@ void main() {
   test('source copyright', () {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-      ObjcOptions(
-          header: 'foo.h',
-          prefix: 'ABC',
-          copyrightHeader: makeIterable('hello world')),
-      root,
-      sink,
-    );
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(
+        ObjcOptions(
+            header: 'foo.h',
+            prefix: 'ABC',
+            copyrightHeader: makeIterable('hello world')),
+        root,
+        sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
   });
@@ -1142,14 +1183,14 @@ void main() {
   test('header copyright', () {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-      ObjcOptions(
-          header: 'foo.h',
-          prefix: 'ABC',
-          copyrightHeader: makeIterable('hello world')),
-      root,
-      sink,
-    );
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(
+        ObjcOptions(
+            header: 'foo.h',
+            prefix: 'ABC',
+            copyrightHeader: makeIterable('hello world')),
+        root,
+        sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
   });
@@ -1174,7 +1215,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, contains('NSArray<NSNumber *> * field1'));
@@ -1204,14 +1246,16 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSNumber *> *)arg'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(
@@ -1245,14 +1289,16 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSNumber *> *)arg'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSNumber *> *)arg'));
@@ -1289,7 +1335,8 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSArray<NSNumber *> *> *)arg'));
@@ -1316,7 +1363,8 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(
@@ -1324,7 +1372,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(code, contains('NSArray<NSNumber *> *output ='));
@@ -1351,7 +1400,8 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(
@@ -1359,7 +1409,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(
@@ -1388,7 +1439,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(
@@ -1398,7 +1450,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(code, contains('NSArray *args = message;'));
@@ -1433,7 +1486,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(
@@ -1443,7 +1497,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(code, contains('NSArray *args = message;'));
@@ -1476,7 +1531,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(
@@ -1486,7 +1542,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
       expect(
@@ -1530,15 +1587,18 @@ void main() {
     final Root divideRoot = getDivideRoot(ApiLocation.host);
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), divideRoot, sink);
       final String code = sink.toString();
       expect(code, matches('divideValue:.*by:.*error.*;'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), divideRoot, sink);
+
       final String code = sink.toString();
       expect(code, matches('divideValue:.*by:.*error.*;'));
     }
@@ -1548,21 +1608,18 @@ void main() {
     final Root divideRoot = getDivideRoot(ApiLocation.flutter);
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'),
-        divideRoot,
-        sink,
-      );
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(
+          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), divideRoot, sink);
       final String code = sink.toString();
       expect(code, matches('divideValue:.*by:.*completion.*;'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'),
-        divideRoot,
-        sink,
-      );
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(
+          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), divideRoot, sink);
+
       final String code = sink.toString();
       expect(code, matches('divideValue:.*by:.*completion.*{'));
     }
@@ -1577,7 +1634,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(code, contains('@property(nonatomic, copy) NSString * field1'));
@@ -1600,7 +1658,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1625,7 +1684,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches(r'doitWithCompletion.*NSNumber \*_Nullable'));
   });
@@ -1647,7 +1707,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches(r'nullable NSNumber.*doitWithError'));
   });
@@ -1674,13 +1735,15 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(const ObjcOptions(), root, sink);
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(const ObjcOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('doitFoo:(nullable NSNumber *)foo'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(const ObjcOptions(), root, sink);
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(const ObjcOptions(), root, sink);
       final String code = sink.toString();
       expect(code,
           contains('NSNumber *arg_foo = GetNullableObjectAtIndex(args, 0);'));
@@ -1709,13 +1772,15 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(const ObjcOptions(), root, sink);
+      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      generator.generate(const ObjcOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('doitFoo:(nullable NSNumber *)foo'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(const ObjcOptions(), root, sink);
+      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      generator.generate(const ObjcOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('- (void)doitFoo:(nullable NSNumber *)arg_foo'));
     }
@@ -1739,7 +1804,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1823,7 +1889,8 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       expect(code, contains('///$comment'));
@@ -1858,7 +1925,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' : FlutterStandardReader')));
   });
@@ -1900,7 +1968,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(), root, sink);
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains(' : FlutterStandardReader'));
   });
diff --git a/packages/pigeon/test/swift_generator_test.dart b/packages/pigeon/test/swift_generator_test.dart
index 74c8aad15ca..305ca203fe7 100644
--- a/packages/pigeon/test/swift_generator_test.dart
+++ b/packages/pigeon/test/swift_generator_test.dart
@@ -26,7 +26,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: Int32? = nil'));
@@ -49,7 +50,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foobar: Int'));
     expect(code, contains('  case one = 0'));
@@ -77,7 +79,8 @@ void main() {
     ]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foo: Int'));
     expect(code, contains('let fooArg = Foo(rawValue: args[0] as! Int)!'));
@@ -120,7 +123,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('protocol Api'));
     expect(code, matches('func doSomething.*Input.*Output'));
@@ -183,7 +187,8 @@ void main() {
 
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('var aBool: Bool? = nil'));
     expect(code, contains('var aInt: Int32? = nil'));
@@ -232,7 +237,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, contains('init(binaryMessenger: FlutterBinaryMessenger)'));
@@ -267,7 +273,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('.*doSomething(.*) ->')));
     expect(code, matches('doSomething(.*)'));
@@ -301,7 +308,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('completion: @escaping () -> Void'));
     expect(code, contains('completion()'));
@@ -329,7 +337,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doSomething() -> Output'));
     expect(code, contains('let result = api.doSomething()'));
@@ -358,7 +367,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code,
         contains('func doSomething(completion: @escaping (Output) -> Void)'));
@@ -378,7 +388,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: [Any?]? = nil'));
@@ -397,7 +408,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: [AnyHashable: Any?]? = nil'));
@@ -433,7 +445,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Outer'));
     expect(code, contains('struct Nested'));
@@ -481,7 +494,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('protocol Api'));
     expect(code, contains('api.doSomething(arg: argArg) { result in'));
@@ -526,7 +540,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, matches('func doSomething.*Input.*completion.*Output.*Void'));
@@ -558,7 +573,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Enum1: Int'));
     expect(code, contains('case one = 0'));
@@ -575,7 +591,8 @@ void main() {
     final SwiftOptions swiftOptions = SwiftOptions(
       copyrightHeader: makeIterable('hello world'),
     );
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
   });
@@ -601,7 +618,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: [Int32?]'));
@@ -629,7 +647,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: [String?: String?]'));
@@ -659,7 +678,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit(arg: [Int32?]'));
   });
@@ -688,7 +708,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit(arg argArg: [Int32?]'));
   });
@@ -713,7 +734,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit() -> [Int32?]'));
     expect(code, contains('let result = api.doit()'));
@@ -740,7 +762,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(
         code, contains('func doit(completion: @escaping ([Int32?]) -> Void'));
@@ -769,7 +792,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func add(x: Int32, y: Int32) -> Int32'));
     expect(code, contains('let args = message as! [Any?]'));
@@ -800,7 +824,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('let channel = FlutterBasicMessageChannel'));
     expect(code, contains('let result = response as! Int32'));
@@ -830,7 +855,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit() -> Int32?'));
   });
@@ -854,7 +880,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit(completion: @escaping (Int32?) -> Void'));
   });
@@ -881,7 +908,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('let fooArg = args[0] as? Int32'));
   });
@@ -908,7 +936,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -944,7 +973,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('var input: String\n'));
   });
@@ -1025,7 +1055,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       expect(code, contains('///$comment'));
@@ -1061,7 +1092,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(': FlutterStandardReader ')));
   });
@@ -1104,7 +1136,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains(': FlutterStandardReader '));
   });

From 5cecc211da254395eaa37c8f93af91da617a3626 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 22 Dec 2022 10:16:00 -0800
Subject: [PATCH 16/87] source -> header

---
 packages/pigeon/test/objc_generator_test.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/pigeon/test/objc_generator_test.dart b/packages/pigeon/test/objc_generator_test.dart
index cc33903df77..7b01154ce82 100644
--- a/packages/pigeon/test/objc_generator_test.dart
+++ b/packages/pigeon/test/objc_generator_test.dart
@@ -107,7 +107,7 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));

From 99f25b5e0f57db7a29c24749a83815987eac471c Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 22 Dec 2022 10:16:30 -0800
Subject: [PATCH 17/87] correct options

---
 packages/pigeon/test/objc_generator_test.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/pigeon/test/objc_generator_test.dart b/packages/pigeon/test/objc_generator_test.dart
index 7b01154ce82..480fe2deff6 100644
--- a/packages/pigeon/test/objc_generator_test.dart
+++ b/packages/pigeon/test/objc_generator_test.dart
@@ -148,7 +148,7 @@ void main() {
     }
     {
       final ObjcSourceGenerator generator = ObjcSourceGenerator();
-      generator.generate(const ObjcOptions(), root, sink);
+      generator.generate(options, root, sink);
       final String code = sink.toString();
       expect(
           code,

From 16df2079a618b4bbdc1076d741fe9ddcb3dbecbc Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 22 Dec 2022 10:19:50 -0800
Subject: [PATCH 18/87] header -> source

---
 packages/pigeon/test/objc_generator_test.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/pigeon/test/objc_generator_test.dart b/packages/pigeon/test/objc_generator_test.dart
index 480fe2deff6..d447000b4f7 100644
--- a/packages/pigeon/test/objc_generator_test.dart
+++ b/packages/pigeon/test/objc_generator_test.dart
@@ -107,7 +107,7 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcSourceGenerator generator = ObjcSourceGenerator();
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));

From 049c6be959d2c0403515b8e1b58d27c6ae41f30b Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 22 Dec 2022 10:23:37 -0800
Subject: [PATCH 19/87] header -> prefix, source -> header

---
 packages/pigeon/test/objc_generator_test.dart | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/pigeon/test/objc_generator_test.dart b/packages/pigeon/test/objc_generator_test.dart
index d447000b4f7..981b5fb6c29 100644
--- a/packages/pigeon/test/objc_generator_test.dart
+++ b/packages/pigeon/test/objc_generator_test.dart
@@ -70,8 +70,8 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
-    generator.generate(const ObjcOptions(header: 'PREFIX'), root, sink);
+    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    generator.generate(const ObjcOptions(prefix: 'PREFIX'), root, sink);
     final String code = sink.toString();
     expect(code, contains('typedef NS_ENUM(NSUInteger, PREFIXEnum1) {'));
     expect(code, contains('  PREFIXEnum1One = 0,'));

From a2dcb1c1c0cdee8761199abb6264d1b005623c92 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 22 Dec 2022 10:27:28 -0800
Subject: [PATCH 20/87] remove headers from generateTestDart

---
 packages/pigeon/lib/dart_generator.dart | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 90b31c7b419..76092aa759d 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -118,7 +118,7 @@ class DartTestGenerator extends Generator<DartOptions> {
   @override
   void writeFileHeaders(
       DartOptions languageOptions, Root root, StringSink sink, Indent indent) {
-    writeHeader(languageOptions, root, sink, indent);
+    writeTestHeader(languageOptions, root, sink, indent);
   }
 }
 
@@ -760,6 +760,20 @@ String _posixify(String inputPath) {
   return context.fromUri(path.toUri(path.absolute(inputPath)));
 }
 
+/// Writes file header to sink.
+void writeTestHeader(
+    DartOptions opt, Root root, StringSink sink, Indent indent) {
+  if (opt.copyrightHeader != null) {
+    addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
+  }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+  indent.writeln(
+    '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, unnecessary_import',
+  );
+  indent.writeln('// ignore_for_file: avoid_relative_lib_imports');
+}
+
 /// Generates Dart source code for test support libraries based on the given AST
 /// represented by [root], outputting the code to [sink]. [dartOutPath] is the
 /// path of the generated dart code to be tested. [testOutPath] is where the
@@ -772,15 +786,6 @@ void generateTestDart(
   required String dartOutPath,
   required String testOutPath,
 }) {
-  if (opt.copyrightHeader != null) {
-    addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
-  }
-  indent.writeln('// $generatedCodeWarning');
-  indent.writeln('// $seeAlsoWarning');
-  indent.writeln(
-    '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, unnecessary_import',
-  );
-  indent.writeln('// ignore_for_file: avoid_relative_lib_imports');
   indent.writeln("import 'dart:async';");
   indent.writeln(
     "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",

From e4c78f58dc71b2a6708680f5efc9ebc1e66f75cc Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 22 Dec 2022 10:33:42 -0800
Subject: [PATCH 21/87] changelog

---
 packages/pigeon/CHANGELOG.md             | 4 ++++
 packages/pigeon/lib/generator_tools.dart | 2 +-
 packages/pigeon/pubspec.yaml             | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index 6e6688e0d85..2ea828e27ff 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 4.2.17
+
+* Adds writeHeaders method to Generator classes and updates tests to use new Generators.
+
 ## 4.2.16
 
 * Creates new Generator classes for each language.
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index ea522eaa04d..ef503c869b8 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -9,7 +9,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon. This must match the version in pubspec.yaml.
-const String pigeonVersion = '4.2.16';
+const String pigeonVersion = '4.2.17';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index 886f56a6ea0..f77ac58c371 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 4.2.16 # This must match the version in lib/generator_tools.dart
+version: 4.2.17 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

From 68a23e20dcb2392a57cf706fba61c688c6bce9e9 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 09:12:28 -0800
Subject: [PATCH 22/87] Nits and combines source and header generators

---
 packages/pigeon/lib/cpp_generator.dart   | 35 ++++++++++++------------
 packages/pigeon/lib/generator.dart       |  7 ++---
 packages/pigeon/lib/generator_tools.dart |  9 ++++++
 packages/pigeon/lib/objc_generator.dart  | 23 ++++++----------
 packages/pigeon/lib/pigeon_lib.dart      |  8 +++---
 5 files changed, 41 insertions(+), 41 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 6bc120bc2d3..5912f6e98ed 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -21,8 +21,12 @@ const String _defaultCodecSerializer = 'flutter::StandardCodecSerializer';
 /// Options that control how C++ code will be generated.
 class CppOptions {
   /// Creates a [CppOptions] object
-  const CppOptions(
-      {this.header, this.namespace, this.copyrightHeader, this.cppHeaderOut});
+  const CppOptions({
+    this.header,
+    this.namespace,
+    this.copyrightHeader,
+    this.cppHeaderOut,
+  });
 
   /// The path to the header that will get placed in the source filed (example:
   /// "foo.h").
@@ -34,7 +38,7 @@ class CppOptions {
   /// A copyright header that will get prepended to generated code.
   final Iterable<String>? copyrightHeader;
 
-  ///
+  /// The path to the output header file location.
   final String? cppHeaderOut;
 
   /// Creates a [CppOptions] from a Map representation where:
@@ -66,27 +70,22 @@ class CppOptions {
 }
 
 /// Class that manages all Cpp header code generation.
-class CppHeaderGenerator extends Generator<CppOptions> {
+class CppGenerator extends Generator<CppOptions> {
   /// Instantiates a Cpp Generator.
-  CppHeaderGenerator();
+  CppGenerator(this.fileType);
 
-  /// Generates Cpp header files with specified [CppOptions]
-  @override
-  void generate(CppOptions languageOptions, Root root, StringSink sink) {
-    generateCppHeader(
-        languageOptions.cppHeaderOut, languageOptions, root, sink);
-  }
-}
-
-/// Class that manages all Cpp code generation.
-class CppSourceGenerator extends Generator<CppOptions> {
-  /// Instantiates a Cpp Generator.
-  CppSourceGenerator();
+  /// Specifies which file type (header or source) will be generated.
+  FileType fileType;
 
   /// Generates Cpp files with specified [CppOptions]
   @override
   void generate(CppOptions languageOptions, Root root, StringSink sink) {
-    generateCppSource(languageOptions, root, sink);
+    if (fileType == FileType.header) {
+      generateCppHeader(
+          languageOptions.cppHeaderOut, languageOptions, root, sink);
+    } else {
+      generateCppSource(languageOptions, root, sink);
+    }
   }
 }
 
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 0979627b3ac..02667e4a5c9 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -4,13 +4,10 @@
 
 import 'ast.dart';
 
-/// A Super class of generator classes.
+/// A superclass of generator classes.
 ///
-/// This is meant to provide structure and direction for future generator work.
+/// This provides the structure that is common across generators for different languages.
 abstract class Generator<T> {
-  /// Instantiates a Generator.
-  const Generator();
-
   /// Generates files for specified language with specified [languageOptions]
   void generate(T languageOptions, Root root, StringSink sink);
 }
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index ea522eaa04d..65f9c4b7a42 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -497,3 +497,12 @@ Iterable<NamedType> getFieldsInSerializationOrder(Class klass) {
   // This returns the fields in the order they are declared in the pigeon file.
   return klass.fields;
 }
+
+/// Enum to specify which file will be generated for multi-file generators
+enum FileType {
+  /// header file.
+  header,
+
+  /// source file.
+  source,
+}
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 0d376e1a582..2ef59abdf4a 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -65,26 +65,21 @@ class ObjcOptions {
 }
 
 /// Class that manages all Objc header code generation.
-class ObjcHeaderGenerator extends Generator<ObjcOptions> {
+class ObjcGenerator extends Generator<ObjcOptions> {
   /// Instantiates a Objc Generator.
-  ObjcHeaderGenerator();
+  ObjcGenerator(this.fileType);
 
-  /// Generates Objc header files with specified [ObjcOptions]
-  @override
-  void generate(ObjcOptions languageOptions, Root root, StringSink sink) {
-    generateObjcHeader(languageOptions, root, sink);
-  }
-}
-
-/// Class that manages all Objc code generation.
-class ObjcSourceGenerator extends Generator<ObjcOptions> {
-  /// Instantiates a Objc Generator.
-  ObjcSourceGenerator();
+  /// Specifies which file type (header or source) will be generated.
+  FileType fileType;
 
   /// Generates Objc files with specified [ObjcOptions]
   @override
   void generate(ObjcOptions languageOptions, Root root, StringSink sink) {
-    generateObjcSource(languageOptions, root, sink);
+    if (fileType == FileType.header) {
+      generateObjcHeader(languageOptions, root, sink);
+    } else {
+      generateObjcSource(languageOptions, root, sink);
+    }
   }
 }
 
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index e630a09c438..c5fa3264bc6 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -468,7 +468,7 @@ class ObjcHeaderAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(objcOptionsWithHeader, root, sink);
   }
 
@@ -493,7 +493,7 @@ class ObjcSourceAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(objcOptionsWithHeader, root, sink);
   }
 
@@ -566,7 +566,7 @@ class CppHeaderAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final CppHeaderGenerator generator = CppHeaderGenerator();
+    final CppGenerator generator = CppGenerator(FileType.header);
     generator.generate(cppOptionsWithHeader, root, sink);
   }
 
@@ -591,7 +591,7 @@ class CppSourceAdapter implements Adapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final CppSourceGenerator generator = CppSourceGenerator();
+    final CppGenerator generator = CppGenerator(FileType.source);
     generator.generate(cppOptionsWithHeader, root, sink);
   }
 

From 67282cf045f5ee0b565de848373e0280dad0ea13 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 09:14:27 -0800
Subject: [PATCH 23/87] renames Adapter to GeneratorAdapter

---
 packages/pigeon/lib/pigeon_lib.dart       | 122 +++++++++++-----------
 packages/pigeon/test/pigeon_lib_test.dart |  56 +++++-----
 2 files changed, 93 insertions(+), 85 deletions(-)

diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index c5fa3264bc6..7ad64df5e0c 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -357,17 +357,17 @@ IOSink? _openSink(String? output) {
 
 /// An adapter that will call a generator to write code to a sink
 /// based on the contents of [PigeonOptions].
-abstract class Adapter {
-  /// Returns an [IOSink] instance to be written to if the [Adapter] should
-  /// generate.  If it returns `null`, the [Adapter] will be skipped.
+abstract class GeneratorAdapter {
+  /// Returns an [IOSink] instance to be written to if the [GeneratorAdapter] should
+  /// generate.  If it returns `null`, the [GeneratorAdapter] will be skipped.
   IOSink? shouldGenerate(PigeonOptions options);
 
   /// Write the generated code described in [root] to [sink] using the
   /// [options].
   void generate(StringSink sink, PigeonOptions options, Root root);
 
-  /// Generates errors that would only be appropriate for this [Adapter]. For
-  /// example, maybe a certain feature isn't implemented in a [Adapter] yet.
+  /// Generates errors that would only be appropriate for this [GeneratorAdapter]. For
+  /// example, maybe a certain feature isn't implemented in a [GeneratorAdapter] yet.
   List<Error> validate(PigeonOptions options, Root root);
 }
 
@@ -385,10 +385,10 @@ DartOptions _dartOptionsWithCopyrightHeader(
       copyrightHeader: parsedCopyrightHeader);
 }
 
-/// An [Adapter] that generates the AST.
-class AstAdapter implements Adapter {
-  /// Constructor for [AstAdapter].
-  const AstAdapter();
+/// An [GeneratorAdapter] that generates the AST.
+class AstGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [AstGeneratorAdapter].
+  const AstGeneratorAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -402,10 +402,10 @@ class AstAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [Adapter] that generates Dart source code.
-class DartAdapter implements Adapter {
-  /// Constructor for [DartAdapter].
-  const DartAdapter();
+/// An [GeneratorAdapter] that generates Dart source code.
+class DartGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [DartGeneratorAdapter].
+  const DartGeneratorAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -422,10 +422,10 @@ class DartAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [Adapter] that generates Dart test source code.
-class DartTestAdapter implements Adapter {
-  /// Constructor for [DartTestAdapter].
-  const DartTestAdapter();
+/// An [GeneratorAdapter] that generates Dart test source code.
+class DartTestGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [DartTestGeneratorAdapter].
+  const DartTestGeneratorAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -456,10 +456,10 @@ class DartTestAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [Adapter] that generates Objective-C header code.
-class ObjcHeaderAdapter implements Adapter {
-  /// Constructor for [ObjcHeaderAdapter].
-  const ObjcHeaderAdapter();
+/// An [GeneratorAdapter] that generates Objective-C header code.
+class ObjcHeaderGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [ObjcHeaderGeneratorAdapter].
+  const ObjcHeaderGeneratorAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -481,10 +481,10 @@ class ObjcHeaderAdapter implements Adapter {
       validateObjc(options.objcOptions!, root);
 }
 
-/// An [Adapter] that generates Objective-C source code.
-class ObjcSourceAdapter implements Adapter {
-  /// Constructor for [ObjcSourceAdapter].
-  const ObjcSourceAdapter();
+/// An [GeneratorAdapter] that generates Objective-C source code.
+class ObjcSourceGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [ObjcSourceGeneratorAdapter].
+  const ObjcSourceGeneratorAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -505,10 +505,10 @@ class ObjcSourceAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [Adapter] that generates Java source code.
-class JavaAdapter implements Adapter {
-  /// Constructor for [JavaAdapter].
-  const JavaAdapter();
+/// An [GeneratorAdapter] that generates Java source code.
+class JavaGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [JavaGeneratorAdapter].
+  const JavaGeneratorAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -530,10 +530,10 @@ class JavaAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [Adapter] that generates Swift source code.
-class SwiftAdapter implements Adapter {
-  /// Constructor for [SwiftAdapter].
-  const SwiftAdapter();
+/// An [GeneratorAdapter] that generates Swift source code.
+class SwiftGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [SwiftGeneratorAdapter].
+  const SwiftGeneratorAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -553,10 +553,10 @@ class SwiftAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [Adapter] that generates C++ header code.
-class CppHeaderAdapter implements Adapter {
-  /// Constructor for [CppHeaderAdapter].
-  const CppHeaderAdapter();
+/// An [GeneratorAdapter] that generates C++ header code.
+class CppHeaderGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [CppHeaderGeneratorAdapter].
+  const CppHeaderGeneratorAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -579,10 +579,10 @@ class CppHeaderAdapter implements Adapter {
       validateCpp(options.cppOptions!, root);
 }
 
-/// An [Adapter] that generates C++ source code.
-class CppSourceAdapter implements Adapter {
-  /// Constructor for [CppSourceAdapter].
-  const CppSourceAdapter();
+/// An [GeneratorAdapter] that generates C++ source code.
+class CppSourceGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [CppSourceGeneratorAdapter].
+  const CppSourceGeneratorAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -603,10 +603,10 @@ class CppSourceAdapter implements Adapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [Adapter] that generates Kotlin source code.
-class KotlinAdapter implements Adapter {
-  /// Constructor for [KotlinAdapter].
-  const KotlinAdapter();
+/// An [GeneratorAdapter] that generates Kotlin source code.
+class KotlinGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [KotlinGeneratorAdapter].
+  const KotlinGeneratorAdapter();
 
   @override
   void generate(StringSink sink, PigeonOptions options, Root root) {
@@ -1353,7 +1353,7 @@ ${_argParser.usage}''';
   /// customize the generators that pigeon will use. The optional parameter
   /// [sdkPath] allows you to specify the Dart SDK path.
   static Future<int> run(List<String> args,
-      {List<Adapter>? adapters, String? sdkPath}) {
+      {List<GeneratorAdapter>? adapters, String? sdkPath}) {
     final PigeonOptions options = Pigeon.parseArgs(args);
     return runWithOptions(options, adapters: adapters, sdkPath: sdkPath);
   }
@@ -1363,23 +1363,23 @@ ${_argParser.usage}''';
   /// customize the generators that pigeon will use. The optional parameter
   /// [sdkPath] allows you to specify the Dart SDK path.
   static Future<int> runWithOptions(PigeonOptions options,
-      {List<Adapter>? adapters, String? sdkPath}) async {
+      {List<GeneratorAdapter>? adapters, String? sdkPath}) async {
     final Pigeon pigeon = Pigeon.setup();
     if (options.debugGenerators ?? false) {
       generator_tools.debugGenerators = true;
     }
-    final List<Adapter> safeAdapters = adapters ??
-        <Adapter>[
-          const DartAdapter(),
-          const JavaAdapter(),
-          const SwiftAdapter(),
-          const KotlinAdapter(),
-          const CppHeaderAdapter(),
-          const CppSourceAdapter(),
-          const DartTestAdapter(),
-          const ObjcHeaderAdapter(),
-          const ObjcSourceAdapter(),
-          const AstAdapter(),
+    final List<GeneratorAdapter> safeGeneratorAdapters = adapters ??
+        <GeneratorAdapter>[
+          const DartGeneratorAdapter(),
+          const JavaGeneratorAdapter(),
+          const SwiftGeneratorAdapter(),
+          const KotlinGeneratorAdapter(),
+          const CppHeaderGeneratorAdapter(),
+          const CppSourceGeneratorAdapter(),
+          const DartTestGeneratorAdapter(),
+          const ObjcHeaderGeneratorAdapter(),
+          const ObjcSourceGeneratorAdapter(),
+          const AstGeneratorAdapter(),
         ];
     _executeConfigurePigeon(options);
 
@@ -1401,7 +1401,7 @@ ${_argParser.usage}''';
       }
     }
 
-    for (final Adapter adapter in safeAdapters) {
+    for (final GeneratorAdapter adapter in safeGeneratorAdapters) {
       final IOSink? sink = adapter.shouldGenerate(options);
       if (sink != null) {
         final List<Error> adapterErrors =
@@ -1443,7 +1443,7 @@ ${_argParser.usage}''';
               CppOptions(header: path.basename(options.cppHeaderOut!)))));
     }
 
-    for (final Adapter adapter in safeAdapters) {
+    for (final GeneratorAdapter adapter in safeGeneratorAdapters) {
       final IOSink? sink = adapter.shouldGenerate(options);
       if (sink != null) {
         adapter.generate(sink, options, parseResults.root);
diff --git a/packages/pigeon/test/pigeon_lib_test.dart b/packages/pigeon/test/pigeon_lib_test.dart
index 411643f679f..8d06f78cecc 100644
--- a/packages/pigeon/test/pigeon_lib_test.dart
+++ b/packages/pigeon/test/pigeon_lib_test.dart
@@ -9,8 +9,8 @@ import 'package:pigeon/ast.dart';
 import 'package:pigeon/pigeon_lib.dart';
 import 'package:test/test.dart';
 
-class _ValidatorAdapter implements Adapter {
-  _ValidatorAdapter(this.sink);
+class _ValidatorGeneratorAdapter implements GeneratorAdapter {
+  _ValidatorGeneratorAdapter(this.sink);
   bool didCallValidate = false;
 
   final IOSink? sink;
@@ -397,9 +397,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const DartAdapter dartAdapter = DartAdapter();
+    const DartGeneratorAdapter dartGeneratorAdapter = DartGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    dartAdapter.generate(buffer, options, root);
+    dartGeneratorAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -407,9 +407,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options = PigeonOptions(
         javaOut: 'Foo.java', copyrightHeader: './copyright_header.txt');
-    const JavaAdapter javaAdapter = JavaAdapter();
+    const JavaGeneratorAdapter javaGeneratorAdapter = JavaGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    javaAdapter.generate(buffer, options, root);
+    javaGeneratorAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -417,9 +417,10 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const ObjcHeaderAdapter objcHeaderAdapter = ObjcHeaderAdapter();
+    const ObjcHeaderGeneratorAdapter objcHeaderGeneratorAdapter =
+        ObjcHeaderGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    objcHeaderAdapter.generate(buffer, options, root);
+    objcHeaderGeneratorAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -427,9 +428,10 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const ObjcSourceAdapter objcSourceAdapter = ObjcSourceAdapter();
+    const ObjcSourceGeneratorAdapter objcSourceGeneratorAdapter =
+        ObjcSourceGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    objcSourceAdapter.generate(buffer, options, root);
+    objcSourceGeneratorAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -437,9 +439,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options = PigeonOptions(
         swiftOut: 'Foo.swift', copyrightHeader: './copyright_header.txt');
-    const SwiftAdapter swiftAdapter = SwiftAdapter();
+    const SwiftGeneratorAdapter swiftGeneratorAdapter = SwiftGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    swiftAdapter.generate(buffer, options, root);
+    swiftGeneratorAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -447,9 +449,10 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options = PigeonOptions(
         cppHeaderOut: 'Foo.h', copyrightHeader: './copyright_header.txt');
-    const CppHeaderAdapter cppHeaderAdapter = CppHeaderAdapter();
+    const CppHeaderGeneratorAdapter cppHeaderGeneratorAdapter =
+        CppHeaderGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    cppHeaderAdapter.generate(buffer, options, root);
+    cppHeaderGeneratorAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -457,9 +460,10 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const CppSourceAdapter cppSourceAdapter = CppSourceAdapter();
+    const CppSourceGeneratorAdapter cppSourceGeneratorAdapter =
+        CppSourceGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    cppSourceAdapter.generate(buffer, options, root);
+    cppSourceGeneratorAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -929,9 +933,10 @@ abstract class Api {
       dartTestOut: 'stdout',
       dartOut: 'stdout',
     );
-    const DartTestAdapter dartAdapter = DartTestAdapter();
+    const DartTestGeneratorAdapter dartGeneratorAdapter =
+        DartTestGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    dartAdapter.generate(buffer, options, root);
+    dartGeneratorAdapter.generate(buffer, options, root);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -1187,9 +1192,10 @@ abstract class Api {
   test('generator validation', () async {
     final Completer<void> completer = Completer<void>();
     withTempFile('foo.dart', (File input) async {
-      final _ValidatorAdapter generator = _ValidatorAdapter(stdout);
+      final _ValidatorGeneratorAdapter generator =
+          _ValidatorGeneratorAdapter(stdout);
       final int result = await Pigeon.run(<String>['--input', input.path],
-          adapters: <Adapter>[generator]);
+          adapters: <GeneratorAdapter>[generator]);
       expect(generator.didCallValidate, isTrue);
       expect(result, isNot(0));
       completer.complete();
@@ -1200,10 +1206,11 @@ abstract class Api {
   test('generator validation skipped', () async {
     final Completer<void> completer = Completer<void>();
     withTempFile('foo.dart', (File input) async {
-      final _ValidatorAdapter generator = _ValidatorAdapter(null);
+      final _ValidatorGeneratorAdapter generator =
+          _ValidatorGeneratorAdapter(null);
       final int result = await Pigeon.run(
           <String>['--input', input.path, '--dart_out', 'foo.dart'],
-          adapters: <Adapter>[generator]);
+          adapters: <GeneratorAdapter>[generator]);
       expect(generator.didCallValidate, isFalse);
       expect(result, equals(0));
       completer.complete();
@@ -1214,10 +1221,11 @@ abstract class Api {
   test('run with PigeonOptions', () async {
     final Completer<void> completer = Completer<void>();
     withTempFile('foo.dart', (File input) async {
-      final _ValidatorAdapter generator = _ValidatorAdapter(null);
+      final _ValidatorGeneratorAdapter generator =
+          _ValidatorGeneratorAdapter(null);
       final int result = await Pigeon.runWithOptions(
           PigeonOptions(input: input.path, dartOut: 'foo.dart'),
-          adapters: <Adapter>[generator]);
+          adapters: <GeneratorAdapter>[generator]);
       expect(generator.didCallValidate, isFalse);
       expect(result, equals(0));
       completer.complete();

From d08606caca00e0bc2b48f08a8d820493e6e8b2dc Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 09:17:15 -0800
Subject: [PATCH 24/87] Update version number for breaking changes

---
 packages/pigeon/CHANGELOG.md             | 2 +-
 packages/pigeon/lib/generator_tools.dart | 2 +-
 packages/pigeon/pubspec.yaml             | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index 6e6688e0d85..30a5cbfe6df 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 4.2.16
+## 5.0.0
 
 * Creates new Generator classes for each language.
 
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 65f9c4b7a42..89188846af9 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -9,7 +9,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon. This must match the version in pubspec.yaml.
-const String pigeonVersion = '4.2.16';
+const String pigeonVersion = '5.0.0';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index 886f56a6ea0..e4ada89edd1 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 4.2.16 # This must match the version in lib/generator_tools.dart
+version: 5.0.0 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

From 90fcb67c67e15222e8fca60d8c7598674c04a6dd Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 09:24:36 -0800
Subject: [PATCH 25/87] nits

---
 packages/pigeon/lib/cpp_generator.dart | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 5912f6e98ed..632de008f0e 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -45,10 +45,11 @@ class CppOptions {
   /// `x = CppOptions.fromMap(x.toMap())`.
   static CppOptions fromMap(Map<String, Object> map) {
     return CppOptions(
-        header: map['header'] as String?,
-        namespace: map['namespace'] as String?,
-        copyrightHeader: map['copyrightHeader'] as Iterable<String>?,
-        cppHeaderOut: map['cppHeaderOut'] as String?);
+      header: map['header'] as String?,
+      namespace: map['namespace'] as String?,
+      copyrightHeader: map['copyrightHeader'] as Iterable<String>?,
+      cppHeaderOut: map['cppHeaderOut'] as String?,
+    );
   }
 
   /// Converts a [CppOptions] to a Map representation where:

From ea0ec6c702e1b2b8b1685d4568bd47970dc68ddf Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 09:29:55 -0800
Subject: [PATCH 26/87] more personal nits

---
 packages/pigeon/lib/cpp_generator.dart  |  2 +-
 packages/pigeon/lib/objc_generator.dart |  2 +-
 packages/pigeon/lib/pigeon_lib.dart     | 27 +++++++++++++------------
 3 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 632de008f0e..4bf5f0c868b 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -72,7 +72,7 @@ class CppOptions {
 
 /// Class that manages all Cpp header code generation.
 class CppGenerator extends Generator<CppOptions> {
-  /// Instantiates a Cpp Generator.
+  /// Instantiates a Cpp Generator for the specified file type.
   CppGenerator(this.fileType);
 
   /// Specifies which file type (header or source) will be generated.
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 2ef59abdf4a..48d512d65c1 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -66,7 +66,7 @@ class ObjcOptions {
 
 /// Class that manages all Objc header code generation.
 class ObjcGenerator extends Generator<ObjcOptions> {
-  /// Instantiates a Objc Generator.
+  /// Instantiates a Objc Generator for the specified file type.
   ObjcGenerator(this.fileType);
 
   /// Specifies which file type (header or source) will be generated.
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 7ad64df5e0c..8871fe1f732 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -380,12 +380,13 @@ DartOptions _dartOptionsWithCopyrightHeader(
           ? _lineReader(copyrightHeader)
           : null;
   return DartOptions(
-      dartOutPath: dartOutPath,
-      testOutPath: testOutPath,
-      copyrightHeader: parsedCopyrightHeader);
+    dartOutPath: dartOutPath,
+    testOutPath: testOutPath,
+    copyrightHeader: parsedCopyrightHeader,
+  );
 }
 
-/// An [GeneratorAdapter] that generates the AST.
+/// A [GeneratorAdapter] that generates the AST.
 class AstGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [AstGeneratorAdapter].
   const AstGeneratorAdapter();
@@ -402,7 +403,7 @@ class AstGeneratorAdapter implements GeneratorAdapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [GeneratorAdapter] that generates Dart source code.
+/// A [GeneratorAdapter] that generates Dart source code.
 class DartGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [DartGeneratorAdapter].
   const DartGeneratorAdapter();
@@ -422,7 +423,7 @@ class DartGeneratorAdapter implements GeneratorAdapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [GeneratorAdapter] that generates Dart test source code.
+/// A [GeneratorAdapter] that generates Dart test source code.
 class DartTestGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [DartTestGeneratorAdapter].
   const DartTestGeneratorAdapter();
@@ -456,7 +457,7 @@ class DartTestGeneratorAdapter implements GeneratorAdapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [GeneratorAdapter] that generates Objective-C header code.
+/// A [GeneratorAdapter] that generates Objective-C header code.
 class ObjcHeaderGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [ObjcHeaderGeneratorAdapter].
   const ObjcHeaderGeneratorAdapter();
@@ -481,7 +482,7 @@ class ObjcHeaderGeneratorAdapter implements GeneratorAdapter {
       validateObjc(options.objcOptions!, root);
 }
 
-/// An [GeneratorAdapter] that generates Objective-C source code.
+/// A [GeneratorAdapter] that generates Objective-C source code.
 class ObjcSourceGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [ObjcSourceGeneratorAdapter].
   const ObjcSourceGeneratorAdapter();
@@ -505,7 +506,7 @@ class ObjcSourceGeneratorAdapter implements GeneratorAdapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [GeneratorAdapter] that generates Java source code.
+/// A [GeneratorAdapter] that generates Java source code.
 class JavaGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [JavaGeneratorAdapter].
   const JavaGeneratorAdapter();
@@ -530,7 +531,7 @@ class JavaGeneratorAdapter implements GeneratorAdapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [GeneratorAdapter] that generates Swift source code.
+/// A [GeneratorAdapter] that generates Swift source code.
 class SwiftGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [SwiftGeneratorAdapter].
   const SwiftGeneratorAdapter();
@@ -553,7 +554,7 @@ class SwiftGeneratorAdapter implements GeneratorAdapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [GeneratorAdapter] that generates C++ header code.
+/// A [GeneratorAdapter] that generates C++ header code.
 class CppHeaderGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [CppHeaderGeneratorAdapter].
   const CppHeaderGeneratorAdapter();
@@ -579,7 +580,7 @@ class CppHeaderGeneratorAdapter implements GeneratorAdapter {
       validateCpp(options.cppOptions!, root);
 }
 
-/// An [GeneratorAdapter] that generates C++ source code.
+/// A [GeneratorAdapter] that generates C++ source code.
 class CppSourceGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [CppSourceGeneratorAdapter].
   const CppSourceGeneratorAdapter();
@@ -603,7 +604,7 @@ class CppSourceGeneratorAdapter implements GeneratorAdapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// An [GeneratorAdapter] that generates Kotlin source code.
+/// A [GeneratorAdapter] that generates Kotlin source code.
 class KotlinGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [KotlinGeneratorAdapter].
   const KotlinGeneratorAdapter();

From d5c5f1fca7d22e806251877b1fd974c248352edc Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 09:48:50 -0800
Subject: [PATCH 27/87] update tests to match new merged generators

---
 packages/pigeon/test/cpp_generator_test.dart  |  55 +++----
 packages/pigeon/test/objc_generator_test.dart | 149 +++++++++---------
 2 files changed, 103 insertions(+), 101 deletions(-)

diff --git a/packages/pigeon/test/cpp_generator_test.dart b/packages/pigeon/test/cpp_generator_test.dart
index 4e4a3a1a354..ead8b73e202 100644
--- a/packages/pigeon/test/cpp_generator_test.dart
+++ b/packages/pigeon/test/cpp_generator_test.dart
@@ -4,6 +4,7 @@
 
 import 'package:pigeon/ast.dart';
 import 'package:pigeon/cpp_generator.dart';
+import 'package:pigeon/generator_tools.dart';
 import 'package:pigeon/pigeon.dart' show Error;
 import 'package:test/test.dart';
 
@@ -45,7 +46,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('class Input'));
@@ -54,7 +55,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppSourceGenerator generator = CppSourceGenerator();
+      final CppGenerator generator = CppGenerator(FileType.source);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('Input::Input()'));
@@ -103,7 +104,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Method name and argument names should be adjusted.
@@ -119,7 +120,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppSourceGenerator generator = CppSourceGenerator();
+      final CppGenerator generator = CppGenerator(FileType.source);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('pointer_input_field'));
@@ -148,7 +149,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
 
@@ -189,7 +190,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
 
@@ -244,7 +245,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, isNot(contains('){')));
@@ -252,7 +253,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppSourceGenerator generator = CppSourceGenerator();
+      final CppGenerator generator = CppGenerator(FileType.source);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, isNot(contains('){')));
@@ -279,7 +280,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('''
@@ -295,7 +296,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppSourceGenerator generator = CppSourceGenerator();
+      final CppGenerator generator = CppGenerator(FileType.source);
       generator.generate(const CppOptions(header: 'a_header.h'), root, sink);
       final String code = sink.toString();
       expect(code, contains('''
@@ -332,7 +333,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(namespace: 'foo'), root, sink);
       final String code = sink.toString();
       expect(code, contains('namespace foo {'));
@@ -340,7 +341,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppSourceGenerator generator = CppSourceGenerator();
+      final CppGenerator generator = CppGenerator(FileType.source);
       generator.generate(const CppOptions(namespace: 'foo'), root, sink);
       final String code = sink.toString();
       expect(code, contains('namespace foo {'));
@@ -402,7 +403,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Getters should return const pointers.
@@ -435,7 +436,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppSourceGenerator generator = CppSourceGenerator();
+      final CppGenerator generator = CppGenerator(FileType.source);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Getters extract optionals.
@@ -535,7 +536,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // POD getters should return copies references.
@@ -561,7 +562,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppSourceGenerator generator = CppSourceGenerator();
+      final CppGenerator generator = CppGenerator(FileType.source);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Getters just return the value.
@@ -660,7 +661,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(
@@ -766,7 +767,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('ErrorOr<bool> ReturnBool()'));
@@ -843,7 +844,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(
@@ -857,7 +858,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppSourceGenerator generator = CppSourceGenerator();
+      final CppGenerator generator = CppGenerator(FileType.source);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Most types should just use get_if, since the parameter is a pointer,
@@ -963,7 +964,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppHeaderGenerator generator = CppHeaderGenerator();
+      final CppGenerator generator = CppGenerator(FileType.header);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(
@@ -977,7 +978,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppSourceGenerator generator = CppSourceGenerator();
+      final CppGenerator generator = CppGenerator(FileType.source);
       generator.generate(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Most types should extract references. Since the type is non-nullable,
@@ -1032,7 +1033,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    final CppSourceGenerator generator = CppSourceGenerator();
+    final CppGenerator generator = CppGenerator(FileType.source);
     generator.generate(const CppOptions(), root, sink);
     final String code = sink.toString();
     // A bare 'auto' here would create a copy, not a reference, which is
@@ -1145,7 +1146,7 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    final CppHeaderGenerator generator = CppHeaderGenerator();
+    final CppGenerator generator = CppGenerator(FileType.header);
     generator.generate(const CppOptions(cppHeaderOut: 'foo'), root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
@@ -1181,7 +1182,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final CppHeaderGenerator generator = CppHeaderGenerator();
+    final CppGenerator generator = CppGenerator(FileType.header);
     generator.generate(const CppOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' : public flutter::StandardCodecSerializer')));
@@ -1224,7 +1225,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final CppHeaderGenerator generator = CppHeaderGenerator();
+    final CppGenerator generator = CppGenerator(FileType.header);
     generator.generate(const CppOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains(' : public flutter::StandardCodecSerializer'));
@@ -1294,7 +1295,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final CppSourceGenerator generator = CppSourceGenerator();
+    final CppGenerator generator = CppGenerator(FileType.source);
     generator.generate(const CppOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains('reply(wrap')));
diff --git a/packages/pigeon/test/objc_generator_test.dart b/packages/pigeon/test/objc_generator_test.dart
index 981b5fb6c29..d978f477051 100644
--- a/packages/pigeon/test/objc_generator_test.dart
+++ b/packages/pigeon/test/objc_generator_test.dart
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:pigeon/ast.dart';
+import 'package:pigeon/generator_tools.dart';
 import 'package:pigeon/objc_generator.dart';
 import 'package:pigeon/pigeon_lib.dart';
 import 'package:test/test.dart';
@@ -17,7 +18,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
@@ -33,7 +34,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
@@ -51,7 +52,7 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('typedef NS_ENUM(NSUInteger, Enum1) {'));
@@ -70,7 +71,7 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(prefix: 'PREFIX'), root, sink);
     final String code = sink.toString();
     expect(code, contains('typedef NS_ENUM(NSUInteger, PREFIXEnum1) {'));
@@ -107,7 +108,7 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
@@ -140,14 +141,14 @@ void main() {
     final StringBuffer sink = StringBuffer();
     const ObjcOptions options = ObjcOptions(header: 'foo.h', prefix: 'AC');
     {
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(options, root, sink);
       final String code = sink.toString();
       expect(code, contains('typedef NS_ENUM(NSUInteger, ACFoo)'));
       expect(code, contains(':(ACFoo)foo error:'));
     }
     {
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(options, root, sink);
       final String code = sink.toString();
       expect(
@@ -211,7 +212,7 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@property(nonatomic, assign) Enum1 enum1'));
@@ -244,7 +245,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Input'));
@@ -284,7 +285,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
@@ -332,7 +333,7 @@ void main() {
     ], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
@@ -361,7 +362,7 @@ void main() {
     ], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation Foobar'));
@@ -383,7 +384,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code,
@@ -404,7 +405,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(
@@ -424,7 +425,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface ABCFoobar'));
@@ -439,7 +440,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation ABCFoobar'));
@@ -474,7 +475,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, matches('property.*ABCInput'));
@@ -511,7 +512,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(prefix: 'ABC'), root, sink);
     final String code = sink.toString();
     expect(code, contains('ABCInput fromList'));
@@ -548,7 +549,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Api : NSObject'));
@@ -588,7 +589,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation Api'));
@@ -618,7 +619,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
 
@@ -649,7 +650,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -681,7 +682,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -711,7 +712,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -736,7 +737,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -760,7 +761,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -784,7 +785,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -811,7 +812,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -831,7 +832,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
@@ -847,7 +848,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
@@ -869,7 +870,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
@@ -899,7 +900,7 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('(NSDictionary<NSString *, id> *)foo'));
@@ -934,7 +935,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -974,7 +975,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -1002,7 +1003,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -1023,7 +1024,7 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -1063,7 +1064,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -1102,7 +1103,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -1123,7 +1124,7 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -1151,7 +1152,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -1168,7 +1169,7 @@ void main() {
   test('source copyright', () {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(
         ObjcOptions(
             header: 'foo.h',
@@ -1183,7 +1184,7 @@ void main() {
   test('header copyright', () {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(
         ObjcOptions(
             header: 'foo.h',
@@ -1215,7 +1216,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(
         const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
     final String code = sink.toString();
@@ -1246,7 +1247,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1254,7 +1255,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1289,7 +1290,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1297,7 +1298,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1335,7 +1336,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1363,7 +1364,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1372,7 +1373,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1400,7 +1401,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1409,7 +1410,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1439,7 +1440,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1450,7 +1451,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1486,7 +1487,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1497,7 +1498,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1531,7 +1532,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1542,7 +1543,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
       final String code = sink.toString();
@@ -1587,7 +1588,7 @@ void main() {
     final Root divideRoot = getDivideRoot(ApiLocation.host);
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), divideRoot, sink);
       final String code = sink.toString();
@@ -1595,7 +1596,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), divideRoot, sink);
 
@@ -1608,7 +1609,7 @@ void main() {
     final Root divideRoot = getDivideRoot(ApiLocation.flutter);
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), divideRoot, sink);
       final String code = sink.toString();
@@ -1616,7 +1617,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(
           const ObjcOptions(header: 'foo.h', prefix: 'ABC'), divideRoot, sink);
 
@@ -1634,7 +1635,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
@@ -1658,7 +1659,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(
@@ -1684,7 +1685,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches(r'doitWithCompletion.*NSNumber \*_Nullable'));
@@ -1707,7 +1708,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches(r'nullable NSNumber.*doitWithError'));
@@ -1735,14 +1736,14 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(const ObjcOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('doitFoo:(nullable NSNumber *)foo'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(const ObjcOptions(), root, sink);
       final String code = sink.toString();
       expect(code,
@@ -1772,14 +1773,14 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.header);
       generator.generate(const ObjcOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('doitFoo:(nullable NSNumber *)foo'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcSourceGenerator generator = ObjcSourceGenerator();
+      final ObjcGenerator generator = ObjcGenerator(FileType.source);
       generator.generate(const ObjcOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('- (void)doitFoo:(nullable NSNumber *)arg_foo'));
@@ -1804,7 +1805,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(
@@ -1889,7 +1890,7 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcHeaderGenerator generator = ObjcHeaderGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.header);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
@@ -1925,7 +1926,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' : FlutterStandardReader')));
@@ -1968,7 +1969,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcSourceGenerator generator = ObjcSourceGenerator();
+    final ObjcGenerator generator = ObjcGenerator(FileType.source);
     generator.generate(const ObjcOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains(' : FlutterStandardReader'));

From 6856812a09573e40884d27c72cb6abe1db9eca8d Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 14:29:27 -0800
Subject: [PATCH 28/87] cleaner header methods

---
 packages/pigeon/lib/cpp_generator.dart    | 17 ++++++++---------
 packages/pigeon/lib/dart_generator.dart   |  1 +
 packages/pigeon/lib/java_generator.dart   |  2 +-
 packages/pigeon/lib/kotlin_generator.dart |  2 +-
 packages/pigeon/lib/objc_generator.dart   |  2 ++
 packages/pigeon/lib/swift_generator.dart  |  2 +-
 6 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 1c339726915..df0a188e573 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -1054,15 +1054,15 @@ void writeCppHeaderHeader(
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
   }
+  indent.writeln('$_commentPrefix $generatedCodeWarning');
+  indent.writeln('$_commentPrefix $seeAlsoWarning');
+  indent.addln('');
 }
 
 /// Generates the ".h" file for the AST represented by [root] to [sink] with the
 /// provided [options] and [headerFileName].
 void generateCppHeader(String? headerFileName, CppOptions options, Root root,
     StringSink sink, Indent indent) {
-  indent.writeln('$_commentPrefix $generatedCodeWarning');
-  indent.writeln('$_commentPrefix $seeAlsoWarning');
-  indent.addln('');
   final String guardName = _getGuardName(headerFileName, options.namespace);
   indent.writeln('#ifndef $guardName');
   indent.writeln('#define $guardName');
@@ -1149,18 +1149,17 @@ void writeCppSourceHeader(
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
   }
-}
-
-/// Generates the ".cpp" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateCppSource(
-    CppOptions options, Root root, StringSink sink, Indent indent) {
   indent.writeln('$_commentPrefix $generatedCodeWarning');
   indent.writeln('$_commentPrefix $seeAlsoWarning');
   indent.addln('');
   indent.addln('#undef _HAS_EXCEPTIONS');
   indent.addln('');
+}
 
+/// Generates the ".cpp" file for the AST represented by [root] to [sink] with the
+/// provided [options].
+void generateCppSource(
+    CppOptions options, Root root, StringSink sink, Indent indent) {
   indent.writeln('#include "${options.header}"');
   indent.addln('');
   _writeSystemHeaderIncludeBlock(indent, <String>[
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 76092aa759d..e0ce71c3830 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -532,6 +532,7 @@ void writeHeader(DartOptions opt, Root root, StringSink sink, Indent indent) {
   indent.writeln(
     '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import',
   );
+  indent.addln('');
 }
 
 /// Generates Dart source code for the given AST represented by [root],
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 310125937da..2feb511a846 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -551,6 +551,7 @@ void writeHeader(
   }
   indent.writeln('// $generatedCodeWarning');
   indent.writeln('// $seeAlsoWarning');
+  indent.addln('');
 }
 
 /// Generates the ".java" file for the AST represented by [root] to [sink] with the
@@ -775,7 +776,6 @@ void generateJava(
 }''');
   }
 
-  indent.addln('');
   if (options.package != null) {
     indent.writeln('package ${options.package};');
   }
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index abdf83aa74f..9cb43bc295f 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -464,6 +464,7 @@ void writeHeader(
   }
   indent.writeln('// $generatedCodeWarning');
   indent.writeln('// $seeAlsoWarning');
+  indent.addln('');
 }
 
 /// Generates the ".kotlin" file for the AST represented by [root] to [sink] with the
@@ -674,7 +675,6 @@ void generateKotlin(
     });
   }
 
-  indent.addln('');
   if (options.package != null) {
     indent.writeln('package ${options.package}');
   }
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 56a19a52cdf..9866b4ce910 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -572,6 +572,7 @@ void writeObjcHeaderHeader(
   }
   indent.writeln('// $generatedCodeWarning');
   indent.writeln('// $seeAlsoWarning');
+  indent.addln('');
 }
 
 /// Generates the ".h" file for the AST represented by [root] to [sink] with the
@@ -915,6 +916,7 @@ void writeObjcSourceHeader(
   }
   indent.writeln('// $generatedCodeWarning');
   indent.writeln('// $seeAlsoWarning');
+  indent.addln('');
 }
 
 /// Generates the ".m" file for the AST represented by [root] to [sink] with the
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 8ea5ed88065..489f44b660f 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -458,6 +458,7 @@ void writeHeader(
   }
   indent.writeln('// $generatedCodeWarning');
   indent.writeln('// $seeAlsoWarning');
+  indent.addln('');
 }
 
 /// Generates the ".swift" file for the AST represented by [root] to [sink] with the
@@ -642,7 +643,6 @@ import FlutterMacOS
     });
   }
 
-  indent.addln('');
   writeImports();
   indent.addln('');
   indent.writeln('$_docCommentPrefix Generated class from Pigeon.');

From 6206bad51e327c8fde4354d97a3bdb36127cf935 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 14:41:13 -0800
Subject: [PATCH 29/87] Fixes dart header bug

---
 packages/pigeon/lib/pigeon_lib.dart | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 8871fe1f732..467ade2bd0c 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -374,16 +374,12 @@ abstract class GeneratorAdapter {
 DartOptions _dartOptionsWithCopyrightHeader(
     DartOptions? dartOptions, String? copyrightHeader,
     [String? dartOutPath, String? testOutPath]) {
-  final Iterable<String>? parsedCopyrightHeader = dartOptions != null
-      ? dartOptions.copyrightHeader
-      : copyrightHeader != null
-          ? _lineReader(copyrightHeader)
-          : null;
-  return DartOptions(
-    dartOutPath: dartOutPath,
-    testOutPath: testOutPath,
-    copyrightHeader: parsedCopyrightHeader,
-  );
+  dartOptions = dartOptions ?? DartOptions();
+  return dartOptions.merge(DartOptions(
+      dartOutPath: dartOutPath,
+      testOutPath: testOutPath,
+      copyrightHeader:
+          copyrightHeader != null ? _lineReader(copyrightHeader) : null));
 }
 
 /// A [GeneratorAdapter] that generates the AST.

From 7c3d35cf1f974ab2c815492cb505f1de79d37a60 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 14:49:05 -0800
Subject: [PATCH 30/87] add gen files for clarity

---
 .../mock_handler_tester/test/message.dart     |  2 +-
 .../pigeon/mock_handler_tester/test/test.dart |  2 +-
 .../CoreTests.java                            |  2 +-
 .../ios/Classes/CoreTests.gen.h               |  2 +-
 .../ios/Classes/CoreTests.gen.m               |  2 +-
 .../lib/core_tests.gen.dart                   |  2 +-
 .../lib/multiple_arity.gen.dart               |  2 +-
 .../lib/non_null_fields.gen.dart              |  2 +-
 .../lib/null_fields.gen.dart                  |  2 +-
 .../lib/null_safe_pigeon.dart                 |  2 +-
 .../lib/nullable_returns.gen.dart             |  2 +-
 .../lib/primitive.dart                        |  2 +-
 .../lib/src/generated/core_tests.gen.dart     |  2 +-
 .../com/example/test_plugin/CoreTests.gen.kt  |  2 +-
 .../ios/Classes/CoreTests.gen.swift           |  2 +-
 .../macos/Classes/CoreTests.gen.swift         |  2 +-
 .../windows/pigeon/core_tests.gen.cpp         | 81 ++++++++++---------
 .../windows/pigeon/core_tests.gen.h           |  8 +-
 18 files changed, 65 insertions(+), 56 deletions(-)

diff --git a/packages/pigeon/mock_handler_tester/test/message.dart b/packages/pigeon/mock_handler_tester/test/message.dart
index f64aa5dc142..4f6c9d14457 100644
--- a/packages/pigeon/mock_handler_tester/test/message.dart
+++ b/packages/pigeon/mock_handler_tester/test/message.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.11), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 import 'dart:async';
diff --git a/packages/pigeon/mock_handler_tester/test/test.dart b/packages/pigeon/mock_handler_tester/test/test.dart
index d0ecdc5d205..9b97826b605 100644
--- a/packages/pigeon/mock_handler_tester/test/test.dart
+++ b/packages/pigeon/mock_handler_tester/test/test.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.11), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, unnecessary_import
 // ignore_for_file: avoid_relative_lib_imports
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
index 9c0256252ea..2d81d4b59f1 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.12), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package com.example.alternate_language_test_plugin;
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
index 80a40d52c85..dcdee87c5d9 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.12), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 #import <Foundation/Foundation.h>
 @protocol FlutterBinaryMessenger;
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
index adb33d0bdf9..bcdd86394a6 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.12), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 #import "CoreTests.gen.h"
 #import <Flutter/Flutter.h>
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
index 4ff2bc07562..ee79a4b1a27 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.12), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 import 'dart:async';
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
index a3145679319..e92ab29cebd 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.11), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 import 'dart:async';
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
index 0dafa689085..1ff71bfa346 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.11), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 import 'dart:async';
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
index 94c9b86a8a5..88f4611e746 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.11), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 import 'dart:async';
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
index f376a13a932..13fe926bcf1 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.11), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 import 'dart:async';
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
index e88028363d8..be1979c8adf 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.11), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 import 'dart:async';
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
index 178e3154578..36a569e4f46 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.11), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 import 'dart:async';
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
index 4ff2bc07562..ee79a4b1a27 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.12), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 import 'dart:async';
diff --git a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
index bcd41b05492..c1add054eaf 100644
--- a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
+++ b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v4.2.12), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package com.example.test_plugin
diff --git a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
index 385b507191a..c9850b70d36 100644
--- a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v4.2.12), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
diff --git a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
index 385b507191a..c9850b70d36 100644
--- a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v4.2.12), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
index 990732ca635..f0d5929ce4a 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.12), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #undef _HAS_EXCEPTIONS
@@ -576,7 +576,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -597,7 +597,8 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
               const auto& args = std::get<flutter::EncodableList>(message);
               const auto& encodable_everything_arg = args.at(0);
               if (encodable_everything_arg.IsNull()) {
-                reply(WrapError("everything_arg unexpectedly null."));
+                reply(flutter::EncodableValue(
+                    WrapError("everything_arg unexpectedly null.")));
                 return;
               }
               const auto& everything_arg = std::any_cast<const AllTypes&>(
@@ -613,7 +614,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -653,7 +654,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -680,7 +681,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -700,7 +701,8 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
               const auto& args = std::get<flutter::EncodableList>(message);
               const auto& encodable_an_int_arg = args.at(0);
               if (encodable_an_int_arg.IsNull()) {
-                reply(WrapError("an_int_arg unexpectedly null."));
+                reply(flutter::EncodableValue(
+                    WrapError("an_int_arg unexpectedly null.")));
                 return;
               }
               const int64_t an_int_arg = encodable_an_int_arg.LongValue();
@@ -714,7 +716,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -735,7 +737,8 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
               const auto& args = std::get<flutter::EncodableList>(message);
               const auto& encodable_a_double_arg = args.at(0);
               if (encodable_a_double_arg.IsNull()) {
-                reply(WrapError("a_double_arg unexpectedly null."));
+                reply(flutter::EncodableValue(
+                    WrapError("a_double_arg unexpectedly null.")));
                 return;
               }
               const auto& a_double_arg =
@@ -750,7 +753,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -770,7 +773,8 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
               const auto& args = std::get<flutter::EncodableList>(message);
               const auto& encodable_a_bool_arg = args.at(0);
               if (encodable_a_bool_arg.IsNull()) {
-                reply(WrapError("a_bool_arg unexpectedly null."));
+                reply(flutter::EncodableValue(
+                    WrapError("a_bool_arg unexpectedly null.")));
                 return;
               }
               const auto& a_bool_arg = std::get<bool>(encodable_a_bool_arg);
@@ -784,7 +788,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -805,7 +809,8 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
               const auto& args = std::get<flutter::EncodableList>(message);
               const auto& encodable_a_string_arg = args.at(0);
               if (encodable_a_string_arg.IsNull()) {
-                reply(WrapError("a_string_arg unexpectedly null."));
+                reply(flutter::EncodableValue(
+                    WrapError("a_string_arg unexpectedly null.")));
                 return;
               }
               const auto& a_string_arg =
@@ -820,7 +825,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -841,7 +846,8 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
               const auto& args = std::get<flutter::EncodableList>(message);
               const auto& encodable_a_uint8_list_arg = args.at(0);
               if (encodable_a_uint8_list_arg.IsNull()) {
-                reply(WrapError("a_uint8_list_arg unexpectedly null."));
+                reply(flutter::EncodableValue(
+                    WrapError("a_uint8_list_arg unexpectedly null.")));
                 return;
               }
               const auto& a_uint8_list_arg =
@@ -857,7 +863,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -878,7 +884,8 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
               const auto& args = std::get<flutter::EncodableList>(message);
               const auto& encodable_wrapper_arg = args.at(0);
               if (encodable_wrapper_arg.IsNull()) {
-                reply(WrapError("wrapper_arg unexpectedly null."));
+                reply(flutter::EncodableValue(
+                    WrapError("wrapper_arg unexpectedly null.")));
                 return;
               }
               const auto& wrapper_arg =
@@ -901,7 +908,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -934,7 +941,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -980,7 +987,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -1024,7 +1031,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -1062,7 +1069,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -1100,7 +1107,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -1138,7 +1145,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -1177,7 +1184,7 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
@@ -1201,11 +1208,11 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
                     } else {
                       wrapped.push_back(flutter::EncodableValue());
                     }
-                    reply(wrapped);
+                    reply(flutter::EncodableValue(std::move(wrapped)));
                   });
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
-              reply(wrapped);
+              reply(flutter::EncodableValue(std::move(wrapped)));
             }
           });
     } else {
@@ -1227,7 +1234,8 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
               const auto& args = std::get<flutter::EncodableList>(message);
               const auto& encodable_a_string_arg = args.at(0);
               if (encodable_a_string_arg.IsNull()) {
-                reply(WrapError("a_string_arg unexpectedly null."));
+                reply(flutter::EncodableValue(
+                    WrapError("a_string_arg unexpectedly null.")));
                 return;
               }
               const auto& a_string_arg =
@@ -1241,11 +1249,11 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
                       wrapped.push_back(flutter::EncodableValue(
                           std::move(output).TakeValue()));
                     }
-                    reply(wrapped);
+                    reply(flutter::EncodableValue(std::move(wrapped)));
                   });
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
-              reply(wrapped);
+              reply(flutter::EncodableValue(std::move(wrapped)));
             }
           });
     } else {
@@ -1271,11 +1279,11 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
                     } else {
                       wrapped.push_back(flutter::EncodableValue());
                     }
-                    reply(wrapped);
+                    reply(flutter::EncodableValue(std::move(wrapped)));
                   });
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
-              reply(wrapped);
+              reply(flutter::EncodableValue(std::move(wrapped)));
             }
           });
     } else {
@@ -1297,7 +1305,8 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
               const auto& args = std::get<flutter::EncodableList>(message);
               const auto& encodable_a_string_arg = args.at(0);
               if (encodable_a_string_arg.IsNull()) {
-                reply(WrapError("a_string_arg unexpectedly null."));
+                reply(flutter::EncodableValue(
+                    WrapError("a_string_arg unexpectedly null.")));
                 return;
               }
               const auto& a_string_arg =
@@ -1311,11 +1320,11 @@ void HostIntegrationCoreApi::SetUp(flutter::BinaryMessenger* binary_messenger,
                       wrapped.push_back(flutter::EncodableValue(
                           std::move(output).TakeValue()));
                     }
-                    reply(wrapped);
+                    reply(flutter::EncodableValue(std::move(wrapped)));
                   });
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
-              reply(wrapped);
+              reply(flutter::EncodableValue(std::move(wrapped)));
             }
           });
     } else {
@@ -1500,7 +1509,7 @@ void HostTrivialApi::SetUp(flutter::BinaryMessenger* binary_messenger,
             } catch (const std::exception& exception) {
               wrapped = WrapError(exception.what());
             }
-            reply(wrapped);
+            reply(flutter::EncodableValue(std::move(wrapped)));
           });
     } else {
       channel->SetMessageHandler(nullptr);
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
index 5100fdb753d..a2ea204b578 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.12), do not edit directly.
+// Autogenerated from Pigeon (v5.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
-#ifndef PIGEON_CORE_TESTS_GEN_CORE_TESTS_PIGEONTEST_H_
-#define PIGEON_CORE_TESTS_GEN_CORE_TESTS_PIGEONTEST_H_
+#ifndef PIGEON_CORE_TESTS_PIGEONTEST_H_
+#define PIGEON_CORE_TESTS_PIGEONTEST_H_
 #include <flutter/basic_message_channel.h>
 #include <flutter/binary_messenger.h>
 #include <flutter/encodable_value.h>
@@ -406,4 +406,4 @@ class HostTrivialApi {
   HostTrivialApi() = default;
 };
 }  // namespace core_tests_pigeontest
-#endif  // PIGEON_CORE_TESTS_GEN_CORE_TESTS_PIGEONTEST_H_
+#endif  // PIGEON_CORE_TESTS_PIGEONTEST_H_

From 8bf2dfbd484af7718d7d0621da2995ecc5cc9ece Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 16:09:57 -0800
Subject: [PATCH 31/87] better field naming

---
 packages/pigeon/lib/cpp_generator.dart        | 23 ++++++------
 packages/pigeon/lib/dart_generator.dart       | 20 +++++------
 packages/pigeon/lib/pigeon_lib.dart           |  8 ++---
 packages/pigeon/test/cpp_generator_test.dart  | 35 ++++++++++---------
 packages/pigeon/test/dart_generator_test.dart |  6 ++--
 5 files changed, 46 insertions(+), 46 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 4bf5f0c868b..225b8e9ca7b 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -22,15 +22,15 @@ const String _defaultCodecSerializer = 'flutter::StandardCodecSerializer';
 class CppOptions {
   /// Creates a [CppOptions] object
   const CppOptions({
-    this.header,
+    this.headerIncludePath,
     this.namespace,
     this.copyrightHeader,
-    this.cppHeaderOut,
+    this.headerOutPath,
   });
 
   /// The path to the header that will get placed in the source filed (example:
   /// "foo.h").
-  final String? header;
+  final String? headerIncludePath;
 
   /// The namespace where the generated class will live.
   final String? namespace;
@@ -39,16 +39,16 @@ class CppOptions {
   final Iterable<String>? copyrightHeader;
 
   /// The path to the output header file location.
-  final String? cppHeaderOut;
+  final String? headerOutPath;
 
   /// Creates a [CppOptions] from a Map representation where:
   /// `x = CppOptions.fromMap(x.toMap())`.
   static CppOptions fromMap(Map<String, Object> map) {
     return CppOptions(
-      header: map['header'] as String?,
+      headerIncludePath: map['header'] as String?,
       namespace: map['namespace'] as String?,
       copyrightHeader: map['copyrightHeader'] as Iterable<String>?,
-      cppHeaderOut: map['cppHeaderOut'] as String?,
+      headerOutPath: map['cppHeaderOut'] as String?,
     );
   }
 
@@ -56,7 +56,7 @@ class CppOptions {
   /// `x = CppOptions.fromMap(x.toMap())`.
   Map<String, Object> toMap() {
     final Map<String, Object> result = <String, Object>{
-      if (header != null) 'header': header!,
+      if (headerIncludePath != null) 'header': headerIncludePath!,
       if (namespace != null) 'namespace': namespace!,
       if (copyrightHeader != null) 'copyrightHeader': copyrightHeader!,
     };
@@ -82,8 +82,7 @@ class CppGenerator extends Generator<CppOptions> {
   @override
   void generate(CppOptions languageOptions, Root root, StringSink sink) {
     if (fileType == FileType.header) {
-      generateCppHeader(
-          languageOptions.cppHeaderOut, languageOptions, root, sink);
+      generateCppHeader(languageOptions, root, sink);
     } else {
       generateCppSource(languageOptions, root, sink);
     }
@@ -1037,8 +1036,8 @@ void _writeSystemHeaderIncludeBlock(Indent indent, List<String> headers) {
 
 /// Generates the ".h" file for the AST represented by [root] to [sink] with the
 /// provided [options] and [headerFileName].
-void generateCppHeader(
-    String? headerFileName, CppOptions options, Root root, StringSink sink) {
+void generateCppHeader(CppOptions options, Root root, StringSink sink) {
+  final String? headerFileName = options.headerOutPath;
   final Indent indent = Indent(sink);
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
@@ -1139,7 +1138,7 @@ void generateCppSource(CppOptions options, Root root, StringSink sink) {
   indent.addln('#undef _HAS_EXCEPTIONS');
   indent.addln('');
 
-  indent.writeln('#include "${options.header}"');
+  indent.writeln('#include "${options.headerIncludePath}"');
   indent.addln('');
   _writeSystemHeaderIncludeBlock(indent, <String>[
     'flutter/basic_message_channel.h',
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 604becc9c30..6d4b005d764 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -27,7 +27,7 @@ class DartOptions {
   /// Constructor for DartOptions.
   DartOptions({
     this.copyrightHeader,
-    this.dartOutPath,
+    this.sourceOutPath,
     this.testOutPath,
   });
 
@@ -35,7 +35,7 @@ class DartOptions {
   final Iterable<String>? copyrightHeader;
 
   /// Path to output generated Dart file for tests.
-  String? dartOutPath;
+  String? sourceOutPath;
 
   /// Path to output generated Test file for tests.
   String? testOutPath;
@@ -47,7 +47,7 @@ class DartOptions {
         map['copyrightHeader'] as Iterable<dynamic>?;
     return DartOptions(
       copyrightHeader: copyrightHeader?.cast<String>(),
-      dartOutPath: map['dartOutPath'] as String?,
+      sourceOutPath: map['sourceOutPath'] as String?,
       testOutPath: map['testOutPath'] as String?,
     );
   }
@@ -57,7 +57,7 @@ class DartOptions {
   Map<String, Object> toMap() {
     final Map<String, Object> result = <String, Object>{
       if (copyrightHeader != null) 'copyrightHeader': copyrightHeader!,
-      if (dartOutPath != null) 'dartOutPath': dartOutPath!,
+      if (sourceOutPath != null) 'sourceOutPath': sourceOutPath!,
       if (testOutPath != null) 'testOutPath': testOutPath!,
     };
     return result;
@@ -90,13 +90,13 @@ class DartTestGenerator extends Generator<DartOptions> {
   /// Generates Dart files with specified [DartOptions]
   @override
   void generate(DartOptions languageOptions, Root root, StringSink sink) {
-    final String dartOutPath = languageOptions.dartOutPath ?? '';
+    final String sourceOutPath = languageOptions.sourceOutPath ?? '';
     final String testOutPath = languageOptions.testOutPath ?? '';
     generateTestDart(
       languageOptions,
       root,
       sink,
-      dartOutPath: dartOutPath,
+      sourceOutPath: sourceOutPath,
       testOutPath: testOutPath,
     );
   }
@@ -742,14 +742,14 @@ String _posixify(String inputPath) {
 }
 
 /// Generates Dart source code for test support libraries based on the given AST
-/// represented by [root], outputting the code to [sink]. [dartOutPath] is the
+/// represented by [root], outputting the code to [sink]. [sourceOutPath] is the
 /// path of the generated dart code to be tested. [testOutPath] is where the
 /// test code will be generated.
 void generateTestDart(
   DartOptions opt,
   Root root,
   StringSink sink, {
-  required String dartOutPath,
+  required String sourceOutPath,
   required String testOutPath,
 }) {
   final Indent indent = Indent(sink);
@@ -773,10 +773,10 @@ void generateTestDart(
   indent.writeln('');
   final String relativeDartPath =
       path.Context(style: path.Style.posix).relative(
-    _posixify(dartOutPath),
+    _posixify(sourceOutPath),
     from: _posixify(path.dirname(testOutPath)),
   );
-  late final String? packageName = _deducePackageName(dartOutPath);
+  late final String? packageName = _deducePackageName(sourceOutPath);
   if (!relativeDartPath.contains('/lib/') || packageName == null) {
     // If we can't figure out the package name or the relative path doesn't
     // include a 'lib' directory, try relative path import which only works in
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 467ade2bd0c..327ce27c08b 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -376,7 +376,7 @@ DartOptions _dartOptionsWithCopyrightHeader(
     [String? dartOutPath, String? testOutPath]) {
   dartOptions = dartOptions ?? DartOptions();
   return dartOptions.merge(DartOptions(
-      dartOutPath: dartOutPath,
+      sourceOutPath: dartOutPath,
       testOutPath: testOutPath,
       copyrightHeader:
           copyrightHeader != null ? _lineReader(copyrightHeader) : null));
@@ -559,7 +559,7 @@ class CppHeaderGeneratorAdapter implements GeneratorAdapter {
   void generate(StringSink sink, PigeonOptions options, Root root) {
     final CppOptions cppOptions = options.cppOptions ?? const CppOptions();
     final CppOptions cppOptionsWithHeader = cppOptions.merge(CppOptions(
-        cppHeaderOut: path.basenameWithoutExtension(options.cppHeaderOut!),
+        headerOutPath: path.basenameWithoutExtension(options.cppHeaderOut!),
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
@@ -1436,8 +1436,8 @@ ${_argParser.usage}''';
 
     if (options.cppHeaderOut != null) {
       options = options.merge(PigeonOptions(
-          cppOptions: options.cppOptions!.merge(
-              CppOptions(header: path.basename(options.cppHeaderOut!)))));
+          cppOptions: options.cppOptions!.merge(CppOptions(
+              headerIncludePath: path.basename(options.cppHeaderOut!)))));
     }
 
     for (final GeneratorAdapter adapter in safeGeneratorAdapters) {
diff --git a/packages/pigeon/test/cpp_generator_test.dart b/packages/pigeon/test/cpp_generator_test.dart
index d089b0a4480..39d6bedd8f5 100644
--- a/packages/pigeon/test/cpp_generator_test.dart
+++ b/packages/pigeon/test/cpp_generator_test.dart
@@ -45,7 +45,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('class Input'));
       expect(code, contains('class Output'));
@@ -101,7 +101,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Method name and argument names should be adjusted.
       expect(code, contains(' DoSomething(const Input& some_input)'));
@@ -144,7 +144,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
 
       expect(
@@ -184,7 +184,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
 
       expect(
@@ -238,7 +238,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, isNot(contains('){')));
       expect(code, isNot(contains('const{')));
@@ -271,7 +271,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('''
 #include <flutter/basic_message_channel.h>
@@ -286,7 +286,8 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(header: 'a_header.h'), root, sink);
+      generateCppSource(
+          const CppOptions(headerIncludePath: 'a_header.h'), root, sink);
       final String code = sink.toString();
       expect(code, contains('''
 #include "a_header.h"
@@ -322,7 +323,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(namespace: 'foo'), root, sink);
+      generateCppHeader(const CppOptions(namespace: 'foo'), root, sink);
       final String code = sink.toString();
       expect(code, contains('namespace foo {'));
       expect(code, contains('}  // namespace foo'));
@@ -390,7 +391,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
       // Getters should return const pointers.
       expect(code, contains('const bool* nullable_bool()'));
@@ -521,7 +522,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
       // POD getters should return copies references.
       expect(code, contains('bool non_nullable_bool()'));
@@ -644,7 +645,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(
           code, contains('ErrorOr<std::optional<bool>> ReturnNullableBool()'));
@@ -749,7 +750,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(code, contains('ErrorOr<bool> ReturnBool()'));
       expect(code, contains('ErrorOr<int64_t> ReturnInt()'));
@@ -825,7 +826,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -943,7 +944,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader('', const CppOptions(), root, sink);
+      generateCppHeader(const CppOptions(), root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -1122,7 +1123,7 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateCppHeader('foo', const CppOptions(), root, sink);
+    generateCppHeader(const CppOptions(headerIncludePath: 'foo'), root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       expect(code, contains('//$comment'));
@@ -1157,7 +1158,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateCppHeader('', const CppOptions(), root, sink);
+    generateCppHeader(const CppOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' : public flutter::StandardCodecSerializer')));
   });
@@ -1199,7 +1200,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateCppHeader('', const CppOptions(), root, sink);
+    generateCppHeader(const CppOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains(' : public flutter::StandardCodecSerializer'));
   });
diff --git a/packages/pigeon/test/dart_generator_test.dart b/packages/pigeon/test/dart_generator_test.dart
index 38442ccd358..c77e5d89e37 100644
--- a/packages/pigeon/test/dart_generator_test.dart
+++ b/packages/pigeon/test/dart_generator_test.dart
@@ -582,7 +582,7 @@ void main() {
       DartOptions(),
       root,
       testCodeSink,
-      dartOutPath: "fo'o.dart",
+      sourceOutPath: "fo'o.dart",
       testOutPath: 'test.dart',
     );
     final String testCode = testCodeSink.toString();
@@ -1154,7 +1154,7 @@ name: foobar
         DartOptions(),
         root,
         sink,
-        dartOutPath: path.join(foo.path, 'bar.dart'),
+        sourceOutPath: path.join(foo.path, 'bar.dart'),
         testOutPath: path.join(tempDir.path, 'test', 'bar_test.dart'),
       );
       final String code = sink.toString();
@@ -1358,7 +1358,7 @@ name: foobar
       DartOptions(),
       root,
       sink,
-      dartOutPath: 'code.dart',
+      sourceOutPath: 'code.dart',
       testOutPath: 'test.dart',
     );
     final String testCode = sink.toString();

From 8c6abf2d240e184422a8864547934a06a90fb683 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 16:18:24 -0800
Subject: [PATCH 32/87] better field naming

---
 packages/pigeon/lib/objc_generator.dart       |  10 +-
 packages/pigeon/lib/pigeon_lib.dart           |   4 +-
 packages/pigeon/test/objc_generator_test.dart | 179 +++++++++++++-----
 3 files changed, 136 insertions(+), 57 deletions(-)

diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 48d512d65c1..a3cf3a7da2a 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -19,14 +19,14 @@ const DocumentCommentSpecification _docCommentSpec =
 class ObjcOptions {
   /// Parametric constructor for ObjcOptions.
   const ObjcOptions({
-    this.header,
+    this.headerIncludePath,
     this.prefix,
     this.copyrightHeader,
   });
 
   /// The path to the header that will get placed in the source filed (example:
   /// "foo.h").
-  final String? header;
+  final String? headerIncludePath;
 
   /// Prefix that will be appended before all generated classes and protocols.
   final String? prefix;
@@ -40,7 +40,7 @@ class ObjcOptions {
     final Iterable<dynamic>? copyrightHeader =
         map['copyrightHeader'] as Iterable<dynamic>?;
     return ObjcOptions(
-      header: map['header'] as String?,
+      headerIncludePath: map['header'] as String?,
       prefix: map['prefix'] as String?,
       copyrightHeader: copyrightHeader?.cast<String>(),
     );
@@ -50,7 +50,7 @@ class ObjcOptions {
   /// `x = ObjcOptions.fromMap(x.toMap())`.
   Map<String, Object> toMap() {
     final Map<String, Object> result = <String, Object>{
-      if (header != null) 'header': header!,
+      if (headerIncludePath != null) 'header': headerIncludePath!,
       if (prefix != null) 'prefix': prefix!,
       if (copyrightHeader != null) 'copyrightHeader': copyrightHeader!,
     };
@@ -910,7 +910,7 @@ void generateObjcSource(ObjcOptions options, Root root, StringSink sink) {
   }
 
   void writeImports() {
-    indent.writeln('#import "${options.header}"');
+    indent.writeln('#import "${options.headerIncludePath}"');
     indent.writeln('#import <Flutter/Flutter.h>');
   }
 
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 327ce27c08b..46ac932694a 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -1430,8 +1430,8 @@ ${_argParser.usage}''';
 
     if (options.objcHeaderOut != null) {
       options = options.merge(PigeonOptions(
-          objcOptions: options.objcOptions!.merge(
-              ObjcOptions(header: path.basename(options.objcHeaderOut!)))));
+          objcOptions: options.objcOptions!.merge(ObjcOptions(
+              headerIncludePath: path.basename(options.objcHeaderOut!)))));
     }
 
     if (options.cppHeaderOut != null) {
diff --git a/packages/pigeon/test/objc_generator_test.dart b/packages/pigeon/test/objc_generator_test.dart
index cf83029338e..aeb2db68e26 100644
--- a/packages/pigeon/test/objc_generator_test.dart
+++ b/packages/pigeon/test/objc_generator_test.dart
@@ -32,7 +32,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    generateObjcSource(
+        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
     expect(code, contains('@implementation Foobar'));
@@ -103,7 +104,8 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    generateObjcSource(
+        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
     expect(code, contains('@implementation Foobar'));
@@ -133,7 +135,8 @@ void main() {
       ])
     ]);
     final StringBuffer sink = StringBuffer();
-    const ObjcOptions options = ObjcOptions(header: 'foo.h', prefix: 'AC');
+    const ObjcOptions options =
+        ObjcOptions(headerIncludePath: 'foo.h', prefix: 'AC');
     {
       generateObjcHeader(options, root, sink);
       final String code = sink.toString();
@@ -169,7 +172,7 @@ void main() {
         EnumMember(name: 'two'),
       ])
     ]);
-    const ObjcOptions options = ObjcOptions(header: 'foo.h');
+    const ObjcOptions options = ObjcOptions(headerIncludePath: 'foo.h');
     final List<Error> errors = validateObjc(options, root);
     expect(errors.length, 1);
     expect(errors[0].message, contains('Nullable enum'));
@@ -204,7 +207,8 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(header: 'foo.h'), root, sink);
+    generateObjcHeader(
+        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@property(nonatomic, assign) Enum1 enum1'));
   });
@@ -275,7 +279,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    generateObjcSource(
+        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
     expect(code, contains('@implementation Input'));
@@ -322,7 +327,8 @@ void main() {
     ], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(header: 'foo.h'), root, sink);
+    generateObjcHeader(
+        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(code, contains('@class FlutterStandardTypedData;'));
@@ -350,7 +356,8 @@ void main() {
     ], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    generateObjcSource(
+        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation Foobar'));
     expect(code,
@@ -371,7 +378,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(header: 'foo.h'), root, sink);
+    generateObjcHeader(
+        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code,
         contains('@property(nonatomic, strong, nullable) Input * nested;'));
@@ -391,7 +399,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    generateObjcSource(
+        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -530,7 +539,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(header: 'foo.h'), root, sink);
+    generateObjcHeader(
+        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Api : NSObject'));
     expect(
@@ -569,7 +579,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
+    generateObjcSource(
+        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation Api'));
     expect(code, matches('void.*doSomething.*Input.*Output.*{'));
@@ -599,7 +610,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcHeader(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(code, contains('(void)doSomething:'));
   });
@@ -628,7 +641,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcSource(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(code, isNot(matches('=.*doSomething')));
     expect(code, matches('[.*doSomething:.*]'));
@@ -659,7 +674,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcHeader(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(code, contains('completion:(void(^)(NSError *_Nullable))'));
   });
@@ -688,7 +705,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcSource(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(code, contains('completion:(void(^)(NSError *_Nullable))'));
     expect(code, contains('completion(nil)'));
@@ -712,7 +731,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcHeader(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(code, matches('ABCOutput.*doSomethingWithError:[(]FlutterError'));
   });
@@ -735,7 +756,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcSource(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(code, matches('output.*=.*api doSomethingWithError:&error'));
   });
@@ -758,7 +781,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcHeader(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(
         code,
@@ -784,7 +809,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcSource(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(
         code,
@@ -902,7 +929,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcHeader(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(
         code,
@@ -941,7 +970,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcHeader(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(
         code,
@@ -968,7 +999,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcHeader(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(
         code,
@@ -988,7 +1021,9 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcHeader(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1027,7 +1062,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcSource(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1065,7 +1102,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcSource(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1085,7 +1124,9 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcSource(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1112,7 +1153,9 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     generateObjcSource(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1129,7 +1172,7 @@ void main() {
     final StringBuffer sink = StringBuffer();
     generateObjcSource(
       ObjcOptions(
-          header: 'foo.h',
+          headerIncludePath: 'foo.h',
           prefix: 'ABC',
           copyrightHeader: makeIterable('hello world')),
       root,
@@ -1144,7 +1187,7 @@ void main() {
     final StringBuffer sink = StringBuffer();
     generateObjcHeader(
       ObjcOptions(
-          header: 'foo.h',
+          headerIncludePath: 'foo.h',
           prefix: 'ABC',
           copyrightHeader: makeIterable('hello world')),
       root,
@@ -1175,7 +1218,9 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     generateObjcHeader(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+        root,
+        sink);
     final String code = sink.toString();
     expect(code, contains('NSArray<NSNumber *> * field1'));
   });
@@ -1205,14 +1250,18 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcHeader(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSNumber *> *)arg'));
     }
     {
       final StringBuffer sink = StringBuffer();
       generateObjcSource(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(
           code,
@@ -1246,14 +1295,18 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcHeader(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSNumber *> *)arg'));
     }
     {
       final StringBuffer sink = StringBuffer();
       generateObjcSource(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSNumber *> *)arg'));
     }
@@ -1290,7 +1343,9 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcHeader(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSArray<NSNumber *> *> *)arg'));
     }
@@ -1317,7 +1372,9 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcHeader(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(
           code, contains('- (nullable NSArray<NSNumber *> *)doitWithError:'));
@@ -1325,7 +1382,9 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcSource(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(code, contains('NSArray<NSNumber *> *output ='));
     }
@@ -1352,7 +1411,9 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcHeader(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(
           code, contains('doitWithCompletion:(void(^)(NSArray<NSNumber *> *'));
@@ -1360,7 +1421,9 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcSource(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(
           code, contains('doitWithCompletion:(void(^)(NSArray<NSNumber *> *'));
@@ -1389,7 +1452,9 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcHeader(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(
           code,
@@ -1399,7 +1464,9 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcSource(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(code, contains('NSArray *args = message;'));
       expect(code,
@@ -1434,7 +1501,9 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcHeader(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(
           code,
@@ -1444,7 +1513,9 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcSource(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(code, contains('NSArray *args = message;'));
       expect(code,
@@ -1477,7 +1548,9 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcHeader(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(
           code,
@@ -1487,7 +1560,9 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcSource(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), root, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          root,
+          sink);
       final String code = sink.toString();
       expect(
           code,
@@ -1531,14 +1606,18 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcHeader(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), divideRoot, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          divideRoot,
+          sink);
       final String code = sink.toString();
       expect(code, matches('divideValue:.*by:.*error.*;'));
     }
     {
       final StringBuffer sink = StringBuffer();
       generateObjcSource(
-          const ObjcOptions(header: 'foo.h', prefix: 'ABC'), divideRoot, sink);
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+          divideRoot,
+          sink);
       final String code = sink.toString();
       expect(code, matches('divideValue:.*by:.*error.*;'));
     }
@@ -1549,7 +1628,7 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcHeader(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'),
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
         divideRoot,
         sink,
       );
@@ -1559,7 +1638,7 @@ void main() {
     {
       final StringBuffer sink = StringBuffer();
       generateObjcSource(
-        const ObjcOptions(header: 'foo.h', prefix: 'ABC'),
+        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
         divideRoot,
         sink,
       );

From 93a5d1bf619e53f558c1444995a83db867098f23 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 16:23:53 -0800
Subject: [PATCH 33/87] removed unneeded dart test generator

---
 packages/pigeon/lib/dart_generator.dart | 11 ++---------
 packages/pigeon/lib/pigeon_lib.dart     |  4 ++--
 2 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 6d4b005d764..dca3c0fcd57 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -80,16 +80,9 @@ class DartGenerator extends Generator<DartOptions> {
   void generate(DartOptions languageOptions, Root root, StringSink sink) {
     generateDart(languageOptions, root, sink);
   }
-}
-
-/// Class that manages all Dart code generation.
-class DartTestGenerator extends Generator<DartOptions> {
-  /// Instantiates a Dart Generator.
-  DartTestGenerator();
 
-  /// Generates Dart files with specified [DartOptions]
-  @override
-  void generate(DartOptions languageOptions, Root root, StringSink sink) {
+  /// Generates Dart files for testing with specified [DartOptions]
+  void generateTest(DartOptions languageOptions, Root root, StringSink sink) {
     final String sourceOutPath = languageOptions.sourceOutPath ?? '';
     final String testOutPath = languageOptions.testOutPath ?? '';
     generateTestDart(
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 46ac932694a..bfde7735b43 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -432,8 +432,8 @@ class DartTestGeneratorAdapter implements GeneratorAdapter {
       options.dartOut,
       options.dartTestOut,
     );
-    final DartTestGenerator testGenerator = DartTestGenerator();
-    testGenerator.generate(
+    final DartGenerator testGenerator = DartGenerator();
+    testGenerator.generateTest(
       dartOptionsWithHeader,
       root,
       sink,

From 710d1a1f2bc05a00da447684f0cd13921353d3f6 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 27 Dec 2022 16:29:24 -0800
Subject: [PATCH 34/87] Add filetype to generator

---
 packages/pigeon/lib/cpp_generator.dart    |  8 +++-----
 packages/pigeon/lib/dart_generator.dart   |  3 ++-
 packages/pigeon/lib/generator.dart        |  4 +++-
 packages/pigeon/lib/java_generator.dart   |  3 ++-
 packages/pigeon/lib/kotlin_generator.dart |  3 ++-
 packages/pigeon/lib/objc_generator.dart   |  8 +++-----
 packages/pigeon/lib/pigeon_lib.dart       | 24 +++++++++++------------
 packages/pigeon/lib/swift_generator.dart  |  3 ++-
 8 files changed, 29 insertions(+), 27 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 225b8e9ca7b..ff7239efd2d 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -73,14 +73,12 @@ class CppOptions {
 /// Class that manages all Cpp header code generation.
 class CppGenerator extends Generator<CppOptions> {
   /// Instantiates a Cpp Generator for the specified file type.
-  CppGenerator(this.fileType);
-
-  /// Specifies which file type (header or source) will be generated.
-  FileType fileType;
+  CppGenerator();
 
   /// Generates Cpp files with specified [CppOptions]
   @override
-  void generate(CppOptions languageOptions, Root root, StringSink sink) {
+  void generate(CppOptions languageOptions, Root root, StringSink sink,
+      FileType fileType) {
     if (fileType == FileType.header) {
       generateCppHeader(languageOptions, root, sink);
     } else {
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index dca3c0fcd57..f450d2ddeaa 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -77,7 +77,8 @@ class DartGenerator extends Generator<DartOptions> {
 
   /// Generates Dart files with specified [DartOptions]
   @override
-  void generate(DartOptions languageOptions, Root root, StringSink sink) {
+  void generate(
+      DartOptions languageOptions, Root root, StringSink sink, FileType _) {
     generateDart(languageOptions, root, sink);
   }
 
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 02667e4a5c9..6cf63113a1f 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -3,11 +3,13 @@
 // found in the LICENSE file.
 
 import 'ast.dart';
+import 'generator_tools.dart';
 
 /// A superclass of generator classes.
 ///
 /// This provides the structure that is common across generators for different languages.
 abstract class Generator<T> {
   /// Generates files for specified language with specified [languageOptions]
-  void generate(T languageOptions, Root root, StringSink sink);
+  void generate(
+      T languageOptions, Root root, StringSink sink, FileType fileType);
 }
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 00293bfc0e8..e7b2ebcaf18 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -92,7 +92,8 @@ class JavaGenerator extends Generator<JavaOptions> {
 
   /// Generates Java files with specified [JavaOptions]
   @override
-  void generate(JavaOptions languageOptions, Root root, StringSink sink) {
+  void generate(
+      JavaOptions languageOptions, Root root, StringSink sink, FileType _) {
     generateJava(languageOptions, root, sink);
   }
 }
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 99690a4ac92..a570da4674b 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -72,7 +72,8 @@ class KotlinGenerator extends Generator<KotlinOptions> {
 
   /// Generates Kotlin files with specified [KotlinOptions]
   @override
-  void generate(KotlinOptions languageOptions, Root root, StringSink sink) {
+  void generate(
+      KotlinOptions languageOptions, Root root, StringSink sink, FileType _) {
     generateKotlin(languageOptions, root, sink);
   }
 }
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index a3cf3a7da2a..4576ed6a66c 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -67,14 +67,12 @@ class ObjcOptions {
 /// Class that manages all Objc header code generation.
 class ObjcGenerator extends Generator<ObjcOptions> {
   /// Instantiates a Objc Generator for the specified file type.
-  ObjcGenerator(this.fileType);
-
-  /// Specifies which file type (header or source) will be generated.
-  FileType fileType;
+  ObjcGenerator();
 
   /// Generates Objc files with specified [ObjcOptions]
   @override
-  void generate(ObjcOptions languageOptions, Root root, StringSink sink) {
+  void generate(ObjcOptions languageOptions, Root root, StringSink sink,
+      FileType fileType) {
     if (fileType == FileType.header) {
       generateObjcHeader(languageOptions, root, sink);
     } else {
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index bfde7735b43..0311d31e714 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -409,7 +409,7 @@ class DartGeneratorAdapter implements GeneratorAdapter {
     final DartOptions dartOptionsWithHeader = _dartOptionsWithCopyrightHeader(
         options.dartOptions, options.copyrightHeader);
     final DartGenerator generator = DartGenerator();
-    generator.generate(dartOptionsWithHeader, root, sink);
+    generator.generate(dartOptionsWithHeader, root, sink, FileType.source);
   }
 
   @override
@@ -465,8 +465,8 @@ class ObjcHeaderGeneratorAdapter implements GeneratorAdapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final ObjcGenerator generator = ObjcGenerator(FileType.header);
-    generator.generate(objcOptionsWithHeader, root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    generator.generate(objcOptionsWithHeader, root, sink, FileType.header);
   }
 
   @override
@@ -490,8 +490,8 @@ class ObjcSourceGeneratorAdapter implements GeneratorAdapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final ObjcGenerator generator = ObjcGenerator(FileType.source);
-    generator.generate(objcOptionsWithHeader, root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    generator.generate(objcOptionsWithHeader, root, sink, FileType.source);
   }
 
   @override
@@ -517,7 +517,7 @@ class JavaGeneratorAdapter implements GeneratorAdapter {
             ? _lineReader(options.copyrightHeader!)
             : null));
     final JavaGenerator generator = JavaGenerator();
-    generator.generate(javaOptions, root, sink);
+    generator.generate(javaOptions, root, sink, FileType.source);
   }
 
   @override
@@ -540,7 +540,7 @@ class SwiftGeneratorAdapter implements GeneratorAdapter {
             ? _lineReader(options.copyrightHeader!)
             : null));
     final SwiftGenerator generator = SwiftGenerator();
-    generator.generate(swiftOptions, root, sink);
+    generator.generate(swiftOptions, root, sink, FileType.source);
   }
 
   @override
@@ -563,8 +563,8 @@ class CppHeaderGeneratorAdapter implements GeneratorAdapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final CppGenerator generator = CppGenerator(FileType.header);
-    generator.generate(cppOptionsWithHeader, root, sink);
+    final CppGenerator generator = CppGenerator();
+    generator.generate(cppOptionsWithHeader, root, sink, FileType.header);
   }
 
   @override
@@ -588,8 +588,8 @@ class CppSourceGeneratorAdapter implements GeneratorAdapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final CppGenerator generator = CppGenerator(FileType.source);
-    generator.generate(cppOptionsWithHeader, root, sink);
+    final CppGenerator generator = CppGenerator();
+    generator.generate(cppOptionsWithHeader, root, sink, FileType.source);
   }
 
   @override
@@ -614,7 +614,7 @@ class KotlinGeneratorAdapter implements GeneratorAdapter {
             ? _lineReader(options.copyrightHeader!)
             : null));
     final KotlinGenerator generator = KotlinGenerator();
-    generator.generate(kotlinOptions, root, sink);
+    generator.generate(kotlinOptions, root, sink, FileType.source);
   }
 
   @override
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index b25931c03e3..45c15341116 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -55,7 +55,8 @@ class SwiftGenerator extends Generator<SwiftOptions> {
 
   /// Generates Swift files with specified [SwiftOptions]
   @override
-  void generate(SwiftOptions languageOptions, Root root, StringSink sink) {
+  void generate(
+      SwiftOptions languageOptions, Root root, StringSink sink, FileType _) {
     generateSwift(languageOptions, root, sink);
   }
 }

From d189d11ad0dfd028252607a3d8399d9cd51d5d53 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 28 Dec 2022 23:04:36 -0800
Subject: [PATCH 35/87] Adds filetype as field to generatorAdapters

---
 packages/pigeon/lib/cpp_generator.dart    |   2 +-
 packages/pigeon/lib/objc_generator.dart   |   2 +-
 packages/pigeon/lib/pigeon_lib.dart       | 213 +++++++++++-----------
 packages/pigeon/test/pigeon_lib_test.dart |  49 ++---
 4 files changed, 139 insertions(+), 127 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index ff7239efd2d..fbb90b39483 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -72,7 +72,7 @@ class CppOptions {
 
 /// Class that manages all Cpp header code generation.
 class CppGenerator extends Generator<CppOptions> {
-  /// Instantiates a Cpp Generator for the specified file type.
+  /// Instantiates a Cpp Generator.
   CppGenerator();
 
   /// Generates Cpp files with specified [CppOptions]
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 4576ed6a66c..110625414a2 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -66,7 +66,7 @@ class ObjcOptions {
 
 /// Class that manages all Objc header code generation.
 class ObjcGenerator extends Generator<ObjcOptions> {
-  /// Instantiates a Objc Generator for the specified file type.
+  /// Instantiates a Objc Generator.
   ObjcGenerator();
 
   /// Generates Objc files with specified [ObjcOptions]
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 0311d31e714..4e949ec3dd3 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -358,13 +358,21 @@ IOSink? _openSink(String? output) {
 /// An adapter that will call a generator to write code to a sink
 /// based on the contents of [PigeonOptions].
 abstract class GeneratorAdapter {
+  /// Constructor for [GeneratorAdapter]
+  GeneratorAdapter(this.fileTypeList);
+
+  /// A list of [FileType]
+  /// Used to tell the generator method which type of file to create.
+  List<FileType> fileTypeList;
+
   /// Returns an [IOSink] instance to be written to if the [GeneratorAdapter] should
   /// generate.  If it returns `null`, the [GeneratorAdapter] will be skipped.
-  IOSink? shouldGenerate(PigeonOptions options);
+  IOSink? shouldGenerate(PigeonOptions options, FileType fileType);
 
   /// Write the generated code described in [root] to [sink] using the
   /// [options].
-  void generate(StringSink sink, PigeonOptions options, Root root);
+  void generate(
+      StringSink sink, PigeonOptions options, Root root, FileType fileType);
 
   /// Generates errors that would only be appropriate for this [GeneratorAdapter]. For
   /// example, maybe a certain feature isn't implemented in a [GeneratorAdapter] yet.
@@ -385,15 +393,20 @@ DartOptions _dartOptionsWithCopyrightHeader(
 /// A [GeneratorAdapter] that generates the AST.
 class AstGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [AstGeneratorAdapter].
-  const AstGeneratorAdapter();
+  AstGeneratorAdapter();
+
+  @override
+  List<FileType> fileTypeList = const <FileType>[FileType.source];
 
   @override
-  void generate(StringSink sink, PigeonOptions options, Root root) {
+  void generate(
+      StringSink sink, PigeonOptions options, Root root, FileType fileType) {
     generateAst(root, sink);
   }
 
   @override
-  IOSink? shouldGenerate(PigeonOptions options) => _openSink(options.astOut);
+  IOSink? shouldGenerate(PigeonOptions options, FileType _) =>
+      _openSink(options.astOut);
 
   @override
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
@@ -402,18 +415,23 @@ class AstGeneratorAdapter implements GeneratorAdapter {
 /// A [GeneratorAdapter] that generates Dart source code.
 class DartGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [DartGeneratorAdapter].
-  const DartGeneratorAdapter();
+  DartGeneratorAdapter();
 
   @override
-  void generate(StringSink sink, PigeonOptions options, Root root) {
+  List<FileType> fileTypeList = const <FileType>[FileType.source];
+
+  @override
+  void generate(
+      StringSink sink, PigeonOptions options, Root root, FileType fileType) {
     final DartOptions dartOptionsWithHeader = _dartOptionsWithCopyrightHeader(
         options.dartOptions, options.copyrightHeader);
     final DartGenerator generator = DartGenerator();
-    generator.generate(dartOptionsWithHeader, root, sink, FileType.source);
+    generator.generate(dartOptionsWithHeader, root, sink, fileType);
   }
 
   @override
-  IOSink? shouldGenerate(PigeonOptions options) => _openSink(options.dartOut);
+  IOSink? shouldGenerate(PigeonOptions options, FileType _) =>
+      _openSink(options.dartOut);
 
   @override
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
@@ -422,10 +440,14 @@ class DartGeneratorAdapter implements GeneratorAdapter {
 /// A [GeneratorAdapter] that generates Dart test source code.
 class DartTestGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [DartTestGeneratorAdapter].
-  const DartTestGeneratorAdapter();
+  DartTestGeneratorAdapter();
 
   @override
-  void generate(StringSink sink, PigeonOptions options, Root root) {
+  List<FileType> fileTypeList = const <FileType>[FileType.source];
+
+  @override
+  void generate(
+      StringSink sink, PigeonOptions options, Root root, FileType fileType) {
     final DartOptions dartOptionsWithHeader = _dartOptionsWithCopyrightHeader(
       options.dartOptions,
       options.copyrightHeader,
@@ -441,7 +463,7 @@ class DartTestGeneratorAdapter implements GeneratorAdapter {
   }
 
   @override
-  IOSink? shouldGenerate(PigeonOptions options) {
+  IOSink? shouldGenerate(PigeonOptions options, FileType _) {
     if (options.dartTestOut != null) {
       return _openSink(options.dartTestOut);
     } else {
@@ -453,50 +475,35 @@ class DartTestGeneratorAdapter implements GeneratorAdapter {
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [GeneratorAdapter] that generates Objective-C header code.
-class ObjcHeaderGeneratorAdapter implements GeneratorAdapter {
-  /// Constructor for [ObjcHeaderGeneratorAdapter].
-  const ObjcHeaderGeneratorAdapter();
-
-  @override
-  void generate(StringSink sink, PigeonOptions options, Root root) {
-    final ObjcOptions objcOptions = options.objcOptions ?? const ObjcOptions();
-    final ObjcOptions objcOptionsWithHeader = objcOptions.merge(ObjcOptions(
-        copyrightHeader: options.copyrightHeader != null
-            ? _lineReader(options.copyrightHeader!)
-            : null));
-    final ObjcGenerator generator = ObjcGenerator();
-    generator.generate(objcOptionsWithHeader, root, sink, FileType.header);
-  }
-
-  @override
-  IOSink? shouldGenerate(PigeonOptions options) =>
-      _openSink(options.objcHeaderOut);
+/// A [GeneratorAdapter] that generates Objective-C code.
+class ObjcGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [ObjcGeneratorAdapter].
+  ObjcGeneratorAdapter(
+      {this.fileTypeList = const <FileType>[FileType.header, FileType.source]});
 
   @override
-  List<Error> validate(PigeonOptions options, Root root) =>
-      validateObjc(options.objcOptions!, root);
-}
-
-/// A [GeneratorAdapter] that generates Objective-C source code.
-class ObjcSourceGeneratorAdapter implements GeneratorAdapter {
-  /// Constructor for [ObjcSourceGeneratorAdapter].
-  const ObjcSourceGeneratorAdapter();
+  List<FileType> fileTypeList;
 
   @override
-  void generate(StringSink sink, PigeonOptions options, Root root) {
+  void generate(
+      StringSink sink, PigeonOptions options, Root root, FileType fileType) {
     final ObjcOptions objcOptions = options.objcOptions ?? const ObjcOptions();
     final ObjcOptions objcOptionsWithHeader = objcOptions.merge(ObjcOptions(
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
     final ObjcGenerator generator = ObjcGenerator();
-    generator.generate(objcOptionsWithHeader, root, sink, FileType.source);
+    generator.generate(objcOptionsWithHeader, root, sink, fileType);
   }
 
   @override
-  IOSink? shouldGenerate(PigeonOptions options) =>
-      _openSink(options.objcSourceOut);
+  IOSink? shouldGenerate(PigeonOptions options, FileType fileType) {
+    if (fileType == FileType.source) {
+      return _openSink(options.objcSourceOut);
+    } else {
+      return _openSink(options.objcHeaderOut);
+    }
+  }
 
   @override
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
@@ -505,10 +512,14 @@ class ObjcSourceGeneratorAdapter implements GeneratorAdapter {
 /// A [GeneratorAdapter] that generates Java source code.
 class JavaGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [JavaGeneratorAdapter].
-  const JavaGeneratorAdapter();
+  JavaGeneratorAdapter();
+
+  @override
+  List<FileType> fileTypeList = const <FileType>[FileType.source];
 
   @override
-  void generate(StringSink sink, PigeonOptions options, Root root) {
+  void generate(
+      StringSink sink, PigeonOptions options, Root root, FileType fileType) {
     JavaOptions javaOptions = options.javaOptions ?? const JavaOptions();
     javaOptions = javaOptions.merge(JavaOptions(
         className: javaOptions.className ??
@@ -517,11 +528,12 @@ class JavaGeneratorAdapter implements GeneratorAdapter {
             ? _lineReader(options.copyrightHeader!)
             : null));
     final JavaGenerator generator = JavaGenerator();
-    generator.generate(javaOptions, root, sink, FileType.source);
+    generator.generate(javaOptions, root, sink, fileType);
   }
 
   @override
-  IOSink? shouldGenerate(PigeonOptions options) => _openSink(options.javaOut);
+  IOSink? shouldGenerate(PigeonOptions options, FileType _) =>
+      _openSink(options.javaOut);
 
   @override
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
@@ -530,71 +542,60 @@ class JavaGeneratorAdapter implements GeneratorAdapter {
 /// A [GeneratorAdapter] that generates Swift source code.
 class SwiftGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [SwiftGeneratorAdapter].
-  const SwiftGeneratorAdapter();
+  SwiftGeneratorAdapter();
 
   @override
-  void generate(StringSink sink, PigeonOptions options, Root root) {
+  List<FileType> fileTypeList = const <FileType>[FileType.source];
+
+  @override
+  void generate(
+      StringSink sink, PigeonOptions options, Root root, FileType fileType) {
     SwiftOptions swiftOptions = options.swiftOptions ?? const SwiftOptions();
     swiftOptions = swiftOptions.merge(SwiftOptions(
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
     final SwiftGenerator generator = SwiftGenerator();
-    generator.generate(swiftOptions, root, sink, FileType.source);
+    generator.generate(swiftOptions, root, sink, fileType);
   }
 
   @override
-  IOSink? shouldGenerate(PigeonOptions options) => _openSink(options.swiftOut);
+  IOSink? shouldGenerate(PigeonOptions options, FileType _) =>
+      _openSink(options.swiftOut);
 
   @override
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
 }
 
-/// A [GeneratorAdapter] that generates C++ header code.
-class CppHeaderGeneratorAdapter implements GeneratorAdapter {
-  /// Constructor for [CppHeaderGeneratorAdapter].
-  const CppHeaderGeneratorAdapter();
-
-  @override
-  void generate(StringSink sink, PigeonOptions options, Root root) {
-    final CppOptions cppOptions = options.cppOptions ?? const CppOptions();
-    final CppOptions cppOptionsWithHeader = cppOptions.merge(CppOptions(
-        headerOutPath: path.basenameWithoutExtension(options.cppHeaderOut!),
-        copyrightHeader: options.copyrightHeader != null
-            ? _lineReader(options.copyrightHeader!)
-            : null));
-    final CppGenerator generator = CppGenerator();
-    generator.generate(cppOptionsWithHeader, root, sink, FileType.header);
-  }
-
-  @override
-  IOSink? shouldGenerate(PigeonOptions options) =>
-      _openSink(options.cppHeaderOut);
+/// A [GeneratorAdapter] that generates C++ source code.
+class CppGeneratorAdapter implements GeneratorAdapter {
+  /// Constructor for [CppGeneratorAdapter].
+  CppGeneratorAdapter(
+      {this.fileTypeList = const <FileType>[FileType.header, FileType.source]});
 
   @override
-  List<Error> validate(PigeonOptions options, Root root) =>
-      validateCpp(options.cppOptions!, root);
-}
-
-/// A [GeneratorAdapter] that generates C++ source code.
-class CppSourceGeneratorAdapter implements GeneratorAdapter {
-  /// Constructor for [CppSourceGeneratorAdapter].
-  const CppSourceGeneratorAdapter();
+  List<FileType> fileTypeList;
 
   @override
-  void generate(StringSink sink, PigeonOptions options, Root root) {
+  void generate(
+      StringSink sink, PigeonOptions options, Root root, FileType fileType) {
     final CppOptions cppOptions = options.cppOptions ?? const CppOptions();
     final CppOptions cppOptionsWithHeader = cppOptions.merge(CppOptions(
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
     final CppGenerator generator = CppGenerator();
-    generator.generate(cppOptionsWithHeader, root, sink, FileType.source);
+    generator.generate(cppOptionsWithHeader, root, sink, fileType);
   }
 
   @override
-  IOSink? shouldGenerate(PigeonOptions options) =>
-      _openSink(options.cppSourceOut);
+  IOSink? shouldGenerate(PigeonOptions options, FileType fileType) {
+    if (fileType == FileType.source) {
+      return _openSink(options.cppSourceOut);
+    } else {
+      return _openSink(options.cppHeaderOut);
+    }
+  }
 
   @override
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
@@ -603,10 +604,15 @@ class CppSourceGeneratorAdapter implements GeneratorAdapter {
 /// A [GeneratorAdapter] that generates Kotlin source code.
 class KotlinGeneratorAdapter implements GeneratorAdapter {
   /// Constructor for [KotlinGeneratorAdapter].
-  const KotlinGeneratorAdapter();
+  KotlinGeneratorAdapter(
+      {this.fileTypeList = const <FileType>[FileType.source]});
+
+  @override
+  List<FileType> fileTypeList;
 
   @override
-  void generate(StringSink sink, PigeonOptions options, Root root) {
+  void generate(
+      StringSink sink, PigeonOptions options, Root root, FileType fileType) {
     KotlinOptions kotlinOptions =
         options.kotlinOptions ?? const KotlinOptions();
     kotlinOptions = kotlinOptions.merge(KotlinOptions(
@@ -614,11 +620,12 @@ class KotlinGeneratorAdapter implements GeneratorAdapter {
             ? _lineReader(options.copyrightHeader!)
             : null));
     final KotlinGenerator generator = KotlinGenerator();
-    generator.generate(kotlinOptions, root, sink, FileType.source);
+    generator.generate(kotlinOptions, root, sink, fileType);
   }
 
   @override
-  IOSink? shouldGenerate(PigeonOptions options) => _openSink(options.kotlinOut);
+  IOSink? shouldGenerate(PigeonOptions options, FileType _) =>
+      _openSink(options.kotlinOut);
 
   @override
   List<Error> validate(PigeonOptions options, Root root) => <Error>[];
@@ -1367,16 +1374,14 @@ ${_argParser.usage}''';
     }
     final List<GeneratorAdapter> safeGeneratorAdapters = adapters ??
         <GeneratorAdapter>[
-          const DartGeneratorAdapter(),
-          const JavaGeneratorAdapter(),
-          const SwiftGeneratorAdapter(),
-          const KotlinGeneratorAdapter(),
-          const CppHeaderGeneratorAdapter(),
-          const CppSourceGeneratorAdapter(),
-          const DartTestGeneratorAdapter(),
-          const ObjcHeaderGeneratorAdapter(),
-          const ObjcSourceGeneratorAdapter(),
-          const AstGeneratorAdapter(),
+          DartGeneratorAdapter(),
+          JavaGeneratorAdapter(),
+          SwiftGeneratorAdapter(),
+          KotlinGeneratorAdapter(),
+          CppGeneratorAdapter(),
+          DartTestGeneratorAdapter(),
+          ObjcGeneratorAdapter(),
+          AstGeneratorAdapter(),
         ];
     _executeConfigurePigeon(options);
 
@@ -1399,7 +1404,7 @@ ${_argParser.usage}''';
     }
 
     for (final GeneratorAdapter adapter in safeGeneratorAdapters) {
-      final IOSink? sink = adapter.shouldGenerate(options);
+      final IOSink? sink = adapter.shouldGenerate(options, FileType.source);
       if (sink != null) {
         final List<Error> adapterErrors =
             adapter.validate(options, parseResults.root);
@@ -1441,11 +1446,13 @@ ${_argParser.usage}''';
     }
 
     for (final GeneratorAdapter adapter in safeGeneratorAdapters) {
-      final IOSink? sink = adapter.shouldGenerate(options);
-      if (sink != null) {
-        adapter.generate(sink, options, parseResults.root);
-        await sink.flush();
-        await releaseSink(sink);
+      for (final FileType fileType in adapter.fileTypeList) {
+        final IOSink? sink = adapter.shouldGenerate(options, fileType);
+        if (sink != null) {
+          adapter.generate(sink, options, parseResults.root, fileType);
+          await sink.flush();
+          await releaseSink(sink);
+        }
       }
     }
 
diff --git a/packages/pigeon/test/pigeon_lib_test.dart b/packages/pigeon/test/pigeon_lib_test.dart
index 8d06f78cecc..1ff074d3a0f 100644
--- a/packages/pigeon/test/pigeon_lib_test.dart
+++ b/packages/pigeon/test/pigeon_lib_test.dart
@@ -6,20 +6,26 @@ import 'dart:async';
 import 'dart:io';
 
 import 'package:pigeon/ast.dart';
+import 'package:pigeon/generator_tools.dart';
 import 'package:pigeon/pigeon_lib.dart';
 import 'package:test/test.dart';
 
 class _ValidatorGeneratorAdapter implements GeneratorAdapter {
   _ValidatorGeneratorAdapter(this.sink);
+
+  @override
+  List<FileType> fileTypeList = const <FileType>[FileType.source];
+
   bool didCallValidate = false;
 
   final IOSink? sink;
 
   @override
-  void generate(StringSink sink, PigeonOptions options, Root root) {}
+  void generate(
+      StringSink sink, PigeonOptions options, Root root, FileType fileType) {}
 
   @override
-  IOSink? shouldGenerate(PigeonOptions options) => sink;
+  IOSink? shouldGenerate(PigeonOptions options, FileType _) => sink;
 
   @override
   List<Error> validate(PigeonOptions options, Root root) {
@@ -397,9 +403,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const DartGeneratorAdapter dartGeneratorAdapter = DartGeneratorAdapter();
+    final DartGeneratorAdapter dartGeneratorAdapter = DartGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    dartGeneratorAdapter.generate(buffer, options, root);
+    dartGeneratorAdapter.generate(buffer, options, root, FileType.source);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -407,9 +413,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options = PigeonOptions(
         javaOut: 'Foo.java', copyrightHeader: './copyright_header.txt');
-    const JavaGeneratorAdapter javaGeneratorAdapter = JavaGeneratorAdapter();
+    final JavaGeneratorAdapter javaGeneratorAdapter = JavaGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    javaGeneratorAdapter.generate(buffer, options, root);
+    javaGeneratorAdapter.generate(buffer, options, root, FileType.source);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -417,10 +423,10 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const ObjcHeaderGeneratorAdapter objcHeaderGeneratorAdapter =
-        ObjcHeaderGeneratorAdapter();
+    final ObjcGeneratorAdapter objcHeaderGeneratorAdapter =
+        ObjcGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    objcHeaderGeneratorAdapter.generate(buffer, options, root);
+    objcHeaderGeneratorAdapter.generate(buffer, options, root, FileType.header);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -428,10 +434,10 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const ObjcSourceGeneratorAdapter objcSourceGeneratorAdapter =
-        ObjcSourceGeneratorAdapter();
+    final ObjcGeneratorAdapter objcSourceGeneratorAdapter =
+        ObjcGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    objcSourceGeneratorAdapter.generate(buffer, options, root);
+    objcSourceGeneratorAdapter.generate(buffer, options, root, FileType.source);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -439,9 +445,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options = PigeonOptions(
         swiftOut: 'Foo.swift', copyrightHeader: './copyright_header.txt');
-    const SwiftGeneratorAdapter swiftGeneratorAdapter = SwiftGeneratorAdapter();
+    final SwiftGeneratorAdapter swiftGeneratorAdapter = SwiftGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    swiftGeneratorAdapter.generate(buffer, options, root);
+    swiftGeneratorAdapter.generate(buffer, options, root, FileType.source);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -449,10 +455,9 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options = PigeonOptions(
         cppHeaderOut: 'Foo.h', copyrightHeader: './copyright_header.txt');
-    const CppHeaderGeneratorAdapter cppHeaderGeneratorAdapter =
-        CppHeaderGeneratorAdapter();
+    final CppGeneratorAdapter cppHeaderGeneratorAdapter = CppGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    cppHeaderGeneratorAdapter.generate(buffer, options, root);
+    cppHeaderGeneratorAdapter.generate(buffer, options, root, FileType.header);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -460,10 +465,10 @@ abstract class NestorApi {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     const PigeonOptions options =
         PigeonOptions(copyrightHeader: './copyright_header.txt');
-    const CppSourceGeneratorAdapter cppSourceGeneratorAdapter =
-        CppSourceGeneratorAdapter();
+    final CppGeneratorAdapter cppSourceGeneratorAdapter =
+        CppGeneratorAdapter(fileTypeList: <FileType>[FileType.source]);
     final StringBuffer buffer = StringBuffer();
-    cppSourceGeneratorAdapter.generate(buffer, options, root);
+    cppSourceGeneratorAdapter.generate(buffer, options, root, FileType.source);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
@@ -933,10 +938,10 @@ abstract class Api {
       dartTestOut: 'stdout',
       dartOut: 'stdout',
     );
-    const DartTestGeneratorAdapter dartGeneratorAdapter =
+    final DartTestGeneratorAdapter dartGeneratorAdapter =
         DartTestGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    dartGeneratorAdapter.generate(buffer, options, root);
+    dartGeneratorAdapter.generate(buffer, options, root, FileType.source);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 

From 859c6cbb7aee800113817348d40a1ebe095ad3ba Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 29 Dec 2022 11:53:04 -0800
Subject: [PATCH 36/87] merge

---
 packages/pigeon/lib/dart_generator.dart                   | 1 +
 packages/pigeon/mock_handler_tester/test/message.dart     | 3 ++-
 packages/pigeon/mock_handler_tester/test/test.dart        | 2 +-
 .../example/alternate_language_test_plugin/CoreTests.java | 2 +-
 .../ios/Classes/CoreTests.gen.h                           | 3 ++-
 .../ios/Classes/CoreTests.gen.m                           | 3 ++-
 .../flutter_null_safe_unit_tests/lib/core_tests.gen.dart  | 3 ++-
 .../lib/multiple_arity.gen.dart                           | 3 ++-
 .../lib/non_null_fields.gen.dart                          | 3 ++-
 .../flutter_null_safe_unit_tests/lib/null_fields.gen.dart | 3 ++-
 .../lib/null_safe_pigeon.dart                             | 3 ++-
 .../lib/nullable_returns.gen.dart                         | 3 ++-
 .../flutter_null_safe_unit_tests/lib/primitive.dart       | 3 ++-
 .../lib/src/generated/core_tests.gen.dart                 | 3 ++-
 .../main/kotlin/com/example/test_plugin/CoreTests.gen.kt  | 2 +-
 .../test_plugin/ios/Classes/CoreTests.gen.swift           | 2 +-
 .../test_plugin/macos/Classes/CoreTests.gen.swift         | 2 +-
 .../test_plugin/windows/pigeon/core_tests.gen.cpp         | 2 +-
 .../test_plugin/windows/pigeon/core_tests.gen.h           | 8 ++++----
 packages/pigeon/test/pigeon_lib_test.dart                 | 4 ++--
 20 files changed, 35 insertions(+), 23 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 9c6e1360e23..ae17374e18e 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -96,6 +96,7 @@ class DartGenerator extends Generator<DartOptions> {
     final Indent indent = Indent(sink);
     final String sourceOutPath = languageOptions.sourceOutPath ?? '';
     final String testOutPath = languageOptions.testOutPath ?? '';
+    writeTestHeader(languageOptions, root, sink, indent);
     generateTestDart(
       languageOptions,
       root,
diff --git a/packages/pigeon/mock_handler_tester/test/message.dart b/packages/pigeon/mock_handler_tester/test/message.dart
index 4f6c9d14457..94024e73bc7 100644
--- a/packages/pigeon/mock_handler_tester/test/message.dart
+++ b/packages/pigeon/mock_handler_tester/test/message.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/mock_handler_tester/test/test.dart b/packages/pigeon/mock_handler_tester/test/test.dart
index 9b97826b605..e1644f13686 100644
--- a/packages/pigeon/mock_handler_tester/test/test.dart
+++ b/packages/pigeon/mock_handler_tester/test/test.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, unnecessary_import
 // ignore_for_file: avoid_relative_lib_imports
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
index 2d81d4b59f1..a6d28a36db7 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package com.example.alternate_language_test_plugin;
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
index dcdee87c5d9..3e921d36aee 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
@@ -2,8 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
+
 #import <Foundation/Foundation.h>
 @protocol FlutterBinaryMessenger;
 @protocol FlutterMessageCodec;
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
index bcdd86394a6..3fb7d4b98d5 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
@@ -2,8 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
+
 #import "CoreTests.gen.h"
 #import <Flutter/Flutter.h>
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
index ee79a4b1a27..49d7d40d13a 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
index e92ab29cebd..4bed42b32dd 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
index 1ff71bfa346..5d4cbd0096e 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
index 88f4611e746..0d151dc54e4 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
index 13fe926bcf1..820749f7bef 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
index be1979c8adf..a050c155e05 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
index 36a569e4f46..a5e4e6b318f 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
index ee79a4b1a27..49d7d40d13a 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
index c1add054eaf..d5c9882ba12 100644
--- a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
+++ b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package com.example.test_plugin
diff --git a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
index c9850b70d36..b21cbd5fbc0 100644
--- a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
diff --git a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
index c9850b70d36..b21cbd5fbc0 100644
--- a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
index f0d5929ce4a..2b46028b18e 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #undef _HAS_EXCEPTIONS
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
index a2ea204b578..fca12d2ec92 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
-#ifndef PIGEON_CORE_TESTS_PIGEONTEST_H_
-#define PIGEON_CORE_TESTS_PIGEONTEST_H_
+#ifndef PIGEON_CORE_TESTS_GEN_H_CORE_TESTS_PIGEONTEST_H_
+#define PIGEON_CORE_TESTS_GEN_H_CORE_TESTS_PIGEONTEST_H_
 #include <flutter/basic_message_channel.h>
 #include <flutter/binary_messenger.h>
 #include <flutter/encodable_value.h>
@@ -406,4 +406,4 @@ class HostTrivialApi {
   HostTrivialApi() = default;
 };
 }  // namespace core_tests_pigeontest
-#endif  // PIGEON_CORE_TESTS_PIGEONTEST_H_
+#endif  // PIGEON_CORE_TESTS_GEN_H_CORE_TESTS_PIGEONTEST_H_
diff --git a/packages/pigeon/test/pigeon_lib_test.dart b/packages/pigeon/test/pigeon_lib_test.dart
index 1ff074d3a0f..d7201bb688b 100644
--- a/packages/pigeon/test/pigeon_lib_test.dart
+++ b/packages/pigeon/test/pigeon_lib_test.dart
@@ -938,10 +938,10 @@ abstract class Api {
       dartTestOut: 'stdout',
       dartOut: 'stdout',
     );
-    final DartTestGeneratorAdapter dartGeneratorAdapter =
+    final DartTestGeneratorAdapter dartTestGeneratorAdapter =
         DartTestGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    dartGeneratorAdapter.generate(buffer, options, root, FileType.source);
+    dartTestGeneratorAdapter.generate(buffer, options, root, FileType.source);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 

From 6dff8cbae4489240c2d4fc2f75c801a06e5e6b80 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 29 Dec 2022 12:17:46 -0800
Subject: [PATCH 37/87] analyze

---
 packages/pigeon/lib/cpp_generator.dart | 2 --
 1 file changed, 2 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index b291e9aea19..65fa011722c 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:io';
-
 import 'ast.dart';
 import 'functional.dart';
 import 'generator.dart';

From c17c1e4d6e58af11f8735622b95567a7f5003497 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 29 Dec 2022 12:48:36 -0800
Subject: [PATCH 38/87] add import method

---
 packages/pigeon/lib/dart_generator.dart | 31 +++++++++++++++----------
 packages/pigeon/lib/generator.dart      | 12 +++++++++-
 2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index ae17374e18e..ce7b5631448 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -82,6 +82,7 @@ class DartGenerator extends Generator<DartOptions> {
     final Indent indent = Indent(sink);
 
     writeFileHeaders(languageOptions, root, sink, indent, fileType);
+    writeFileImports(languageOptions, root, sink, indent, fileType);
     generateDart(languageOptions, root, sink, indent);
   }
 
@@ -91,6 +92,12 @@ class DartGenerator extends Generator<DartOptions> {
     writeHeader(languageOptions, root, sink, indent);
   }
 
+  @override
+  void writeFileImports(DartOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType) {
+    writeImports(languageOptions, root, sink, indent);
+  }
+
   /// Generates Dart files for testing with specified [DartOptions]
   void generateTest(DartOptions languageOptions, Root root, StringSink sink) {
     final Indent indent = Indent(sink);
@@ -553,6 +560,18 @@ void writeHeader(DartOptions opt, Root root, StringSink sink, Indent indent) {
   indent.addln('');
 }
 
+/// Writes file imports to sink.
+void writeImports(DartOptions opt, Root root, StringSink sink, Indent indent) {
+  indent.writeln("import 'dart:async';");
+  indent.writeln(
+    "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
+  );
+  indent.addln('');
+  indent.writeln(
+      "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;");
+  indent.writeln("import 'package:flutter/services.dart';");
+}
+
 /// Generates Dart source code for the given AST represented by [root],
 /// outputting the code to [sink].
 void generateDart(DartOptions opt, Root root, StringSink sink, Indent indent) {
@@ -577,17 +596,6 @@ void generateDart(DartOptions opt, Root root, StringSink sink, Indent indent) {
     }
   }
 
-  void writeImports() {
-    indent.writeln("import 'dart:async';");
-    indent.writeln(
-      "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
-    );
-    indent.addln('');
-    indent.writeln(
-        "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;");
-    indent.writeln("import 'package:flutter/services.dart';");
-  }
-
   void writeDataClass(Class klass) {
     void writeConstructor() {
       indent.write(klass.name);
@@ -718,7 +726,6 @@ $resultAt != null
     }
   }
 
-  writeImports();
   writeEnums();
   for (final Class klass in root.classes) {
     indent.writeln('');
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 9f4b835bb3c..86fa40fbbc5 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -14,7 +14,8 @@ abstract class Generator<T> {
   /// This method, when overridden, should follow a generic structure that is currently:
   /// 1. Create Indent
   /// 2. Write File Headers
-  /// 3. Generate File
+  /// 3. Write Imports
+  /// 4. Generate File
   void generate(
     T languageOptions,
     Root root,
@@ -30,4 +31,13 @@ abstract class Generator<T> {
     Indent indent,
     FileType fileType,
   );
+
+  /// Adds specified imports.
+  void writeFileImports(
+    T languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+  );
 }

From d9f116ff4ea9a4417cb9e051f4478acd08b8e24e Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 29 Dec 2022 12:56:38 -0800
Subject: [PATCH 39/87] re-remove DartTestGenerator

---
 packages/pigeon/lib/dart_generator.dart       | 32 -----------
 packages/pigeon/test/dart_generator_test.dart | 54 +++++++++----------
 2 files changed, 27 insertions(+), 59 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index ae17374e18e..25d505c8dff 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -108,38 +108,6 @@ class DartGenerator extends Generator<DartOptions> {
   }
 }
 
-/// Class that manages all Dart code generation.
-class DartTestGenerator extends Generator<DartOptions> {
-  /// Instantiates a Dart Generator.
-  DartTestGenerator();
-
-  /// Generates Dart files with specified [DartOptions]
-  @override
-  void generate(DartOptions languageOptions, Root root, StringSink sink,
-      FileType fileType) {
-    final Indent indent = Indent(sink);
-
-    final String sourceOutPath = languageOptions.sourceOutPath ?? '';
-    final String testOutPath = languageOptions.testOutPath ?? '';
-
-    writeFileHeaders(languageOptions, root, sink, indent, fileType);
-    generateTestDart(
-      languageOptions,
-      root,
-      sink,
-      indent,
-      sourceOutPath: sourceOutPath,
-      testOutPath: testOutPath,
-    );
-  }
-
-  @override
-  void writeFileHeaders(DartOptions languageOptions, Root root, StringSink sink,
-      Indent indent, FileType fileType) {
-    writeTestHeader(languageOptions, root, sink, indent);
-  }
-}
-
 String _escapeForDartSingleQuotedString(String raw) {
   return raw
       .replaceAll(r'\', r'\\')
diff --git a/packages/pigeon/test/dart_generator_test.dart b/packages/pigeon/test/dart_generator_test.dart
index c8d5f3af04c..31ff53a92cc 100644
--- a/packages/pigeon/test/dart_generator_test.dart
+++ b/packages/pigeon/test/dart_generator_test.dart
@@ -595,15 +595,15 @@ void main() {
     expect(mainCode, isNot(contains("'${Keys.result}': output")));
     expect(mainCode, isNot(contains('return <Object>[];')));
 
-    final DartTestGenerator testGenerator = DartTestGenerator();
-    testGenerator.generate(
-        DartOptions(
-          sourceOutPath: "fo'o.dart",
-          testOutPath: 'test.dart',
-        ),
-        root,
-        testCodeSink,
-        FileType.source);
+    final DartGenerator testGenerator = DartGenerator();
+    testGenerator.generateTest(
+      DartOptions(
+        sourceOutPath: "fo'o.dart",
+        testOutPath: 'test.dart',
+      ),
+      root,
+      testCodeSink,
+    );
     final String testCode = testCodeSink.toString();
     expect(testCode, contains(r"import 'fo\'o.dart';"));
     expect(testCode, isNot(contains('class Api {')));
@@ -1189,15 +1189,15 @@ name: foobar
       final Root root =
           Root(classes: <Class>[], apis: <Api>[], enums: <Enum>[]);
       final StringBuffer sink = StringBuffer();
-      final DartTestGenerator testGenerator = DartTestGenerator();
-      testGenerator.generate(
-          DartOptions(
-            sourceOutPath: path.join(foo.path, 'bar.dart'),
-            testOutPath: path.join(tempDir.path, 'test', 'bar_test.dart'),
-          ),
-          root,
-          sink,
-          FileType.source);
+      final DartGenerator testGenerator = DartGenerator();
+      testGenerator.generateTest(
+        DartOptions(
+          sourceOutPath: path.join(foo.path, 'bar.dart'),
+          testOutPath: path.join(tempDir.path, 'test', 'bar_test.dart'),
+        ),
+        root,
+        sink,
+      );
       final String code = sink.toString();
       expect(code, contains("import 'package:foobar/foo/bar.dart';"));
     } finally {
@@ -1399,15 +1399,15 @@ name: foobar
     );
     final StringBuffer sink = StringBuffer();
 
-    final DartTestGenerator testGenerator = DartTestGenerator();
-    testGenerator.generate(
-        DartOptions(
-          sourceOutPath: 'code.dart',
-          testOutPath: 'test.dart',
-        ),
-        root,
-        sink,
-        FileType.source);
+    final DartGenerator testGenerator = DartGenerator();
+    testGenerator.generateTest(
+      DartOptions(
+        sourceOutPath: 'code.dart',
+        testOutPath: 'test.dart',
+      ),
+      root,
+      sink,
+    );
 
     final String testCode = sink.toString();
     expect(

From e57de98a9d752efcf2c91ed565edcb24ab3c490e Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 29 Dec 2022 13:48:01 -0800
Subject: [PATCH 40/87] Moves imports to new method

---
 packages/pigeon/lib/cpp_generator.dart        | 39 ++++++++---
 packages/pigeon/lib/dart_generator.dart       | 24 ++++---
 packages/pigeon/lib/java_generator.dart       | 55 ++++++++-------
 packages/pigeon/lib/kotlin_generator.dart     | 40 ++++++-----
 packages/pigeon/lib/objc_generator.dart       | 68 +++++++++++--------
 packages/pigeon/lib/swift_generator.dart      | 38 +++++++----
 .../ios/Classes/CoreTests.gen.h               |  1 +
 .../windows/pigeon/core_tests.gen.h           |  1 +
 8 files changed, 162 insertions(+), 104 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 65fa011722c..e41a9480129 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -80,11 +80,11 @@ class CppGenerator extends Generator<CppOptions> {
   void generate(CppOptions languageOptions, Root root, StringSink sink,
       FileType fileType) {
     final Indent indent = Indent(sink);
+    writeFileHeaders(languageOptions, root, sink, indent, fileType);
+    writeFileImports(languageOptions, root, sink, indent, fileType);
     if (fileType == FileType.header) {
-      writeFileHeaders(languageOptions, root, sink, indent, fileType);
       generateCppHeader(languageOptions, root, sink, indent);
     } else {
-      writeFileHeaders(languageOptions, root, sink, indent, fileType);
       generateCppSource(languageOptions, root, sink, indent);
     }
   }
@@ -98,6 +98,16 @@ class CppGenerator extends Generator<CppOptions> {
       writeCppSourceHeader(languageOptions, root, sink, indent);
     }
   }
+
+  @override
+  void writeFileImports(CppOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType) {
+    if (fileType == FileType.header) {
+      writeCppHeaderImports(languageOptions, root, sink, indent);
+    } else {
+      writeCppSourceImports(languageOptions, root, sink, indent);
+    }
+  }
 }
 
 String _getCodecSerializerName(Api api) => '${api.name}CodecSerializer';
@@ -1056,9 +1066,8 @@ void writeCppHeaderHeader(
   indent.addln('');
 }
 
-/// Generates the ".h" file for the AST represented by [root] to [sink] with the
-/// provided [options] and [headerFileName].
-void generateCppHeader(
+/// Writes Cpp header file imports to sink.
+void writeCppHeaderImports(
     CppOptions options, Root root, StringSink sink, Indent indent) {
   final String guardName =
       _getGuardName(options.headerIncludePath, options.namespace);
@@ -1078,11 +1087,16 @@ void generateCppHeader(
     'optional',
   ]);
   indent.addln('');
-
   if (options.namespace != null) {
     indent.writeln('namespace ${options.namespace} {');
   }
+  indent.addln('');
+}
 
+/// Generates the ".h" file for the AST represented by [root] to [sink] with the
+/// provided [options] and [headerFileName].
+void generateCppHeader(
+    CppOptions options, Root root, StringSink sink, Indent indent) {
   // When generating for a Pigeon unit test, add a test fixture friend class to
   // allow unit testing private methods, since testing serialization via public
   // methods is essentially an end-to-end test.
@@ -1137,7 +1151,8 @@ void generateCppHeader(
   if (options.namespace != null) {
     indent.writeln('}  // namespace ${options.namespace}');
   }
-
+  final String guardName =
+      _getGuardName(options.headerIncludePath, options.namespace);
   indent.writeln('#endif  // $guardName');
 }
 
@@ -1154,9 +1169,8 @@ void writeCppSourceHeader(
   indent.addln('');
 }
 
-/// Generates the ".cpp" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateCppSource(
+/// Writes Cpp source file imports to sink.
+void writeCppSourceImports(
     CppOptions options, Root root, StringSink sink, Indent indent) {
   indent.writeln('#include "${options.headerIncludePath}"');
   indent.addln('');
@@ -1177,7 +1191,12 @@ void generateCppSource(
   if (options.namespace != null) {
     indent.writeln('namespace ${options.namespace} {');
   }
+}
 
+/// Generates the ".cpp" file for the AST represented by [root] to [sink] with the
+/// provided [options].
+void generateCppSource(
+    CppOptions options, Root root, StringSink sink, Indent indent) {
   for (final Class klass in root.classes) {
     _writeDataClassImplementation(indent, klass, root);
   }
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 506b7e55158..6d233121de6 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -104,6 +104,7 @@ class DartGenerator extends Generator<DartOptions> {
     final String sourceOutPath = languageOptions.sourceOutPath ?? '';
     final String testOutPath = languageOptions.testOutPath ?? '';
     writeTestHeader(languageOptions, root, sink, indent);
+    writeTestImports(languageOptions, root, sink, indent);
     generateTestDart(
       languageOptions,
       root,
@@ -768,6 +769,20 @@ void writeTestHeader(
   indent.writeln('// ignore_for_file: avoid_relative_lib_imports');
 }
 
+/// Writes file imports to sink.
+void writeTestImports(
+    DartOptions opt, Root root, StringSink sink, Indent indent) {
+  indent.writeln("import 'dart:async';");
+  indent.writeln(
+    "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
+  );
+  indent.writeln(
+      "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;");
+  indent.writeln("import 'package:flutter/services.dart';");
+  indent.writeln("import 'package:flutter_test/flutter_test.dart';");
+  indent.writeln('');
+}
+
 /// Generates Dart source code for test support libraries based on the given AST
 /// represented by [root], outputting the code to [sink]. [dartOutPath] is the
 /// path of the generated dart code to be tested. [testOutPath] is where the
@@ -780,15 +795,6 @@ void generateTestDart(
   required String sourceOutPath,
   required String testOutPath,
 }) {
-  indent.writeln("import 'dart:async';");
-  indent.writeln(
-    "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
-  );
-  indent.writeln(
-      "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;");
-  indent.writeln("import 'package:flutter/services.dart';");
-  indent.writeln("import 'package:flutter_test/flutter_test.dart';");
-  indent.writeln('');
   final String relativeDartPath =
       path.Context(style: path.Style.posix).relative(
     _posixify(sourceOutPath),
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 3e89aa0b190..89ca7daba33 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -97,6 +97,7 @@ class JavaGenerator extends Generator<JavaOptions> {
     final Indent indent = Indent(sink);
 
     writeFileHeaders(languageOptions, root, sink, indent, fileType);
+    writeFileImports(languageOptions, root, sink, indent, fileType);
     generateJava(languageOptions, root, sink, indent);
   }
 
@@ -105,6 +106,12 @@ class JavaGenerator extends Generator<JavaOptions> {
       Indent indent, FileType fileType) {
     writeHeader(languageOptions, root, sink, indent);
   }
+
+  @override
+  void writeFileImports(JavaOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType) {
+    writeImports(languageOptions, root, sink, indent);
+  }
 }
 
 /// Calculates the name of the codec that will be generated for [api].
@@ -555,6 +562,30 @@ void writeHeader(
   indent.addln('');
 }
 
+/// Writes file imports to sink.
+void writeImports(
+    JavaOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.package != null) {
+    indent.writeln('package ${options.package};');
+  }
+  indent.writeln('import android.util.Log;');
+  indent.writeln('import androidx.annotation.NonNull;');
+  indent.writeln('import androidx.annotation.Nullable;');
+  indent.writeln('import io.flutter.plugin.common.BasicMessageChannel;');
+  indent.writeln('import io.flutter.plugin.common.BinaryMessenger;');
+  indent.writeln('import io.flutter.plugin.common.MessageCodec;');
+  indent.writeln('import io.flutter.plugin.common.StandardMessageCodec;');
+  indent.writeln('import java.io.ByteArrayOutputStream;');
+  indent.writeln('import java.nio.ByteBuffer;');
+  indent.writeln('import java.util.Arrays;');
+  indent.writeln('import java.util.ArrayList;');
+  indent.writeln('import java.util.Collections;');
+  indent.writeln('import java.util.List;');
+  indent.writeln('import java.util.Map;');
+  indent.writeln('import java.util.HashMap;');
+  indent.addln('');
+}
+
 /// Generates the ".java" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateJava(
@@ -564,24 +595,6 @@ void generateJava(
   final Set<String> rootEnumNameSet =
       root.enums.map((Enum x) => x.name).toSet();
 
-  void writeImports() {
-    indent.writeln('import android.util.Log;');
-    indent.writeln('import androidx.annotation.NonNull;');
-    indent.writeln('import androidx.annotation.Nullable;');
-    indent.writeln('import io.flutter.plugin.common.BasicMessageChannel;');
-    indent.writeln('import io.flutter.plugin.common.BinaryMessenger;');
-    indent.writeln('import io.flutter.plugin.common.MessageCodec;');
-    indent.writeln('import io.flutter.plugin.common.StandardMessageCodec;');
-    indent.writeln('import java.io.ByteArrayOutputStream;');
-    indent.writeln('import java.nio.ByteBuffer;');
-    indent.writeln('import java.util.Arrays;');
-    indent.writeln('import java.util.ArrayList;');
-    indent.writeln('import java.util.Collections;');
-    indent.writeln('import java.util.List;');
-    indent.writeln('import java.util.Map;');
-    indent.writeln('import java.util.HashMap;');
-  }
-
   String camelToSnake(String camelCase) {
     final RegExp regex = RegExp('([a-z])([A-Z]+)');
     return camelCase
@@ -777,12 +790,6 @@ void generateJava(
 }''');
   }
 
-  if (options.package != null) {
-    indent.writeln('package ${options.package};');
-  }
-  indent.addln('');
-  writeImports();
-  indent.addln('');
   indent.writeln(
       '$_docCommentPrefix Generated class from Pigeon.$_docCommentSuffix');
   indent.writeln(
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 3ee47a29cd1..ed4af8e4413 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -77,6 +77,7 @@ class KotlinGenerator extends Generator<KotlinOptions> {
     final Indent indent = Indent(sink);
 
     writeFileHeaders(languageOptions, root, sink, indent, fileType);
+    writeFileImports(languageOptions, root, sink, indent, fileType);
     generateKotlin(languageOptions, root, sink, indent);
   }
 
@@ -85,6 +86,12 @@ class KotlinGenerator extends Generator<KotlinOptions> {
       StringSink sink, Indent indent, FileType fileType) {
     writeHeader(languageOptions, root, sink, indent);
   }
+
+  @override
+  void writeFileImports(KotlinOptions languageOptions, Root root,
+      StringSink sink, Indent indent, FileType fileType) {
+    writeImports(languageOptions, root, sink, indent);
+  }
 }
 
 /// Calculates the name of the codec that will be generated for [api].
@@ -468,6 +475,23 @@ void writeHeader(
   indent.addln('');
 }
 
+/// Writes file imports to sink.
+void writeImports(
+    KotlinOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.package != null) {
+    indent.writeln('package ${options.package}');
+  }
+  indent.addln('');
+  indent.writeln('import android.util.Log');
+  indent.writeln('import io.flutter.plugin.common.BasicMessageChannel');
+  indent.writeln('import io.flutter.plugin.common.BinaryMessenger');
+  indent.writeln('import io.flutter.plugin.common.MessageCodec');
+  indent.writeln('import io.flutter.plugin.common.StandardMessageCodec');
+  indent.writeln('import java.io.ByteArrayOutputStream');
+  indent.writeln('import java.nio.ByteBuffer');
+  indent.addln('');
+}
+
 /// Generates the ".kotlin" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateKotlin(
@@ -482,16 +506,6 @@ void generateKotlin(
         (TypeDeclaration x) => _kotlinTypeForBuiltinDartType(x));
   }
 
-  void writeImports() {
-    indent.writeln('import android.util.Log');
-    indent.writeln('import io.flutter.plugin.common.BasicMessageChannel');
-    indent.writeln('import io.flutter.plugin.common.BinaryMessenger');
-    indent.writeln('import io.flutter.plugin.common.MessageCodec');
-    indent.writeln('import io.flutter.plugin.common.StandardMessageCodec');
-    indent.writeln('import java.io.ByteArrayOutputStream');
-    indent.writeln('import java.nio.ByteBuffer');
-  }
-
   void writeEnum(Enum anEnum) {
     addDocumentationComments(
         indent, anEnum.documentationComments, _docCommentSpec);
@@ -676,12 +690,6 @@ void generateKotlin(
     });
   }
 
-  if (options.package != null) {
-    indent.writeln('package ${options.package}');
-  }
-  indent.addln('');
-  writeImports();
-  indent.addln('');
   indent.writeln('/** Generated class from Pigeon. */');
   for (final Enum anEnum in root.enums) {
     indent.writeln('');
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 68b4d63f064..b1f2cff6fac 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -75,11 +75,11 @@ class ObjcGenerator extends Generator<ObjcOptions> {
       FileType fileType) {
     final Indent indent = Indent(sink);
 
+    writeFileHeaders(languageOptions, root, sink, indent, fileType);
+    writeFileImports(languageOptions, root, sink, indent, fileType);
     if (fileType == FileType.header) {
-      writeFileHeaders(languageOptions, root, sink, indent, fileType);
       generateObjcHeader(languageOptions, root, sink, indent);
     } else {
-      writeFileHeaders(languageOptions, root, sink, indent, fileType);
       generateObjcSource(languageOptions, root, sink, indent);
     }
   }
@@ -93,6 +93,16 @@ class ObjcGenerator extends Generator<ObjcOptions> {
       writeObjcSourceHeader(languageOptions, root, sink, indent);
     }
   }
+
+  @override
+  void writeFileImports(ObjcOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType) {
+    if (fileType == FileType.header) {
+      writeObjcHeaderImports(languageOptions, root, sink, indent);
+    } else {
+      writeObjcSourceImports(languageOptions, root, sink, indent);
+    }
+  }
 }
 
 /// Calculates the ObjC class name, possibly prefixed.
@@ -573,21 +583,23 @@ void writeObjcHeaderHeader(
   indent.addln('');
 }
 
+/// Writes Objc header file imports to sink.
+void writeObjcHeaderImports(
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {
+  indent.writeln('#import <Foundation/Foundation.h>');
+  indent.addln('');
+
+  indent.writeln('@protocol FlutterBinaryMessenger;');
+  indent.writeln('@protocol FlutterMessageCodec;');
+  indent.writeln('@class FlutterError;');
+  indent.writeln('@class FlutterStandardTypedData;');
+  indent.addln('');
+}
+
 /// Generates the ".h" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateObjcHeader(
     ObjcOptions options, Root root, StringSink sink, Indent indent) {
-  void writeImports() {
-    indent.writeln('#import <Foundation/Foundation.h>');
-  }
-
-  void writeForwardDeclarations() {
-    indent.writeln('@protocol FlutterBinaryMessenger;');
-    indent.writeln('@protocol FlutterMessageCodec;');
-    indent.writeln('@class FlutterError;');
-    indent.writeln('@class FlutterStandardTypedData;');
-  }
-
   void writeEnum(Enum anEnum) {
     final String enumName = _className(options.prefix, anEnum.name);
     addDocumentationComments(
@@ -605,8 +617,6 @@ void generateObjcHeader(
     });
   }
 
-  writeImports();
-  writeForwardDeclarations();
   indent.writeln('');
 
   indent.writeln('NS_ASSUME_NONNULL_BEGIN');
@@ -917,6 +927,19 @@ void writeObjcSourceHeader(
   indent.addln('');
 }
 
+/// Writes Objc source file imports to sink.
+void writeObjcSourceImports(
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {
+  indent.writeln('#import "${options.headerIncludePath}"');
+  indent.writeln('#import <Flutter/Flutter.h>');
+  indent.addln('');
+
+  indent.writeln('#if !__has_feature(objc_arc)');
+  indent.writeln('#error File requires ARC to be enabled.');
+  indent.writeln('#endif');
+  indent.addln('');
+}
+
 /// Generates the ".m" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateObjcSource(
@@ -925,17 +948,6 @@ void generateObjcSource(
       root.classes.map((Class x) => x.name).toList();
   final List<String> enumNames = root.enums.map((Enum x) => x.name).toList();
 
-  void writeImports() {
-    indent.writeln('#import "${options.headerIncludePath}"');
-    indent.writeln('#import <Flutter/Flutter.h>');
-  }
-
-  void writeArcEnforcer() {
-    indent.writeln('#if !__has_feature(objc_arc)');
-    indent.writeln('#error File requires ARC to be enabled.');
-    indent.writeln('#endif');
-  }
-
   void writeHelperFunctions() {
     indent.format('''
 static NSArray *wrapResult(id result, FlutterError *error) {
@@ -1041,10 +1053,6 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
     }
   }
 
-  writeImports();
-  indent.writeln('');
-  writeArcEnforcer();
-  indent.addln('');
   writeHelperFunctions();
   indent.addln('');
   root.classes.forEach(writeDataClassExtension);
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 76093450f66..38311dc614d 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -59,6 +59,7 @@ class SwiftGenerator extends Generator<SwiftOptions> {
       FileType fileType) {
     final Indent indent = Indent(sink);
     writeFileHeaders(languageOptions, root, sink, indent, fileType);
+    writeFileImports(languageOptions, root, sink, indent, fileType);
     generateSwift(languageOptions, root, sink, indent);
   }
 
@@ -67,6 +68,12 @@ class SwiftGenerator extends Generator<SwiftOptions> {
       StringSink sink, Indent indent, FileType fileType) {
     writeHeader(languageOptions, root, sink, indent);
   }
+
+  @override
+  void writeFileImports(SwiftOptions languageOptions, Root root,
+      StringSink sink, Indent indent, FileType fileType) {
+    writeImports(languageOptions, root, sink, indent);
+  }
 }
 
 /// Calculates the name of the codec that will be generated for [api].
@@ -462,6 +469,22 @@ void writeHeader(
   indent.addln('');
 }
 
+/// Writes file header to sink.
+void writeImports(
+    SwiftOptions options, Root root, StringSink sink, Indent indent) {
+  indent.writeln('import Foundation');
+  indent.format('''
+#if os(iOS)
+import Flutter
+#elseif os(macOS)
+import FlutterMacOS
+#else
+#error("Unsupported platform.")
+#endif
+''');
+  indent.writeln('');
+}
+
 /// Generates the ".swift" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateSwift(
@@ -476,19 +499,6 @@ void generateSwift(
         (TypeDeclaration x) => _swiftTypeForBuiltinDartType(x));
   }
 
-  void writeImports() {
-    indent.writeln('import Foundation');
-    indent.format('''
-#if os(iOS)
-import Flutter
-#elseif os(macOS)
-import FlutterMacOS
-#else
-#error("Unsupported platform.")
-#endif
-''');
-  }
-
   void writeEnum(Enum anEnum) {
     addDocumentationComments(
         indent, anEnum.documentationComments, _docCommentSpec);
@@ -644,8 +654,6 @@ import FlutterMacOS
     });
   }
 
-  writeImports();
-  indent.addln('');
   indent.writeln('$_docCommentPrefix Generated class from Pigeon.');
   for (final Enum anEnum in root.enums) {
     indent.writeln('');
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
index 3e921d36aee..5e235e67567 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
@@ -6,6 +6,7 @@
 // See also: https://pub.dev/packages/pigeon
 
 #import <Foundation/Foundation.h>
+
 @protocol FlutterBinaryMessenger;
 @protocol FlutterMessageCodec;
 @class FlutterError;
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
index fca12d2ec92..aa954c0de5e 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
@@ -17,6 +17,7 @@
 #include <string>
 
 namespace core_tests_pigeontest {
+
 class CoreTestsTest;
 
 // Generated class from Pigeon.

From fc63d50ed664a698ee3efd271d196516657c968e Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 30 Dec 2022 12:57:22 -0800
Subject: [PATCH 41/87] adds writeEnum method to generator class

---
 packages/pigeon/lib/cpp_generator.dart    |  62 ++++---
 packages/pigeon/lib/dart_generator.dart   |  88 +++++-----
 packages/pigeon/lib/generator.dart        |  18 +-
 packages/pigeon/lib/java_generator.dart   | 195 +++++++++++-----------
 packages/pigeon/lib/kotlin_generator.dart | 127 +++++++-------
 packages/pigeon/lib/swift_generator.dart  |  97 +++++------
 6 files changed, 290 insertions(+), 297 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index e41a9480129..78a7a1ffabd 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -80,8 +80,17 @@ class CppGenerator extends Generator<CppOptions> {
   void generate(CppOptions languageOptions, Root root, StringSink sink,
       FileType fileType) {
     final Indent indent = Indent(sink);
-    writeFileHeaders(languageOptions, root, sink, indent, fileType);
-    writeFileImports(languageOptions, root, sink, indent, fileType);
+    writeHeaders(languageOptions, root, sink, indent, fileType);
+    writeImports(languageOptions, root, sink, indent, fileType);
+
+    indent.writeln('$_commentPrefix Generated class from Pigeon.');
+
+    for (final Enum anEnum in root.enums) {
+      writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
+    }
+
+    indent.addln('');
+
     if (fileType == FileType.header) {
       generateCppHeader(languageOptions, root, sink, indent);
     } else {
@@ -90,7 +99,7 @@ class CppGenerator extends Generator<CppOptions> {
   }
 
   @override
-  void writeFileHeaders(CppOptions languageOptions, Root root, StringSink sink,
+  void writeHeaders(CppOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
     if (fileType == FileType.header) {
       writeCppHeaderHeader(languageOptions, root, sink, indent);
@@ -100,7 +109,7 @@ class CppGenerator extends Generator<CppOptions> {
   }
 
   @override
-  void writeFileImports(CppOptions languageOptions, Root root, StringSink sink,
+  void writeImports(CppOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
     if (fileType == FileType.header) {
       writeCppHeaderImports(languageOptions, root, sink, indent);
@@ -108,6 +117,14 @@ class CppGenerator extends Generator<CppOptions> {
       writeCppSourceImports(languageOptions, root, sink, indent);
     }
   }
+
+  @override
+  void writeEnum(CppOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Enum anEnum) {
+    if (fileType == FileType.header) {
+      writeCppHeaderEnum(languageOptions, root, sink, indent, anEnum);
+    }
+  }
 }
 
 String _getCodecSerializerName(Api api) => '${api.name}CodecSerializer';
@@ -1093,6 +1110,23 @@ void writeCppHeaderImports(
   indent.addln('');
 }
 
+/// Writes Cpp header enum to sink.
+void writeCppHeaderEnum(CppOptions options, Root root, StringSink sink,
+    Indent indent, Enum anEnum) {
+  indent.writeln('');
+  addDocumentationComments(
+      indent, anEnum.documentationComments, _docCommentSpec);
+  indent.write('enum class ${anEnum.name} ');
+  indent.scoped('{', '};', () {
+    enumerate(anEnum.members, (int index, final EnumMember member) {
+      addDocumentationComments(
+          indent, member.documentationComments, _docCommentSpec);
+      indent.writeln(
+          '${member.name} = $index${index == anEnum.members.length - 1 ? '' : ','}');
+    });
+  });
+}
+
 /// Generates the ".h" file for the AST represented by [root] to [sink] with the
 /// provided [options] and [headerFileName].
 void generateCppHeader(
@@ -1107,26 +1141,6 @@ void generateCppHeader(
     indent.writeln('class $testFixtureClass;');
   }
 
-  indent.addln('');
-  indent.writeln('$_commentPrefix Generated class from Pigeon.');
-
-  for (final Enum anEnum in root.enums) {
-    indent.writeln('');
-    addDocumentationComments(
-        indent, anEnum.documentationComments, _docCommentSpec);
-    indent.write('enum class ${anEnum.name} ');
-    indent.scoped('{', '};', () {
-      enumerate(anEnum.members, (int index, final EnumMember member) {
-        addDocumentationComments(
-            indent, member.documentationComments, _docCommentSpec);
-        indent.writeln(
-            '${member.name} = $index${index == anEnum.members.length - 1 ? '' : ','}');
-      });
-    });
-  }
-
-  indent.addln('');
-
   _writeErrorOr(indent, friends: root.apis.map((Api api) => api.name));
 
   for (final Class klass in root.classes) {
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 6d233121de6..08223d010a8 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -81,21 +81,55 @@ class DartGenerator extends Generator<DartOptions> {
       FileType fileType) {
     final Indent indent = Indent(sink);
 
-    writeFileHeaders(languageOptions, root, sink, indent, fileType);
-    writeFileImports(languageOptions, root, sink, indent, fileType);
+    writeHeaders(languageOptions, root, sink, indent, fileType);
+    writeImports(languageOptions, root, sink, indent, fileType);
+    for (final Enum anEnum in root.enums) {
+      writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
+    }
     generateDart(languageOptions, root, sink, indent);
   }
 
   @override
-  void writeFileHeaders(DartOptions languageOptions, Root root, StringSink sink,
+  void writeHeaders(DartOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
-    writeHeader(languageOptions, root, sink, indent);
+    if (languageOptions.copyrightHeader != null) {
+      addLines(indent, languageOptions.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('// $generatedCodeWarning');
+    indent.writeln('// $seeAlsoWarning');
+    indent.writeln(
+      '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import',
+    );
+    indent.addln('');
   }
 
   @override
-  void writeFileImports(DartOptions languageOptions, Root root, StringSink sink,
+  void writeImports(DartOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
-    writeImports(languageOptions, root, sink, indent);
+    indent.writeln("import 'dart:async';");
+    indent.writeln(
+      "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
+    );
+    indent.addln('');
+    indent.writeln(
+        "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;");
+    indent.writeln("import 'package:flutter/services.dart';");
+  }
+
+  @override
+  void writeEnum(DartOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Enum anEnum) {
+    indent.writeln('');
+    addDocumentationComments(
+        indent, anEnum.documentationComments, _docCommentSpec);
+    indent.write('enum ${anEnum.name} ');
+    indent.scoped('{', '}', () {
+      for (final EnumMember member in anEnum.members) {
+        addDocumentationComments(
+            indent, member.documentationComments, _docCommentSpec);
+        indent.writeln('${member.name},');
+      }
+    });
   }
 
   /// Generates Dart files for testing with specified [DartOptions]
@@ -516,31 +550,6 @@ String _addGenericTypesNullable(TypeDeclaration type) {
   return type.isNullable ? '$genericdType?' : genericdType;
 }
 
-/// Writes file header to sink.
-void writeHeader(DartOptions opt, Root root, StringSink sink, Indent indent) {
-  if (opt.copyrightHeader != null) {
-    addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
-  }
-  indent.writeln('// $generatedCodeWarning');
-  indent.writeln('// $seeAlsoWarning');
-  indent.writeln(
-    '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import',
-  );
-  indent.addln('');
-}
-
-/// Writes file imports to sink.
-void writeImports(DartOptions opt, Root root, StringSink sink, Indent indent) {
-  indent.writeln("import 'dart:async';");
-  indent.writeln(
-    "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
-  );
-  indent.addln('');
-  indent.writeln(
-      "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;");
-  indent.writeln("import 'package:flutter/services.dart';");
-}
-
 /// Generates Dart source code for the given AST represented by [root],
 /// outputting the code to [sink].
 void generateDart(DartOptions opt, Root root, StringSink sink, Indent indent) {
@@ -549,22 +558,6 @@ void generateDart(DartOptions opt, Root root, StringSink sink, Indent indent) {
   final List<String> customEnumNames =
       root.enums.map((Enum x) => x.name).toList();
 
-  void writeEnums() {
-    for (final Enum anEnum in root.enums) {
-      indent.writeln('');
-      addDocumentationComments(
-          indent, anEnum.documentationComments, _docCommentSpec);
-      indent.write('enum ${anEnum.name} ');
-      indent.scoped('{', '}', () {
-        for (final EnumMember member in anEnum.members) {
-          addDocumentationComments(
-              indent, member.documentationComments, _docCommentSpec);
-          indent.writeln('${member.name},');
-        }
-      });
-    }
-  }
-
   void writeDataClass(Class klass) {
     void writeConstructor() {
       indent.write(klass.name);
@@ -695,7 +688,6 @@ $resultAt != null
     }
   }
 
-  writeEnums();
   for (final Class klass in root.classes) {
     indent.writeln('');
     writeDataClass(klass);
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 86fa40fbbc5..c7fcd06d51a 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -23,8 +23,8 @@ abstract class Generator<T> {
     FileType fileType,
   );
 
-  /// Adds specified file headers.
-  void writeFileHeaders(
+  /// Adds specified headers to file.
+  void writeHeaders(
     T languageOptions,
     Root root,
     StringSink sink,
@@ -32,12 +32,22 @@ abstract class Generator<T> {
     FileType fileType,
   );
 
-  /// Adds specified imports.
-  void writeFileImports(
+  /// Adds specified imports to file.
+  void writeImports(
     T languageOptions,
     Root root,
     StringSink sink,
     Indent indent,
     FileType fileType,
   );
+
+  /// Writes single Enum to file.
+  void writeEnum(
+    T languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Enum anEnum,
+  );
 }
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 89ca7daba33..d488c3425ae 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -96,21 +96,94 @@ class JavaGenerator extends Generator<JavaOptions> {
       FileType fileType) {
     final Indent indent = Indent(sink);
 
-    writeFileHeaders(languageOptions, root, sink, indent, fileType);
-    writeFileImports(languageOptions, root, sink, indent, fileType);
-    generateJava(languageOptions, root, sink, indent);
+    writeHeaders(languageOptions, root, sink, indent, fileType);
+    writeImports(languageOptions, root, sink, indent, fileType);
+    writeMainClass(languageOptions, root, sink, indent, fileType);
   }
 
   @override
-  void writeFileHeaders(JavaOptions languageOptions, Root root, StringSink sink,
+  void writeHeaders(JavaOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
-    writeHeader(languageOptions, root, sink, indent);
+    if (languageOptions.copyrightHeader != null) {
+      addLines(indent, languageOptions.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('// $generatedCodeWarning');
+    indent.writeln('// $seeAlsoWarning');
+    indent.addln('');
   }
 
   @override
-  void writeFileImports(JavaOptions languageOptions, Root root, StringSink sink,
+  void writeImports(JavaOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
-    writeImports(languageOptions, root, sink, indent);
+    if (languageOptions.package != null) {
+      indent.writeln('package ${languageOptions.package};');
+    }
+    indent.writeln('import android.util.Log;');
+    indent.writeln('import androidx.annotation.NonNull;');
+    indent.writeln('import androidx.annotation.Nullable;');
+    indent.writeln('import io.flutter.plugin.common.BasicMessageChannel;');
+    indent.writeln('import io.flutter.plugin.common.BinaryMessenger;');
+    indent.writeln('import io.flutter.plugin.common.MessageCodec;');
+    indent.writeln('import io.flutter.plugin.common.StandardMessageCodec;');
+    indent.writeln('import java.io.ByteArrayOutputStream;');
+    indent.writeln('import java.nio.ByteBuffer;');
+    indent.writeln('import java.util.Arrays;');
+    indent.writeln('import java.util.ArrayList;');
+    indent.writeln('import java.util.Collections;');
+    indent.writeln('import java.util.List;');
+    indent.writeln('import java.util.Map;');
+    indent.writeln('import java.util.HashMap;');
+    indent.addln('');
+  }
+
+  @override
+  void writeEnum(JavaOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Enum anEnum) {
+    String camelToSnake(String camelCase) {
+      final RegExp regex = RegExp('([a-z])([A-Z]+)');
+      return camelCase
+          .replaceAllMapped(regex, (Match m) => '${m[1]}_${m[2]}')
+          .toUpperCase();
+    }
+
+    addDocumentationComments(
+        indent, anEnum.documentationComments, _docCommentSpec);
+
+    indent.write('public enum ${anEnum.name} ');
+    indent.scoped('{', '}', () {
+      enumerate(anEnum.members, (int index, final EnumMember member) {
+        addDocumentationComments(
+            indent, member.documentationComments, _docCommentSpec);
+        indent.writeln(
+            '${camelToSnake(member.name)}($index)${index == anEnum.members.length - 1 ? ';' : ','}');
+      });
+      indent.writeln('');
+      indent.writeln('private final int index;');
+      indent.write('private ${anEnum.name}(final int index) ');
+      indent.scoped('{', '}', () {
+        indent.writeln('this.index = index;');
+      });
+    });
+  }
+
+  /// Writes main class to sink. wraps enums, apis, and classes.
+  void writeMainClass(JavaOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType) {
+    indent.writeln(
+        '$_docCommentPrefix Generated class from Pigeon.$_docCommentSuffix');
+    indent.writeln(
+        '@SuppressWarnings({"unused", "unchecked", "CodeBlock2Expr", "RedundantSuppression"})');
+    if (languageOptions.useGeneratedAnnotation ?? false) {
+      indent.writeln('@javax.annotation.Generated("dev.flutter.pigeon")');
+    }
+    indent.write('public class ${languageOptions.className!} ');
+    indent.scoped('{', '}', () {
+      for (final Enum anEnum in root.enums) {
+        indent.writeln('');
+        writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
+      }
+      generateJava(languageOptions, root, sink, indent);
+    });
   }
 }
 
@@ -551,41 +624,6 @@ String _castObject(
   }
 }
 
-/// Writes file header to sink.
-void writeHeader(
-    JavaOptions options, Root root, StringSink sink, Indent indent) {
-  if (options.copyrightHeader != null) {
-    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-  }
-  indent.writeln('// $generatedCodeWarning');
-  indent.writeln('// $seeAlsoWarning');
-  indent.addln('');
-}
-
-/// Writes file imports to sink.
-void writeImports(
-    JavaOptions options, Root root, StringSink sink, Indent indent) {
-  if (options.package != null) {
-    indent.writeln('package ${options.package};');
-  }
-  indent.writeln('import android.util.Log;');
-  indent.writeln('import androidx.annotation.NonNull;');
-  indent.writeln('import androidx.annotation.Nullable;');
-  indent.writeln('import io.flutter.plugin.common.BasicMessageChannel;');
-  indent.writeln('import io.flutter.plugin.common.BinaryMessenger;');
-  indent.writeln('import io.flutter.plugin.common.MessageCodec;');
-  indent.writeln('import io.flutter.plugin.common.StandardMessageCodec;');
-  indent.writeln('import java.io.ByteArrayOutputStream;');
-  indent.writeln('import java.nio.ByteBuffer;');
-  indent.writeln('import java.util.Arrays;');
-  indent.writeln('import java.util.ArrayList;');
-  indent.writeln('import java.util.Collections;');
-  indent.writeln('import java.util.List;');
-  indent.writeln('import java.util.Map;');
-  indent.writeln('import java.util.HashMap;');
-  indent.addln('');
-}
-
 /// Generates the ".java" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateJava(
@@ -595,34 +633,6 @@ void generateJava(
   final Set<String> rootEnumNameSet =
       root.enums.map((Enum x) => x.name).toSet();
 
-  String camelToSnake(String camelCase) {
-    final RegExp regex = RegExp('([a-z])([A-Z]+)');
-    return camelCase
-        .replaceAllMapped(regex, (Match m) => '${m[1]}_${m[2]}')
-        .toUpperCase();
-  }
-
-  void writeEnum(Enum anEnum) {
-    addDocumentationComments(
-        indent, anEnum.documentationComments, _docCommentSpec);
-
-    indent.write('public enum ${anEnum.name} ');
-    indent.scoped('{', '}', () {
-      enumerate(anEnum.members, (int index, final EnumMember member) {
-        addDocumentationComments(
-            indent, member.documentationComments, _docCommentSpec);
-        indent.writeln(
-            '${camelToSnake(member.name)}($index)${index == anEnum.members.length - 1 ? ';' : ','}');
-      });
-      indent.writeln('');
-      indent.writeln('private final int index;');
-      indent.write('private ${anEnum.name}(final int index) ');
-      indent.scoped('{', '}', () {
-        indent.writeln('this.index = index;');
-      });
-    });
-  }
-
   void writeDataClass(Class klass) {
     void writeField(NamedType field) {
       final HostDatatype hostDatatype = getFieldHostDatatype(
@@ -790,40 +800,25 @@ void generateJava(
 }''');
   }
 
-  indent.writeln(
-      '$_docCommentPrefix Generated class from Pigeon.$_docCommentSuffix');
-  indent.writeln(
-      '@SuppressWarnings({"unused", "unchecked", "CodeBlock2Expr", "RedundantSuppression"})');
-  if (options.useGeneratedAnnotation ?? false) {
-    indent.writeln('@javax.annotation.Generated("dev.flutter.pigeon")');
+  for (final Class klass in root.classes) {
+    indent.addln('');
+    writeDataClass(klass);
   }
-  indent.write('public class ${options.className!} ');
-  indent.scoped('{', '}', () {
-    for (final Enum anEnum in root.enums) {
-      indent.writeln('');
-      writeEnum(anEnum);
-    }
 
-    for (final Class klass in root.classes) {
-      indent.addln('');
-      writeDataClass(klass);
-    }
+  if (root.apis.any((Api api) =>
+      api.location == ApiLocation.host &&
+      api.methods.any((Method it) => it.isAsynchronous))) {
+    indent.addln('');
+    writeResultInterface();
+  }
 
-    if (root.apis.any((Api api) =>
-        api.location == ApiLocation.host &&
-        api.methods.any((Method it) => it.isAsynchronous))) {
+  for (final Api api in root.apis) {
+    if (getCodecClasses(api, root).isNotEmpty) {
+      _writeCodec(indent, api, root);
       indent.addln('');
-      writeResultInterface();
-    }
-
-    for (final Api api in root.apis) {
-      if (getCodecClasses(api, root).isNotEmpty) {
-        _writeCodec(indent, api, root);
-        indent.addln('');
-      }
-      writeApi(api);
     }
+    writeApi(api);
+  }
 
-    writeWrapError();
-  });
+  writeWrapError();
 }
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index ed4af8e4413..71ca87bb00f 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -76,21 +76,71 @@ class KotlinGenerator extends Generator<KotlinOptions> {
       FileType fileType) {
     final Indent indent = Indent(sink);
 
-    writeFileHeaders(languageOptions, root, sink, indent, fileType);
-    writeFileImports(languageOptions, root, sink, indent, fileType);
+    writeHeaders(languageOptions, root, sink, indent, fileType);
+    writeImports(languageOptions, root, sink, indent, fileType);
+    indent.writeln('/** Generated class from Pigeon. */');
+    for (final Enum anEnum in root.enums) {
+      indent.writeln('');
+      writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
+    }
     generateKotlin(languageOptions, root, sink, indent);
   }
 
   @override
-  void writeFileHeaders(KotlinOptions languageOptions, Root root,
-      StringSink sink, Indent indent, FileType fileType) {
-    writeHeader(languageOptions, root, sink, indent);
+  void writeHeaders(KotlinOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType) {
+    if (languageOptions.copyrightHeader != null) {
+      addLines(indent, languageOptions.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('// $generatedCodeWarning');
+    indent.writeln('// $seeAlsoWarning');
+    indent.addln('');
   }
 
   @override
-  void writeFileImports(KotlinOptions languageOptions, Root root,
-      StringSink sink, Indent indent, FileType fileType) {
-    writeImports(languageOptions, root, sink, indent);
+  void writeImports(KotlinOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType) {
+    if (languageOptions.package != null) {
+      indent.writeln('package ${languageOptions.package}');
+    }
+    indent.addln('');
+    indent.writeln('import android.util.Log');
+    indent.writeln('import io.flutter.plugin.common.BasicMessageChannel');
+    indent.writeln('import io.flutter.plugin.common.BinaryMessenger');
+    indent.writeln('import io.flutter.plugin.common.MessageCodec');
+    indent.writeln('import io.flutter.plugin.common.StandardMessageCodec');
+    indent.writeln('import java.io.ByteArrayOutputStream');
+    indent.writeln('import java.nio.ByteBuffer');
+    indent.addln('');
+  }
+
+  @override
+  void writeEnum(KotlinOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Enum anEnum) {
+    addDocumentationComments(
+        indent, anEnum.documentationComments, _docCommentSpec);
+    indent.write('enum class ${anEnum.name}(val raw: Int) ');
+    indent.scoped('{', '}', () {
+      enumerate(anEnum.members, (int index, final EnumMember member) {
+        addDocumentationComments(
+            indent, member.documentationComments, _docCommentSpec);
+        indent.write('${member.name.toUpperCase()}($index)');
+        if (index != anEnum.members.length - 1) {
+          indent.addln(',');
+        } else {
+          indent.addln(';');
+        }
+      });
+
+      indent.writeln('');
+      indent.write('companion object ');
+      indent.scoped('{', '}', () {
+        indent.write('fun ofRaw(raw: Int): ${anEnum.name}? ');
+        indent.scoped('{', '}', () {
+          indent.writeln('return values().firstOrNull { it.raw == raw }');
+        });
+      });
+    });
   }
 }
 
@@ -464,34 +514,6 @@ String _nullsafeKotlinTypeForDartType(TypeDeclaration type) {
   return '${_kotlinTypeForDartType(type)}$nullSafe';
 }
 
-/// Writes file header to sink.
-void writeHeader(
-    KotlinOptions options, Root root, StringSink sink, Indent indent) {
-  if (options.copyrightHeader != null) {
-    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-  }
-  indent.writeln('// $generatedCodeWarning');
-  indent.writeln('// $seeAlsoWarning');
-  indent.addln('');
-}
-
-/// Writes file imports to sink.
-void writeImports(
-    KotlinOptions options, Root root, StringSink sink, Indent indent) {
-  if (options.package != null) {
-    indent.writeln('package ${options.package}');
-  }
-  indent.addln('');
-  indent.writeln('import android.util.Log');
-  indent.writeln('import io.flutter.plugin.common.BasicMessageChannel');
-  indent.writeln('import io.flutter.plugin.common.BinaryMessenger');
-  indent.writeln('import io.flutter.plugin.common.MessageCodec');
-  indent.writeln('import io.flutter.plugin.common.StandardMessageCodec');
-  indent.writeln('import java.io.ByteArrayOutputStream');
-  indent.writeln('import java.nio.ByteBuffer');
-  indent.addln('');
-}
-
 /// Generates the ".kotlin" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateKotlin(
@@ -506,33 +528,6 @@ void generateKotlin(
         (TypeDeclaration x) => _kotlinTypeForBuiltinDartType(x));
   }
 
-  void writeEnum(Enum anEnum) {
-    addDocumentationComments(
-        indent, anEnum.documentationComments, _docCommentSpec);
-    indent.write('enum class ${anEnum.name}(val raw: Int) ');
-    indent.scoped('{', '}', () {
-      enumerate(anEnum.members, (int index, final EnumMember member) {
-        addDocumentationComments(
-            indent, member.documentationComments, _docCommentSpec);
-        indent.write('${member.name.toUpperCase()}($index)');
-        if (index != anEnum.members.length - 1) {
-          indent.addln(',');
-        } else {
-          indent.addln(';');
-        }
-      });
-
-      indent.writeln('');
-      indent.write('companion object ');
-      indent.scoped('{', '}', () {
-        indent.write('fun ofRaw(raw: Int): ${anEnum.name}? ');
-        indent.scoped('{', '}', () {
-          indent.writeln('return values().firstOrNull { it.raw == raw }');
-        });
-      });
-    });
-  }
-
   void writeDataClass(Class klass) {
     void writeField(NamedType field) {
       addDocumentationComments(
@@ -690,12 +685,6 @@ void generateKotlin(
     });
   }
 
-  indent.writeln('/** Generated class from Pigeon. */');
-  for (final Enum anEnum in root.enums) {
-    indent.writeln('');
-    writeEnum(anEnum);
-  }
-
   for (final Class klass in root.classes) {
     indent.addln('');
     writeDataClass(klass);
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 38311dc614d..9f362fa4aef 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -58,21 +58,57 @@ class SwiftGenerator extends Generator<SwiftOptions> {
   void generate(SwiftOptions languageOptions, Root root, StringSink sink,
       FileType fileType) {
     final Indent indent = Indent(sink);
-    writeFileHeaders(languageOptions, root, sink, indent, fileType);
-    writeFileImports(languageOptions, root, sink, indent, fileType);
+    writeHeaders(languageOptions, root, sink, indent, fileType);
+    writeImports(languageOptions, root, sink, indent, fileType);
+    indent.writeln('$_docCommentPrefix Generated class from Pigeon.');
+    for (final Enum anEnum in root.enums) {
+      indent.writeln('');
+      writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
+    }
     generateSwift(languageOptions, root, sink, indent);
   }
 
   @override
-  void writeFileHeaders(SwiftOptions languageOptions, Root root,
-      StringSink sink, Indent indent, FileType fileType) {
-    writeHeader(languageOptions, root, sink, indent);
+  void writeHeaders(SwiftOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType) {
+    if (languageOptions.copyrightHeader != null) {
+      addLines(indent, languageOptions.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('// $generatedCodeWarning');
+    indent.writeln('// $seeAlsoWarning');
+    indent.addln('');
+  }
+
+  @override
+  void writeImports(SwiftOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType) {
+    indent.writeln('import Foundation');
+    indent.format('''
+#if os(iOS)
+import Flutter
+#elseif os(macOS)
+import FlutterMacOS
+#else
+#error("Unsupported platform.")
+#endif
+''');
+    indent.writeln('');
   }
 
   @override
-  void writeFileImports(SwiftOptions languageOptions, Root root,
-      StringSink sink, Indent indent, FileType fileType) {
-    writeImports(languageOptions, root, sink, indent);
+  void writeEnum(SwiftOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Enum anEnum) {
+    addDocumentationComments(
+        indent, anEnum.documentationComments, _docCommentSpec);
+
+    indent.write('enum ${anEnum.name}: Int ');
+    indent.scoped('{', '}', () {
+      enumerate(anEnum.members, (int index, final EnumMember member) {
+        addDocumentationComments(
+            indent, member.documentationComments, _docCommentSpec);
+        indent.writeln('case ${_camelCase(member.name)} = $index');
+      });
+    });
   }
 }
 
@@ -458,32 +494,9 @@ String _nullsafeSwiftTypeForDartType(TypeDeclaration type) {
   return '${_swiftTypeForDartType(type)}$nullSafe';
 }
 
-/// Writes file header to sink.
-void writeHeader(
-    SwiftOptions options, Root root, StringSink sink, Indent indent) {
-  if (options.copyrightHeader != null) {
-    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-  }
-  indent.writeln('// $generatedCodeWarning');
-  indent.writeln('// $seeAlsoWarning');
-  indent.addln('');
-}
-
 /// Writes file header to sink.
 void writeImports(
-    SwiftOptions options, Root root, StringSink sink, Indent indent) {
-  indent.writeln('import Foundation');
-  indent.format('''
-#if os(iOS)
-import Flutter
-#elseif os(macOS)
-import FlutterMacOS
-#else
-#error("Unsupported platform.")
-#endif
-''');
-  indent.writeln('');
-}
+    SwiftOptions options, Root root, StringSink sink, Indent indent) {}
 
 /// Generates the ".swift" file for the AST represented by [root] to [sink] with the
 /// provided [options].
@@ -499,20 +512,6 @@ void generateSwift(
         (TypeDeclaration x) => _swiftTypeForBuiltinDartType(x));
   }
 
-  void writeEnum(Enum anEnum) {
-    addDocumentationComments(
-        indent, anEnum.documentationComments, _docCommentSpec);
-
-    indent.write('enum ${anEnum.name}: Int ');
-    indent.scoped('{', '}', () {
-      enumerate(anEnum.members, (int index, final EnumMember member) {
-        addDocumentationComments(
-            indent, member.documentationComments, _docCommentSpec);
-        indent.writeln('case ${_camelCase(member.name)} = $index');
-      });
-    });
-  }
-
   void writeDataClass(Class klass) {
     void writeField(NamedType field) {
       addDocumentationComments(
@@ -654,12 +653,6 @@ void generateSwift(
     });
   }
 
-  indent.writeln('$_docCommentPrefix Generated class from Pigeon.');
-  for (final Enum anEnum in root.enums) {
-    indent.writeln('');
-    writeEnum(anEnum);
-  }
-
   for (final Class klass in root.classes) {
     indent.addln('');
     writeDataClass(klass);

From 29decb9c934378483137aacc74a0189ee4515f58 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 30 Dec 2022 13:12:33 -0800
Subject: [PATCH 42/87] nits

---
 packages/pigeon/lib/cpp_generator.dart  |  2 +-
 packages/pigeon/lib/dart_generator.dart |  2 +-
 packages/pigeon/lib/pigeon_lib.dart     | 23 ++++++++++++-----------
 3 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index fbb90b39483..d5cce4c5744 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -70,7 +70,7 @@ class CppOptions {
   }
 }
 
-/// Class that manages all Cpp header code generation.
+/// Class that manages all Cpp code generation.
 class CppGenerator extends Generator<CppOptions> {
   /// Instantiates a Cpp Generator.
   CppGenerator();
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index f450d2ddeaa..5a38061ec8e 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -34,7 +34,7 @@ class DartOptions {
   /// A copyright header that will get prepended to generated code.
   final Iterable<String>? copyrightHeader;
 
-  /// Path to output generated Dart file for tests.
+  /// Path to output generated Dart file.
   String? sourceOutPath;
 
   /// Path to output generated Test file for tests.
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 4e949ec3dd3..d54f64d3bf0 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -361,27 +361,28 @@ abstract class GeneratorAdapter {
   /// Constructor for [GeneratorAdapter]
   GeneratorAdapter(this.fileTypeList);
 
-  /// A list of [FileType]
-  /// Used to tell the generator method which type of file to create.
+  /// A list of file types the generator should create.
   List<FileType> fileTypeList;
 
-  /// Returns an [IOSink] instance to be written to if the [GeneratorAdapter] should
-  /// generate.  If it returns `null`, the [GeneratorAdapter] will be skipped.
+  /// Returns an [IOSink] instance to be written to
+  /// if the [GeneratorAdapter] should generate.
+  ///
+  /// If it returns `null`, the [GeneratorAdapter] will be skipped.
   IOSink? shouldGenerate(PigeonOptions options, FileType fileType);
 
-  /// Write the generated code described in [root] to [sink] using the
-  /// [options].
+  /// Write the generated code described in [root] to [sink] using the [options].
   void generate(
       StringSink sink, PigeonOptions options, Root root, FileType fileType);
 
-  /// Generates errors that would only be appropriate for this [GeneratorAdapter]. For
-  /// example, maybe a certain feature isn't implemented in a [GeneratorAdapter] yet.
+  /// Generates errors that would only be appropriate for this [GeneratorAdapter].
+  ///
+  /// For example, if a certain feature isn't implemented in a [GeneratorAdapter] yet.
   List<Error> validate(PigeonOptions options, Root root);
 }
 
 DartOptions _dartOptionsWithCopyrightHeader(
     DartOptions? dartOptions, String? copyrightHeader,
-    [String? dartOutPath, String? testOutPath]) {
+    {String? dartOutPath, String? testOutPath}) {
   dartOptions = dartOptions ?? DartOptions();
   return dartOptions.merge(DartOptions(
       sourceOutPath: dartOutPath,
@@ -451,8 +452,8 @@ class DartTestGeneratorAdapter implements GeneratorAdapter {
     final DartOptions dartOptionsWithHeader = _dartOptionsWithCopyrightHeader(
       options.dartOptions,
       options.copyrightHeader,
-      options.dartOut,
-      options.dartTestOut,
+      dartOutPath: options.dartOut,
+      testOutPath: options.dartTestOut,
     );
     final DartGenerator testGenerator = DartGenerator();
     testGenerator.generateTest(

From b7abbe402c2c0a0588ec65311aab65fd9eecd4c0 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Mon, 2 Jan 2023 23:33:08 -0800
Subject: [PATCH 43/87] assert

---
 packages/pigeon/lib/dart_generator.dart   | 5 +++--
 packages/pigeon/lib/java_generator.dart   | 5 +++--
 packages/pigeon/lib/kotlin_generator.dart | 5 +++--
 packages/pigeon/lib/swift_generator.dart  | 5 +++--
 4 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 5a38061ec8e..852b3cfa08c 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -77,8 +77,9 @@ class DartGenerator extends Generator<DartOptions> {
 
   /// Generates Dart files with specified [DartOptions]
   @override
-  void generate(
-      DartOptions languageOptions, Root root, StringSink sink, FileType _) {
+  void generate(DartOptions languageOptions, Root root, StringSink sink,
+      FileType fileType) {
+    assert(fileType == FileType.source);
     generateDart(languageOptions, root, sink);
   }
 
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index e7b2ebcaf18..d62612db23d 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -92,8 +92,9 @@ class JavaGenerator extends Generator<JavaOptions> {
 
   /// Generates Java files with specified [JavaOptions]
   @override
-  void generate(
-      JavaOptions languageOptions, Root root, StringSink sink, FileType _) {
+  void generate(JavaOptions languageOptions, Root root, StringSink sink,
+      FileType fileType) {
+    assert(fileType == FileType.source);
     generateJava(languageOptions, root, sink);
   }
 }
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index a570da4674b..07855c226b1 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -72,8 +72,9 @@ class KotlinGenerator extends Generator<KotlinOptions> {
 
   /// Generates Kotlin files with specified [KotlinOptions]
   @override
-  void generate(
-      KotlinOptions languageOptions, Root root, StringSink sink, FileType _) {
+  void generate(KotlinOptions languageOptions, Root root, StringSink sink,
+      FileType fileType) {
+    assert(fileType == FileType.source);
     generateKotlin(languageOptions, root, sink);
   }
 }
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 45c15341116..6a278344d00 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -55,8 +55,9 @@ class SwiftGenerator extends Generator<SwiftOptions> {
 
   /// Generates Swift files with specified [SwiftOptions]
   @override
-  void generate(
-      SwiftOptions languageOptions, Root root, StringSink sink, FileType _) {
+  void generate(SwiftOptions languageOptions, Root root, StringSink sink,
+      FileType fileType) {
+    assert(fileType == FileType.source);
     generateSwift(languageOptions, root, sink);
   }
 }

From 2508a81b2185912c157c49fa0ec9d94a367a1ad1 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 3 Jan 2023 00:33:23 -0800
Subject: [PATCH 44/87] objc enum

---
 packages/pigeon/lib/objc_generator.dart | 69 ++++++++++++++-----------
 1 file changed, 38 insertions(+), 31 deletions(-)

diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index b1f2cff6fac..bd229cf1fa1 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -75,9 +75,16 @@ class ObjcGenerator extends Generator<ObjcOptions> {
       FileType fileType) {
     final Indent indent = Indent(sink);
 
-    writeFileHeaders(languageOptions, root, sink, indent, fileType);
-    writeFileImports(languageOptions, root, sink, indent, fileType);
+    writeHeaders(languageOptions, root, sink, indent, fileType);
+    writeImports(languageOptions, root, sink, indent, fileType);
     if (fileType == FileType.header) {
+      indent.writeln('NS_ASSUME_NONNULL_BEGIN');
+
+      for (final Enum anEnum in root.enums) {
+        indent.writeln('');
+        writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
+      }
+      indent.writeln('');
       generateObjcHeader(languageOptions, root, sink, indent);
     } else {
       generateObjcSource(languageOptions, root, sink, indent);
@@ -85,7 +92,7 @@ class ObjcGenerator extends Generator<ObjcOptions> {
   }
 
   @override
-  void writeFileHeaders(ObjcOptions languageOptions, Root root, StringSink sink,
+  void writeHeaders(ObjcOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
     if (fileType == FileType.header) {
       writeObjcHeaderHeader(languageOptions, root, sink, indent);
@@ -95,7 +102,7 @@ class ObjcGenerator extends Generator<ObjcOptions> {
   }
 
   @override
-  void writeFileImports(ObjcOptions languageOptions, Root root, StringSink sink,
+  void writeImports(ObjcOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
     if (fileType == FileType.header) {
       writeObjcHeaderImports(languageOptions, root, sink, indent);
@@ -103,6 +110,14 @@ class ObjcGenerator extends Generator<ObjcOptions> {
       writeObjcSourceImports(languageOptions, root, sink, indent);
     }
   }
+
+  @override
+  void writeEnum(ObjcOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Enum anEnum) {
+    if (fileType == FileType.header) {
+      writeObjcHeaderEnum(languageOptions, root, sink, indent, anEnum);
+    }
+  }
 }
 
 /// Calculates the ObjC class name, possibly prefixed.
@@ -596,37 +611,29 @@ void writeObjcHeaderImports(
   indent.addln('');
 }
 
+/// Writes single Objc header enum.
+void writeObjcHeaderEnum(ObjcOptions options, Root root, StringSink sink,
+    Indent indent, Enum anEnum) {
+  final String enumName = _className(options.prefix, anEnum.name);
+  addDocumentationComments(
+      indent, anEnum.documentationComments, _docCommentSpec);
+
+  indent.write('typedef NS_ENUM(NSUInteger, $enumName) ');
+  indent.scoped('{', '};', () {
+    enumerate(anEnum.members, (int index, final EnumMember member) {
+      addDocumentationComments(
+          indent, member.documentationComments, _docCommentSpec);
+      // Capitalized first letter to ensure Swift compatibility
+      indent.writeln(
+          '$enumName${member.name[0].toUpperCase()}${member.name.substring(1)} = $index,');
+    });
+  });
+}
+
 /// Generates the ".h" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateObjcHeader(
     ObjcOptions options, Root root, StringSink sink, Indent indent) {
-  void writeEnum(Enum anEnum) {
-    final String enumName = _className(options.prefix, anEnum.name);
-    addDocumentationComments(
-        indent, anEnum.documentationComments, _docCommentSpec);
-
-    indent.write('typedef NS_ENUM(NSUInteger, $enumName) ');
-    indent.scoped('{', '};', () {
-      enumerate(anEnum.members, (int index, final EnumMember member) {
-        addDocumentationComments(
-            indent, member.documentationComments, _docCommentSpec);
-        // Capitalized first letter to ensure Swift compatibility
-        indent.writeln(
-            '$enumName${member.name[0].toUpperCase()}${member.name.substring(1)} = $index,');
-      });
-    });
-  }
-
-  indent.writeln('');
-
-  indent.writeln('NS_ASSUME_NONNULL_BEGIN');
-
-  for (final Enum anEnum in root.enums) {
-    indent.writeln('');
-    writeEnum(anEnum);
-  }
-  indent.writeln('');
-
   for (final Class klass in root.classes) {
     indent.writeln('@class ${_className(options.prefix, klass.name)};');
   }

From e4ac916e28252ca86f5255d6daa8bfd856bf5488 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 3 Jan 2023 01:50:47 -0800
Subject: [PATCH 45/87] fix code order issues

---
 packages/pigeon/lib/cpp_generator.dart | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 2cb1cc03c73..da3ba128307 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -83,8 +83,6 @@ class CppGenerator extends Generator<CppOptions> {
     writeHeaders(languageOptions, root, sink, indent, fileType);
     writeImports(languageOptions, root, sink, indent, fileType);
 
-    indent.writeln('$_commentPrefix Generated class from Pigeon.');
-
     for (final Enum anEnum in root.enums) {
       writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
     }
@@ -1108,6 +1106,13 @@ void writeCppHeaderImports(
     indent.writeln('namespace ${options.namespace} {');
   }
   indent.addln('');
+  if (options.namespace?.endsWith('_pigeontest') ?? false) {
+    final String testFixtureClass =
+        '${_pascalCaseFromSnakeCase(options.namespace!.replaceAll('_pigeontest', ''))}Test';
+    indent.writeln('class $testFixtureClass;');
+  }
+  indent.addln('');
+  indent.writeln('$_commentPrefix Generated class from Pigeon.');
 }
 
 /// Writes Cpp header enum to sink.
@@ -1138,7 +1143,6 @@ void generateCppHeader(
   if (options.namespace?.endsWith('_pigeontest') ?? false) {
     testFixtureClass =
         '${_pascalCaseFromSnakeCase(options.namespace!.replaceAll('_pigeontest', ''))}Test';
-    indent.writeln('class $testFixtureClass;');
   }
 
   _writeErrorOr(indent, friends: root.apis.map((Api api) => api.name));

From f1a4924144cd13b7644d3b086d0437b80048ad04 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 3 Jan 2023 23:18:35 -0800
Subject: [PATCH 46/87] add writeDataClass method

---
 packages/pigeon/lib/dart_generator.dart | 316 +++++++++++++-----------
 packages/pigeon/lib/generator.dart      |  50 +++-
 2 files changed, 218 insertions(+), 148 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index c3f0e9e9250..f6ec330b7d7 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -84,9 +84,16 @@ class DartGenerator extends Generator<DartOptions> {
 
     writeHeaders(languageOptions, root, sink, indent, fileType);
     writeImports(languageOptions, root, sink, indent, fileType);
+
     for (final Enum anEnum in root.enums) {
       writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
     }
+
+    for (final Class klass in root.classes) {
+      indent.writeln('');
+      writeDataClass(languageOptions, root, sink, indent, fileType, klass);
+    }
+
     generateDart(languageOptions, root, sink, indent);
   }
 
@@ -133,24 +140,174 @@ class DartGenerator extends Generator<DartOptions> {
     });
   }
 
-  /// Generates Dart files for testing with specified [DartOptions]
-  void generateTest(DartOptions languageOptions, Root root, StringSink sink) {
-    final Indent indent = Indent(sink);
-    final String sourceOutPath = languageOptions.sourceOutPath ?? '';
-    final String testOutPath = languageOptions.testOutPath ?? '';
-    writeTestHeader(languageOptions, root, sink, indent);
-    writeTestImports(languageOptions, root, sink, indent);
-    generateTestDart(
-      languageOptions,
-      root,
-      sink,
-      indent,
-      sourceOutPath: sourceOutPath,
-      testOutPath: testOutPath,
+  @override
+  void writeDataClass(DartOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Class klass) {
+    final List<String> customClassNames =
+        root.classes.map((Class x) => x.name).toList();
+    final List<String> customEnumNames =
+        root.enums.map((Enum x) => x.name).toList();
+    void writeConstructor() {
+      indent.write(klass.name);
+      indent.scoped('({', '});', () {
+        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+          final String required = field.type.isNullable ? '' : 'required ';
+          indent.writeln('${required}this.${field.name},');
+        }
+      });
+    }
+
+    addDocumentationComments(
+        indent, klass.documentationComments, _docCommentSpec);
+
+    indent.write('class ${klass.name} ');
+    indent.scoped('{', '}', () {
+      writeConstructor();
+      indent.addln('');
+      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+        addDocumentationComments(
+            indent, field.documentationComments, _docCommentSpec);
+
+        final String datatype = _addGenericTypesNullable(field.type);
+        indent.writeln('$datatype ${field.name};');
+        indent.writeln('');
+      }
+      writeEncode(languageOptions, root, sink, indent, fileType, klass,
+          customClassNames, customEnumNames);
+      indent.writeln('');
+      writeDecode(languageOptions, root, sink, indent, fileType, klass,
+          customClassNames, customEnumNames);
+    });
+  }
+
+  @override
+  void writeEncode(
+    DartOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    List<String> customClassNames,
+    List<String> customEnumNames,
+  ) {
+    indent.write('Object encode() ');
+    indent.scoped('{', '}', () {
+      indent.write(
+        'return <Object?>',
+      );
+      indent.scoped('[', '];', () {
+        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+          final String conditional = field.type.isNullable ? '?' : '';
+          if (customClassNames.contains(field.type.baseName)) {
+            indent.writeln(
+              '${field.name}$conditional.encode(),',
+            );
+          } else if (customEnumNames.contains(field.type.baseName)) {
+            indent.writeln(
+              '${field.name}$conditional.index,',
+            );
+          } else {
+            indent.writeln('${field.name},');
+          }
+        }
+      });
+    });
+  }
+
+  @override
+  void writeDecode(
+    DartOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    List<String> customClassNames,
+    List<String> customEnumNames,
+  ) {
+    void writeValueDecode(NamedType field, int index) {
+      final String resultAt = 'result[$index]';
+      if (customClassNames.contains(field.type.baseName)) {
+        final String nonNullValue =
+            '${field.type.baseName}.decode($resultAt! as List<Object?>)';
+        indent.format(
+            field.type.isNullable
+                ? '''
+$resultAt != null
+\t\t? $nonNullValue
+\t\t: null'''
+                : nonNullValue,
+            leadingSpace: false,
+            trailingNewline: false);
+      } else if (customEnumNames.contains(field.type.baseName)) {
+        final String nonNullValue =
+            '${field.type.baseName}.values[$resultAt! as int]';
+        indent.format(
+            field.type.isNullable
+                ? '''
+$resultAt != null
+\t\t? $nonNullValue
+\t\t: null'''
+                : nonNullValue,
+            leadingSpace: false,
+            trailingNewline: false);
+      } else if (field.type.typeArguments.isNotEmpty) {
+        final String genericType = _makeGenericTypeArguments(field.type);
+        final String castCall = _makeGenericCastCall(field.type);
+        final String castCallPrefix = field.type.isNullable ? '?' : '!';
+        indent.add(
+          '($resultAt as $genericType?)$castCallPrefix$castCall',
+        );
+      } else {
+        final String genericdType = _addGenericTypesNullable(field.type);
+        if (field.type.isNullable) {
+          indent.add(
+            '$resultAt as $genericdType',
+          );
+        } else {
+          indent.add(
+            '$resultAt! as $genericdType',
+          );
+        }
+      }
+    }
+
+    indent.write(
+      'static ${klass.name} decode(Object result) ',
     );
+    indent.scoped('{', '}', () {
+      indent.writeln('result as List<Object?>;');
+      indent.write('return ${klass.name}');
+      indent.scoped('(', ');', () {
+        enumerate(getFieldsInSerializationOrder(klass),
+            (int index, final NamedType field) {
+          indent.write('${field.name}: ');
+          writeValueDecode(field, index);
+          indent.addln(',');
+        });
+      });
+    });
   }
 }
 
+/// Generates Dart files for testing with specified [DartOptions]
+void generateTest(DartOptions languageOptions, Root root, StringSink sink) {
+  final Indent indent = Indent(sink);
+  final String sourceOutPath = languageOptions.sourceOutPath ?? '';
+  final String testOutPath = languageOptions.testOutPath ?? '';
+  writeTestHeader(languageOptions, root, sink, indent);
+  writeTestImports(languageOptions, root, sink, indent);
+  generateTestDart(
+    languageOptions,
+    root,
+    sink,
+    indent,
+    sourceOutPath: sourceOutPath,
+    testOutPath: testOutPath,
+  );
+}
+
 String _escapeForDartSingleQuotedString(String raw) {
   return raw
       .replaceAll(r'\', r'\\')
@@ -554,133 +711,6 @@ String _addGenericTypesNullable(TypeDeclaration type) {
 /// Generates Dart source code for the given AST represented by [root],
 /// outputting the code to [sink].
 void generateDart(DartOptions opt, Root root, StringSink sink, Indent indent) {
-  final List<String> customClassNames =
-      root.classes.map((Class x) => x.name).toList();
-  final List<String> customEnumNames =
-      root.enums.map((Enum x) => x.name).toList();
-
-  void writeDataClass(Class klass) {
-    void writeConstructor() {
-      indent.write(klass.name);
-      indent.scoped('({', '});', () {
-        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-          final String required = field.type.isNullable ? '' : 'required ';
-          indent.writeln('${required}this.${field.name},');
-        }
-      });
-    }
-
-    void writeEncode() {
-      indent.write('Object encode() ');
-      indent.scoped('{', '}', () {
-        indent.write(
-          'return <Object?>',
-        );
-        indent.scoped('[', '];', () {
-          for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-            final String conditional = field.type.isNullable ? '?' : '';
-            if (customClassNames.contains(field.type.baseName)) {
-              indent.writeln(
-                '${field.name}$conditional.encode(),',
-              );
-            } else if (customEnumNames.contains(field.type.baseName)) {
-              indent.writeln(
-                '${field.name}$conditional.index,',
-              );
-            } else {
-              indent.writeln('${field.name},');
-            }
-          }
-        });
-      });
-    }
-
-    void writeDecode() {
-      void writeValueDecode(NamedType field, int index) {
-        final String resultAt = 'result[$index]';
-        if (customClassNames.contains(field.type.baseName)) {
-          final String nonNullValue =
-              '${field.type.baseName}.decode($resultAt! as List<Object?>)';
-          indent.format(
-              field.type.isNullable
-                  ? '''
-$resultAt != null
-\t\t? $nonNullValue
-\t\t: null'''
-                  : nonNullValue,
-              leadingSpace: false,
-              trailingNewline: false);
-        } else if (customEnumNames.contains(field.type.baseName)) {
-          final String nonNullValue =
-              '${field.type.baseName}.values[$resultAt! as int]';
-          indent.format(
-              field.type.isNullable
-                  ? '''
-$resultAt != null
-\t\t? $nonNullValue
-\t\t: null'''
-                  : nonNullValue,
-              leadingSpace: false,
-              trailingNewline: false);
-        } else if (field.type.typeArguments.isNotEmpty) {
-          final String genericType = _makeGenericTypeArguments(field.type);
-          final String castCall = _makeGenericCastCall(field.type);
-          final String castCallPrefix = field.type.isNullable ? '?' : '!';
-          indent.add(
-            '($resultAt as $genericType?)$castCallPrefix$castCall',
-          );
-        } else {
-          final String genericdType = _addGenericTypesNullable(field.type);
-          if (field.type.isNullable) {
-            indent.add(
-              '$resultAt as $genericdType',
-            );
-          } else {
-            indent.add(
-              '$resultAt! as $genericdType',
-            );
-          }
-        }
-      }
-
-      indent.write(
-        'static ${klass.name} decode(Object result) ',
-      );
-      indent.scoped('{', '}', () {
-        indent.writeln('result as List<Object?>;');
-        indent.write('return ${klass.name}');
-        indent.scoped('(', ');', () {
-          enumerate(getFieldsInSerializationOrder(klass),
-              (int index, final NamedType field) {
-            indent.write('${field.name}: ');
-            writeValueDecode(field, index);
-            indent.addln(',');
-          });
-        });
-      });
-    }
-
-    addDocumentationComments(
-        indent, klass.documentationComments, _docCommentSpec);
-
-    indent.write('class ${klass.name} ');
-    indent.scoped('{', '}', () {
-      writeConstructor();
-      indent.addln('');
-      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-        addDocumentationComments(
-            indent, field.documentationComments, _docCommentSpec);
-
-        final String datatype = _addGenericTypesNullable(field.type);
-        indent.writeln('$datatype ${field.name};');
-        indent.writeln('');
-      }
-      writeEncode();
-      indent.writeln('');
-      writeDecode();
-    });
-  }
-
   void writeApi(Api api) {
     if (api.location == ApiLocation.host) {
       _writeHostApi(opt, indent, api, root);
@@ -689,10 +719,6 @@ $resultAt != null
     }
   }
 
-  for (final Class klass in root.classes) {
-    indent.writeln('');
-    writeDataClass(klass);
-  }
   for (final Api api in root.apis) {
     indent.writeln('');
     writeApi(api);
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index c7fcd06d51a..d64fd67b92a 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -9,13 +9,15 @@ import 'generator_tools.dart';
 ///
 /// This provides the structure that is common across generators for different languages.
 abstract class Generator<T> {
-  /// Generates files for specified language with specified [languageOptions]
+  /// Generates files for the specified language with specified [languageOptions]
   ///
   /// This method, when overridden, should follow a generic structure that is currently:
   /// 1. Create Indent
   /// 2. Write File Headers
   /// 3. Write Imports
-  /// 4. Generate File
+  /// 4. Write Enums
+  /// 5. Write Data Classes
+  /// 6. Write Apis
   void generate(
     T languageOptions,
     Root root,
@@ -41,7 +43,7 @@ abstract class Generator<T> {
     FileType fileType,
   );
 
-  /// Writes single Enum to file.
+  /// Writes a single Enum to file.
   void writeEnum(
     T languageOptions,
     Root root,
@@ -50,4 +52,46 @@ abstract class Generator<T> {
     FileType fileType,
     Enum anEnum,
   );
+
+  /// Writes a single data class to file.
+  void writeDataClass(
+    T languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+  );
+
+  /// Writes a single class encode method to file.
+  void writeEncode(
+    T languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    List<String> customClassNames,
+    List<String> customEnumNames,
+  );
+
+  /// Writes a single class decode method to file.
+  void writeDecode(
+    T languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    List<String> customClassNames,
+    List<String> customEnumNames,
+  );
+
+  // /// Writes a single Flutter Api to file.
+  // void writeFlutterApi(T languageOptions, Root root, StringSink sink,
+  //     Indent indent, FileType fileType, Api api,);
+
+  // /// Writes a single Host Api to file.
+  // void writeHostApi(T languageOptions, Root root, StringSink sink,
+  //     Indent indent, FileType fileType, Api api,);
 }

From 6e51c031546c2c05d945b2467e8c68bb87120227 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 3 Jan 2023 23:42:01 -0800
Subject: [PATCH 47/87] remove writeMainClass from java

---
 packages/pigeon/lib/java_generator.dart | 36 +++++++++++--------------
 1 file changed, 15 insertions(+), 21 deletions(-)

diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 7a94aa98be7..db64956842e 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -99,7 +99,21 @@ class JavaGenerator extends Generator<JavaOptions> {
 
     writeHeaders(languageOptions, root, sink, indent, fileType);
     writeImports(languageOptions, root, sink, indent, fileType);
-    writeMainClass(languageOptions, root, sink, indent, fileType);
+    indent.writeln(
+        '$_docCommentPrefix Generated class from Pigeon.$_docCommentSuffix');
+    indent.writeln(
+        '@SuppressWarnings({"unused", "unchecked", "CodeBlock2Expr", "RedundantSuppression"})');
+    if (languageOptions.useGeneratedAnnotation ?? false) {
+      indent.writeln('@javax.annotation.Generated("dev.flutter.pigeon")');
+    }
+    indent.write('public class ${languageOptions.className!} ');
+    indent.scoped('{', '}', () {
+      for (final Enum anEnum in root.enums) {
+        indent.writeln('');
+        writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
+      }
+      generateJava(languageOptions, root, sink, indent);
+    });
   }
 
   @override
@@ -166,26 +180,6 @@ class JavaGenerator extends Generator<JavaOptions> {
       });
     });
   }
-
-  /// Writes main class to sink. wraps enums, apis, and classes.
-  void writeMainClass(JavaOptions languageOptions, Root root, StringSink sink,
-      Indent indent, FileType fileType) {
-    indent.writeln(
-        '$_docCommentPrefix Generated class from Pigeon.$_docCommentSuffix');
-    indent.writeln(
-        '@SuppressWarnings({"unused", "unchecked", "CodeBlock2Expr", "RedundantSuppression"})');
-    if (languageOptions.useGeneratedAnnotation ?? false) {
-      indent.writeln('@javax.annotation.Generated("dev.flutter.pigeon")');
-    }
-    indent.write('public class ${languageOptions.className!} ');
-    indent.scoped('{', '}', () {
-      for (final Enum anEnum in root.enums) {
-        indent.writeln('');
-        writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
-      }
-      generateJava(languageOptions, root, sink, indent);
-    });
-  }
 }
 
 /// Calculates the name of the codec that will be generated for [api].

From 6041fd7d7a11a4faca112e6fa73860f50166e2a3 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 4 Jan 2023 13:18:53 -0800
Subject: [PATCH 48/87] java + kotlin

---
 packages/pigeon/lib/dart_generator.dart   |  24 +-
 packages/pigeon/lib/generator.dart        |  12 +-
 packages/pigeon/lib/java_generator.dart   | 327 ++++++++++++----------
 packages/pigeon/lib/kotlin_generator.dart | 310 ++++++++++----------
 4 files changed, 361 insertions(+), 312 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index f6ec330b7d7..fbc86f54869 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -143,10 +143,10 @@ class DartGenerator extends Generator<DartOptions> {
   @override
   void writeDataClass(DartOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType, Class klass) {
-    final List<String> customClassNames =
-        root.classes.map((Class x) => x.name).toList();
-    final List<String> customEnumNames =
-        root.enums.map((Enum x) => x.name).toList();
+    final Set<String> customClassNames =
+        root.classes.map((Class x) => x.name).toSet();
+    final Set<String> customEnumNames =
+        root.enums.map((Enum x) => x.name).toSet();
     void writeConstructor() {
       indent.write(klass.name);
       indent.scoped('({', '});', () {
@@ -172,24 +172,24 @@ class DartGenerator extends Generator<DartOptions> {
         indent.writeln('$datatype ${field.name};');
         indent.writeln('');
       }
-      writeEncode(languageOptions, root, sink, indent, fileType, klass,
+      writeClassEncode(languageOptions, root, sink, indent, fileType, klass,
           customClassNames, customEnumNames);
       indent.writeln('');
-      writeDecode(languageOptions, root, sink, indent, fileType, klass,
+      writeClassDecode(languageOptions, root, sink, indent, fileType, klass,
           customClassNames, customEnumNames);
     });
   }
 
   @override
-  void writeEncode(
+  void writeClassEncode(
     DartOptions languageOptions,
     Root root,
     StringSink sink,
     Indent indent,
     FileType fileType,
     Class klass,
-    List<String> customClassNames,
-    List<String> customEnumNames,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
   ) {
     indent.write('Object encode() ');
     indent.scoped('{', '}', () {
@@ -216,15 +216,15 @@ class DartGenerator extends Generator<DartOptions> {
   }
 
   @override
-  void writeDecode(
+  void writeClassDecode(
     DartOptions languageOptions,
     Root root,
     StringSink sink,
     Indent indent,
     FileType fileType,
     Class klass,
-    List<String> customClassNames,
-    List<String> customEnumNames,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
   ) {
     void writeValueDecode(NamedType field, int index) {
       final String resultAt = 'result[$index]';
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index d64fd67b92a..a44cb934b4f 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -64,27 +64,27 @@ abstract class Generator<T> {
   );
 
   /// Writes a single class encode method to file.
-  void writeEncode(
+  void writeClassEncode(
     T languageOptions,
     Root root,
     StringSink sink,
     Indent indent,
     FileType fileType,
     Class klass,
-    List<String> customClassNames,
-    List<String> customEnumNames,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
   );
 
   /// Writes a single class decode method to file.
-  void writeDecode(
+  void writeClassDecode(
     T languageOptions,
     Root root,
     StringSink sink,
     Indent indent,
     FileType fileType,
     Class klass,
-    List<String> customClassNames,
-    List<String> customEnumNames,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
   );
 
   // /// Writes a single Flutter Api to file.
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index db64956842e..eb41ed10899 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -112,6 +112,10 @@ class JavaGenerator extends Generator<JavaOptions> {
         indent.writeln('');
         writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
       }
+      for (final Class klass in root.classes) {
+        indent.addln('');
+        writeDataClass(languageOptions, root, sink, indent, fileType, klass);
+      }
       generateJava(languageOptions, root, sink, indent);
     });
   }
@@ -180,6 +184,179 @@ class JavaGenerator extends Generator<JavaOptions> {
       });
     });
   }
+
+  @override
+  void writeDataClass(JavaOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Class klass) {
+    final Set<String> customClassNames =
+        root.classes.map((Class x) => x.name).toSet();
+    final Set<String> customEnumNames =
+        root.enums.map((Enum x) => x.name).toSet();
+
+    const List<String> generatedMessages = <String>[
+      ' Generated class from Pigeon that represents data sent in messages.'
+    ];
+    addDocumentationComments(
+        indent, klass.documentationComments, _docCommentSpec,
+        generatorComments: generatedMessages);
+
+    indent.write('public static class ${klass.name} ');
+    indent.scoped('{', '}', () {
+      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+        _writeClassField(languageOptions, root, sink, indent, fileType, field);
+        indent.addln('');
+      }
+
+      if (getFieldsInSerializationOrder(klass)
+          .map((NamedType e) => !e.type.isNullable)
+          .any((bool e) => e)) {
+        indent.writeln(
+            '${_docCommentPrefix}Constructor is private to enforce null safety; use Builder.$_docCommentSuffix');
+        indent.writeln('private ${klass.name}() {}');
+      }
+
+      _writeClassBuilder(languageOptions, root, sink, indent, fileType, klass);
+      writeClassEncode(languageOptions, root, sink, indent, fileType, klass,
+          customClassNames, customEnumNames);
+      writeClassDecode(languageOptions, root, sink, indent, fileType, klass,
+          customClassNames, customEnumNames);
+    });
+  }
+
+  void _writeClassField(JavaOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, NamedType field) {
+    final HostDatatype hostDatatype = getFieldHostDatatype(field, root.classes,
+        root.enums, (TypeDeclaration x) => _javaTypeForBuiltinDartType(x));
+    final String nullability = field.type.isNullable ? '@Nullable' : '@NonNull';
+    addDocumentationComments(
+        indent, field.documentationComments, _docCommentSpec);
+
+    indent.writeln(
+        'private $nullability ${hostDatatype.datatype} ${field.name};');
+    indent.writeln(
+        'public $nullability ${hostDatatype.datatype} ${_makeGetter(field)}() { return ${field.name}; }');
+    indent.writeScoped(
+        'public void ${_makeSetter(field)}($nullability ${hostDatatype.datatype} setterArg) {',
+        '}', () {
+      if (!field.type.isNullable) {
+        indent.writeScoped('if (setterArg == null) {', '}', () {
+          indent.writeln(
+              'throw new IllegalStateException("Nonnull field \\"${field.name}\\" is null.");');
+        });
+      }
+      indent.writeln('this.${field.name} = setterArg;');
+    });
+  }
+
+  void _writeClassBuilder(
+    JavaOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+  ) {
+    indent.write('public static final class Builder ');
+    indent.scoped('{', '}', () {
+      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+        final HostDatatype hostDatatype = getFieldHostDatatype(
+            field,
+            root.classes,
+            root.enums,
+            (TypeDeclaration x) => _javaTypeForBuiltinDartType(x));
+        final String nullability =
+            field.type.isNullable ? '@Nullable' : '@NonNull';
+        indent.writeln(
+            'private @Nullable ${hostDatatype.datatype} ${field.name};');
+        indent.writeScoped(
+            'public @NonNull Builder ${_makeSetter(field)}($nullability ${hostDatatype.datatype} setterArg) {',
+            '}', () {
+          indent.writeln('this.${field.name} = setterArg;');
+          indent.writeln('return this;');
+        });
+      }
+      indent.write('public @NonNull ${klass.name} build() ');
+      indent.scoped('{', '}', () {
+        const String returnVal = 'pigeonReturn';
+        indent.writeln('${klass.name} $returnVal = new ${klass.name}();');
+        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+          indent.writeln('$returnVal.${_makeSetter(field)}(${field.name});');
+        }
+        indent.writeln('return $returnVal;');
+      });
+    });
+  }
+
+  @override
+  void writeClassEncode(
+    JavaOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    indent.write('@NonNull ArrayList<Object> toList() ');
+    indent.scoped('{', '}', () {
+      indent.writeln(
+          'ArrayList<Object> toListResult = new ArrayList<Object>(${klass.fields.length});');
+      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+        final HostDatatype hostDatatype = getFieldHostDatatype(
+            field,
+            root.classes,
+            root.enums,
+            (TypeDeclaration x) => _javaTypeForBuiltinDartType(x));
+        String toWriteValue = '';
+        final String fieldName = field.name;
+        if (!hostDatatype.isBuiltin &&
+            customClassNames.contains(field.type.baseName)) {
+          toWriteValue = '($fieldName == null) ? null : $fieldName.toList()';
+        } else if (!hostDatatype.isBuiltin &&
+            customEnumNames.contains(field.type.baseName)) {
+          toWriteValue = '$fieldName == null ? null : $fieldName.index';
+        } else {
+          toWriteValue = field.name;
+        }
+        indent.writeln('toListResult.add($toWriteValue);');
+      }
+      indent.writeln('return toListResult;');
+    });
+  }
+
+  @override
+  void writeClassDecode(
+    JavaOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    indent.write(
+        'static @NonNull ${klass.name} fromList(@NonNull ArrayList<Object> list) ');
+    indent.scoped('{', '}', () {
+      const String result = 'pigeonResult';
+      indent.writeln('${klass.name} $result = new ${klass.name}();');
+      enumerate(getFieldsInSerializationOrder(klass),
+          (int index, final NamedType field) {
+        final String fieldVariable = field.name;
+        final String setter = _makeSetter(field);
+        indent.writeln('Object $fieldVariable = list.get($index);');
+        if (customEnumNames.contains(field.type.baseName)) {
+          indent.writeln(
+              '$result.$setter(${_intToEnum(fieldVariable, field.type.baseName)});');
+        } else {
+          indent.writeln(
+              '$result.$setter(${_castObject(field, root.classes, root.enums, fieldVariable)});');
+        }
+      });
+      indent.writeln('return $result;');
+    });
+  }
 }
 
 /// Calculates the name of the codec that will be generated for [api].
@@ -623,151 +800,6 @@ String _castObject(
 /// provided [options].
 void generateJava(
     JavaOptions options, Root root, StringSink sink, Indent indent) {
-  final Set<String> rootClassNameSet =
-      root.classes.map((Class x) => x.name).toSet();
-  final Set<String> rootEnumNameSet =
-      root.enums.map((Enum x) => x.name).toSet();
-
-  void writeDataClass(Class klass) {
-    void writeField(NamedType field) {
-      final HostDatatype hostDatatype = getFieldHostDatatype(
-          field,
-          root.classes,
-          root.enums,
-          (TypeDeclaration x) => _javaTypeForBuiltinDartType(x));
-      final String nullability =
-          field.type.isNullable ? '@Nullable' : '@NonNull';
-      addDocumentationComments(
-          indent, field.documentationComments, _docCommentSpec);
-
-      indent.writeln(
-          'private $nullability ${hostDatatype.datatype} ${field.name};');
-      indent.writeln(
-          'public $nullability ${hostDatatype.datatype} ${_makeGetter(field)}() { return ${field.name}; }');
-      indent.writeScoped(
-          'public void ${_makeSetter(field)}($nullability ${hostDatatype.datatype} setterArg) {',
-          '}', () {
-        if (!field.type.isNullable) {
-          indent.writeScoped('if (setterArg == null) {', '}', () {
-            indent.writeln(
-                'throw new IllegalStateException("Nonnull field \\"${field.name}\\" is null.");');
-          });
-        }
-        indent.writeln('this.${field.name} = setterArg;');
-      });
-    }
-
-    void writeToList() {
-      indent.write('@NonNull ArrayList<Object> toList() ');
-      indent.scoped('{', '}', () {
-        indent.writeln(
-            'ArrayList<Object> toListResult = new ArrayList<Object>(${klass.fields.length});');
-        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-          final HostDatatype hostDatatype = getFieldHostDatatype(
-              field,
-              root.classes,
-              root.enums,
-              (TypeDeclaration x) => _javaTypeForBuiltinDartType(x));
-          String toWriteValue = '';
-          final String fieldName = field.name;
-          if (!hostDatatype.isBuiltin &&
-              rootClassNameSet.contains(field.type.baseName)) {
-            toWriteValue = '($fieldName == null) ? null : $fieldName.toList()';
-          } else if (!hostDatatype.isBuiltin &&
-              rootEnumNameSet.contains(field.type.baseName)) {
-            toWriteValue = '$fieldName == null ? null : $fieldName.index';
-          } else {
-            toWriteValue = field.name;
-          }
-          indent.writeln('toListResult.add($toWriteValue);');
-        }
-        indent.writeln('return toListResult;');
-      });
-    }
-
-    void writeFromList() {
-      indent.write(
-          'static @NonNull ${klass.name} fromList(@NonNull ArrayList<Object> list) ');
-      indent.scoped('{', '}', () {
-        const String result = 'pigeonResult';
-        indent.writeln('${klass.name} $result = new ${klass.name}();');
-        enumerate(getFieldsInSerializationOrder(klass),
-            (int index, final NamedType field) {
-          final String fieldVariable = field.name;
-          final String setter = _makeSetter(field);
-          indent.writeln('Object $fieldVariable = list.get($index);');
-          if (rootEnumNameSet.contains(field.type.baseName)) {
-            indent.writeln(
-                '$result.$setter(${_intToEnum(fieldVariable, field.type.baseName)});');
-          } else {
-            indent.writeln(
-                '$result.$setter(${_castObject(field, root.classes, root.enums, fieldVariable)});');
-          }
-        });
-        indent.writeln('return $result;');
-      });
-    }
-
-    void writeBuilder() {
-      indent.write('public static final class Builder ');
-      indent.scoped('{', '}', () {
-        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-          final HostDatatype hostDatatype = getFieldHostDatatype(
-              field,
-              root.classes,
-              root.enums,
-              (TypeDeclaration x) => _javaTypeForBuiltinDartType(x));
-          final String nullability =
-              field.type.isNullable ? '@Nullable' : '@NonNull';
-          indent.writeln(
-              'private @Nullable ${hostDatatype.datatype} ${field.name};');
-          indent.writeScoped(
-              'public @NonNull Builder ${_makeSetter(field)}($nullability ${hostDatatype.datatype} setterArg) {',
-              '}', () {
-            indent.writeln('this.${field.name} = setterArg;');
-            indent.writeln('return this;');
-          });
-        }
-        indent.write('public @NonNull ${klass.name} build() ');
-        indent.scoped('{', '}', () {
-          const String returnVal = 'pigeonReturn';
-          indent.writeln('${klass.name} $returnVal = new ${klass.name}();');
-          for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-            indent.writeln('$returnVal.${_makeSetter(field)}(${field.name});');
-          }
-          indent.writeln('return $returnVal;');
-        });
-      });
-    }
-
-    const List<String> generatedMessages = <String>[
-      ' Generated class from Pigeon that represents data sent in messages.'
-    ];
-    addDocumentationComments(
-        indent, klass.documentationComments, _docCommentSpec,
-        generatorComments: generatedMessages);
-
-    indent.write('public static class ${klass.name} ');
-    indent.scoped('{', '}', () {
-      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-        writeField(field);
-        indent.addln('');
-      }
-
-      if (getFieldsInSerializationOrder(klass)
-          .map((NamedType e) => !e.type.isNullable)
-          .any((bool e) => e)) {
-        indent.writeln(
-            '${_docCommentPrefix}Constructor is private to enforce null safety; use Builder.$_docCommentSuffix');
-        indent.writeln('private ${klass.name}() {}');
-      }
-
-      writeBuilder();
-      writeToList();
-      writeFromList();
-    });
-  }
-
   void writeResultInterface() {
     indent.write('public interface Result<T> ');
     indent.scoped('{', '}', () {
@@ -795,11 +827,6 @@ void generateJava(
 }''');
   }
 
-  for (final Class klass in root.classes) {
-    indent.addln('');
-    writeDataClass(klass);
-  }
-
   if (root.apis.any((Api api) =>
       api.location == ApiLocation.host &&
       api.methods.any((Method it) => it.isAsynchronous))) {
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index f16e46d1e8f..34df75ddda0 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -84,6 +84,10 @@ class KotlinGenerator extends Generator<KotlinOptions> {
       indent.writeln('');
       writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
     }
+    for (final Class klass in root.classes) {
+      indent.addln('');
+      writeDataClass(languageOptions, root, sink, indent, fileType, klass);
+    }
     generateKotlin(languageOptions, root, sink, indent);
   }
 
@@ -143,6 +147,168 @@ class KotlinGenerator extends Generator<KotlinOptions> {
       });
     });
   }
+
+  @override
+  void writeDataClass(KotlinOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Class klass) {
+    final Set<String> customClassNames =
+        root.classes.map((Class x) => x.name).toSet();
+    final Set<String> customEnumNames =
+        root.enums.map((Enum x) => x.name).toSet();
+    void writeField(NamedType field) {
+      addDocumentationComments(
+          indent, field.documentationComments, _docCommentSpec);
+      indent.write(
+          'val ${field.name}: ${_nullsafeKotlinTypeForDartType(field.type)}');
+      final String defaultNil = field.type.isNullable ? ' = null' : '';
+      indent.add(defaultNil);
+    }
+
+    const List<String> generatedMessages = <String>[
+      ' Generated class from Pigeon that represents data sent in messages.'
+    ];
+    addDocumentationComments(
+        indent, klass.documentationComments, _docCommentSpec,
+        generatorComments: generatedMessages);
+
+    indent.write('data class ${klass.name} ');
+    indent.scoped('(', '', () {
+      for (final NamedType element in getFieldsInSerializationOrder(klass)) {
+        writeField(element);
+        if (getFieldsInSerializationOrder(klass).last != element) {
+          indent.addln(',');
+        } else {
+          indent.addln('');
+        }
+      }
+    });
+
+    indent.scoped(') {', '}', () {
+      writeClassDecode(languageOptions, root, sink, indent, fileType, klass,
+          customClassNames, customEnumNames);
+      writeClassEncode(languageOptions, root, sink, indent, fileType, klass,
+          customClassNames, customEnumNames);
+    });
+  }
+
+  @override
+  void writeClassEncode(
+    KotlinOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    indent.write('fun toList(): List<Any?> ');
+    indent.scoped('{', '}', () {
+      indent.write('return listOf<Any?>');
+      indent.scoped('(', ')', () {
+        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+          final HostDatatype hostDatatype = _getHostDatatype(root, field);
+          String toWriteValue = '';
+          final String fieldName = field.name;
+          if (!hostDatatype.isBuiltin &&
+              customClassNames.contains(field.type.baseName)) {
+            toWriteValue = '$fieldName?.toList()';
+          } else if (!hostDatatype.isBuiltin &&
+              customEnumNames.contains(field.type.baseName)) {
+            toWriteValue = '$fieldName?.raw';
+          } else {
+            toWriteValue = fieldName;
+          }
+          indent.writeln('$toWriteValue,');
+        }
+      });
+    });
+  }
+
+  @override
+  void writeClassDecode(
+    KotlinOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    final String className = klass.name;
+
+    indent.write('companion object ');
+    indent.scoped('{', '}', () {
+      indent.writeln('@Suppress("UNCHECKED_CAST")');
+      indent.write('fun fromList(list: List<Any?>): $className ');
+
+      indent.scoped('{', '}', () {
+        enumerate(getFieldsInSerializationOrder(klass),
+            (int index, final NamedType field) {
+          final HostDatatype hostDatatype = _getHostDatatype(root, field);
+
+          // The StandardMessageCodec can give us [Integer, Long] for
+          // a Dart 'int'.  To keep things simple we just use 64bit
+          // longs in Pigeon with Kotlin.
+          final bool isInt = field.type.baseName == 'int';
+
+          final String listValue = 'list[$index]';
+          final String fieldType = _kotlinTypeForDartType(field.type);
+
+          if (field.type.isNullable) {
+            if (!hostDatatype.isBuiltin &&
+                customClassNames.contains(field.type.baseName)) {
+              indent.write('val ${field.name}: $fieldType? = ');
+              indent.add('($listValue as? List<Any?>)?.let ');
+              indent.scoped('{', '}', () {
+                indent.writeln('$fieldType.fromList(it)');
+              });
+            } else if (!hostDatatype.isBuiltin &&
+                customEnumNames.contains(field.type.baseName)) {
+              indent.write('val ${field.name}: $fieldType? = ');
+              indent.add('($listValue as? Int)?.let ');
+              indent.scoped('{', '}', () {
+                indent.writeln('$fieldType.ofRaw(it)');
+              });
+            } else if (isInt) {
+              indent.write('val ${field.name} = $listValue');
+              indent.addln(
+                  '.let { if (it is Int) it.toLong() else it as? Long }');
+            } else {
+              indent.writeln('val ${field.name} = $listValue as? $fieldType');
+            }
+          } else {
+            if (!hostDatatype.isBuiltin &&
+                customClassNames.contains(field.type.baseName)) {
+              indent.writeln(
+                  'val ${field.name} = $fieldType.fromList($listValue as List<Any?>)');
+            } else if (!hostDatatype.isBuiltin &&
+                customEnumNames.contains(field.type.baseName)) {
+              indent.write(
+                  'val ${field.name} = $fieldType.ofRaw($listValue as Int)!!');
+            } else {
+              indent.writeln('val ${field.name} = $listValue as $fieldType');
+            }
+          }
+        });
+
+        indent.writeln('');
+        indent.write('return $className(');
+        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+          final String comma =
+              getFieldsInSerializationOrder(klass).last == field ? '' : ', ';
+          indent.add('${field.name}$comma');
+        }
+        indent.addln(')');
+      });
+    });
+  }
+
+  HostDatatype _getHostDatatype(Root root, NamedType field) {
+    return getFieldHostDatatype(field, root.classes, root.enums,
+        (TypeDeclaration x) => _kotlinTypeForBuiltinDartType(x));
+  }
 }
 
 /// Calculates the name of the codec that will be generated for [api].
@@ -519,145 +685,6 @@ String _nullsafeKotlinTypeForDartType(TypeDeclaration type) {
 /// provided [options].
 void generateKotlin(
     KotlinOptions options, Root root, StringSink sink, Indent indent) {
-  final Set<String> rootClassNameSet =
-      root.classes.map((Class x) => x.name).toSet();
-  final Set<String> rootEnumNameSet =
-      root.enums.map((Enum x) => x.name).toSet();
-
-  HostDatatype getHostDatatype(NamedType field) {
-    return getFieldHostDatatype(field, root.classes, root.enums,
-        (TypeDeclaration x) => _kotlinTypeForBuiltinDartType(x));
-  }
-
-  void writeDataClass(Class klass) {
-    void writeField(NamedType field) {
-      addDocumentationComments(
-          indent, field.documentationComments, _docCommentSpec);
-      indent.write(
-          'val ${field.name}: ${_nullsafeKotlinTypeForDartType(field.type)}');
-      final String defaultNil = field.type.isNullable ? ' = null' : '';
-      indent.add(defaultNil);
-    }
-
-    void writeToList() {
-      indent.write('fun toList(): List<Any?> ');
-      indent.scoped('{', '}', () {
-        indent.write('return listOf<Any?>');
-        indent.scoped('(', ')', () {
-          for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-            final HostDatatype hostDatatype = getHostDatatype(field);
-            String toWriteValue = '';
-            final String fieldName = field.name;
-            if (!hostDatatype.isBuiltin &&
-                rootClassNameSet.contains(field.type.baseName)) {
-              toWriteValue = '$fieldName?.toList()';
-            } else if (!hostDatatype.isBuiltin &&
-                rootEnumNameSet.contains(field.type.baseName)) {
-              toWriteValue = '$fieldName?.raw';
-            } else {
-              toWriteValue = fieldName;
-            }
-            indent.writeln('$toWriteValue,');
-          }
-        });
-      });
-    }
-
-    void writeFromList() {
-      final String className = klass.name;
-
-      indent.write('companion object ');
-      indent.scoped('{', '}', () {
-        indent.writeln('@Suppress("UNCHECKED_CAST")');
-        indent.write('fun fromList(list: List<Any?>): $className ');
-
-        indent.scoped('{', '}', () {
-          enumerate(getFieldsInSerializationOrder(klass),
-              (int index, final NamedType field) {
-            final HostDatatype hostDatatype = getHostDatatype(field);
-
-            // The StandardMessageCodec can give us [Integer, Long] for
-            // a Dart 'int'.  To keep things simple we just use 64bit
-            // longs in Pigeon with Kotlin.
-            final bool isInt = field.type.baseName == 'int';
-
-            final String listValue = 'list[$index]';
-            final String fieldType = _kotlinTypeForDartType(field.type);
-
-            if (field.type.isNullable) {
-              if (!hostDatatype.isBuiltin &&
-                  rootClassNameSet.contains(field.type.baseName)) {
-                indent.write('val ${field.name}: $fieldType? = ');
-                indent.add('($listValue as? List<Any?>)?.let ');
-                indent.scoped('{', '}', () {
-                  indent.writeln('$fieldType.fromList(it)');
-                });
-              } else if (!hostDatatype.isBuiltin &&
-                  rootEnumNameSet.contains(field.type.baseName)) {
-                indent.write('val ${field.name}: $fieldType? = ');
-                indent.add('($listValue as? Int)?.let ');
-                indent.scoped('{', '}', () {
-                  indent.writeln('$fieldType.ofRaw(it)');
-                });
-              } else if (isInt) {
-                indent.write('val ${field.name} = $listValue');
-                indent.addln(
-                    '.let { if (it is Int) it.toLong() else it as? Long }');
-              } else {
-                indent.writeln('val ${field.name} = $listValue as? $fieldType');
-              }
-            } else {
-              if (!hostDatatype.isBuiltin &&
-                  rootClassNameSet.contains(field.type.baseName)) {
-                indent.writeln(
-                    'val ${field.name} = $fieldType.fromList($listValue as List<Any?>)');
-              } else if (!hostDatatype.isBuiltin &&
-                  rootEnumNameSet.contains(field.type.baseName)) {
-                indent.write(
-                    'val ${field.name} = $fieldType.ofRaw($listValue as Int)!!');
-              } else {
-                indent.writeln('val ${field.name} = $listValue as $fieldType');
-              }
-            }
-          });
-
-          indent.writeln('');
-          indent.write('return $className(');
-          for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-            final String comma =
-                getFieldsInSerializationOrder(klass).last == field ? '' : ', ';
-            indent.add('${field.name}$comma');
-          }
-          indent.addln(')');
-        });
-      });
-    }
-
-    const List<String> generatedMessages = <String>[
-      ' Generated class from Pigeon that represents data sent in messages.'
-    ];
-    addDocumentationComments(
-        indent, klass.documentationComments, _docCommentSpec,
-        generatorComments: generatedMessages);
-
-    indent.write('data class ${klass.name} ');
-    indent.scoped('(', '', () {
-      for (final NamedType element in getFieldsInSerializationOrder(klass)) {
-        writeField(element);
-        if (getFieldsInSerializationOrder(klass).last != element) {
-          indent.addln(',');
-        } else {
-          indent.addln('');
-        }
-      }
-    });
-
-    indent.scoped(') {', '}', () {
-      writeFromList();
-      writeToList();
-    });
-  }
-
   void writeApi(Api api) {
     if (api.location == ApiLocation.host) {
       _writeHostApi(indent, api, root);
@@ -686,11 +713,6 @@ void generateKotlin(
     });
   }
 
-  for (final Class klass in root.classes) {
-    indent.addln('');
-    writeDataClass(klass);
-  }
-
   if (root.apis.any((Api api) =>
       api.location == ApiLocation.host &&
       api.methods.any((Method it) => it.isAsynchronous))) {

From b0b55a4ee0b58802ffebca67c2f010e86763ac88 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 4 Jan 2023 13:19:24 -0800
Subject: [PATCH 49/87] remove dead code

---
 packages/pigeon/lib/swift_generator.dart | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 1df15574fe0..b9c026c2f51 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -495,10 +495,6 @@ String _nullsafeSwiftTypeForDartType(TypeDeclaration type) {
   return '${_swiftTypeForDartType(type)}$nullSafe';
 }
 
-/// Writes file header to sink.
-void writeImports(
-    SwiftOptions options, Root root, StringSink sink, Indent indent) {}
-
 /// Generates the ".swift" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateSwift(

From 3e2857d208476c1d040ec444447f2db5ba785404 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 4 Jan 2023 13:29:44 -0800
Subject: [PATCH 50/87] swift

---
 packages/pigeon/lib/kotlin_generator.dart |  19 +-
 packages/pigeon/lib/swift_generator.dart  | 282 ++++++++++++----------
 2 files changed, 163 insertions(+), 138 deletions(-)

diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 34df75ddda0..f3710179f7a 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -155,14 +155,6 @@ class KotlinGenerator extends Generator<KotlinOptions> {
         root.classes.map((Class x) => x.name).toSet();
     final Set<String> customEnumNames =
         root.enums.map((Enum x) => x.name).toSet();
-    void writeField(NamedType field) {
-      addDocumentationComments(
-          indent, field.documentationComments, _docCommentSpec);
-      indent.write(
-          'val ${field.name}: ${_nullsafeKotlinTypeForDartType(field.type)}');
-      final String defaultNil = field.type.isNullable ? ' = null' : '';
-      indent.add(defaultNil);
-    }
 
     const List<String> generatedMessages = <String>[
       ' Generated class from Pigeon that represents data sent in messages.'
@@ -174,7 +166,7 @@ class KotlinGenerator extends Generator<KotlinOptions> {
     indent.write('data class ${klass.name} ');
     indent.scoped('(', '', () {
       for (final NamedType element in getFieldsInSerializationOrder(klass)) {
-        writeField(element);
+        _writeClassField(indent, element);
         if (getFieldsInSerializationOrder(klass).last != element) {
           indent.addln(',');
         } else {
@@ -305,6 +297,15 @@ class KotlinGenerator extends Generator<KotlinOptions> {
     });
   }
 
+  void _writeClassField(Indent indent, NamedType field) {
+    addDocumentationComments(
+        indent, field.documentationComments, _docCommentSpec);
+    indent.write(
+        'val ${field.name}: ${_nullsafeKotlinTypeForDartType(field.type)}');
+    final String defaultNil = field.type.isNullable ? ' = null' : '';
+    indent.add(defaultNil);
+  }
+
   HostDatatype _getHostDatatype(Root root, NamedType field) {
     return getFieldHostDatatype(field, root.classes, root.enums,
         (TypeDeclaration x) => _kotlinTypeForBuiltinDartType(x));
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index b9c026c2f51..bfd7dab1009 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -66,6 +66,10 @@ class SwiftGenerator extends Generator<SwiftOptions> {
       indent.writeln('');
       writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
     }
+    for (final Class klass in root.classes) {
+      indent.addln('');
+      writeDataClass(languageOptions, root, sink, indent, fileType, klass);
+    }
     generateSwift(languageOptions, root, sink, indent);
   }
 
@@ -111,6 +115,155 @@ import FlutterMacOS
       });
     });
   }
+
+  @override
+  void writeDataClass(SwiftOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Class klass) {
+    final Set<String> customClassNames =
+        root.classes.map((Class x) => x.name).toSet();
+    final Set<String> customEnumNames =
+        root.enums.map((Enum x) => x.name).toSet();
+
+    const List<String> generatedComments = <String>[
+      ' Generated class from Pigeon that represents data sent in messages.'
+    ];
+    addDocumentationComments(
+        indent, klass.documentationComments, _docCommentSpec,
+        generatorComments: generatedComments);
+
+    indent.write('struct ${klass.name} ');
+    indent.scoped('{', '}', () {
+      getFieldsInSerializationOrder(klass).forEach((NamedType field) {
+        _writeClassField(indent, field);
+      });
+
+      indent.writeln('');
+      writeClassDecode(languageOptions, root, sink, indent, fileType, klass,
+          customClassNames, customEnumNames);
+      writeClassEncode(languageOptions, root, sink, indent, fileType, klass,
+          customClassNames, customEnumNames);
+    });
+  }
+
+  void _writeClassField(Indent indent, NamedType field) {
+    addDocumentationComments(
+        indent, field.documentationComments, _docCommentSpec);
+
+    indent.write(
+        'var ${field.name}: ${_nullsafeSwiftTypeForDartType(field.type)}');
+    final String defaultNil = field.type.isNullable ? ' = nil' : '';
+    indent.addln(defaultNil);
+  }
+
+  @override
+  void writeClassEncode(
+    SwiftOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    indent.write('func toList() -> [Any?] ');
+    indent.scoped('{', '}', () {
+      indent.write('return ');
+      indent.scoped('[', ']', () {
+        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+          final HostDatatype hostDatatype = _getHostDatatype(root, field);
+          String toWriteValue = '';
+          final String fieldName = field.name;
+          final String nullsafe = field.type.isNullable ? '?' : '';
+          if (!hostDatatype.isBuiltin &&
+              customClassNames.contains(field.type.baseName)) {
+            toWriteValue = '$fieldName$nullsafe.toList()';
+          } else if (!hostDatatype.isBuiltin &&
+              customEnumNames.contains(field.type.baseName)) {
+            toWriteValue = '$fieldName$nullsafe.rawValue';
+          } else {
+            toWriteValue = field.name;
+          }
+
+          indent.writeln('$toWriteValue,');
+        }
+      });
+    });
+  }
+
+  @override
+  void writeClassDecode(
+    SwiftOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    final String className = klass.name;
+    indent.write('static func fromList(_ list: [Any?]) -> $className? ');
+
+    indent.scoped('{', '}', () {
+      enumerate(getFieldsInSerializationOrder(klass),
+          (int index, final NamedType field) {
+        final HostDatatype hostDatatype = _getHostDatatype(root, field);
+
+        final String listValue = 'list[$index]';
+        final String fieldType = _swiftTypeForDartType(field.type);
+
+        if (field.type.isNullable) {
+          if (!hostDatatype.isBuiltin &&
+              customClassNames.contains(field.type.baseName)) {
+            indent.writeln('var ${field.name}: $fieldType? = nil');
+            indent.write('if let ${field.name}List = $listValue as? [Any?] ');
+            indent.scoped('{', '}', () {
+              indent.writeln(
+                  '${field.name} = $fieldType.fromList(${field.name}List)');
+            });
+          } else if (!hostDatatype.isBuiltin &&
+              customEnumNames.contains(field.type.baseName)) {
+            indent.writeln('var ${field.name}: $fieldType? = nil');
+            indent.write('if let ${field.name}RawValue = $listValue as? Int ');
+            indent.scoped('{', '}', () {
+              indent.writeln(
+                  '${field.name} = $fieldType(rawValue: ${field.name}RawValue)');
+            });
+          } else {
+            indent.writeln('let ${field.name} = $listValue as? $fieldType ');
+          }
+        } else {
+          if (!hostDatatype.isBuiltin &&
+              customClassNames.contains(field.type.baseName)) {
+            indent.writeln(
+                'let ${field.name} = $fieldType.fromList($listValue as! [Any?])!');
+          } else if (!hostDatatype.isBuiltin &&
+              customEnumNames.contains(field.type.baseName)) {
+            indent.writeln(
+                'let ${field.name} = $fieldType(rawValue: $listValue as! Int)!');
+          } else {
+            indent.writeln('let ${field.name} = $listValue as! $fieldType');
+          }
+        }
+      });
+
+      indent.writeln('');
+      indent.write('return ');
+      indent.scoped('$className(', ')', () {
+        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+          final String comma =
+              getFieldsInSerializationOrder(klass).last == field ? '' : ',';
+          indent.writeln('${field.name}: ${field.name}$comma');
+        }
+      });
+    });
+  }
+
+  HostDatatype _getHostDatatype(Root root, NamedType field) {
+    return getFieldHostDatatype(field, root.classes, root.enums,
+        (TypeDeclaration x) => _swiftTypeForBuiltinDartType(x));
+  }
 }
 
 /// Calculates the name of the codec that will be generated for [api].
@@ -499,130 +652,6 @@ String _nullsafeSwiftTypeForDartType(TypeDeclaration type) {
 /// provided [options].
 void generateSwift(
     SwiftOptions options, Root root, StringSink sink, Indent indent) {
-  final Set<String> rootClassNameSet =
-      root.classes.map((Class x) => x.name).toSet();
-  final Set<String> rootEnumNameSet =
-      root.enums.map((Enum x) => x.name).toSet();
-
-  HostDatatype getHostDatatype(NamedType field) {
-    return getFieldHostDatatype(field, root.classes, root.enums,
-        (TypeDeclaration x) => _swiftTypeForBuiltinDartType(x));
-  }
-
-  void writeDataClass(Class klass) {
-    void writeField(NamedType field) {
-      addDocumentationComments(
-          indent, field.documentationComments, _docCommentSpec);
-
-      indent.write(
-          'var ${field.name}: ${_nullsafeSwiftTypeForDartType(field.type)}');
-      final String defaultNil = field.type.isNullable ? ' = nil' : '';
-      indent.addln(defaultNil);
-    }
-
-    void writeToList() {
-      indent.write('func toList() -> [Any?] ');
-      indent.scoped('{', '}', () {
-        indent.write('return ');
-        indent.scoped('[', ']', () {
-          for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-            final HostDatatype hostDatatype = getHostDatatype(field);
-            String toWriteValue = '';
-            final String fieldName = field.name;
-            final String nullsafe = field.type.isNullable ? '?' : '';
-            if (!hostDatatype.isBuiltin &&
-                rootClassNameSet.contains(field.type.baseName)) {
-              toWriteValue = '$fieldName$nullsafe.toList()';
-            } else if (!hostDatatype.isBuiltin &&
-                rootEnumNameSet.contains(field.type.baseName)) {
-              toWriteValue = '$fieldName$nullsafe.rawValue';
-            } else {
-              toWriteValue = field.name;
-            }
-
-            indent.writeln('$toWriteValue,');
-          }
-        });
-      });
-    }
-
-    void writeFromList() {
-      final String className = klass.name;
-      indent.write('static func fromList(_ list: [Any?]) -> $className? ');
-
-      indent.scoped('{', '}', () {
-        enumerate(getFieldsInSerializationOrder(klass),
-            (int index, final NamedType field) {
-          final HostDatatype hostDatatype = getHostDatatype(field);
-
-          final String listValue = 'list[$index]';
-          final String fieldType = _swiftTypeForDartType(field.type);
-
-          if (field.type.isNullable) {
-            if (!hostDatatype.isBuiltin &&
-                rootClassNameSet.contains(field.type.baseName)) {
-              indent.writeln('var ${field.name}: $fieldType? = nil');
-              indent.write('if let ${field.name}List = $listValue as? [Any?] ');
-              indent.scoped('{', '}', () {
-                indent.writeln(
-                    '${field.name} = $fieldType.fromList(${field.name}List)');
-              });
-            } else if (!hostDatatype.isBuiltin &&
-                rootEnumNameSet.contains(field.type.baseName)) {
-              indent.writeln('var ${field.name}: $fieldType? = nil');
-              indent
-                  .write('if let ${field.name}RawValue = $listValue as? Int ');
-              indent.scoped('{', '}', () {
-                indent.writeln(
-                    '${field.name} = $fieldType(rawValue: ${field.name}RawValue)');
-              });
-            } else {
-              indent.writeln('let ${field.name} = $listValue as? $fieldType ');
-            }
-          } else {
-            if (!hostDatatype.isBuiltin &&
-                rootClassNameSet.contains(field.type.baseName)) {
-              indent.writeln(
-                  'let ${field.name} = $fieldType.fromList($listValue as! [Any?])!');
-            } else if (!hostDatatype.isBuiltin &&
-                rootEnumNameSet.contains(field.type.baseName)) {
-              indent.writeln(
-                  'let ${field.name} = $fieldType(rawValue: $listValue as! Int)!');
-            } else {
-              indent.writeln('let ${field.name} = $listValue as! $fieldType');
-            }
-          }
-        });
-
-        indent.writeln('');
-        indent.write('return ');
-        indent.scoped('$className(', ')', () {
-          for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-            final String comma =
-                getFieldsInSerializationOrder(klass).last == field ? '' : ',';
-            indent.writeln('${field.name}: ${field.name}$comma');
-          }
-        });
-      });
-    }
-
-    const List<String> generatedComments = <String>[
-      ' Generated class from Pigeon that represents data sent in messages.'
-    ];
-    addDocumentationComments(
-        indent, klass.documentationComments, _docCommentSpec,
-        generatorComments: generatedComments);
-
-    indent.write('struct ${klass.name} ');
-    indent.scoped('{', '}', () {
-      getFieldsInSerializationOrder(klass).forEach(writeField);
-
-      indent.writeln('');
-      writeFromList();
-      writeToList();
-    });
-  }
-
   void writeApi(Api api, Root root) {
     if (api.location == ApiLocation.host) {
       _writeHostApi(indent, api, root);
@@ -650,11 +679,6 @@ void generateSwift(
     });
   }
 
-  for (final Class klass in root.classes) {
-    indent.addln('');
-    writeDataClass(klass);
-  }
-
   if (root.apis.any((Api api) =>
       api.location == ApiLocation.host &&
       api.methods.any((Method it) => it.isAsynchronous))) {

From 3b51c03e01926e6ee8ea7c5da3454adc6e75a0f7 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 4 Jan 2023 13:31:10 -0800
Subject: [PATCH 51/87] fix dart test error

---
 packages/pigeon/lib/dart_generator.dart | 32 ++++++++++++-------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index fbc86f54869..a5a2b1cdffa 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -289,23 +289,23 @@ $resultAt != null
       });
     });
   }
-}
 
-/// Generates Dart files for testing with specified [DartOptions]
-void generateTest(DartOptions languageOptions, Root root, StringSink sink) {
-  final Indent indent = Indent(sink);
-  final String sourceOutPath = languageOptions.sourceOutPath ?? '';
-  final String testOutPath = languageOptions.testOutPath ?? '';
-  writeTestHeader(languageOptions, root, sink, indent);
-  writeTestImports(languageOptions, root, sink, indent);
-  generateTestDart(
-    languageOptions,
-    root,
-    sink,
-    indent,
-    sourceOutPath: sourceOutPath,
-    testOutPath: testOutPath,
-  );
+  /// Generates Dart files for testing with specified [DartOptions]
+  void generateTest(DartOptions languageOptions, Root root, StringSink sink) {
+    final Indent indent = Indent(sink);
+    final String sourceOutPath = languageOptions.sourceOutPath ?? '';
+    final String testOutPath = languageOptions.testOutPath ?? '';
+    writeTestHeader(languageOptions, root, sink, indent);
+    writeTestImports(languageOptions, root, sink, indent);
+    generateTestDart(
+      languageOptions,
+      root,
+      sink,
+      indent,
+      sourceOutPath: sourceOutPath,
+      testOutPath: testOutPath,
+    );
+  }
 }
 
 String _escapeForDartSingleQuotedString(String raw) {

From f0503dc023720bf3c46e43da99faf330d5ed070d Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 4 Jan 2023 14:43:13 -0800
Subject: [PATCH 52/87] cpp + objc

---
 packages/pigeon/lib/cpp_generator.dart  |  88 ++++--
 packages/pigeon/lib/objc_generator.dart | 355 +++++++++++++++---------
 2 files changed, 277 insertions(+), 166 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index da3ba128307..05f7c25306c 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -88,7 +88,12 @@ class CppGenerator extends Generator<CppOptions> {
     }
 
     indent.addln('');
-
+    if (fileType == FileType.header) {
+      _writeErrorOr(indent, friends: root.apis.map((Api api) => api.name));
+    }
+    for (final Class klass in root.classes) {
+      writeDataClass(languageOptions, root, sink, indent, fileType, klass);
+    }
     if (fileType == FileType.header) {
       generateCppHeader(languageOptions, root, sink, indent);
     } else {
@@ -123,6 +128,53 @@ class CppGenerator extends Generator<CppOptions> {
       writeCppHeaderEnum(languageOptions, root, sink, indent, anEnum);
     }
   }
+
+  @override
+  void writeDataClass(CppOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Class klass) {
+    if (fileType == FileType.header) {
+      // When generating for a Pigeon unit test, add a test fixture friend class to
+      // allow unit testing private methods, since testing serialization via public
+      // methods is essentially an end-to-end test.
+      String? testFixtureClass;
+      if (languageOptions.namespace?.endsWith('_pigeontest') ?? false) {
+        testFixtureClass =
+            '${_pascalCaseFromSnakeCase(languageOptions.namespace!.replaceAll('_pigeontest', ''))}Test';
+      }
+      _writeCppHeaderDataClass(languageOptions, root, sink, indent, klass,
+          testFriend: testFixtureClass);
+    } else {
+      _writeCppSourceDataClass(languageOptions, root, sink, indent, klass);
+    }
+  }
+
+  @override
+  void writeClassEncode(
+    CppOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    // Left blank until functions fully converted to methods.
+  }
+
+  @override
+  void writeClassDecode(
+    CppOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    // Left blank until functions fully converted to methods.
+  }
 }
 
 String _getCodecSerializerName(Api api) => '${api.name}CodecSerializer';
@@ -251,9 +303,10 @@ $friendLines
 
 /// Writes the declaration for the custom class [klass].
 ///
-/// See [_writeDataClassImplementation] for the corresponding declaration.
+/// See [_writeCppSourceDataClass] for the corresponding declaration.
 /// This is intended to be added to the header.
-void _writeDataClassDeclaration(Indent indent, Class klass, Root root,
+void _writeCppHeaderDataClass(CppOptions languageOptions, Root root,
+    StringSink sink, Indent indent, Class klass,
     {String? testFriend}) {
   indent.addln('');
 
@@ -328,9 +381,10 @@ void _writeDataClassDeclaration(Indent indent, Class klass, Root root,
 
 /// Writes the implementation for the custom class [klass].
 ///
-/// See [_writeDataClassDeclaration] for the corresponding declaration.
+/// See [_writeCppHeaderDataClass] for the corresponding declaration.
 /// This is intended to be added to the implementation file.
-void _writeDataClassImplementation(Indent indent, Class klass, Root root) {
+void _writeCppSourceDataClass(CppOptions languageOptions, Root root,
+    StringSink sink, Indent indent, Class klass) {
   final Set<String> rootClassNameSet =
       root.classes.map((Class x) => x.name).toSet();
   final Set<String> rootEnumNameSet =
@@ -369,7 +423,7 @@ void _writeDataClassImplementation(Indent indent, Class klass, Root root) {
         '{ return $returnExpression; }');
     indent.writeln(makeSetter(hostDatatype));
     if (hostDatatype.isNullable) {
-      // Write the non-nullable variant; see _writeDataClassDeclaration.
+      // Write the non-nullable variant; see _writeCppHeaderDataClass.
       final HostDatatype nonNullType = _nonNullableType(hostDatatype);
       indent.writeln(makeSetter(nonNullType));
     }
@@ -1136,24 +1190,6 @@ void writeCppHeaderEnum(CppOptions options, Root root, StringSink sink,
 /// provided [options] and [headerFileName].
 void generateCppHeader(
     CppOptions options, Root root, StringSink sink, Indent indent) {
-  // When generating for a Pigeon unit test, add a test fixture friend class to
-  // allow unit testing private methods, since testing serialization via public
-  // methods is essentially an end-to-end test.
-  String? testFixtureClass;
-  if (options.namespace?.endsWith('_pigeontest') ?? false) {
-    testFixtureClass =
-        '${_pascalCaseFromSnakeCase(options.namespace!.replaceAll('_pigeontest', ''))}Test';
-  }
-
-  _writeErrorOr(indent, friends: root.apis.map((Api api) => api.name));
-
-  for (final Class klass in root.classes) {
-    _writeDataClassDeclaration(indent, klass, root,
-        // Add a hook for unit testing data classes when using the namespace
-        // used by pigeon tests.
-        testFriend: testFixtureClass);
-  }
-
   for (final Api api in root.apis) {
     if (getCodecClasses(api, root).isNotEmpty) {
       _writeCodecHeader(indent, api, root);
@@ -1215,10 +1251,6 @@ void writeCppSourceImports(
 /// provided [options].
 void generateCppSource(
     CppOptions options, Root root, StringSink sink, Indent indent) {
-  for (final Class klass in root.classes) {
-    _writeDataClassImplementation(indent, klass, root);
-  }
-
   for (final Api api in root.apis) {
     if (getCodecClasses(api, root).isNotEmpty) {
       _writeCodecSource(indent, api, root);
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index bd229cf1fa1..1d2421f51af 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -85,6 +85,25 @@ class ObjcGenerator extends Generator<ObjcOptions> {
         writeEnum(languageOptions, root, sink, indent, fileType, anEnum);
       }
       indent.writeln('');
+      for (final Class klass in root.classes) {
+        indent.writeln(
+            '@class ${_className(languageOptions.prefix, klass.name)};');
+      }
+    } else if (fileType == FileType.source) {
+      _writeObjcSourceHelperFunctions(indent);
+      indent.addln('');
+
+      for (final Class klass in root.classes) {
+        _writeObjcSourceDataClassExtension(languageOptions, indent, klass);
+      }
+      indent.writeln('');
+    }
+
+    for (final Class klass in root.classes) {
+      writeDataClass(languageOptions, root, sink, indent, fileType, klass);
+    }
+
+    if (fileType == FileType.header) {
       generateObjcHeader(languageOptions, root, sink, indent);
     } else {
       generateObjcSource(languageOptions, root, sink, indent);
@@ -118,6 +137,46 @@ class ObjcGenerator extends Generator<ObjcOptions> {
       writeObjcHeaderEnum(languageOptions, root, sink, indent, anEnum);
     }
   }
+
+  @override
+  void writeDataClass(ObjcOptions languageOptions, Root root, StringSink sink,
+      Indent indent, FileType fileType, Class klass) {
+    if (fileType == FileType.header) {
+      _writeObjcHeaderDataClass(languageOptions, root, sink, indent, klass);
+    } else {
+      _writeObjcSourceDataClassImplementation(
+          languageOptions, root, sink, indent, klass);
+      indent.writeln('');
+    }
+  }
+
+  @override
+  void writeClassEncode(
+    ObjcOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    // Left blank until functions fully converted to methods.
+  }
+
+  @override
+  void writeClassDecode(
+    ObjcOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    FileType fileType,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    // Left blank until functions fully converted to methods.
+  }
 }
 
 /// Calculates the ObjC class name, possibly prefixed.
@@ -221,7 +280,7 @@ bool _isNullable(HostDatatype hostDatatype, TypeDeclaration type) =>
 /// Example '+ (instancetype)makeWithFoo:(NSString *)foo'
 void _writeInitializerDeclaration(Indent indent, Class klass,
     List<Class> classes, List<Enum> enums, String? prefix) {
-  final List<String> enumNames = enums.map((Enum x) => x.name).toList();
+  final List<String> customEnumNames = enums.map((Enum x) => x.name).toList();
   indent.write('+ (instancetype)makeWith');
   bool isFirst = true;
   indent.nest(2, () {
@@ -239,7 +298,7 @@ void _writeInitializerDeclaration(Indent indent, Class klass,
           classes,
           enums,
           (TypeDeclaration x) => _objcTypePtrForPrimitiveDartType(prefix, x),
-          customResolver: enumNames.contains(field.type.baseName)
+          customResolver: customEnumNames.contains(field.type.baseName)
               ? (String x) => _className(prefix, x)
               : (String x) => '${_className(prefix, x)} *');
       final String nullable =
@@ -255,50 +314,52 @@ void _writeInitializerDeclaration(Indent indent, Class klass,
 /// @interface Foo : NSObject
 /// @property (nonatomic, copy) NSString *bar;
 /// @end
-void _writeClassDeclarations(
-    Indent indent, List<Class> classes, List<Enum> enums, String? prefix) {
-  final List<String> enumNames = enums.map((Enum x) => x.name).toList();
-  for (final Class klass in classes) {
-    addDocumentationComments(
-        indent, klass.documentationComments, _docCommentSpec);
+void _writeObjcHeaderDataClass(ObjcOptions languageOptions, Root root,
+    StringSink sink, Indent indent, Class klass) {
+  final List<Class> classes = root.classes;
+  final List<Enum> enums = root.enums;
+  final String? prefix = languageOptions.prefix;
+  final List<String> customEnumNames = enums.map((Enum x) => x.name).toList();
 
-    indent.writeln('@interface ${_className(prefix, klass.name)} : NSObject');
-    if (getFieldsInSerializationOrder(klass).isNotEmpty) {
-      if (getFieldsInSerializationOrder(klass)
-          .map((NamedType e) => !e.type.isNullable)
-          .any((bool e) => e)) {
-        indent.writeln(
-            '$_docCommentPrefix `init` unavailable to enforce nonnull fields, see the `make` class method.');
-        indent.writeln('- (instancetype)init NS_UNAVAILABLE;');
-      }
-      _writeInitializerDeclaration(indent, klass, classes, enums, prefix);
-      indent.addln(';');
-    }
-    for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-      final HostDatatype hostDatatype = getFieldHostDatatype(
-          field,
-          classes,
-          enums,
-          (TypeDeclaration x) => _objcTypePtrForPrimitiveDartType(prefix, x),
-          customResolver: enumNames.contains(field.type.baseName)
-              ? (String x) => _className(prefix, x)
-              : (String x) => '${_className(prefix, x)} *');
-      late final String propertyType;
-      addDocumentationComments(
-          indent, field.documentationComments, _docCommentSpec);
-      if (enumNames.contains(field.type.baseName)) {
-        propertyType = 'assign';
-      } else {
-        propertyType = _propertyTypeForDartType(field);
-      }
-      final String nullability =
-          _isNullable(hostDatatype, field.type) ? ', nullable' : '';
+  addDocumentationComments(
+      indent, klass.documentationComments, _docCommentSpec);
+
+  indent.writeln('@interface ${_className(prefix, klass.name)} : NSObject');
+  if (getFieldsInSerializationOrder(klass).isNotEmpty) {
+    if (getFieldsInSerializationOrder(klass)
+        .map((NamedType e) => !e.type.isNullable)
+        .any((bool e) => e)) {
       indent.writeln(
-          '@property(nonatomic, $propertyType$nullability) ${hostDatatype.datatype} ${field.name};');
+          '$_docCommentPrefix `init` unavailable to enforce nonnull fields, see the `make` class method.');
+      indent.writeln('- (instancetype)init NS_UNAVAILABLE;');
     }
-    indent.writeln('@end');
-    indent.writeln('');
+    _writeInitializerDeclaration(indent, klass, classes, enums, prefix);
+    indent.addln(';');
   }
+  for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+    final HostDatatype hostDatatype = getFieldHostDatatype(
+        field,
+        classes,
+        enums,
+        (TypeDeclaration x) => _objcTypePtrForPrimitiveDartType(prefix, x),
+        customResolver: customEnumNames.contains(field.type.baseName)
+            ? (String x) => _className(prefix, x)
+            : (String x) => '${_className(prefix, x)} *');
+    late final String propertyType;
+    addDocumentationComments(
+        indent, field.documentationComments, _docCommentSpec);
+    if (customEnumNames.contains(field.type.baseName)) {
+      propertyType = 'assign';
+    } else {
+      propertyType = _propertyTypeForDartType(field);
+    }
+    final String nullability =
+        _isNullable(hostDatatype, field.type) ? ', nullable' : '';
+    indent.writeln(
+        '@property(nonatomic, $propertyType$nullability) ${hostDatatype.datatype} ${field.name};');
+  }
+  indent.writeln('@end');
+  indent.writeln('');
 }
 
 /// Generates the name of the codec that will be generated.
@@ -634,14 +695,8 @@ void writeObjcHeaderEnum(ObjcOptions options, Root root, StringSink sink,
 /// provided [options].
 void generateObjcHeader(
     ObjcOptions options, Root root, StringSink sink, Indent indent) {
-  for (final Class klass in root.classes) {
-    indent.writeln('@class ${_className(options.prefix, klass.name)};');
-  }
-
   indent.writeln('');
 
-  _writeClassDeclarations(indent, root.classes, root.enums, options.prefix);
-
   for (final Api api in root.apis) {
     indent.writeln(
         '$_docCommentPrefix The codec used by ${_className(options.prefix, api.name)}.');
@@ -658,9 +713,9 @@ void generateObjcHeader(
   indent.writeln('NS_ASSUME_NONNULL_END');
 }
 
-String _listGetter(List<String> classNames, String list, NamedType field,
+String _listGetter(Set<String> customClassNames, String list, NamedType field,
     int index, String? prefix) {
-  if (classNames.contains(field.type.baseName)) {
+  if (customClassNames.contains(field.type.baseName)) {
     String className = field.type.baseName;
     if (prefix != null) {
       className = '$prefix$className';
@@ -671,11 +726,11 @@ String _listGetter(List<String> classNames, String list, NamedType field,
   }
 }
 
-String _arrayValue(
-    List<String> classNames, List<String> enumNames, NamedType field) {
-  if (classNames.contains(field.type.baseName)) {
+String _arrayValue(Set<String> customClassNames, Set<String> customEnumNames,
+    NamedType field) {
+  if (customClassNames.contains(field.type.baseName)) {
     return '(self.${field.name} ? [self.${field.name} toList] : [NSNull null])';
-  } else if (enumNames.contains(field.type.baseName)) {
+  } else if (customEnumNames.contains(field.type.baseName)) {
     return '@(self.${field.name})';
   } else {
     return '(self.${field.name} ?: [NSNull null])';
@@ -947,23 +1002,15 @@ void writeObjcSourceImports(
   indent.addln('');
 }
 
-/// Generates the ".m" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateObjcSource(
-    ObjcOptions options, Root root, StringSink sink, Indent indent) {
-  final List<String> classNames =
-      root.classes.map((Class x) => x.name).toList();
-  final List<String> enumNames = root.enums.map((Enum x) => x.name).toList();
-
-  void writeHelperFunctions() {
-    indent.format('''
+void _writeObjcSourceHelperFunctions(Indent indent) {
+  indent.format('''
 static NSArray *wrapResult(id result, FlutterError *error) {
 \tif (error) {
 \t\treturn @[ error.code ?: [NSNull null], error.message ?: [NSNull null], error.details ?: [NSNull null] ];
 \t}
 \treturn @[ result ?: [NSNull null]  ];
 }''');
-    indent.format('''
+  indent.format('''
 static id GetNullableObject(NSDictionary* dict, id key) {
 \tid result = dict[key];
 \treturn (result == [NSNull null]) ? nil : result;
@@ -973,78 +1020,118 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
 \treturn (result == [NSNull null]) ? nil : result;
 }
 ''');
-  }
-
-  void writeDataClassExtension(Class klass) {
-    final String className = _className(options.prefix, klass.name);
-    indent.writeln('@interface $className ()');
-    indent.writeln('+ ($className *)fromList:(NSArray *)list;');
-    indent
-        .writeln('+ (nullable $className *)nullableFromList:(NSArray *)list;');
-    indent.writeln('- (NSArray *)toList;');
-    indent.writeln('@end');
-  }
+}
 
-  void writeDataClassImplementation(Class klass) {
-    final String className = _className(options.prefix, klass.name);
-    void writeInitializer() {
-      _writeInitializerDeclaration(
-          indent, klass, root.classes, root.enums, options.prefix);
-      indent.writeScoped(' {', '}', () {
-        const String result = 'pigeonResult';
-        indent.writeln('$className* $result = [[$className alloc] init];');
-        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-          indent.writeln('$result.${field.name} = ${field.name};');
-        }
-        indent.writeln('return $result;');
-      });
-    }
+void _writeObjcSourceDataClassExtension(
+    ObjcOptions languageOptions, Indent indent, Class klass) {
+  final String className = _className(languageOptions.prefix, klass.name);
+  indent.writeln('@interface $className ()');
+  indent.writeln('+ ($className *)fromList:(NSArray *)list;');
+  indent.writeln('+ (nullable $className *)nullableFromList:(NSArray *)list;');
+  indent.writeln('- (NSArray *)toList;');
+  indent.writeln('@end');
+}
 
-    void writeFromList() {
-      indent.write('+ ($className *)fromList:(NSArray *)list ');
-      indent.scoped('{', '}', () {
-        const String resultName = 'pigeonResult';
-        indent.writeln('$className *$resultName = [[$className alloc] init];');
-        enumerate(getFieldsInSerializationOrder(klass),
-            (int index, final NamedType field) {
-          if (enumNames.contains(field.type.baseName)) {
-            indent.writeln(
-                '$resultName.${field.name} = [${_listGetter(classNames, 'list', field, index, options.prefix)} integerValue];');
-          } else {
-            indent.writeln(
-                '$resultName.${field.name} = ${_listGetter(classNames, 'list', field, index, options.prefix)};');
-            if (!field.type.isNullable) {
-              indent
-                  .writeln('NSAssert($resultName.${field.name} != nil, @"");');
-            }
-          }
-        });
-        indent.writeln('return $resultName;');
-      });
+void _writeObjcSourceDataClassImplementation(ObjcOptions options, Root root,
+    StringSink sink, Indent indent, Class klass) {
+  final Set<String> customClassNames =
+      root.classes.map((Class x) => x.name).toSet();
+  final Set<String> customEnumNames =
+      root.enums.map((Enum x) => x.name).toSet();
+  final String className = _className(options.prefix, klass.name);
+
+  indent.writeln('@implementation $className');
+  _writeInitializer(options, root, sink, indent, klass, customClassNames,
+      customEnumNames, className);
+  _writeClassDecode(options, root, sink, indent, klass, customClassNames,
+      customEnumNames, className);
+  _writeClassEncode(options, root, sink, indent, klass, customClassNames,
+      customEnumNames, className);
+  indent.writeln('@end');
+}
 
-      indent.writeln(
-          '+ (nullable $className *)nullableFromList:(NSArray *)list { return (list) ? [$className fromList:list] : nil; }');
+void _writeInitializer(
+  ObjcOptions options,
+  Root root,
+  StringSink sink,
+  Indent indent,
+  Class klass,
+  Set<String> customClassNames,
+  Set<String> customEnumNames,
+  String className,
+) {
+  _writeInitializerDeclaration(
+      indent, klass, root.classes, root.enums, options.prefix);
+  indent.writeScoped(' {', '}', () {
+    const String result = 'pigeonResult';
+    indent.writeln('$className* $result = [[$className alloc] init];');
+    for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+      indent.writeln('$result.${field.name} = ${field.name};');
     }
+    indent.writeln('return $result;');
+  });
+}
 
-    void writeToList() {
-      indent.write('- (NSArray *)toList ');
-      indent.scoped('{', '}', () {
-        indent.write('return');
-        indent.scoped(' @[', '];', () {
-          for (final NamedType field in klass.fields) {
-            indent.writeln('${_arrayValue(classNames, enumNames, field)},');
-          }
-        });
-      });
-    }
+void _writeClassDecode(
+  ObjcOptions options,
+  Root root,
+  StringSink sink,
+  Indent indent,
+  Class klass,
+  Set<String> customClassNames,
+  Set<String> customEnumNames,
+  String className,
+) {
+  indent.write('+ ($className *)fromList:(NSArray *)list ');
+  indent.scoped('{', '}', () {
+    const String resultName = 'pigeonResult';
+    indent.writeln('$className *$resultName = [[$className alloc] init];');
+    enumerate(getFieldsInSerializationOrder(klass),
+        (int index, final NamedType field) {
+      if (customEnumNames.contains(field.type.baseName)) {
+        indent.writeln(
+            '$resultName.${field.name} = [${_listGetter(customClassNames, 'list', field, index, options.prefix)} integerValue];');
+      } else {
+        indent.writeln(
+            '$resultName.${field.name} = ${_listGetter(customClassNames, 'list', field, index, options.prefix)};');
+        if (!field.type.isNullable) {
+          indent.writeln('NSAssert($resultName.${field.name} != nil, @"");');
+        }
+      }
+    });
+    indent.writeln('return $resultName;');
+  });
 
-    indent.writeln('@implementation $className');
-    writeInitializer();
-    writeFromList();
-    writeToList();
-    indent.writeln('@end');
-  }
+  indent.writeln(
+      '+ (nullable $className *)nullableFromList:(NSArray *)list { return (list) ? [$className fromList:list] : nil; }');
+}
 
+void _writeClassEncode(
+  ObjcOptions options,
+  Root root,
+  StringSink sink,
+  Indent indent,
+  Class klass,
+  Set<String> customClassNames,
+  Set<String> customEnumNames,
+  String className,
+) {
+  indent.write('- (NSArray *)toList ');
+  indent.scoped('{', '}', () {
+    indent.write('return');
+    indent.scoped(' @[', '];', () {
+      for (final NamedType field in klass.fields) {
+        indent.writeln(
+            '${_arrayValue(customClassNames, customEnumNames, field)},');
+      }
+    });
+  });
+}
+
+/// Generates the ".m" file for the AST represented by [root] to [sink] with the
+/// provided [options].
+void generateObjcSource(
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {
   void writeApi(Api api) {
     final String codecName = _getCodecName(options.prefix, api.name);
     if (getCodecClasses(api, root).isNotEmpty) {
@@ -1060,14 +1147,6 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
     }
   }
 
-  writeHelperFunctions();
-  indent.addln('');
-  root.classes.forEach(writeDataClassExtension);
-  indent.writeln('');
-  for (final Class klass in root.classes) {
-    writeDataClassImplementation(klass);
-    indent.writeln('');
-  }
   root.apis.forEach(writeApi);
 }
 

From f5cd262b3d7f536c90532bdc2cd70204b9d14923 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 4 Jan 2023 15:42:40 -0800
Subject: [PATCH 53/87] objc + cpp

---
 packages/pigeon/lib/cpp_generator.dart  | 158 ++++++++++++++----------
 packages/pigeon/lib/objc_generator.dart |  15 ++-
 2 files changed, 108 insertions(+), 65 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 05f7c25306c..cb1fd35dc74 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -159,7 +159,8 @@ class CppGenerator extends Generator<CppOptions> {
     Set<String> customClassNames,
     Set<String> customEnumNames,
   ) {
-    // Left blank until functions fully converted to methods.
+    _writeCppSourceClassEncode(languageOptions, root, sink, indent, klass,
+        customClassNames, customEnumNames);
   }
 
   @override
@@ -173,7 +174,8 @@ class CppGenerator extends Generator<CppOptions> {
     Set<String> customClassNames,
     Set<String> customEnumNames,
   ) {
-    // Left blank until functions fully converted to methods.
+    _writeCppSourceClassDecode(languageOptions, root, sink, indent, klass,
+        customClassNames, customEnumNames);
   }
 }
 
@@ -379,59 +381,15 @@ void _writeCppHeaderDataClass(CppOptions languageOptions, Root root,
   indent.writeln('');
 }
 
-/// Writes the implementation for the custom class [klass].
-///
-/// See [_writeCppHeaderDataClass] for the corresponding declaration.
-/// This is intended to be added to the implementation file.
-void _writeCppSourceDataClass(CppOptions languageOptions, Root root,
-    StringSink sink, Indent indent, Class klass) {
-  final Set<String> rootClassNameSet =
-      root.classes.map((Class x) => x.name).toSet();
-  final Set<String> rootEnumNameSet =
-      root.enums.map((Enum x) => x.name).toSet();
-
-  indent.addln('');
-  indent.writeln('$_commentPrefix ${klass.name}');
-  indent.addln('');
-
-  // Getters and setters.
-  for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-    final HostDatatype hostDatatype = getFieldHostDatatype(field, root.classes,
-        root.enums, (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-    final String instanceVariableName = _makeInstanceVariableName(field);
-    final String qualifiedGetterName =
-        '${klass.name}::${_makeGetterName(field)}';
-    final String qualifiedSetterName =
-        '${klass.name}::${_makeSetterName(field)}';
-    final String returnExpression = hostDatatype.isNullable
-        ? '$instanceVariableName ? &(*$instanceVariableName) : nullptr'
-        : instanceVariableName;
-
-    // Generates the string for a setter treating the type as [type], to allow
-    // generating multiple setter variants.
-    String makeSetter(HostDatatype type) {
-      const String setterArgumentName = 'value_arg';
-      final String valueExpression = type.isNullable
-          ? '$setterArgumentName ? ${_valueType(type)}(*$setterArgumentName) : std::nullopt'
-          : setterArgumentName;
-      return 'void $qualifiedSetterName(${_unownedArgumentType(type)} $setterArgumentName) '
-          '{ $instanceVariableName = $valueExpression; }';
-    }
-
-    indent.writeln(
-        '${_getterReturnType(hostDatatype)} $qualifiedGetterName() const '
-        '{ return $returnExpression; }');
-    indent.writeln(makeSetter(hostDatatype));
-    if (hostDatatype.isNullable) {
-      // Write the non-nullable variant; see _writeCppHeaderDataClass.
-      final HostDatatype nonNullType = _nonNullableType(hostDatatype);
-      indent.writeln(makeSetter(nonNullType));
-    }
-
-    indent.addln('');
-  }
-
-  // Serialization.
+void _writeCppSourceClassEncode(
+  CppOptions languageOptions,
+  Root root,
+  StringSink sink,
+  Indent indent,
+  Class klass,
+  Set<String> customClassNames,
+  Set<String> customEnumNames,
+) {
   indent
       .write('flutter::EncodableList ${klass.name}::ToEncodableList() const ');
   indent.scoped('{', '}', () {
@@ -447,12 +405,12 @@ void _writeCppSourceDataClass(CppOptions languageOptions, Root root,
 
         String encodableValue = '';
         if (!hostDatatype.isBuiltin &&
-            rootClassNameSet.contains(field.type.baseName)) {
+            customClassNames.contains(field.type.baseName)) {
           final String operator = field.type.isNullable ? '->' : '.';
           encodableValue =
               'flutter::EncodableValue($instanceVariable${operator}ToEncodableList())';
         } else if (!hostDatatype.isBuiltin &&
-            rootEnumNameSet.contains(field.type.baseName)) {
+            customEnumNames.contains(field.type.baseName)) {
           final String nonNullValue =
               field.type.isNullable ? '(*$instanceVariable)' : instanceVariable;
           encodableValue = 'flutter::EncodableValue((int)$nonNullValue)';
@@ -472,12 +430,17 @@ void _writeCppSourceDataClass(CppOptions languageOptions, Root root,
     });
   });
   indent.addln('');
+}
 
-  // Default constructor.
-  indent.writeln('${klass.name}::${klass.name}() {}');
-  indent.addln('');
-
-  // Deserialization.
+void _writeCppSourceClassDecode(
+  CppOptions languageOptions,
+  Root root,
+  StringSink sink,
+  Indent indent,
+  Class klass,
+  Set<String> customClassNames,
+  Set<String> customEnumNames,
+) {
   indent.write(
       '${klass.name}::${klass.name}(const flutter::EncodableList& list) ');
   indent.scoped('{', '}', () {
@@ -489,7 +452,7 @@ void _writeCppSourceDataClass(CppOptions languageOptions, Root root,
       final String encodableFieldName =
           '${_encodablePrefix}_${_makeVariableName(field)}';
       indent.writeln('auto& $encodableFieldName = list[$index];');
-      if (rootEnumNameSet.contains(field.type.baseName)) {
+      if (customEnumNames.contains(field.type.baseName)) {
         indent.writeln(
             'if (const int32_t* $pointerFieldName = std::get_if<int32_t>(&$encodableFieldName))\t$instanceVariableName = (${field.type.baseName})*$pointerFieldName;');
       } else {
@@ -527,6 +490,75 @@ else if (const int64_t* ${pointerFieldName}_64 = std::get_if<int64_t>(&$encodabl
   indent.addln('');
 }
 
+void _writeCppSourceClassField(CppOptions languageOptions, Root root,
+    StringSink sink, Indent indent, Class klass, NamedType field) {
+  final HostDatatype hostDatatype = getFieldHostDatatype(field, root.classes,
+      root.enums, (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
+  final String instanceVariableName = _makeInstanceVariableName(field);
+  final String qualifiedGetterName = '${klass.name}::${_makeGetterName(field)}';
+  final String qualifiedSetterName = '${klass.name}::${_makeSetterName(field)}';
+  final String returnExpression = hostDatatype.isNullable
+      ? '$instanceVariableName ? &(*$instanceVariableName) : nullptr'
+      : instanceVariableName;
+
+  // Generates the string for a setter treating the type as [type], to allow
+  // generating multiple setter variants.
+  String makeSetter(HostDatatype type) {
+    const String setterArgumentName = 'value_arg';
+    final String valueExpression = type.isNullable
+        ? '$setterArgumentName ? ${_valueType(type)}(*$setterArgumentName) : std::nullopt'
+        : setterArgumentName;
+    return 'void $qualifiedSetterName(${_unownedArgumentType(type)} $setterArgumentName) '
+        '{ $instanceVariableName = $valueExpression; }';
+  }
+
+  indent.writeln(
+      '${_getterReturnType(hostDatatype)} $qualifiedGetterName() const '
+      '{ return $returnExpression; }');
+  indent.writeln(makeSetter(hostDatatype));
+  if (hostDatatype.isNullable) {
+    // Write the non-nullable variant; see _writeCppHeaderDataClass.
+    final HostDatatype nonNullType = _nonNullableType(hostDatatype);
+    indent.writeln(makeSetter(nonNullType));
+  }
+
+  indent.addln('');
+}
+
+/// Writes the implementation for the custom class [klass].
+///
+/// See [_writeCppHeaderDataClass] for the corresponding declaration.
+/// This is intended to be added to the implementation file.
+void _writeCppSourceDataClass(CppOptions languageOptions, Root root,
+    StringSink sink, Indent indent, Class klass) {
+  final Set<String> customClassNames =
+      root.classes.map((Class x) => x.name).toSet();
+  final Set<String> customEnumNames =
+      root.enums.map((Enum x) => x.name).toSet();
+
+  indent.addln('');
+  indent.writeln('$_commentPrefix ${klass.name}');
+  indent.addln('');
+
+  // Getters and setters.
+  for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+    _writeCppSourceClassField(
+        languageOptions, root, sink, indent, klass, field);
+  }
+
+  // Serialization.
+  _writeCppSourceClassEncode(languageOptions, root, sink, indent, klass,
+      customClassNames, customEnumNames);
+
+  // Default constructor.
+  indent.writeln('${klass.name}::${klass.name}() {}');
+  indent.addln('');
+
+  // Deserialization.
+  _writeCppSourceClassDecode(languageOptions, root, sink, indent, klass,
+      customClassNames, customEnumNames);
+}
+
 void _writeHostApiHeader(Indent indent, Api api, Root root) {
   assert(api.location == ApiLocation.host);
 
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 1d2421f51af..32552eaa447 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -89,6 +89,7 @@ class ObjcGenerator extends Generator<ObjcOptions> {
         indent.writeln(
             '@class ${_className(languageOptions.prefix, klass.name)};');
       }
+      indent.addln('');
     } else if (fileType == FileType.source) {
       _writeObjcSourceHelperFunctions(indent);
       indent.addln('');
@@ -161,7 +162,12 @@ class ObjcGenerator extends Generator<ObjcOptions> {
     Set<String> customClassNames,
     Set<String> customEnumNames,
   ) {
-    // Left blank until functions fully converted to methods.
+    if (fileType == FileType.source) {
+      final String className = _className(languageOptions.prefix, klass.name);
+
+      _writeClassEncode(languageOptions, root, sink, indent, klass,
+          customClassNames, customEnumNames, className);
+    }
   }
 
   @override
@@ -175,7 +181,12 @@ class ObjcGenerator extends Generator<ObjcOptions> {
     Set<String> customClassNames,
     Set<String> customEnumNames,
   ) {
-    // Left blank until functions fully converted to methods.
+    if (fileType == FileType.source) {
+      final String className = _className(languageOptions.prefix, klass.name);
+
+      _writeClassDecode(languageOptions, root, sink, indent, klass,
+          customClassNames, customEnumNames, className);
+    }
   }
 }
 

From b68557b58862925cf8a1a50925734046f3445677 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 4 Jan 2023 18:25:35 -0800
Subject: [PATCH 54/87] Move all migrated methods into class

---
 packages/pigeon/lib/cpp_generator.dart  | 717 ++++++++++++------------
 packages/pigeon/lib/objc_generator.dart | 508 ++++++++---------
 2 files changed, 618 insertions(+), 607 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index cb1fd35dc74..3f94ab2396d 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -144,7 +144,8 @@ class CppGenerator extends Generator<CppOptions> {
       _writeCppHeaderDataClass(languageOptions, root, sink, indent, klass,
           testFriend: testFixtureClass);
     } else {
-      _writeCppSourceDataClass(languageOptions, root, sink, indent, klass);
+      _writeCppSourceDataClass(
+          languageOptions, root, sink, indent, fileType, klass);
     }
   }
 
@@ -177,6 +178,365 @@ class CppGenerator extends Generator<CppOptions> {
     _writeCppSourceClassDecode(languageOptions, root, sink, indent, klass,
         customClassNames, customEnumNames);
   }
+
+  /// Writes the declaration for the custom class [klass].
+  ///
+  /// See [_writeCppSourceDataClass] for the corresponding declaration.
+  /// This is intended to be added to the header.
+  void _writeCppHeaderDataClass(CppOptions languageOptions, Root root,
+      StringSink sink, Indent indent, Class klass,
+      {String? testFriend}) {
+    indent.addln('');
+
+    const List<String> generatedMessages = <String>[
+      ' Generated class from Pigeon that represents data sent in messages.'
+    ];
+
+    addDocumentationComments(
+        indent, klass.documentationComments, _docCommentSpec,
+        generatorComments: generatedMessages);
+
+    indent.write('class ${klass.name} ');
+    indent.scoped('{', '};', () {
+      indent.scoped(' public:', '', () {
+        indent.writeln('${klass.name}();');
+        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+          addDocumentationComments(
+              indent, field.documentationComments, _docCommentSpec);
+          final HostDatatype baseDatatype = getFieldHostDatatype(
+              field,
+              root.classes,
+              root.enums,
+              (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
+          indent.writeln(
+              '${_getterReturnType(baseDatatype)} ${_makeGetterName(field)}() const;');
+          indent.writeln(
+              'void ${_makeSetterName(field)}(${_unownedArgumentType(baseDatatype)} value_arg);');
+          if (field.type.isNullable) {
+            // Add a second setter that takes the non-nullable version of the
+            // argument for convenience, since setting literal values with the
+            // pointer version is non-trivial.
+            final HostDatatype nonNullType = _nonNullableType(baseDatatype);
+            indent.writeln(
+                'void ${_makeSetterName(field)}(${_unownedArgumentType(nonNullType)} value_arg);');
+          }
+          indent.addln('');
+        }
+      });
+
+      indent.scoped(' private:', '', () {
+        indent.writeln('${klass.name}(const flutter::EncodableList& list);');
+        indent.writeln('flutter::EncodableList ToEncodableList() const;');
+        for (final Class friend in root.classes) {
+          if (friend != klass &&
+              friend.fields.any(
+                  (NamedType element) => element.type.baseName == klass.name)) {
+            indent.writeln('friend class ${friend.name};');
+          }
+        }
+        for (final Api api in root.apis) {
+          // TODO(gaaclarke): Find a way to be more precise with our
+          // friendships.
+          indent.writeln('friend class ${api.name};');
+          indent.writeln('friend class ${_getCodecSerializerName(api)};');
+        }
+        if (testFriend != null) {
+          indent.writeln('friend class $testFriend;');
+        }
+
+        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+          final HostDatatype hostDatatype = getFieldHostDatatype(
+              field,
+              root.classes,
+              root.enums,
+              (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
+          indent.writeln(
+              '${_valueType(hostDatatype)} ${_makeInstanceVariableName(field)};');
+        }
+      });
+    }, nestCount: 0);
+    indent.writeln('');
+  }
+
+  void _writeCppSourceClassEncode(
+    CppOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    indent.write(
+        'flutter::EncodableList ${klass.name}::ToEncodableList() const ');
+    indent.scoped('{', '}', () {
+      indent.scoped('return flutter::EncodableList{', '};', () {
+        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+          final HostDatatype hostDatatype = getFieldHostDatatype(
+              field,
+              root.classes,
+              root.enums,
+              (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
+
+          final String instanceVariable = _makeInstanceVariableName(field);
+
+          String encodableValue = '';
+          if (!hostDatatype.isBuiltin &&
+              customClassNames.contains(field.type.baseName)) {
+            final String operator = field.type.isNullable ? '->' : '.';
+            encodableValue =
+                'flutter::EncodableValue($instanceVariable${operator}ToEncodableList())';
+          } else if (!hostDatatype.isBuiltin &&
+              customEnumNames.contains(field.type.baseName)) {
+            final String nonNullValue = field.type.isNullable
+                ? '(*$instanceVariable)'
+                : instanceVariable;
+            encodableValue = 'flutter::EncodableValue((int)$nonNullValue)';
+          } else {
+            final String operator = field.type.isNullable ? '*' : '';
+            encodableValue =
+                'flutter::EncodableValue($operator$instanceVariable)';
+          }
+
+          if (field.type.isNullable) {
+            encodableValue =
+                '$instanceVariable ? $encodableValue : flutter::EncodableValue()';
+          }
+
+          indent.writeln('$encodableValue,');
+        }
+      });
+    });
+    indent.addln('');
+  }
+
+  void _writeCppSourceClassDecode(
+    CppOptions languageOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    indent.write(
+        '${klass.name}::${klass.name}(const flutter::EncodableList& list) ');
+    indent.scoped('{', '}', () {
+      enumerate(getFieldsInSerializationOrder(klass),
+          (int index, final NamedType field) {
+        final String instanceVariableName = _makeInstanceVariableName(field);
+        final String pointerFieldName =
+            '${_pointerPrefix}_${_makeVariableName(field)}';
+        final String encodableFieldName =
+            '${_encodablePrefix}_${_makeVariableName(field)}';
+        indent.writeln('auto& $encodableFieldName = list[$index];');
+        if (customEnumNames.contains(field.type.baseName)) {
+          indent.writeln(
+              'if (const int32_t* $pointerFieldName = std::get_if<int32_t>(&$encodableFieldName))\t$instanceVariableName = (${field.type.baseName})*$pointerFieldName;');
+        } else {
+          final HostDatatype hostDatatype = getFieldHostDatatype(
+              field,
+              root.classes,
+              root.enums,
+              (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
+          if (field.type.baseName == 'int') {
+            indent.format('''
+if (const int32_t* $pointerFieldName = std::get_if<int32_t>(&$encodableFieldName))
+\t$instanceVariableName = *$pointerFieldName;
+else if (const int64_t* ${pointerFieldName}_64 = std::get_if<int64_t>(&$encodableFieldName))
+\t$instanceVariableName = *${pointerFieldName}_64;''');
+          } else if (!hostDatatype.isBuiltin &&
+              root.classes
+                  .map((Class x) => x.name)
+                  .contains(field.type.baseName)) {
+            indent.write(
+                'if (const flutter::EncodableList* $pointerFieldName = std::get_if<flutter::EncodableList>(&$encodableFieldName)) ');
+            indent.scoped('{', '}', () {
+              indent.writeln(
+                  '$instanceVariableName = ${hostDatatype.datatype}(*$pointerFieldName);');
+            });
+          } else {
+            indent.write(
+                'if (const ${hostDatatype.datatype}* $pointerFieldName = std::get_if<${hostDatatype.datatype}>(&$encodableFieldName)) ');
+            indent.scoped('{', '}', () {
+              indent.writeln('$instanceVariableName = *$pointerFieldName;');
+            });
+          }
+        }
+      });
+    });
+    indent.addln('');
+  }
+
+  void _writeCppSourceClassField(CppOptions languageOptions, Root root,
+      StringSink sink, Indent indent, Class klass, NamedType field) {
+    final HostDatatype hostDatatype = getFieldHostDatatype(field, root.classes,
+        root.enums, (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
+    final String instanceVariableName = _makeInstanceVariableName(field);
+    final String qualifiedGetterName =
+        '${klass.name}::${_makeGetterName(field)}';
+    final String qualifiedSetterName =
+        '${klass.name}::${_makeSetterName(field)}';
+    final String returnExpression = hostDatatype.isNullable
+        ? '$instanceVariableName ? &(*$instanceVariableName) : nullptr'
+        : instanceVariableName;
+
+    // Generates the string for a setter treating the type as [type], to allow
+    // generating multiple setter variants.
+    String makeSetter(HostDatatype type) {
+      const String setterArgumentName = 'value_arg';
+      final String valueExpression = type.isNullable
+          ? '$setterArgumentName ? ${_valueType(type)}(*$setterArgumentName) : std::nullopt'
+          : setterArgumentName;
+      return 'void $qualifiedSetterName(${_unownedArgumentType(type)} $setterArgumentName) '
+          '{ $instanceVariableName = $valueExpression; }';
+    }
+
+    indent.writeln(
+        '${_getterReturnType(hostDatatype)} $qualifiedGetterName() const '
+        '{ return $returnExpression; }');
+    indent.writeln(makeSetter(hostDatatype));
+    if (hostDatatype.isNullable) {
+      // Write the non-nullable variant; see _writeCppHeaderDataClass.
+      final HostDatatype nonNullType = _nonNullableType(hostDatatype);
+      indent.writeln(makeSetter(nonNullType));
+    }
+
+    indent.addln('');
+  }
+
+  /// Writes the implementation for the custom class [klass].
+  ///
+  /// See [_writeCppHeaderDataClass] for the corresponding declaration.
+  /// This is intended to be added to the implementation file.
+  void _writeCppSourceDataClass(CppOptions languageOptions, Root root,
+      StringSink sink, Indent indent, FileType fileType, Class klass) {
+    final Set<String> customClassNames =
+        root.classes.map((Class x) => x.name).toSet();
+    final Set<String> customEnumNames =
+        root.enums.map((Enum x) => x.name).toSet();
+
+    indent.addln('');
+    indent.writeln('$_commentPrefix ${klass.name}');
+    indent.addln('');
+
+    // Getters and setters.
+    for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+      _writeCppSourceClassField(
+          languageOptions, root, sink, indent, klass, field);
+    }
+
+    // Serialization.
+    writeClassEncode(languageOptions, root, sink, indent, fileType, klass,
+        customClassNames, customEnumNames);
+
+    // Default constructor.
+    indent.writeln('${klass.name}::${klass.name}() {}');
+    indent.addln('');
+
+    // Deserialization.
+    writeClassDecode(languageOptions, root, sink, indent, fileType, klass,
+        customClassNames, customEnumNames);
+  }
+
+  /// Writes Cpp header file header to sink.
+  void writeCppHeaderHeader(
+      CppOptions options, Root root, StringSink sink, Indent indent) {
+    if (options.copyrightHeader != null) {
+      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('$_commentPrefix $generatedCodeWarning');
+    indent.writeln('$_commentPrefix $seeAlsoWarning');
+    indent.addln('');
+  }
+
+  /// Writes Cpp header file imports to sink.
+  void writeCppHeaderImports(
+      CppOptions options, Root root, StringSink sink, Indent indent) {
+    final String guardName =
+        _getGuardName(options.headerIncludePath, options.namespace);
+    indent.writeln('#ifndef $guardName');
+    indent.writeln('#define $guardName');
+
+    _writeSystemHeaderIncludeBlock(indent, <String>[
+      'flutter/basic_message_channel.h',
+      'flutter/binary_messenger.h',
+      'flutter/encodable_value.h',
+      'flutter/standard_message_codec.h',
+    ]);
+    indent.addln('');
+    _writeSystemHeaderIncludeBlock(indent, <String>[
+      'map',
+      'string',
+      'optional',
+    ]);
+    indent.addln('');
+    if (options.namespace != null) {
+      indent.writeln('namespace ${options.namespace} {');
+    }
+    indent.addln('');
+    if (options.namespace?.endsWith('_pigeontest') ?? false) {
+      final String testFixtureClass =
+          '${_pascalCaseFromSnakeCase(options.namespace!.replaceAll('_pigeontest', ''))}Test';
+      indent.writeln('class $testFixtureClass;');
+    }
+    indent.addln('');
+    indent.writeln('$_commentPrefix Generated class from Pigeon.');
+  }
+
+  /// Writes Cpp header enum to sink.
+  void writeCppHeaderEnum(CppOptions options, Root root, StringSink sink,
+      Indent indent, Enum anEnum) {
+    indent.writeln('');
+    addDocumentationComments(
+        indent, anEnum.documentationComments, _docCommentSpec);
+    indent.write('enum class ${anEnum.name} ');
+    indent.scoped('{', '};', () {
+      enumerate(anEnum.members, (int index, final EnumMember member) {
+        addDocumentationComments(
+            indent, member.documentationComments, _docCommentSpec);
+        indent.writeln(
+            '${member.name} = $index${index == anEnum.members.length - 1 ? '' : ','}');
+      });
+    });
+  }
+
+  /// Writes Cpp source file header to sink.
+  void writeCppSourceHeader(
+      CppOptions options, Root root, StringSink sink, Indent indent) {
+    if (options.copyrightHeader != null) {
+      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('$_commentPrefix $generatedCodeWarning');
+    indent.writeln('$_commentPrefix $seeAlsoWarning');
+    indent.addln('');
+    indent.addln('#undef _HAS_EXCEPTIONS');
+    indent.addln('');
+  }
+
+  /// Writes Cpp source file imports to sink.
+  void writeCppSourceImports(
+      CppOptions options, Root root, StringSink sink, Indent indent) {
+    indent.writeln('#include "${options.headerIncludePath}"');
+    indent.addln('');
+    _writeSystemHeaderIncludeBlock(indent, <String>[
+      'flutter/basic_message_channel.h',
+      'flutter/binary_messenger.h',
+      'flutter/encodable_value.h',
+      'flutter/standard_message_codec.h',
+    ]);
+    indent.addln('');
+    _writeSystemHeaderIncludeBlock(indent, <String>[
+      'map',
+      'string',
+      'optional',
+    ]);
+    indent.addln('');
+
+    if (options.namespace != null) {
+      indent.writeln('namespace ${options.namespace} {');
+    }
+  }
 }
 
 String _getCodecSerializerName(Api api) => '${api.name}CodecSerializer';
@@ -303,262 +663,6 @@ $friendLines
 ''');
 }
 
-/// Writes the declaration for the custom class [klass].
-///
-/// See [_writeCppSourceDataClass] for the corresponding declaration.
-/// This is intended to be added to the header.
-void _writeCppHeaderDataClass(CppOptions languageOptions, Root root,
-    StringSink sink, Indent indent, Class klass,
-    {String? testFriend}) {
-  indent.addln('');
-
-  const List<String> generatedMessages = <String>[
-    ' Generated class from Pigeon that represents data sent in messages.'
-  ];
-
-  addDocumentationComments(indent, klass.documentationComments, _docCommentSpec,
-      generatorComments: generatedMessages);
-
-  indent.write('class ${klass.name} ');
-  indent.scoped('{', '};', () {
-    indent.scoped(' public:', '', () {
-      indent.writeln('${klass.name}();');
-      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-        addDocumentationComments(
-            indent, field.documentationComments, _docCommentSpec);
-        final HostDatatype baseDatatype = getFieldHostDatatype(
-            field,
-            root.classes,
-            root.enums,
-            (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-        indent.writeln(
-            '${_getterReturnType(baseDatatype)} ${_makeGetterName(field)}() const;');
-        indent.writeln(
-            'void ${_makeSetterName(field)}(${_unownedArgumentType(baseDatatype)} value_arg);');
-        if (field.type.isNullable) {
-          // Add a second setter that takes the non-nullable version of the
-          // argument for convenience, since setting literal values with the
-          // pointer version is non-trivial.
-          final HostDatatype nonNullType = _nonNullableType(baseDatatype);
-          indent.writeln(
-              'void ${_makeSetterName(field)}(${_unownedArgumentType(nonNullType)} value_arg);');
-        }
-        indent.addln('');
-      }
-    });
-
-    indent.scoped(' private:', '', () {
-      indent.writeln('${klass.name}(const flutter::EncodableList& list);');
-      indent.writeln('flutter::EncodableList ToEncodableList() const;');
-      for (final Class friend in root.classes) {
-        if (friend != klass &&
-            friend.fields.any(
-                (NamedType element) => element.type.baseName == klass.name)) {
-          indent.writeln('friend class ${friend.name};');
-        }
-      }
-      for (final Api api in root.apis) {
-        // TODO(gaaclarke): Find a way to be more precise with our
-        // friendships.
-        indent.writeln('friend class ${api.name};');
-        indent.writeln('friend class ${_getCodecSerializerName(api)};');
-      }
-      if (testFriend != null) {
-        indent.writeln('friend class $testFriend;');
-      }
-
-      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-        final HostDatatype hostDatatype = getFieldHostDatatype(
-            field,
-            root.classes,
-            root.enums,
-            (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-        indent.writeln(
-            '${_valueType(hostDatatype)} ${_makeInstanceVariableName(field)};');
-      }
-    });
-  }, nestCount: 0);
-  indent.writeln('');
-}
-
-void _writeCppSourceClassEncode(
-  CppOptions languageOptions,
-  Root root,
-  StringSink sink,
-  Indent indent,
-  Class klass,
-  Set<String> customClassNames,
-  Set<String> customEnumNames,
-) {
-  indent
-      .write('flutter::EncodableList ${klass.name}::ToEncodableList() const ');
-  indent.scoped('{', '}', () {
-    indent.scoped('return flutter::EncodableList{', '};', () {
-      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-        final HostDatatype hostDatatype = getFieldHostDatatype(
-            field,
-            root.classes,
-            root.enums,
-            (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-
-        final String instanceVariable = _makeInstanceVariableName(field);
-
-        String encodableValue = '';
-        if (!hostDatatype.isBuiltin &&
-            customClassNames.contains(field.type.baseName)) {
-          final String operator = field.type.isNullable ? '->' : '.';
-          encodableValue =
-              'flutter::EncodableValue($instanceVariable${operator}ToEncodableList())';
-        } else if (!hostDatatype.isBuiltin &&
-            customEnumNames.contains(field.type.baseName)) {
-          final String nonNullValue =
-              field.type.isNullable ? '(*$instanceVariable)' : instanceVariable;
-          encodableValue = 'flutter::EncodableValue((int)$nonNullValue)';
-        } else {
-          final String operator = field.type.isNullable ? '*' : '';
-          encodableValue =
-              'flutter::EncodableValue($operator$instanceVariable)';
-        }
-
-        if (field.type.isNullable) {
-          encodableValue =
-              '$instanceVariable ? $encodableValue : flutter::EncodableValue()';
-        }
-
-        indent.writeln('$encodableValue,');
-      }
-    });
-  });
-  indent.addln('');
-}
-
-void _writeCppSourceClassDecode(
-  CppOptions languageOptions,
-  Root root,
-  StringSink sink,
-  Indent indent,
-  Class klass,
-  Set<String> customClassNames,
-  Set<String> customEnumNames,
-) {
-  indent.write(
-      '${klass.name}::${klass.name}(const flutter::EncodableList& list) ');
-  indent.scoped('{', '}', () {
-    enumerate(getFieldsInSerializationOrder(klass),
-        (int index, final NamedType field) {
-      final String instanceVariableName = _makeInstanceVariableName(field);
-      final String pointerFieldName =
-          '${_pointerPrefix}_${_makeVariableName(field)}';
-      final String encodableFieldName =
-          '${_encodablePrefix}_${_makeVariableName(field)}';
-      indent.writeln('auto& $encodableFieldName = list[$index];');
-      if (customEnumNames.contains(field.type.baseName)) {
-        indent.writeln(
-            'if (const int32_t* $pointerFieldName = std::get_if<int32_t>(&$encodableFieldName))\t$instanceVariableName = (${field.type.baseName})*$pointerFieldName;');
-      } else {
-        final HostDatatype hostDatatype = getFieldHostDatatype(
-            field,
-            root.classes,
-            root.enums,
-            (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-        if (field.type.baseName == 'int') {
-          indent.format('''
-if (const int32_t* $pointerFieldName = std::get_if<int32_t>(&$encodableFieldName))
-\t$instanceVariableName = *$pointerFieldName;
-else if (const int64_t* ${pointerFieldName}_64 = std::get_if<int64_t>(&$encodableFieldName))
-\t$instanceVariableName = *${pointerFieldName}_64;''');
-        } else if (!hostDatatype.isBuiltin &&
-            root.classes
-                .map((Class x) => x.name)
-                .contains(field.type.baseName)) {
-          indent.write(
-              'if (const flutter::EncodableList* $pointerFieldName = std::get_if<flutter::EncodableList>(&$encodableFieldName)) ');
-          indent.scoped('{', '}', () {
-            indent.writeln(
-                '$instanceVariableName = ${hostDatatype.datatype}(*$pointerFieldName);');
-          });
-        } else {
-          indent.write(
-              'if (const ${hostDatatype.datatype}* $pointerFieldName = std::get_if<${hostDatatype.datatype}>(&$encodableFieldName)) ');
-          indent.scoped('{', '}', () {
-            indent.writeln('$instanceVariableName = *$pointerFieldName;');
-          });
-        }
-      }
-    });
-  });
-  indent.addln('');
-}
-
-void _writeCppSourceClassField(CppOptions languageOptions, Root root,
-    StringSink sink, Indent indent, Class klass, NamedType field) {
-  final HostDatatype hostDatatype = getFieldHostDatatype(field, root.classes,
-      root.enums, (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-  final String instanceVariableName = _makeInstanceVariableName(field);
-  final String qualifiedGetterName = '${klass.name}::${_makeGetterName(field)}';
-  final String qualifiedSetterName = '${klass.name}::${_makeSetterName(field)}';
-  final String returnExpression = hostDatatype.isNullable
-      ? '$instanceVariableName ? &(*$instanceVariableName) : nullptr'
-      : instanceVariableName;
-
-  // Generates the string for a setter treating the type as [type], to allow
-  // generating multiple setter variants.
-  String makeSetter(HostDatatype type) {
-    const String setterArgumentName = 'value_arg';
-    final String valueExpression = type.isNullable
-        ? '$setterArgumentName ? ${_valueType(type)}(*$setterArgumentName) : std::nullopt'
-        : setterArgumentName;
-    return 'void $qualifiedSetterName(${_unownedArgumentType(type)} $setterArgumentName) '
-        '{ $instanceVariableName = $valueExpression; }';
-  }
-
-  indent.writeln(
-      '${_getterReturnType(hostDatatype)} $qualifiedGetterName() const '
-      '{ return $returnExpression; }');
-  indent.writeln(makeSetter(hostDatatype));
-  if (hostDatatype.isNullable) {
-    // Write the non-nullable variant; see _writeCppHeaderDataClass.
-    final HostDatatype nonNullType = _nonNullableType(hostDatatype);
-    indent.writeln(makeSetter(nonNullType));
-  }
-
-  indent.addln('');
-}
-
-/// Writes the implementation for the custom class [klass].
-///
-/// See [_writeCppHeaderDataClass] for the corresponding declaration.
-/// This is intended to be added to the implementation file.
-void _writeCppSourceDataClass(CppOptions languageOptions, Root root,
-    StringSink sink, Indent indent, Class klass) {
-  final Set<String> customClassNames =
-      root.classes.map((Class x) => x.name).toSet();
-  final Set<String> customEnumNames =
-      root.enums.map((Enum x) => x.name).toSet();
-
-  indent.addln('');
-  indent.writeln('$_commentPrefix ${klass.name}');
-  indent.addln('');
-
-  // Getters and setters.
-  for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-    _writeCppSourceClassField(
-        languageOptions, root, sink, indent, klass, field);
-  }
-
-  // Serialization.
-  _writeCppSourceClassEncode(languageOptions, root, sink, indent, klass,
-      customClassNames, customEnumNames);
-
-  // Default constructor.
-  indent.writeln('${klass.name}::${klass.name}() {}');
-  indent.addln('');
-
-  // Deserialization.
-  _writeCppSourceClassDecode(languageOptions, root, sink, indent, klass,
-      customClassNames, customEnumNames);
-}
-
 void _writeHostApiHeader(Indent indent, Api api, Root root) {
   assert(api.location == ApiLocation.host);
 
@@ -1156,68 +1260,6 @@ void _writeSystemHeaderIncludeBlock(Indent indent, List<String> headers) {
   }
 }
 
-/// Writes Cpp header file header to sink.
-void writeCppHeaderHeader(
-    CppOptions options, Root root, StringSink sink, Indent indent) {
-  if (options.copyrightHeader != null) {
-    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-  }
-  indent.writeln('$_commentPrefix $generatedCodeWarning');
-  indent.writeln('$_commentPrefix $seeAlsoWarning');
-  indent.addln('');
-}
-
-/// Writes Cpp header file imports to sink.
-void writeCppHeaderImports(
-    CppOptions options, Root root, StringSink sink, Indent indent) {
-  final String guardName =
-      _getGuardName(options.headerIncludePath, options.namespace);
-  indent.writeln('#ifndef $guardName');
-  indent.writeln('#define $guardName');
-
-  _writeSystemHeaderIncludeBlock(indent, <String>[
-    'flutter/basic_message_channel.h',
-    'flutter/binary_messenger.h',
-    'flutter/encodable_value.h',
-    'flutter/standard_message_codec.h',
-  ]);
-  indent.addln('');
-  _writeSystemHeaderIncludeBlock(indent, <String>[
-    'map',
-    'string',
-    'optional',
-  ]);
-  indent.addln('');
-  if (options.namespace != null) {
-    indent.writeln('namespace ${options.namespace} {');
-  }
-  indent.addln('');
-  if (options.namespace?.endsWith('_pigeontest') ?? false) {
-    final String testFixtureClass =
-        '${_pascalCaseFromSnakeCase(options.namespace!.replaceAll('_pigeontest', ''))}Test';
-    indent.writeln('class $testFixtureClass;');
-  }
-  indent.addln('');
-  indent.writeln('$_commentPrefix Generated class from Pigeon.');
-}
-
-/// Writes Cpp header enum to sink.
-void writeCppHeaderEnum(CppOptions options, Root root, StringSink sink,
-    Indent indent, Enum anEnum) {
-  indent.writeln('');
-  addDocumentationComments(
-      indent, anEnum.documentationComments, _docCommentSpec);
-  indent.write('enum class ${anEnum.name} ');
-  indent.scoped('{', '};', () {
-    enumerate(anEnum.members, (int index, final EnumMember member) {
-      addDocumentationComments(
-          indent, member.documentationComments, _docCommentSpec);
-      indent.writeln(
-          '${member.name} = $index${index == anEnum.members.length - 1 ? '' : ','}');
-    });
-  });
-}
-
 /// Generates the ".h" file for the AST represented by [root] to [sink] with the
 /// provided [options] and [headerFileName].
 void generateCppHeader(
@@ -1242,43 +1284,6 @@ void generateCppHeader(
   indent.writeln('#endif  // $guardName');
 }
 
-/// Writes Cpp source file header to sink.
-void writeCppSourceHeader(
-    CppOptions options, Root root, StringSink sink, Indent indent) {
-  if (options.copyrightHeader != null) {
-    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-  }
-  indent.writeln('$_commentPrefix $generatedCodeWarning');
-  indent.writeln('$_commentPrefix $seeAlsoWarning');
-  indent.addln('');
-  indent.addln('#undef _HAS_EXCEPTIONS');
-  indent.addln('');
-}
-
-/// Writes Cpp source file imports to sink.
-void writeCppSourceImports(
-    CppOptions options, Root root, StringSink sink, Indent indent) {
-  indent.writeln('#include "${options.headerIncludePath}"');
-  indent.addln('');
-  _writeSystemHeaderIncludeBlock(indent, <String>[
-    'flutter/basic_message_channel.h',
-    'flutter/binary_messenger.h',
-    'flutter/encodable_value.h',
-    'flutter/standard_message_codec.h',
-  ]);
-  indent.addln('');
-  _writeSystemHeaderIncludeBlock(indent, <String>[
-    'map',
-    'string',
-    'optional',
-  ]);
-  indent.addln('');
-
-  if (options.namespace != null) {
-    indent.writeln('namespace ${options.namespace} {');
-  }
-}
-
 /// Generates the ".cpp" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateCppSource(
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 32552eaa447..3cf8021c002 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -146,7 +146,7 @@ class ObjcGenerator extends Generator<ObjcOptions> {
       _writeObjcHeaderDataClass(languageOptions, root, sink, indent, klass);
     } else {
       _writeObjcSourceDataClassImplementation(
-          languageOptions, root, sink, indent, klass);
+          languageOptions, root, sink, indent, fileType, klass);
       indent.writeln('');
     }
   }
@@ -165,7 +165,7 @@ class ObjcGenerator extends Generator<ObjcOptions> {
     if (fileType == FileType.source) {
       final String className = _className(languageOptions.prefix, klass.name);
 
-      _writeClassEncode(languageOptions, root, sink, indent, klass,
+      _writeObjcSourceClassEncode(languageOptions, root, sink, indent, klass,
           customClassNames, customEnumNames, className);
     }
   }
@@ -184,10 +184,263 @@ class ObjcGenerator extends Generator<ObjcOptions> {
     if (fileType == FileType.source) {
       final String className = _className(languageOptions.prefix, klass.name);
 
-      _writeClassDecode(languageOptions, root, sink, indent, klass,
+      _writeObjcSourceClassDecode(languageOptions, root, sink, indent, klass,
           customClassNames, customEnumNames, className);
     }
   }
+
+  // Header File Methods.
+
+  /// Writes the class declaration for a data class.
+  ///
+  /// Example:
+  /// @interface Foo : NSObject
+  /// @property (nonatomic, copy) NSString *bar;
+  /// @end
+  void _writeObjcHeaderDataClass(ObjcOptions languageOptions, Root root,
+      StringSink sink, Indent indent, Class klass) {
+    final List<Class> classes = root.classes;
+    final List<Enum> enums = root.enums;
+    final String? prefix = languageOptions.prefix;
+    final List<String> customEnumNames = enums.map((Enum x) => x.name).toList();
+
+    addDocumentationComments(
+        indent, klass.documentationComments, _docCommentSpec);
+
+    indent.writeln('@interface ${_className(prefix, klass.name)} : NSObject');
+    if (getFieldsInSerializationOrder(klass).isNotEmpty) {
+      if (getFieldsInSerializationOrder(klass)
+          .map((NamedType e) => !e.type.isNullable)
+          .any((bool e) => e)) {
+        indent.writeln(
+            '$_docCommentPrefix `init` unavailable to enforce nonnull fields, see the `make` class method.');
+        indent.writeln('- (instancetype)init NS_UNAVAILABLE;');
+      }
+      _writeObjcSourceClassInitializerDeclaration(
+          indent, klass, classes, enums, prefix);
+      indent.addln(';');
+    }
+    for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+      final HostDatatype hostDatatype = getFieldHostDatatype(
+          field,
+          classes,
+          enums,
+          (TypeDeclaration x) => _objcTypePtrForPrimitiveDartType(prefix, x),
+          customResolver: customEnumNames.contains(field.type.baseName)
+              ? (String x) => _className(prefix, x)
+              : (String x) => '${_className(prefix, x)} *');
+      late final String propertyType;
+      addDocumentationComments(
+          indent, field.documentationComments, _docCommentSpec);
+      if (customEnumNames.contains(field.type.baseName)) {
+        propertyType = 'assign';
+      } else {
+        propertyType = _propertyTypeForDartType(field);
+      }
+      final String nullability =
+          _isNullable(hostDatatype, field.type) ? ', nullable' : '';
+      indent.writeln(
+          '@property(nonatomic, $propertyType$nullability) ${hostDatatype.datatype} ${field.name};');
+    }
+    indent.writeln('@end');
+    indent.writeln('');
+  }
+
+  /// Writes Objc header file header to sink.
+  void writeObjcHeaderHeader(
+      ObjcOptions options, Root root, StringSink sink, Indent indent) {
+    if (options.copyrightHeader != null) {
+      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('// $generatedCodeWarning');
+    indent.writeln('// $seeAlsoWarning');
+    indent.addln('');
+  }
+
+  /// Writes Objc header file imports to sink.
+  void writeObjcHeaderImports(
+      ObjcOptions options, Root root, StringSink sink, Indent indent) {
+    indent.writeln('#import <Foundation/Foundation.h>');
+    indent.addln('');
+
+    indent.writeln('@protocol FlutterBinaryMessenger;');
+    indent.writeln('@protocol FlutterMessageCodec;');
+    indent.writeln('@class FlutterError;');
+    indent.writeln('@class FlutterStandardTypedData;');
+    indent.addln('');
+  }
+
+  /// Writes single Objc header enum.
+  void writeObjcHeaderEnum(ObjcOptions options, Root root, StringSink sink,
+      Indent indent, Enum anEnum) {
+    final String enumName = _className(options.prefix, anEnum.name);
+    addDocumentationComments(
+        indent, anEnum.documentationComments, _docCommentSpec);
+
+    indent.write('typedef NS_ENUM(NSUInteger, $enumName) ');
+    indent.scoped('{', '};', () {
+      enumerate(anEnum.members, (int index, final EnumMember member) {
+        addDocumentationComments(
+            indent, member.documentationComments, _docCommentSpec);
+        // Capitalized first letter to ensure Swift compatibility
+        indent.writeln(
+            '$enumName${member.name[0].toUpperCase()}${member.name.substring(1)} = $index,');
+      });
+    });
+  }
+
+  // Source File Methods.
+
+  /// Writes Objc Source file header to sink.
+  void writeObjcSourceHeader(
+      ObjcOptions options, Root root, StringSink sink, Indent indent) {
+    if (options.copyrightHeader != null) {
+      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('// $generatedCodeWarning');
+    indent.writeln('// $seeAlsoWarning');
+    indent.addln('');
+  }
+
+  /// Writes Objc source file imports to sink.
+  void writeObjcSourceImports(
+      ObjcOptions options, Root root, StringSink sink, Indent indent) {
+    indent.writeln('#import "${options.headerIncludePath}"');
+    indent.writeln('#import <Flutter/Flutter.h>');
+    indent.addln('');
+
+    indent.writeln('#if !__has_feature(objc_arc)');
+    indent.writeln('#error File requires ARC to be enabled.');
+    indent.writeln('#endif');
+    indent.addln('');
+  }
+
+  void _writeObjcSourceHelperFunctions(Indent indent) {
+    indent.format('''
+static NSArray *wrapResult(id result, FlutterError *error) {
+\tif (error) {
+\t\treturn @[ error.code ?: [NSNull null], error.message ?: [NSNull null], error.details ?: [NSNull null] ];
+\t}
+\treturn @[ result ?: [NSNull null]  ];
+}''');
+    indent.format('''
+static id GetNullableObject(NSDictionary* dict, id key) {
+\tid result = dict[key];
+\treturn (result == [NSNull null]) ? nil : result;
+}
+static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
+\tid result = array[key];
+\treturn (result == [NSNull null]) ? nil : result;
+}
+''');
+  }
+
+  void _writeObjcSourceDataClassExtension(
+      ObjcOptions languageOptions, Indent indent, Class klass) {
+    final String className = _className(languageOptions.prefix, klass.name);
+    indent.writeln('@interface $className ()');
+    indent.writeln('+ ($className *)fromList:(NSArray *)list;');
+    indent
+        .writeln('+ (nullable $className *)nullableFromList:(NSArray *)list;');
+    indent.writeln('- (NSArray *)toList;');
+    indent.writeln('@end');
+  }
+
+  void _writeObjcSourceDataClassImplementation(ObjcOptions options, Root root,
+      StringSink sink, Indent indent, FileType fileType, Class klass) {
+    final Set<String> customClassNames =
+        root.classes.map((Class x) => x.name).toSet();
+    final Set<String> customEnumNames =
+        root.enums.map((Enum x) => x.name).toSet();
+    final String className = _className(options.prefix, klass.name);
+
+    indent.writeln('@implementation $className');
+    _writeObjcSourceClassInitializer(options, root, sink, indent, klass,
+        customClassNames, customEnumNames, className);
+    writeClassDecode(options, root, sink, indent, fileType, klass,
+        customClassNames, customEnumNames);
+    writeClassEncode(options, root, sink, indent, fileType, klass,
+        customClassNames, customEnumNames);
+    indent.writeln('@end');
+  }
+
+  void _writeObjcSourceClassInitializer(
+    ObjcOptions options,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+    String className,
+  ) {
+    _writeObjcSourceClassInitializerDeclaration(
+        indent, klass, root.classes, root.enums, options.prefix);
+    indent.writeScoped(' {', '}', () {
+      const String result = 'pigeonResult';
+      indent.writeln('$className* $result = [[$className alloc] init];');
+      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+        indent.writeln('$result.${field.name} = ${field.name};');
+      }
+      indent.writeln('return $result;');
+    });
+  }
+
+  void _writeObjcSourceClassDecode(
+    ObjcOptions options,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+    String className,
+  ) {
+    indent.write('+ ($className *)fromList:(NSArray *)list ');
+    indent.scoped('{', '}', () {
+      const String resultName = 'pigeonResult';
+      indent.writeln('$className *$resultName = [[$className alloc] init];');
+      enumerate(getFieldsInSerializationOrder(klass),
+          (int index, final NamedType field) {
+        if (customEnumNames.contains(field.type.baseName)) {
+          indent.writeln(
+              '$resultName.${field.name} = [${_listGetter(customClassNames, 'list', field, index, options.prefix)} integerValue];');
+        } else {
+          indent.writeln(
+              '$resultName.${field.name} = ${_listGetter(customClassNames, 'list', field, index, options.prefix)};');
+          if (!field.type.isNullable) {
+            indent.writeln('NSAssert($resultName.${field.name} != nil, @"");');
+          }
+        }
+      });
+      indent.writeln('return $resultName;');
+    });
+
+    indent.writeln(
+        '+ (nullable $className *)nullableFromList:(NSArray *)list { return (list) ? [$className fromList:list] : nil; }');
+  }
+
+  void _writeObjcSourceClassEncode(
+    ObjcOptions options,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+    String className,
+  ) {
+    indent.write('- (NSArray *)toList ');
+    indent.scoped('{', '}', () {
+      indent.write('return');
+      indent.scoped(' @[', '];', () {
+        for (final NamedType field in klass.fields) {
+          indent.writeln(
+              '${_arrayValue(customClassNames, customEnumNames, field)},');
+        }
+      });
+    });
+  }
 }
 
 /// Calculates the ObjC class name, possibly prefixed.
@@ -289,7 +542,7 @@ bool _isNullable(HostDatatype hostDatatype, TypeDeclaration type) =>
 /// Writes the method declaration for the initializer.
 ///
 /// Example '+ (instancetype)makeWithFoo:(NSString *)foo'
-void _writeInitializerDeclaration(Indent indent, Class klass,
+void _writeObjcSourceClassInitializerDeclaration(Indent indent, Class klass,
     List<Class> classes, List<Enum> enums, String? prefix) {
   final List<String> customEnumNames = enums.map((Enum x) => x.name).toList();
   indent.write('+ (instancetype)makeWith');
@@ -319,60 +572,6 @@ void _writeInitializerDeclaration(Indent indent, Class klass,
   });
 }
 
-/// Writes the class declaration for a data class.
-///
-/// Example:
-/// @interface Foo : NSObject
-/// @property (nonatomic, copy) NSString *bar;
-/// @end
-void _writeObjcHeaderDataClass(ObjcOptions languageOptions, Root root,
-    StringSink sink, Indent indent, Class klass) {
-  final List<Class> classes = root.classes;
-  final List<Enum> enums = root.enums;
-  final String? prefix = languageOptions.prefix;
-  final List<String> customEnumNames = enums.map((Enum x) => x.name).toList();
-
-  addDocumentationComments(
-      indent, klass.documentationComments, _docCommentSpec);
-
-  indent.writeln('@interface ${_className(prefix, klass.name)} : NSObject');
-  if (getFieldsInSerializationOrder(klass).isNotEmpty) {
-    if (getFieldsInSerializationOrder(klass)
-        .map((NamedType e) => !e.type.isNullable)
-        .any((bool e) => e)) {
-      indent.writeln(
-          '$_docCommentPrefix `init` unavailable to enforce nonnull fields, see the `make` class method.');
-      indent.writeln('- (instancetype)init NS_UNAVAILABLE;');
-    }
-    _writeInitializerDeclaration(indent, klass, classes, enums, prefix);
-    indent.addln(';');
-  }
-  for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-    final HostDatatype hostDatatype = getFieldHostDatatype(
-        field,
-        classes,
-        enums,
-        (TypeDeclaration x) => _objcTypePtrForPrimitiveDartType(prefix, x),
-        customResolver: customEnumNames.contains(field.type.baseName)
-            ? (String x) => _className(prefix, x)
-            : (String x) => '${_className(prefix, x)} *');
-    late final String propertyType;
-    addDocumentationComments(
-        indent, field.documentationComments, _docCommentSpec);
-    if (customEnumNames.contains(field.type.baseName)) {
-      propertyType = 'assign';
-    } else {
-      propertyType = _propertyTypeForDartType(field);
-    }
-    final String nullability =
-        _isNullable(hostDatatype, field.type) ? ', nullable' : '';
-    indent.writeln(
-        '@property(nonatomic, $propertyType$nullability) ${hostDatatype.datatype} ${field.name};');
-  }
-  indent.writeln('@end');
-  indent.writeln('');
-}
-
 /// Generates the name of the codec that will be generated.
 String _getCodecName(String? prefix, String className) =>
     '${_className(prefix, className)}Codec';
@@ -659,49 +858,6 @@ void _writeFlutterApiDeclaration(
   indent.writeln('@end');
 }
 
-/// Writes Objc header file header to sink.
-void writeObjcHeaderHeader(
-    ObjcOptions options, Root root, StringSink sink, Indent indent) {
-  if (options.copyrightHeader != null) {
-    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-  }
-  indent.writeln('// $generatedCodeWarning');
-  indent.writeln('// $seeAlsoWarning');
-  indent.addln('');
-}
-
-/// Writes Objc header file imports to sink.
-void writeObjcHeaderImports(
-    ObjcOptions options, Root root, StringSink sink, Indent indent) {
-  indent.writeln('#import <Foundation/Foundation.h>');
-  indent.addln('');
-
-  indent.writeln('@protocol FlutterBinaryMessenger;');
-  indent.writeln('@protocol FlutterMessageCodec;');
-  indent.writeln('@class FlutterError;');
-  indent.writeln('@class FlutterStandardTypedData;');
-  indent.addln('');
-}
-
-/// Writes single Objc header enum.
-void writeObjcHeaderEnum(ObjcOptions options, Root root, StringSink sink,
-    Indent indent, Enum anEnum) {
-  final String enumName = _className(options.prefix, anEnum.name);
-  addDocumentationComments(
-      indent, anEnum.documentationComments, _docCommentSpec);
-
-  indent.write('typedef NS_ENUM(NSUInteger, $enumName) ');
-  indent.scoped('{', '};', () {
-    enumerate(anEnum.members, (int index, final EnumMember member) {
-      addDocumentationComments(
-          indent, member.documentationComments, _docCommentSpec);
-      // Capitalized first letter to ensure Swift compatibility
-      indent.writeln(
-          '$enumName${member.name[0].toUpperCase()}${member.name.substring(1)} = $index,');
-    });
-  });
-}
-
 /// Generates the ".h" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateObjcHeader(
@@ -989,156 +1145,6 @@ void _writeFlutterApiSource(
   indent.writeln('@end');
 }
 
-/// Writes Objc Source file header to sink.
-void writeObjcSourceHeader(
-    ObjcOptions options, Root root, StringSink sink, Indent indent) {
-  if (options.copyrightHeader != null) {
-    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-  }
-  indent.writeln('// $generatedCodeWarning');
-  indent.writeln('// $seeAlsoWarning');
-  indent.addln('');
-}
-
-/// Writes Objc source file imports to sink.
-void writeObjcSourceImports(
-    ObjcOptions options, Root root, StringSink sink, Indent indent) {
-  indent.writeln('#import "${options.headerIncludePath}"');
-  indent.writeln('#import <Flutter/Flutter.h>');
-  indent.addln('');
-
-  indent.writeln('#if !__has_feature(objc_arc)');
-  indent.writeln('#error File requires ARC to be enabled.');
-  indent.writeln('#endif');
-  indent.addln('');
-}
-
-void _writeObjcSourceHelperFunctions(Indent indent) {
-  indent.format('''
-static NSArray *wrapResult(id result, FlutterError *error) {
-\tif (error) {
-\t\treturn @[ error.code ?: [NSNull null], error.message ?: [NSNull null], error.details ?: [NSNull null] ];
-\t}
-\treturn @[ result ?: [NSNull null]  ];
-}''');
-  indent.format('''
-static id GetNullableObject(NSDictionary* dict, id key) {
-\tid result = dict[key];
-\treturn (result == [NSNull null]) ? nil : result;
-}
-static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
-\tid result = array[key];
-\treturn (result == [NSNull null]) ? nil : result;
-}
-''');
-}
-
-void _writeObjcSourceDataClassExtension(
-    ObjcOptions languageOptions, Indent indent, Class klass) {
-  final String className = _className(languageOptions.prefix, klass.name);
-  indent.writeln('@interface $className ()');
-  indent.writeln('+ ($className *)fromList:(NSArray *)list;');
-  indent.writeln('+ (nullable $className *)nullableFromList:(NSArray *)list;');
-  indent.writeln('- (NSArray *)toList;');
-  indent.writeln('@end');
-}
-
-void _writeObjcSourceDataClassImplementation(ObjcOptions options, Root root,
-    StringSink sink, Indent indent, Class klass) {
-  final Set<String> customClassNames =
-      root.classes.map((Class x) => x.name).toSet();
-  final Set<String> customEnumNames =
-      root.enums.map((Enum x) => x.name).toSet();
-  final String className = _className(options.prefix, klass.name);
-
-  indent.writeln('@implementation $className');
-  _writeInitializer(options, root, sink, indent, klass, customClassNames,
-      customEnumNames, className);
-  _writeClassDecode(options, root, sink, indent, klass, customClassNames,
-      customEnumNames, className);
-  _writeClassEncode(options, root, sink, indent, klass, customClassNames,
-      customEnumNames, className);
-  indent.writeln('@end');
-}
-
-void _writeInitializer(
-  ObjcOptions options,
-  Root root,
-  StringSink sink,
-  Indent indent,
-  Class klass,
-  Set<String> customClassNames,
-  Set<String> customEnumNames,
-  String className,
-) {
-  _writeInitializerDeclaration(
-      indent, klass, root.classes, root.enums, options.prefix);
-  indent.writeScoped(' {', '}', () {
-    const String result = 'pigeonResult';
-    indent.writeln('$className* $result = [[$className alloc] init];');
-    for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-      indent.writeln('$result.${field.name} = ${field.name};');
-    }
-    indent.writeln('return $result;');
-  });
-}
-
-void _writeClassDecode(
-  ObjcOptions options,
-  Root root,
-  StringSink sink,
-  Indent indent,
-  Class klass,
-  Set<String> customClassNames,
-  Set<String> customEnumNames,
-  String className,
-) {
-  indent.write('+ ($className *)fromList:(NSArray *)list ');
-  indent.scoped('{', '}', () {
-    const String resultName = 'pigeonResult';
-    indent.writeln('$className *$resultName = [[$className alloc] init];');
-    enumerate(getFieldsInSerializationOrder(klass),
-        (int index, final NamedType field) {
-      if (customEnumNames.contains(field.type.baseName)) {
-        indent.writeln(
-            '$resultName.${field.name} = [${_listGetter(customClassNames, 'list', field, index, options.prefix)} integerValue];');
-      } else {
-        indent.writeln(
-            '$resultName.${field.name} = ${_listGetter(customClassNames, 'list', field, index, options.prefix)};');
-        if (!field.type.isNullable) {
-          indent.writeln('NSAssert($resultName.${field.name} != nil, @"");');
-        }
-      }
-    });
-    indent.writeln('return $resultName;');
-  });
-
-  indent.writeln(
-      '+ (nullable $className *)nullableFromList:(NSArray *)list { return (list) ? [$className fromList:list] : nil; }');
-}
-
-void _writeClassEncode(
-  ObjcOptions options,
-  Root root,
-  StringSink sink,
-  Indent indent,
-  Class klass,
-  Set<String> customClassNames,
-  Set<String> customEnumNames,
-  String className,
-) {
-  indent.write('- (NSArray *)toList ');
-  indent.scoped('{', '}', () {
-    indent.write('return');
-    indent.scoped(' @[', '];', () {
-      for (final NamedType field in klass.fields) {
-        indent.writeln(
-            '${_arrayValue(customClassNames, customEnumNames, field)},');
-      }
-    });
-  });
-}
-
 /// Generates the ".m" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateObjcSource(

From 9664a066c47ce2548cac349a13ce2daa573724da Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 13:00:43 -0800
Subject: [PATCH 55/87] Creates writeHeader method on Generator classes

---
 packages/pigeon/CHANGELOG.md                  |   4 +
 packages/pigeon/lib/cpp_generator.dart        |  56 +-
 packages/pigeon/lib/dart_generator.dart       |  75 +-
 packages/pigeon/lib/generator.dart            |  22 +-
 packages/pigeon/lib/generator_tools.dart      |   4 +-
 packages/pigeon/lib/java_generator.dart       |  40 +-
 packages/pigeon/lib/kotlin_generator.dart     |  44 +-
 packages/pigeon/lib/objc_generator.dart       |  76 +-
 packages/pigeon/lib/pigeon_lib.dart           |   6 +-
 packages/pigeon/lib/swift_generator.dart      |  39 +-
 .../mock_handler_tester/test/message.dart     |   3 +-
 .../pigeon/mock_handler_tester/test/test.dart |   2 +-
 .../CoreTests.java                            |   2 +-
 .../ios/Classes/CoreTests.gen.h               |   3 +-
 .../ios/Classes/CoreTests.gen.m               |   3 +-
 .../lib/core_tests.gen.dart                   |   3 +-
 .../lib/multiple_arity.gen.dart               |   3 +-
 .../lib/non_null_fields.gen.dart              |   3 +-
 .../lib/null_fields.gen.dart                  |   3 +-
 .../lib/null_safe_pigeon.dart                 |   3 +-
 .../lib/nullable_returns.gen.dart             |   3 +-
 .../lib/primitive.dart                        |   3 +-
 .../lib/src/generated/core_tests.gen.dart     |   3 +-
 .../com/example/test_plugin/CoreTests.gen.kt  |   2 +-
 .../ios/Classes/CoreTests.gen.swift           |   2 +-
 .../macos/Classes/CoreTests.gen.swift         |   2 +-
 .../windows/pigeon/core_tests.gen.cpp         |   2 +-
 .../windows/pigeon/core_tests.gen.h           |   8 +-
 packages/pigeon/pubspec.yaml                  |   2 +-
 packages/pigeon/test/cpp_generator_test.dart  | 222 +++++-
 packages/pigeon/test/dart_generator_test.dart | 148 ++--
 packages/pigeon/test/java_generator_test.dart | 117 ++-
 .../pigeon/test/kotlin_generator_test.dart    |  99 ++-
 packages/pigeon/test/objc_generator_test.dart | 749 +++++++++++++-----
 packages/pigeon/test/pigeon_lib_test.dart     |   4 +-
 .../pigeon/test/swift_generator_test.dart     |  99 ++-
 36 files changed, 1323 insertions(+), 536 deletions(-)

diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index 2af203239b6..394a84a7f80 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 5.0.1
+
+* Adds writeHeaders method to Generator classes and updates tests to use new Generators.
+
 ## 5.0.0
 
 * Creates new Generator classes for each language.
diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index cddefacfc79..82fb8bf62b7 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -75,16 +75,33 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
   /// Instantiates a Cpp Generator.
   CppGenerator();
 
-  /// Generates Cpp files with specified [OutputFileOptions<CppOptions>]
+  /// Generates Cpp header files with specified [CppOptions]
   @override
-  void generate(OutputFileOptions<CppOptions> languageOptions, Root root,
+  void generate(OutputFileOptions<CppOptions> generatorOptions, Root root,
       StringSink sink) {
-    final FileType fileType = languageOptions.fileType;
+    final FileType fileType = generatorOptions.fileType;
     assert(fileType == FileType.header || fileType == FileType.source);
+
+    final Indent indent = Indent(sink);
     if (fileType == FileType.header) {
-      generateCppHeader(languageOptions.languageOptions, root, sink);
+      writeFileHeaders(generatorOptions, root, sink, indent);
+      generateCppHeader(generatorOptions.languageOptions, root, sink, indent);
     } else {
-      generateCppSource(languageOptions.languageOptions, root, sink);
+      writeFileHeaders(generatorOptions, root, sink, indent);
+      generateCppSource(generatorOptions.languageOptions, root, sink, indent);
+    }
+  }
+
+  @override
+  void writeFileHeaders(OutputFileOptions<CppOptions> generatorOptions,
+      Root root, StringSink sink, Indent indent) {
+    final FileType fileType = generatorOptions.fileType;
+    if (fileType == FileType.header) {
+      writeCppHeaderHeader(
+          generatorOptions.languageOptions, root, sink, indent);
+    } else {
+      writeCppSourceHeader(
+          generatorOptions.languageOptions, root, sink, indent);
     }
   }
 }
@@ -1049,18 +1066,23 @@ void _writeSystemHeaderIncludeBlock(Indent indent, List<String> headers) {
   }
 }
 
-/// Generates the ".h" file for the AST represented by [root] to [sink] with the
-/// provided [options] and [headerFileName].
-void generateCppHeader(CppOptions options, Root root, StringSink sink) {
-  final String? headerFileName = options.headerOutPath;
-  final Indent indent = Indent(sink);
+/// Writes Cpp header file header to sink.
+void writeCppHeaderHeader(
+    CppOptions options, Root root, StringSink sink, Indent indent) {
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
   }
   indent.writeln('$_commentPrefix $generatedCodeWarning');
   indent.writeln('$_commentPrefix $seeAlsoWarning');
   indent.addln('');
-  final String guardName = _getGuardName(headerFileName, options.namespace);
+}
+
+/// Generates the ".h" file for the AST represented by [root] to [sink] with the
+/// provided [options] and [headerFileName].
+void generateCppHeader(
+    CppOptions options, Root root, StringSink sink, Indent indent) {
+  final String guardName =
+      _getGuardName(options.headerIncludePath, options.namespace);
   indent.writeln('#ifndef $guardName');
   indent.writeln('#define $guardName');
 
@@ -1140,10 +1162,9 @@ void generateCppHeader(CppOptions options, Root root, StringSink sink) {
   indent.writeln('#endif  // $guardName');
 }
 
-/// Generates the ".cpp" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateCppSource(CppOptions options, Root root, StringSink sink) {
-  final Indent indent = Indent(sink);
+/// Writes Cpp source file header to sink.
+void writeCppSourceHeader(
+    CppOptions options, Root root, StringSink sink, Indent indent) {
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
   }
@@ -1152,7 +1173,12 @@ void generateCppSource(CppOptions options, Root root, StringSink sink) {
   indent.addln('');
   indent.addln('#undef _HAS_EXCEPTIONS');
   indent.addln('');
+}
 
+/// Generates the ".cpp" file for the AST represented by [root] to [sink] with the
+/// provided [options].
+void generateCppSource(
+    CppOptions options, Root root, StringSink sink, Indent indent) {
   indent.writeln('#include "${options.headerIncludePath}"');
   indent.addln('');
   _writeSystemHeaderIncludeBlock(indent, <String>[
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index e6f685052f1..daf4171754b 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -77,20 +77,30 @@ class DartGenerator extends Generator<DartOptions> {
 
   /// Generates Dart files with specified [DartOptions]
   @override
-  void generate(DartOptions languageOptions, Root root, StringSink sink,
-      {FileType fileType = FileType.na}) {
-    assert(fileType == FileType.na);
-    generateDart(languageOptions, root, sink);
+  void generate(DartOptions generatorOptions, Root root, StringSink sink) {
+    final Indent indent = Indent(sink);
+
+    writeFileHeaders(generatorOptions, root, sink, indent);
+    generateDart(generatorOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(
+      DartOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    writeHeader(generatorOptions, root, sink, indent);
   }
 
   /// Generates Dart files for testing with specified [DartOptions]
   void generateTest(DartOptions languageOptions, Root root, StringSink sink) {
+    final Indent indent = Indent(sink);
     final String sourceOutPath = languageOptions.sourceOutPath ?? '';
     final String testOutPath = languageOptions.testOutPath ?? '';
+    writeTestHeader(languageOptions, root, sink, indent);
     generateTestDart(
       languageOptions,
       root,
       sink,
+      indent,
       sourceOutPath: sourceOutPath,
       testOutPath: testOutPath,
     );
@@ -501,25 +511,26 @@ String _addGenericTypesNullable(TypeDeclaration type) {
   return type.isNullable ? '$genericdType?' : genericdType;
 }
 
+/// Writes file header to sink.
+void writeHeader(DartOptions opt, Root root, StringSink sink, Indent indent) {
+  if (opt.copyrightHeader != null) {
+    addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
+  }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+  indent.writeln(
+    '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import',
+  );
+  indent.addln('');
+}
+
 /// Generates Dart source code for the given AST represented by [root],
 /// outputting the code to [sink].
-void generateDart(DartOptions opt, Root root, StringSink sink) {
+void generateDart(DartOptions opt, Root root, StringSink sink, Indent indent) {
   final List<String> customClassNames =
       root.classes.map((Class x) => x.name).toList();
   final List<String> customEnumNames =
       root.enums.map((Enum x) => x.name).toList();
-  final Indent indent = Indent(sink);
-
-  void writeHeader() {
-    if (opt.copyrightHeader != null) {
-      addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-    indent.writeln(
-      '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import',
-    );
-  }
 
   void writeEnums() {
     for (final Enum anEnum in root.enums) {
@@ -678,7 +689,6 @@ $resultAt != null
     }
   }
 
-  writeHeader();
   writeImports();
   writeEnums();
   for (final Class klass in root.classes) {
@@ -740,18 +750,9 @@ String _posixify(String inputPath) {
   return context.fromUri(path.toUri(path.absolute(inputPath)));
 }
 
-/// Generates Dart source code for test support libraries based on the given AST
-/// represented by [root], outputting the code to [sink]. [sourceOutPath] is the
-/// path of the generated dart code to be tested. [testOutPath] is where the
-/// test code will be generated.
-void generateTestDart(
-  DartOptions opt,
-  Root root,
-  StringSink sink, {
-  required String sourceOutPath,
-  required String testOutPath,
-}) {
-  final Indent indent = Indent(sink);
+/// Writes file header to sink.
+void writeTestHeader(
+    DartOptions opt, Root root, StringSink sink, Indent indent) {
   if (opt.copyrightHeader != null) {
     addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
   }
@@ -761,6 +762,20 @@ void generateTestDart(
     '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, unnecessary_import',
   );
   indent.writeln('// ignore_for_file: avoid_relative_lib_imports');
+}
+
+/// Generates Dart source code for test support libraries based on the given AST
+/// represented by [root], outputting the code to [sink]. [dartOutPath] is the
+/// path of the generated dart code to be tested. [testOutPath] is where the
+/// test code will be generated.
+void generateTestDart(
+  DartOptions opt,
+  Root root,
+  StringSink sink,
+  Indent indent, {
+  required String sourceOutPath,
+  required String testOutPath,
+}) {
   indent.writeln("import 'dart:async';");
   indent.writeln(
     "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 02667e4a5c9..473e1a3e46f 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -3,11 +3,29 @@
 // found in the LICENSE file.
 
 import 'ast.dart';
+import 'generator_tools.dart';
 
 /// A superclass of generator classes.
 ///
 /// This provides the structure that is common across generators for different languages.
 abstract class Generator<T> {
-  /// Generates files for specified language with specified [languageOptions]
-  void generate(T languageOptions, Root root, StringSink sink);
+  /// Generates files for specified language with specified [generatorOptions]
+  ///
+  /// This method, when overridden, should follow a generic structure that is currently:
+  /// 1. Create Indent
+  /// 2. Write File Headers
+  /// 3. Generate File
+  void generate(
+    T generatorOptions,
+    Root root,
+    StringSink sink,
+  );
+
+  /// Adds specified file headers.
+  void writeFileHeaders(
+    T generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+  );
 }
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index b1ee06b01e8..577bf8216de 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -9,7 +9,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon. This must match the version in pubspec.yaml.
-const String pigeonVersion = '5.0.0';
+const String pigeonVersion = '5.0.1';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
@@ -510,7 +510,7 @@ enum FileType {
   na,
 }
 
-/// Options for [Generator]'s that have multiple output file types.
+/// Options for [Generator]s that have multiple output file types.
 ///
 /// Specifies which file to write as well as wraps all language options.
 class OutputFileOptions<T> {
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index daca63876d2..6a18fba04aa 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -92,10 +92,17 @@ class JavaGenerator extends Generator<JavaOptions> {
 
   /// Generates Java files with specified [JavaOptions]
   @override
-  void generate(JavaOptions languageOptions, Root root, StringSink sink,
-      {FileType fileType = FileType.na}) {
-    assert(fileType == FileType.na);
-    generateJava(languageOptions, root, sink);
+  void generate(JavaOptions generatorOptions, Root root, StringSink sink) {
+    final Indent indent = Indent(sink);
+
+    writeFileHeaders(generatorOptions, root, sink, indent);
+    generateJava(generatorOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(
+      JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    writeHeader(generatorOptions, root, sink, indent);
   }
 }
 
@@ -536,22 +543,25 @@ String _castObject(
   }
 }
 
+/// Writes file header to sink.
+void writeHeader(
+    JavaOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.copyrightHeader != null) {
+    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+  }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+  indent.addln('');
+}
+
 /// Generates the ".java" file for the AST represented by [root] to [sink] with the
 /// provided [options].
-void generateJava(JavaOptions options, Root root, StringSink sink) {
+void generateJava(
+    JavaOptions options, Root root, StringSink sink, Indent indent) {
   final Set<String> rootClassNameSet =
       root.classes.map((Class x) => x.name).toSet();
   final Set<String> rootEnumNameSet =
       root.enums.map((Enum x) => x.name).toSet();
-  final Indent indent = Indent(sink);
-
-  void writeHeader() {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-  }
 
   void writeImports() {
     indent.writeln('import android.util.Log;');
@@ -766,8 +776,6 @@ void generateJava(JavaOptions options, Root root, StringSink sink) {
 }''');
   }
 
-  writeHeader();
-  indent.addln('');
   if (options.package != null) {
     indent.writeln('package ${options.package};');
   }
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 18e08c7398a..eed3e6da387 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -72,10 +72,21 @@ class KotlinGenerator extends Generator<KotlinOptions> {
 
   /// Generates Kotlin files with specified [KotlinOptions]
   @override
-  void generate(KotlinOptions languageOptions, Root root, StringSink sink,
-      {FileType fileType = FileType.na}) {
-    assert(fileType == FileType.na);
-    generateKotlin(languageOptions, root, sink);
+  void generate(
+    KotlinOptions generatorOptions,
+    Root root,
+    StringSink sink,
+  ) {
+    final Indent indent = Indent(sink);
+
+    writeFileHeaders(generatorOptions, root, sink, indent);
+    generateKotlin(generatorOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(KotlinOptions generatorOptions, Root root,
+      StringSink sink, Indent indent) {
+    writeHeader(generatorOptions, root, sink, indent);
   }
 }
 
@@ -449,28 +460,31 @@ String _nullsafeKotlinTypeForDartType(TypeDeclaration type) {
   return '${_kotlinTypeForDartType(type)}$nullSafe';
 }
 
+/// Writes file header to sink.
+void writeHeader(
+    KotlinOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.copyrightHeader != null) {
+    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+  }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+  indent.addln('');
+}
+
 /// Generates the ".kotlin" file for the AST represented by [root] to [sink] with the
 /// provided [options].
-void generateKotlin(KotlinOptions options, Root root, StringSink sink) {
+void generateKotlin(
+    KotlinOptions options, Root root, StringSink sink, Indent indent) {
   final Set<String> rootClassNameSet =
       root.classes.map((Class x) => x.name).toSet();
   final Set<String> rootEnumNameSet =
       root.enums.map((Enum x) => x.name).toSet();
-  final Indent indent = Indent(sink);
 
   HostDatatype getHostDatatype(NamedType field) {
     return getFieldHostDatatype(field, root.classes, root.enums,
         (TypeDeclaration x) => _kotlinTypeForBuiltinDartType(x));
   }
 
-  void writeHeader() {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-  }
-
   void writeImports() {
     indent.writeln('import android.util.Log');
     indent.writeln('import io.flutter.plugin.common.BasicMessageChannel');
@@ -665,8 +679,6 @@ void generateKotlin(KotlinOptions options, Root root, StringSink sink) {
     });
   }
 
-  writeHeader();
-  indent.addln('');
   if (options.package != null) {
     indent.writeln('package ${options.package}');
   }
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 3d7e3a64da2..33922019d2c 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -69,17 +69,32 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
   /// Instantiates a Objc Generator.
   ObjcGenerator();
 
-  /// Generates Objc files with specified [OutputFileOptions<ObjcOptions>]
+  /// Generates Objc header files with specified [ObjcOptions]
   @override
-  void generate(OutputFileOptions<ObjcOptions> languageOptions, Root root,
+  void generate(OutputFileOptions<ObjcOptions> generatorOptions, Root root,
       StringSink sink) {
-    final FileType fileType = languageOptions.fileType;
-    assert(fileType == FileType.header || fileType == FileType.source);
+    final FileType fileType = generatorOptions.fileType;
+    final Indent indent = Indent(sink);
 
     if (fileType == FileType.header) {
-      generateObjcHeader(languageOptions.languageOptions, root, sink);
+      writeFileHeaders(generatorOptions, root, sink, indent);
+      generateObjcHeader(generatorOptions.languageOptions, root, sink, indent);
     } else {
-      generateObjcSource(languageOptions.languageOptions, root, sink);
+      writeFileHeaders(generatorOptions, root, sink, indent);
+      generateObjcSource(generatorOptions.languageOptions, root, sink, indent);
+    }
+  }
+
+  @override
+  void writeFileHeaders(OutputFileOptions<ObjcOptions> generatorOptions,
+      Root root, StringSink sink, Indent indent) {
+    final FileType fileType = generatorOptions.fileType;
+    if (fileType == FileType.header) {
+      writeObjcHeaderHeader(
+          generatorOptions.languageOptions, root, sink, indent);
+    } else {
+      writeObjcSourceHeader(
+          generatorOptions.languageOptions, root, sink, indent);
     }
   }
 }
@@ -551,19 +566,21 @@ void _writeFlutterApiDeclaration(
   indent.writeln('@end');
 }
 
-/// Generates the ".h" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateObjcHeader(ObjcOptions options, Root root, StringSink sink) {
-  final Indent indent = Indent(sink);
-
-  void writeHeader() {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
+/// Writes Objc header file header to sink.
+void writeObjcHeaderHeader(
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.copyrightHeader != null) {
+    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
   }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+  indent.addln('');
+}
 
+/// Generates the ".h" file for the AST represented by [root] to [sink] with the
+/// provided [options].
+void generateObjcHeader(
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {
   void writeImports() {
     indent.writeln('#import <Foundation/Foundation.h>');
   }
@@ -592,7 +609,6 @@ void generateObjcHeader(ObjcOptions options, Root root, StringSink sink) {
     });
   }
 
-  writeHeader();
   writeImports();
   writeForwardDeclarations();
   indent.writeln('');
@@ -894,22 +910,25 @@ void _writeFlutterApiSource(
   indent.writeln('@end');
 }
 
+/// Writes Objc Source file header to sink.
+void writeObjcSourceHeader(
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.copyrightHeader != null) {
+    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+  }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+  indent.addln('');
+}
+
 /// Generates the ".m" file for the AST represented by [root] to [sink] with the
 /// provided [options].
-void generateObjcSource(ObjcOptions options, Root root, StringSink sink) {
-  final Indent indent = Indent(sink);
+void generateObjcSource(
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {
   final List<String> classNames =
       root.classes.map((Class x) => x.name).toList();
   final List<String> enumNames = root.enums.map((Enum x) => x.name).toList();
 
-  void writeHeader() {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-  }
-
   void writeImports() {
     indent.writeln('#import "${options.headerIncludePath}"');
     indent.writeln('#import <Flutter/Flutter.h>');
@@ -1026,7 +1045,6 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
     }
   }
 
-  writeHeader();
   writeImports();
   indent.writeln('');
   writeArcEnforcer();
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 5082dd19e8e..40f3fee3048 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -456,11 +456,7 @@ class DartTestGeneratorAdapter implements GeneratorAdapter {
       testOutPath: options.dartTestOut,
     );
     final DartGenerator testGenerator = DartGenerator();
-    testGenerator.generateTest(
-      dartOptionsWithHeader,
-      root,
-      sink,
-    );
+    testGenerator.generateTest(dartOptionsWithHeader, root, sink);
   }
 
   @override
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 77fff7e2fac..44532e91f15 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -55,10 +55,16 @@ class SwiftGenerator extends Generator<SwiftOptions> {
 
   /// Generates Swift files with specified [SwiftOptions]
   @override
-  void generate(SwiftOptions languageOptions, Root root, StringSink sink,
-      {FileType fileType = FileType.na}) {
-    assert(fileType == FileType.na);
-    generateSwift(languageOptions, root, sink);
+  void generate(SwiftOptions generatorOptions, Root root, StringSink sink) {
+    final Indent indent = Indent(sink);
+    writeFileHeaders(generatorOptions, root, sink, indent);
+    generateSwift(generatorOptions, root, sink, indent);
+  }
+
+  @override
+  void writeFileHeaders(SwiftOptions generatorOptions, Root root,
+      StringSink sink, Indent indent) {
+    writeHeader(generatorOptions, root, sink, indent);
   }
 }
 
@@ -447,28 +453,31 @@ String _nullsafeSwiftTypeForDartType(TypeDeclaration type) {
   return '${_swiftTypeForDartType(type)}$nullSafe';
 }
 
+/// Writes file header to sink.
+void writeHeader(
+    SwiftOptions options, Root root, StringSink sink, Indent indent) {
+  if (options.copyrightHeader != null) {
+    addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+  }
+  indent.writeln('// $generatedCodeWarning');
+  indent.writeln('// $seeAlsoWarning');
+  indent.addln('');
+}
+
 /// Generates the ".swift" file for the AST represented by [root] to [sink] with the
 /// provided [options].
-void generateSwift(SwiftOptions options, Root root, StringSink sink) {
+void generateSwift(
+    SwiftOptions options, Root root, StringSink sink, Indent indent) {
   final Set<String> rootClassNameSet =
       root.classes.map((Class x) => x.name).toSet();
   final Set<String> rootEnumNameSet =
       root.enums.map((Enum x) => x.name).toSet();
-  final Indent indent = Indent(sink);
 
   HostDatatype getHostDatatype(NamedType field) {
     return getFieldHostDatatype(field, root.classes, root.enums,
         (TypeDeclaration x) => _swiftTypeForBuiltinDartType(x));
   }
 
-  void writeHeader() {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-  }
-
   void writeImports() {
     indent.writeln('import Foundation');
     indent.format('''
@@ -637,8 +646,6 @@ import FlutterMacOS
     });
   }
 
-  writeHeader();
-  indent.addln('');
   writeImports();
   indent.addln('');
   indent.writeln('$_docCommentPrefix Generated class from Pigeon.');
diff --git a/packages/pigeon/mock_handler_tester/test/message.dart b/packages/pigeon/mock_handler_tester/test/message.dart
index 4f6c9d14457..94024e73bc7 100644
--- a/packages/pigeon/mock_handler_tester/test/message.dart
+++ b/packages/pigeon/mock_handler_tester/test/message.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/mock_handler_tester/test/test.dart b/packages/pigeon/mock_handler_tester/test/test.dart
index 9b97826b605..e1644f13686 100644
--- a/packages/pigeon/mock_handler_tester/test/test.dart
+++ b/packages/pigeon/mock_handler_tester/test/test.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, unnecessary_import
 // ignore_for_file: avoid_relative_lib_imports
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
index 95b0e2a9509..ea8e343c37f 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package com.example.alternate_language_test_plugin;
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
index 1def5e7af69..5a0de3c68c9 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
@@ -2,8 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
+
 #import <Foundation/Foundation.h>
 @protocol FlutterBinaryMessenger;
 @protocol FlutterMessageCodec;
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
index 244b1e236c5..2ed0bd7d9e4 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
@@ -2,8 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
+
 #import "CoreTests.gen.h"
 #import <Flutter/Flutter.h>
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
index fe0fe3335ea..c9dee303f5d 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
index e92ab29cebd..4bed42b32dd 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
index 1ff71bfa346..5d4cbd0096e 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
index 88f4611e746..0d151dc54e4 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
index 13fe926bcf1..820749f7bef 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
index be1979c8adf..a050c155e05 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
index 36a569e4f46..a5e4e6b318f 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
index fe0fe3335ea..c9dee303f5d 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
 
diff --git a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
index 61a957c8b55..17d7e9ffeb9 100644
--- a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
+++ b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package com.example.test_plugin
diff --git a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
index 844e541a562..bcf93bcfcc8 100644
--- a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
diff --git a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
index 844e541a562..bcf93bcfcc8 100644
--- a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
index 110c75e358d..ea282cff0b6 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #undef _HAS_EXCEPTIONS
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
index 527a0ff45c8..be5c851721c 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.0), do not edit directly.
+// Autogenerated from Pigeon (v5.0.1), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
-#ifndef PIGEON_CORE_TESTS_PIGEONTEST_H_
-#define PIGEON_CORE_TESTS_PIGEONTEST_H_
+#ifndef PIGEON_CORE_TESTS_GEN_H_CORE_TESTS_PIGEONTEST_H_
+#define PIGEON_CORE_TESTS_GEN_H_CORE_TESTS_PIGEONTEST_H_
 #include <flutter/basic_message_channel.h>
 #include <flutter/binary_messenger.h>
 #include <flutter/encodable_value.h>
@@ -412,4 +412,4 @@ class HostTrivialApi {
   HostTrivialApi() = default;
 };
 }  // namespace core_tests_pigeontest
-#endif  // PIGEON_CORE_TESTS_PIGEONTEST_H_
+#endif  // PIGEON_CORE_TESTS_GEN_H_CORE_TESTS_PIGEONTEST_H_
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index e4ada89edd1..f2a5a9a6639 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 5.0.0 # This must match the version in lib/generator_tools.dart
+version: 5.0.1 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.12.0 <3.0.0"
diff --git a/packages/pigeon/test/cpp_generator_test.dart b/packages/pigeon/test/cpp_generator_test.dart
index 172ce2ea3fe..bbed3a40c88 100644
--- a/packages/pigeon/test/cpp_generator_test.dart
+++ b/packages/pigeon/test/cpp_generator_test.dart
@@ -4,6 +4,7 @@
 
 import 'package:pigeon/ast.dart';
 import 'package:pigeon/cpp_generator.dart';
+import 'package:pigeon/generator_tools.dart';
 import 'package:pigeon/pigeon.dart' show Error;
 import 'package:test/test.dart';
 
@@ -45,7 +46,13 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('class Input'));
       expect(code, contains('class Output'));
@@ -53,7 +60,13 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.source,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('Input::Input()'));
       expect(code, contains('Output::Output'));
@@ -101,7 +114,13 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       // Method name and argument names should be adjusted.
       expect(code, contains(' DoSomething(const Input& some_input)'));
@@ -116,7 +135,13 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.source,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('pointer_input_field'));
       expect(code, contains('Output::output_field()'));
@@ -144,7 +169,17 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(
+        generatorOptions,
+        root,
+        sink,
+      );
       final String code = sink.toString();
 
       expect(
@@ -184,7 +219,13 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
 
       expect(
@@ -238,14 +279,26 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, isNot(contains('){')));
       expect(code, isNot(contains('const{')));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.source,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, isNot(contains('){')));
       expect(code, isNot(contains('const{')));
@@ -271,7 +324,13 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('''
 #include <flutter/basic_message_channel.h>
@@ -286,8 +345,13 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(
-          const CppOptions(headerIncludePath: 'a_header.h'), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.source,
+        languageOptions: const CppOptions(headerIncludePath: 'a_header.h'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('''
 #include "a_header.h"
@@ -323,14 +387,26 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(namespace: 'foo'), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(namespace: 'foo'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('namespace foo {'));
       expect(code, contains('}  // namespace foo'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(namespace: 'foo'), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.source,
+        languageOptions: const CppOptions(namespace: 'foo'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('namespace foo {'));
       expect(code, contains('}  // namespace foo'));
@@ -391,7 +467,13 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       // Getters should return const pointers.
       expect(code, contains('const bool* nullable_bool()'));
@@ -423,7 +505,13 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.source,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       // Getters extract optionals.
       expect(code,
@@ -522,7 +610,13 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       // POD getters should return copies references.
       expect(code, contains('bool non_nullable_bool()'));
@@ -547,7 +641,13 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.source,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       // Getters just return the value.
       expect(code, contains('return non_nullable_bool_;'));
@@ -645,7 +745,13 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code, contains('ErrorOr<std::optional<bool>> ReturnNullableBool()'));
@@ -750,7 +856,13 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('ErrorOr<bool> ReturnBool()'));
       expect(code, contains('ErrorOr<int64_t> ReturnInt()'));
@@ -832,7 +944,13 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -846,7 +964,13 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.source,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       // Most types should just use get_if, since the parameter is a pointer,
       // and get_if will automatically handle null values (since a null
@@ -963,7 +1087,13 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateCppHeader(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.header,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -977,7 +1107,13 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateCppSource(const CppOptions(), root, sink);
+      final CppGenerator generator = CppGenerator();
+      final OutputFileOptions<CppOptions> generatorOptions =
+          OutputFileOptions<CppOptions>(
+        fileType: FileType.source,
+        languageOptions: const CppOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       // Most types should extract references. Since the type is non-nullable,
       // there's only one possible type.
@@ -1037,7 +1173,13 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    generateCppSource(const CppOptions(), root, sink);
+    final CppGenerator generator = CppGenerator();
+    final OutputFileOptions<CppOptions> generatorOptions =
+        OutputFileOptions<CppOptions>(
+      fileType: FileType.source,
+      languageOptions: const CppOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     // A bare 'auto' here would create a copy, not a reference, which is
     // ineffecient.
@@ -1149,7 +1291,13 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateCppHeader(const CppOptions(headerIncludePath: 'foo'), root, sink);
+    final CppGenerator generator = CppGenerator();
+    final OutputFileOptions<CppOptions> generatorOptions =
+        OutputFileOptions<CppOptions>(
+      fileType: FileType.header,
+      languageOptions: const CppOptions(headerIncludePath: 'foo'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       expect(code, contains('//$comment'));
@@ -1184,7 +1332,13 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateCppHeader(const CppOptions(), root, sink);
+    final CppGenerator generator = CppGenerator();
+    final OutputFileOptions<CppOptions> generatorOptions =
+        OutputFileOptions<CppOptions>(
+      fileType: FileType.header,
+      languageOptions: const CppOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' : public flutter::StandardCodecSerializer')));
   });
@@ -1226,7 +1380,13 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateCppHeader(const CppOptions(), root, sink);
+    final CppGenerator generator = CppGenerator();
+    final OutputFileOptions<CppOptions> generatorOptions =
+        OutputFileOptions<CppOptions>(
+      fileType: FileType.header,
+      languageOptions: const CppOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains(' : public flutter::StandardCodecSerializer'));
   });
@@ -1295,7 +1455,13 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateCppSource(const CppOptions(), root, sink);
+    final CppGenerator generator = CppGenerator();
+    final OutputFileOptions<CppOptions> generatorOptions =
+        OutputFileOptions<CppOptions>(
+      fileType: FileType.source,
+      languageOptions: const CppOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains('reply(wrap')));
     expect(code, contains('reply(flutter::EncodableValue('));
diff --git a/packages/pigeon/test/dart_generator_test.dart b/packages/pigeon/test/dart_generator_test.dart
index c77e5d89e37..15ce9e09ac4 100644
--- a/packages/pigeon/test/dart_generator_test.dart
+++ b/packages/pigeon/test/dart_generator_test.dart
@@ -29,7 +29,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('  dataType1? field1;'));
@@ -49,7 +50,8 @@ void main() {
       enums: <Enum>[anEnum],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foobar'));
     expect(code, contains('  one,'));
@@ -92,7 +94,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, contains('Future<Output> doSomething(Input arg_input)'));
@@ -118,7 +121,8 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, contains('Future<int> add(int arg_x, int arg_y)'));
@@ -145,7 +149,8 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, contains('int add(int x, int y)'));
@@ -182,7 +187,8 @@ void main() {
       )
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
       code,
@@ -224,7 +230,8 @@ void main() {
       )
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
       code,
@@ -276,7 +283,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('abstract class Api'));
     expect(code, contains('static void setup(Api'));
@@ -310,7 +318,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<void> doSomething'));
     expect(code, contains('return;'));
@@ -343,7 +352,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     // The next line verifies that we're not setting a variable to the value of "doSomething", but
     // ignores the line where we assert the value of the argument isn't null, since on that line
@@ -373,7 +383,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('output.*=.*doSomething[(][)]'));
     expect(code, contains('Output doSomething();'));
@@ -415,7 +426,8 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum1?.index,'));
     expect(code, contains('? Enum.values[result[0]! as int]'));
@@ -442,7 +454,8 @@ void main() {
       ])
     ]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foo {'));
     expect(code, contains('Future<void> bar(Foo? arg_foo) async'));
@@ -485,7 +498,8 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum1.index,'));
     expect(code, contains('enum1: Enum.values[result[0]! as int]'));
@@ -512,7 +526,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('channel.send[(]null[)]'));
   });
@@ -570,7 +585,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer mainCodeSink = StringBuffer();
     final StringBuffer testCodeSink = StringBuffer();
-    generateDart(DartOptions(), root, mainCodeSink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, mainCodeSink);
     final String mainCode = mainCodeSink.toString();
     expect(mainCode, isNot(contains(r"import 'fo\'o.dart';")));
     expect(mainCode, contains('class Api {'));
@@ -578,12 +594,15 @@ void main() {
     expect(mainCode, isNot(contains('.ApiMock.doSomething')));
     expect(mainCode, isNot(contains("'${Keys.result}': output")));
     expect(mainCode, isNot(contains('return <Object>[];')));
-    generateTestDart(
-      DartOptions(),
+
+    final DartGenerator testGenerator = DartGenerator();
+    testGenerator.generateTest(
+      DartOptions(
+        sourceOutPath: "fo'o.dart",
+        testOutPath: 'test.dart',
+      ),
       root,
       testCodeSink,
-      sourceOutPath: "fo'o.dart",
-      testOutPath: 'test.dart',
     );
     final String testCode = testCodeSink.toString();
     expect(testCode, contains(r"import 'fo\'o.dart';"));
@@ -631,7 +650,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('abstract class Api'));
     expect(code, contains('Future<Output> doSomething(Input arg0);'));
@@ -675,7 +695,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('=.s*doSomething')));
     expect(code, contains('await api.doSomething('));
@@ -719,7 +740,8 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, matches('Output.*doSomething.*Input'));
@@ -747,7 +769,8 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('channel.send[(]null[)]'));
   });
@@ -759,7 +782,9 @@ void main() {
   test('header', () {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(
+
+    final DartGenerator generator = DartGenerator();
+    generator.generate(
       DartOptions(copyrightHeader: makeIterable('hello world')),
       root,
       sink,
@@ -788,7 +813,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('  List<int?>? field1;'));
@@ -815,7 +841,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('  Map<String?, int?>? field1;'));
@@ -844,7 +871,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(List<int?> arg'));
   });
@@ -872,7 +900,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(List<int?> arg'));
   });
@@ -896,7 +925,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<List<int?>> doit('));
     expect(code,
@@ -931,7 +961,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('List<int?> doit('));
     expect(
@@ -958,7 +989,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit()'));
     expect(code, contains('return (replyList[0] as int?);'));
@@ -983,7 +1015,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<List<int?>?> doit()'));
     expect(code,
@@ -1008,7 +1041,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit()'));
     expect(code, contains('return (replyList[0] as int?);'));
@@ -1031,7 +1065,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('int? doit();'));
     expect(code, contains('final int? output = api.doit();'));
@@ -1055,7 +1090,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit();'));
     expect(code, contains('final int? output = await api.doit();'));
@@ -1078,7 +1114,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1107,7 +1144,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<void> doit(int? arg_foo) async {'));
   });
@@ -1133,7 +1171,8 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('void doit(int? foo);'));
   });
@@ -1150,12 +1189,14 @@ name: foobar
       final Root root =
           Root(classes: <Class>[], apis: <Api>[], enums: <Enum>[]);
       final StringBuffer sink = StringBuffer();
-      generateTestDart(
-        DartOptions(),
+      final DartGenerator testGenerator = DartGenerator();
+      testGenerator.generateTest(
+        DartOptions(
+          sourceOutPath: path.join(foo.path, 'bar.dart'),
+          testOutPath: path.join(tempDir.path, 'test', 'bar_test.dart'),
+        ),
         root,
         sink,
-        sourceOutPath: path.join(foo.path, 'bar.dart'),
-        testOutPath: path.join(tempDir.path, 'test', 'bar_test.dart'),
       );
       final String code = sink.toString();
       expect(code, contains("import 'package:foobar/foo/bar.dart';"));
@@ -1238,7 +1279,8 @@ name: foobar
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       expect(code, contains('///$comment'));
@@ -1273,7 +1315,8 @@ name: foobar
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains('extends StandardMessageCodec')));
     expect(code, contains('StandardMessageCodec'));
@@ -1316,7 +1359,8 @@ name: foobar
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateDart(DartOptions(), root, sink);
+    final DartGenerator generator = DartGenerator();
+    generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('extends StandardMessageCodec'));
   });
@@ -1354,13 +1398,17 @@ name: foobar
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateTestDart(
-      DartOptions(),
+
+    final DartGenerator testGenerator = DartGenerator();
+    testGenerator.generateTest(
+      DartOptions(
+        sourceOutPath: 'code.dart',
+        testOutPath: 'test.dart',
+      ),
       root,
       sink,
-      sourceOutPath: 'code.dart',
-      testOutPath: 'test.dart',
     );
+
     final String testCode = sink.toString();
     expect(
         testCode,
diff --git a/packages/pigeon/test/java_generator_test.dart b/packages/pigeon/test/java_generator_test.dart
index bfcea98cfe2..f2a25288754 100644
--- a/packages/pigeon/test/java_generator_test.dart
+++ b/packages/pigeon/test/java_generator_test.dart
@@ -27,7 +27,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public class Messages'));
     expect(code, contains('public static class Foobar'));
@@ -55,7 +56,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public enum Foobar'));
     expect(code, contains('    ONE(0),'));
@@ -86,7 +88,8 @@ void main() {
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions =
         JavaOptions(className: 'Messages', package: 'com.google.foobar');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('package com.google.foobar;'));
     expect(code, contains('ArrayList<Object> toList()'));
@@ -129,7 +132,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public interface Api'));
     expect(code, matches('Output.*doSomething.*Input'));
@@ -200,7 +204,8 @@ void main() {
 
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('private @Nullable Boolean aBool;'));
     expect(code, contains('private @Nullable Long aInt;'));
@@ -249,7 +254,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Api'));
     expect(code, matches('doSomething.*Input.*Output'));
@@ -283,7 +289,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('=.*doSomething')));
     expect(code, contains('doSomething('));
@@ -317,7 +324,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('Reply<Void>'));
     expect(code, contains('callback.reply(null)'));
@@ -345,7 +353,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('Output doSomething()'));
     expect(code, contains('api.doSomething()'));
@@ -373,7 +382,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doSomething(Reply<Output>'));
     expect(code, contains('channel.send(null'));
@@ -392,7 +402,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Foobar'));
     expect(code, contains('private @Nullable List<Object> field1;'));
@@ -411,7 +422,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Foobar'));
     expect(code, contains('private @Nullable Map<Object, Object> field1;'));
@@ -447,7 +459,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public class Messages'));
     expect(code, contains('public static class Outer'));
@@ -498,7 +511,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public interface Api'));
     expect(code, contains('public interface Result<T> {'));
@@ -549,7 +563,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Api'));
     expect(code, matches('doSomething.*Input.*Output'));
@@ -582,7 +597,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public enum Enum1'));
     expect(code, contains('    ONE(0),'));
@@ -621,7 +637,8 @@ void main() {
     ]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public enum Foo'));
     expect(
@@ -641,7 +658,8 @@ void main() {
       className: 'Messages',
       copyrightHeader: makeIterable('hello world'),
     );
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
   });
@@ -667,7 +685,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('List<Long> field1;'));
@@ -695,7 +714,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
     expect(code, contains('Map<String, String> field1;'));
@@ -725,7 +745,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(@NonNull List<Long> arg'));
   });
@@ -754,7 +775,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(@NonNull List<Long> arg'));
   });
@@ -779,7 +801,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('List<Long> doit('));
     expect(code, contains('List<Long> output ='));
@@ -805,7 +828,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(Reply<List<Long>> callback)'));
     expect(code, contains('List<Long> output ='));
@@ -828,7 +852,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(Reply<Long> callback)'));
     expect(
@@ -858,7 +883,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Messages'));
     expect(code, contains('Long add(@NonNull Long x, @NonNull Long y)'));
@@ -889,7 +915,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Api');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('Object xArg = args.get(0)'));
   });
@@ -915,7 +942,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Messages'));
     expect(code, contains('BasicMessageChannel<Object> channel'));
@@ -947,7 +975,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -973,7 +1002,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@Nullable Long doit();'));
   });
@@ -997,7 +1027,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     // Java doesn't accept nullability annotations in type arguments.
     expect(code, contains('Result<Long>'));
@@ -1025,7 +1056,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('  void doit(@Nullable Long foo);'));
   });
@@ -1052,7 +1084,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1083,7 +1116,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1108,7 +1142,8 @@ void main() {
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions =
         JavaOptions(className: 'Messages', useGeneratedAnnotation: true);
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@javax.annotation.Generated("dev.flutter.pigeon")'));
   });
@@ -1125,7 +1160,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code,
         isNot(contains('@javax.annotation.Generated("dev.flutter.pigeon")')));
@@ -1207,7 +1243,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       // This regex finds the comment only between the open and close comment block
@@ -1247,7 +1284,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' extends StandardMessageCodec')));
     expect(code, contains('StandardMessageCodec'));
@@ -1291,7 +1329,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    generateJava(javaOptions, root, sink);
+    final JavaGenerator generator = JavaGenerator();
+    generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains(' extends StandardMessageCodec'));
   });
diff --git a/packages/pigeon/test/kotlin_generator_test.dart b/packages/pigeon/test/kotlin_generator_test.dart
index 4653410837e..96056c1b1b1 100644
--- a/packages/pigeon/test/kotlin_generator_test.dart
+++ b/packages/pigeon/test/kotlin_generator_test.dart
@@ -27,7 +27,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar ('));
     expect(code, contains('val field1: Long? = null'));
@@ -50,7 +51,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum class Foobar(val raw: Int) {'));
     expect(code, contains('ONE(0)'));
@@ -78,7 +80,8 @@ void main() {
     ]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum class Foo(val raw: Int) {'));
     expect(code, contains('val fooArg = Foo.ofRaw(args[0] as Int)'));
@@ -124,7 +127,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('interface Api'));
     expect(code, contains('fun doSomething(input: Input): Output'));
@@ -213,7 +217,8 @@ void main() {
     final StringBuffer sink = StringBuffer();
 
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('val aBool: Boolean? = null'));
     expect(code, contains('val aInt: Long? = null'));
@@ -265,7 +270,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code,
         contains('class Api(private val binaryMessenger: BinaryMessenger)'));
@@ -302,7 +308,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('.*doSomething(.*) ->')));
     expect(code, matches('doSomething(.*)'));
@@ -338,7 +345,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('callback: () -> Unit'));
     expect(code, contains('callback()'));
@@ -367,7 +375,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doSomething(): Output'));
     expect(code, contains('wrapped = listOf<Any?>(api.doSomething())'));
@@ -398,7 +407,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doSomething(callback: (Output) -> Unit)'));
     expect(code, contains('channel.send(null)'));
@@ -418,7 +428,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
     expect(code, contains('val field1: List<Any?>? = null'));
@@ -438,7 +449,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
     expect(code, contains('val field1: Map<Any, Any?>? = null'));
@@ -476,7 +488,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Outer'));
     expect(code, contains('data class Nested'));
@@ -529,7 +542,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('interface Api'));
     expect(code, contains('api.doSomething(argArg) {'));
@@ -577,7 +591,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, matches('fun doSomething.*Input.*callback.*Output.*Unit'));
@@ -610,7 +625,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum class Enum1(val raw: Int)'));
     expect(code, contains('ONE(0)'));
@@ -627,7 +643,8 @@ void main() {
     final KotlinOptions kotlinOptions = KotlinOptions(
       copyrightHeader: makeIterable('hello world'),
     );
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
   });
@@ -654,7 +671,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
     expect(code, contains('val field1: List<Long?>'));
@@ -683,7 +701,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
     expect(code, contains('val field1: Map<String?, String?>'));
@@ -714,7 +733,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(arg: List<Long?>'));
   });
@@ -744,7 +764,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(argArg: List<Long?>'));
   });
@@ -769,7 +790,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(): List<Long?>'));
     expect(code, contains('wrapped = listOf<Any?>(api.doit())'));
@@ -796,7 +818,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(callback: (List<Long?>) -> Unit'));
     expect(code, contains('val result = it as List<Long?>'));
@@ -824,7 +847,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun add(x: Long, y: Long): Long'));
     expect(code, contains('val args = message as List<Any?>'));
@@ -861,7 +885,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('val channel = BasicMessageChannel'));
     expect(code, contains('val result = it as Long'));
@@ -889,7 +914,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(): Long?'));
   });
@@ -913,7 +939,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(callback: (Long?) -> Unit'));
   });
@@ -940,7 +967,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -970,7 +998,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(fooArg: Long?, callback: () -> Unit'));
   });
@@ -1005,7 +1034,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('val input: String\n'));
   });
@@ -1086,7 +1116,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       // This regex finds the comment only between the open and close comment block
@@ -1126,7 +1157,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' : StandardMessageCodec() ')));
     expect(code, contains('StandardMessageCodec'));
@@ -1170,7 +1202,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    generateKotlin(kotlinOptions, root, sink);
+    final KotlinGenerator generator = KotlinGenerator();
+    generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains(' : StandardMessageCodec() '));
   });
diff --git a/packages/pigeon/test/objc_generator_test.dart b/packages/pigeon/test/objc_generator_test.dart
index aeb2db68e26..c6b45fd4d43 100644
--- a/packages/pigeon/test/objc_generator_test.dart
+++ b/packages/pigeon/test/objc_generator_test.dart
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:pigeon/ast.dart';
+import 'package:pigeon/generator_tools.dart';
 import 'package:pigeon/objc_generator.dart';
 import 'package:pigeon/pigeon_lib.dart';
 import 'package:test/test.dart';
@@ -17,7 +18,13 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(code, matches('@property.*NSString.*field1'));
@@ -32,8 +39,13 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(headerIncludePath: 'foo.h'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
     expect(code, contains('@implementation Foobar'));
@@ -50,7 +62,13 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('typedef NS_ENUM(NSUInteger, Enum1) {'));
     expect(code, contains('  Enum1One = 0,'));
@@ -68,7 +86,13 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(prefix: 'PREFIX'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(prefix: 'PREFIX'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('typedef NS_ENUM(NSUInteger, PREFIXEnum1) {'));
     expect(code, contains('  PREFIXEnum1One = 0,'));
@@ -104,8 +128,13 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(headerIncludePath: 'foo.h'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
     expect(code, contains('@implementation Foobar'));
@@ -138,13 +167,25 @@ void main() {
     const ObjcOptions options =
         ObjcOptions(headerIncludePath: 'foo.h', prefix: 'AC');
     {
-      generateObjcHeader(options, root, sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions: options,
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('typedef NS_ENUM(NSUInteger, ACFoo)'));
       expect(code, contains(':(ACFoo)foo error:'));
     }
     {
-      generateObjcSource(options, root, sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions: options,
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -207,8 +248,13 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(headerIncludePath: 'foo.h'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@property(nonatomic, assign) Enum1 enum1'));
   });
@@ -240,7 +286,13 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Input'));
     expect(code, contains('@interface Output'));
@@ -279,8 +331,13 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(headerIncludePath: 'foo.h'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
     expect(code, contains('@implementation Input'));
@@ -327,8 +384,13 @@ void main() {
     ], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(headerIncludePath: 'foo.h'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(code, contains('@class FlutterStandardTypedData;'));
@@ -356,8 +418,13 @@ void main() {
     ], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(headerIncludePath: 'foo.h'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation Foobar'));
     expect(code,
@@ -378,8 +445,13 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(headerIncludePath: 'foo.h'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code,
         contains('@property(nonatomic, strong, nullable) Input * nested;'));
@@ -399,8 +471,13 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(headerIncludePath: 'foo.h'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -419,7 +496,13 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(prefix: 'ABC'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface ABCFoobar'));
   });
@@ -433,7 +516,13 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(prefix: 'ABC'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation ABCFoobar'));
   });
@@ -467,7 +556,13 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(prefix: 'ABC'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, matches('property.*ABCInput'));
     expect(code, matches('ABCNested.*doSomething.*ABCInput'));
@@ -503,7 +598,13 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(prefix: 'ABC'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('ABCInput fromList'));
     expect(code, matches(r'ABCInput.*=.*args.*0.*\;'));
@@ -539,8 +640,13 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(headerIncludePath: 'foo.h'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Api : NSObject'));
     expect(
@@ -579,8 +685,13 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h'), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(headerIncludePath: 'foo.h'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation Api'));
     expect(code, matches('void.*doSomething.*Input.*Output.*{'));
@@ -609,10 +720,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('(void)doSomething:'));
   });
@@ -640,10 +755,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('=.*doSomething')));
     expect(code, matches('[.*doSomething:.*]'));
@@ -673,10 +792,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('completion:(void(^)(NSError *_Nullable))'));
   });
@@ -704,10 +827,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('completion:(void(^)(NSError *_Nullable))'));
     expect(code, contains('completion(nil)'));
@@ -730,10 +857,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, matches('ABCOutput.*doSomethingWithError:[(]FlutterError'));
   });
@@ -755,10 +886,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, matches('output.*=.*api doSomethingWithError:&error'));
   });
@@ -780,10 +915,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -808,10 +947,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -829,7 +972,13 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(code, matches('@property.*NSArray.*field1'));
@@ -844,7 +993,13 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(code, matches('@property.*NSDictionary.*field1'));
@@ -865,7 +1020,13 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(
@@ -894,7 +1055,13 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('(NSDictionary<NSString *, id> *)foo'));
   });
@@ -928,10 +1095,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -969,10 +1140,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -998,10 +1173,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1020,10 +1199,14 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1061,10 +1244,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1101,10 +1288,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1123,10 +1314,14 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1152,10 +1347,14 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1170,14 +1369,16 @@ void main() {
   test('source copyright', () {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(
-      ObjcOptions(
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: ObjcOptions(
           headerIncludePath: 'foo.h',
           prefix: 'ABC',
           copyrightHeader: makeIterable('hello world')),
-      root,
-      sink,
     );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
   });
@@ -1185,14 +1386,16 @@ void main() {
   test('header copyright', () {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-      ObjcOptions(
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: ObjcOptions(
           headerIncludePath: 'foo.h',
           prefix: 'ABC',
           copyrightHeader: makeIterable('hello world')),
-      root,
-      sink,
     );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
   });
@@ -1217,10 +1420,14 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        root,
-        sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions:
+          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('NSArray<NSNumber *> * field1'));
   });
@@ -1249,19 +1456,27 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSNumber *> *)arg'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -1294,19 +1509,27 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSNumber *> *)arg'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSNumber *> *)arg'));
     }
@@ -1342,10 +1565,14 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('doitArg:(NSArray<NSArray<NSNumber *> *> *)arg'));
     }
@@ -1371,20 +1598,28 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code, contains('- (nullable NSArray<NSNumber *> *)doitWithError:'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('NSArray<NSNumber *> *output ='));
     }
@@ -1410,20 +1645,28 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code, contains('doitWithCompletion:(void(^)(NSArray<NSNumber *> *'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code, contains('doitWithCompletion:(void(^)(NSArray<NSNumber *> *'));
@@ -1451,10 +1694,14 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -1463,10 +1710,14 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('NSArray *args = message;'));
       expect(code,
@@ -1500,10 +1751,14 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -1512,10 +1767,14 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('NSArray *args = message;'));
       expect(code,
@@ -1547,10 +1806,14 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -1559,10 +1822,14 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          root,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(
           code,
@@ -1605,19 +1872,27 @@ void main() {
     final Root divideRoot = getDivideRoot(ApiLocation.host);
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          divideRoot,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, divideRoot, sink);
       final String code = sink.toString();
       expect(code, matches('divideValue:.*by:.*error.*;'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
-          const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-          divideRoot,
-          sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
+      );
+      generator.generate(generatorOptions, divideRoot, sink);
       final String code = sink.toString();
       expect(code, matches('divideValue:.*by:.*error.*;'));
     }
@@ -1627,21 +1902,27 @@ void main() {
     final Root divideRoot = getDivideRoot(ApiLocation.flutter);
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        divideRoot,
-        sink,
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
       );
+      generator.generate(generatorOptions, divideRoot, sink);
       final String code = sink.toString();
       expect(code, matches('divideValue:.*by:.*completion.*;'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(
-        const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
-        divideRoot,
-        sink,
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions:
+            const ObjcOptions(headerIncludePath: 'foo.h', prefix: 'ABC'),
       );
+      generator.generate(generatorOptions, divideRoot, sink);
       final String code = sink.toString();
       expect(code, matches('divideValue:.*by:.*completion.*{'));
     }
@@ -1656,7 +1937,13 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@interface Foobar'));
     expect(code, contains('@property(nonatomic, copy) NSString * field1'));
@@ -1679,7 +1966,13 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1704,7 +1997,13 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, matches(r'doitWithCompletion.*NSNumber \*_Nullable'));
   });
@@ -1726,7 +2025,13 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, matches(r'nullable NSNumber.*doitWithError'));
   });
@@ -1753,13 +2058,25 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(const ObjcOptions(), root, sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions: const ObjcOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('doitFoo:(nullable NSNumber *)foo'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(const ObjcOptions(), root, sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions: const ObjcOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code,
           contains('NSNumber *arg_foo = GetNullableObjectAtIndex(args, 0);'));
@@ -1788,13 +2105,25 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcHeader(const ObjcOptions(), root, sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.header,
+        languageOptions: const ObjcOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('doitFoo:(nullable NSNumber *)foo'));
     }
     {
       final StringBuffer sink = StringBuffer();
-      generateObjcSource(const ObjcOptions(), root, sink);
+      final ObjcGenerator generator = ObjcGenerator();
+      final OutputFileOptions<ObjcOptions> generatorOptions =
+          OutputFileOptions<ObjcOptions>(
+        fileType: FileType.source,
+        languageOptions: const ObjcOptions(),
+      );
+      generator.generate(generatorOptions, root, sink);
       final String code = sink.toString();
       expect(code, contains('- (void)doitFoo:(nullable NSNumber *)arg_foo'));
     }
@@ -1818,7 +2147,13 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -1902,7 +2237,13 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcHeader(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.header,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       expect(code, contains('///$comment'));
@@ -1937,7 +2278,13 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' : FlutterStandardReader')));
   });
@@ -1979,7 +2326,13 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    generateObjcSource(const ObjcOptions(), root, sink);
+    final ObjcGenerator generator = ObjcGenerator();
+    final OutputFileOptions<ObjcOptions> generatorOptions =
+        OutputFileOptions<ObjcOptions>(
+      fileType: FileType.source,
+      languageOptions: const ObjcOptions(),
+    );
+    generator.generate(generatorOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains(' : FlutterStandardReader'));
   });
diff --git a/packages/pigeon/test/pigeon_lib_test.dart b/packages/pigeon/test/pigeon_lib_test.dart
index 64c4af7b5ab..3d5c706bf41 100644
--- a/packages/pigeon/test/pigeon_lib_test.dart
+++ b/packages/pigeon/test/pigeon_lib_test.dart
@@ -938,10 +938,10 @@ abstract class Api {
       dartTestOut: 'stdout',
       dartOut: 'stdout',
     );
-    final DartTestGeneratorAdapter dartGeneratorAdapter =
+    final DartTestGeneratorAdapter dartTestGeneratorAdapter =
         DartTestGeneratorAdapter();
     final StringBuffer buffer = StringBuffer();
-    dartGeneratorAdapter.generate(buffer, options, root, FileType.source);
+    dartTestGeneratorAdapter.generate(buffer, options, root, FileType.source);
     expect(buffer.toString(), startsWith('// Copyright 2013'));
   });
 
diff --git a/packages/pigeon/test/swift_generator_test.dart b/packages/pigeon/test/swift_generator_test.dart
index 74c8aad15ca..305ca203fe7 100644
--- a/packages/pigeon/test/swift_generator_test.dart
+++ b/packages/pigeon/test/swift_generator_test.dart
@@ -26,7 +26,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: Int32? = nil'));
@@ -49,7 +50,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foobar: Int'));
     expect(code, contains('  case one = 0'));
@@ -77,7 +79,8 @@ void main() {
     ]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foo: Int'));
     expect(code, contains('let fooArg = Foo(rawValue: args[0] as! Int)!'));
@@ -120,7 +123,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('protocol Api'));
     expect(code, matches('func doSomething.*Input.*Output'));
@@ -183,7 +187,8 @@ void main() {
 
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('var aBool: Bool? = nil'));
     expect(code, contains('var aInt: Int32? = nil'));
@@ -232,7 +237,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, contains('init(binaryMessenger: FlutterBinaryMessenger)'));
@@ -267,7 +273,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('.*doSomething(.*) ->')));
     expect(code, matches('doSomething(.*)'));
@@ -301,7 +308,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('completion: @escaping () -> Void'));
     expect(code, contains('completion()'));
@@ -329,7 +337,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doSomething() -> Output'));
     expect(code, contains('let result = api.doSomething()'));
@@ -358,7 +367,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code,
         contains('func doSomething(completion: @escaping (Output) -> Void)'));
@@ -378,7 +388,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: [Any?]? = nil'));
@@ -397,7 +408,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: [AnyHashable: Any?]? = nil'));
@@ -433,7 +445,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Outer'));
     expect(code, contains('struct Nested'));
@@ -481,7 +494,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('protocol Api'));
     expect(code, contains('api.doSomething(arg: argArg) { result in'));
@@ -526,7 +540,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, matches('func doSomething.*Input.*completion.*Output.*Void'));
@@ -558,7 +573,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Enum1: Int'));
     expect(code, contains('case one = 0'));
@@ -575,7 +591,8 @@ void main() {
     final SwiftOptions swiftOptions = SwiftOptions(
       copyrightHeader: makeIterable('hello world'),
     );
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
   });
@@ -601,7 +618,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: [Int32?]'));
@@ -629,7 +647,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: [String?: String?]'));
@@ -659,7 +678,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit(arg: [Int32?]'));
   });
@@ -688,7 +708,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit(arg argArg: [Int32?]'));
   });
@@ -713,7 +734,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit() -> [Int32?]'));
     expect(code, contains('let result = api.doit()'));
@@ -740,7 +762,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(
         code, contains('func doit(completion: @escaping ([Int32?]) -> Void'));
@@ -769,7 +792,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func add(x: Int32, y: Int32) -> Int32'));
     expect(code, contains('let args = message as! [Any?]'));
@@ -800,7 +824,8 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('let channel = FlutterBasicMessageChannel'));
     expect(code, contains('let result = response as! Int32'));
@@ -830,7 +855,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit() -> Int32?'));
   });
@@ -854,7 +880,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit(completion: @escaping (Int32?) -> Void'));
   });
@@ -881,7 +908,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('let fooArg = args[0] as? Int32'));
   });
@@ -908,7 +936,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(
         code,
@@ -944,7 +973,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('var input: String\n'));
   });
@@ -1025,7 +1055,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
       expect(code, contains('///$comment'));
@@ -1061,7 +1092,8 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(': FlutterStandardReader ')));
   });
@@ -1104,7 +1136,8 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    generateSwift(swiftOptions, root, sink);
+    final SwiftGenerator generator = SwiftGenerator();
+    generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains(': FlutterStandardReader '));
   });

From 45f3d820041e675d37cec8cbe675de5cca1b1fed Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 14:35:31 -0800
Subject: [PATCH 56/87] private unique methods and reorder

---
 packages/pigeon/lib/cpp_generator.dart   | 208 +++++++++++------------
 packages/pigeon/lib/objc_generator.dart  | 100 +++++------
 packages/pigeon/lib/swift_generator.dart |  20 +--
 3 files changed, 164 insertions(+), 164 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 3f94ab2396d..d280cea61c4 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -105,9 +105,9 @@ class CppGenerator extends Generator<CppOptions> {
   void writeHeaders(CppOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
     if (fileType == FileType.header) {
-      writeCppHeaderHeader(languageOptions, root, sink, indent);
+      _writeCppHeaderHeader(languageOptions, root, sink, indent);
     } else {
-      writeCppSourceHeader(languageOptions, root, sink, indent);
+      _writeCppSourceHeader(languageOptions, root, sink, indent);
     }
   }
 
@@ -115,9 +115,9 @@ class CppGenerator extends Generator<CppOptions> {
   void writeImports(CppOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
     if (fileType == FileType.header) {
-      writeCppHeaderImports(languageOptions, root, sink, indent);
+      _writeCppHeaderImports(languageOptions, root, sink, indent);
     } else {
-      writeCppSourceImports(languageOptions, root, sink, indent);
+      _writeCppSourceImports(languageOptions, root, sink, indent);
     }
   }
 
@@ -125,7 +125,7 @@ class CppGenerator extends Generator<CppOptions> {
   void writeEnum(CppOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType, Enum anEnum) {
     if (fileType == FileType.header) {
-      writeCppHeaderEnum(languageOptions, root, sink, indent, anEnum);
+      _writeCppHeaderEnum(languageOptions, root, sink, indent, anEnum);
     }
   }
 
@@ -179,6 +179,68 @@ class CppGenerator extends Generator<CppOptions> {
         customClassNames, customEnumNames);
   }
 
+  /// Writes Cpp header file header to sink.
+  void _writeCppHeaderHeader(
+      CppOptions options, Root root, StringSink sink, Indent indent) {
+    if (options.copyrightHeader != null) {
+      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('$_commentPrefix $generatedCodeWarning');
+    indent.writeln('$_commentPrefix $seeAlsoWarning');
+    indent.addln('');
+  }
+
+  /// Writes Cpp header file imports to sink.
+  void _writeCppHeaderImports(
+      CppOptions options, Root root, StringSink sink, Indent indent) {
+    final String guardName =
+        _getGuardName(options.headerIncludePath, options.namespace);
+    indent.writeln('#ifndef $guardName');
+    indent.writeln('#define $guardName');
+
+    _writeSystemHeaderIncludeBlock(indent, <String>[
+      'flutter/basic_message_channel.h',
+      'flutter/binary_messenger.h',
+      'flutter/encodable_value.h',
+      'flutter/standard_message_codec.h',
+    ]);
+    indent.addln('');
+    _writeSystemHeaderIncludeBlock(indent, <String>[
+      'map',
+      'string',
+      'optional',
+    ]);
+    indent.addln('');
+    if (options.namespace != null) {
+      indent.writeln('namespace ${options.namespace} {');
+    }
+    indent.addln('');
+    if (options.namespace?.endsWith('_pigeontest') ?? false) {
+      final String testFixtureClass =
+          '${_pascalCaseFromSnakeCase(options.namespace!.replaceAll('_pigeontest', ''))}Test';
+      indent.writeln('class $testFixtureClass;');
+    }
+    indent.addln('');
+    indent.writeln('$_commentPrefix Generated class from Pigeon.');
+  }
+
+  /// Writes Cpp header enum to sink.
+  void _writeCppHeaderEnum(CppOptions options, Root root, StringSink sink,
+      Indent indent, Enum anEnum) {
+    indent.writeln('');
+    addDocumentationComments(
+        indent, anEnum.documentationComments, _docCommentSpec);
+    indent.write('enum class ${anEnum.name} ');
+    indent.scoped('{', '};', () {
+      enumerate(anEnum.members, (int index, final EnumMember member) {
+        addDocumentationComments(
+            indent, member.documentationComments, _docCommentSpec);
+        indent.writeln(
+            '${member.name} = $index${index == anEnum.members.length - 1 ? '' : ','}');
+      });
+    });
+  }
+
   /// Writes the declaration for the custom class [klass].
   ///
   /// See [_writeCppSourceDataClass] for the corresponding declaration.
@@ -258,6 +320,43 @@ class CppGenerator extends Generator<CppOptions> {
     indent.writeln('');
   }
 
+  /// Writes Cpp source file header to sink.
+  void _writeCppSourceHeader(
+      CppOptions options, Root root, StringSink sink, Indent indent) {
+    if (options.copyrightHeader != null) {
+      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('$_commentPrefix $generatedCodeWarning');
+    indent.writeln('$_commentPrefix $seeAlsoWarning');
+    indent.addln('');
+    indent.addln('#undef _HAS_EXCEPTIONS');
+    indent.addln('');
+  }
+
+  /// Writes Cpp source file imports to sink.
+  void _writeCppSourceImports(
+      CppOptions options, Root root, StringSink sink, Indent indent) {
+    indent.writeln('#include "${options.headerIncludePath}"');
+    indent.addln('');
+    _writeSystemHeaderIncludeBlock(indent, <String>[
+      'flutter/basic_message_channel.h',
+      'flutter/binary_messenger.h',
+      'flutter/encodable_value.h',
+      'flutter/standard_message_codec.h',
+    ]);
+    indent.addln('');
+    _writeSystemHeaderIncludeBlock(indent, <String>[
+      'map',
+      'string',
+      'optional',
+    ]);
+    indent.addln('');
+
+    if (options.namespace != null) {
+      indent.writeln('namespace ${options.namespace} {');
+    }
+  }
+
   void _writeCppSourceClassEncode(
     CppOptions languageOptions,
     Root root,
@@ -438,105 +537,6 @@ else if (const int64_t* ${pointerFieldName}_64 = std::get_if<int64_t>(&$encodabl
     writeClassDecode(languageOptions, root, sink, indent, fileType, klass,
         customClassNames, customEnumNames);
   }
-
-  /// Writes Cpp header file header to sink.
-  void writeCppHeaderHeader(
-      CppOptions options, Root root, StringSink sink, Indent indent) {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('$_commentPrefix $generatedCodeWarning');
-    indent.writeln('$_commentPrefix $seeAlsoWarning');
-    indent.addln('');
-  }
-
-  /// Writes Cpp header file imports to sink.
-  void writeCppHeaderImports(
-      CppOptions options, Root root, StringSink sink, Indent indent) {
-    final String guardName =
-        _getGuardName(options.headerIncludePath, options.namespace);
-    indent.writeln('#ifndef $guardName');
-    indent.writeln('#define $guardName');
-
-    _writeSystemHeaderIncludeBlock(indent, <String>[
-      'flutter/basic_message_channel.h',
-      'flutter/binary_messenger.h',
-      'flutter/encodable_value.h',
-      'flutter/standard_message_codec.h',
-    ]);
-    indent.addln('');
-    _writeSystemHeaderIncludeBlock(indent, <String>[
-      'map',
-      'string',
-      'optional',
-    ]);
-    indent.addln('');
-    if (options.namespace != null) {
-      indent.writeln('namespace ${options.namespace} {');
-    }
-    indent.addln('');
-    if (options.namespace?.endsWith('_pigeontest') ?? false) {
-      final String testFixtureClass =
-          '${_pascalCaseFromSnakeCase(options.namespace!.replaceAll('_pigeontest', ''))}Test';
-      indent.writeln('class $testFixtureClass;');
-    }
-    indent.addln('');
-    indent.writeln('$_commentPrefix Generated class from Pigeon.');
-  }
-
-  /// Writes Cpp header enum to sink.
-  void writeCppHeaderEnum(CppOptions options, Root root, StringSink sink,
-      Indent indent, Enum anEnum) {
-    indent.writeln('');
-    addDocumentationComments(
-        indent, anEnum.documentationComments, _docCommentSpec);
-    indent.write('enum class ${anEnum.name} ');
-    indent.scoped('{', '};', () {
-      enumerate(anEnum.members, (int index, final EnumMember member) {
-        addDocumentationComments(
-            indent, member.documentationComments, _docCommentSpec);
-        indent.writeln(
-            '${member.name} = $index${index == anEnum.members.length - 1 ? '' : ','}');
-      });
-    });
-  }
-
-  /// Writes Cpp source file header to sink.
-  void writeCppSourceHeader(
-      CppOptions options, Root root, StringSink sink, Indent indent) {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('$_commentPrefix $generatedCodeWarning');
-    indent.writeln('$_commentPrefix $seeAlsoWarning');
-    indent.addln('');
-    indent.addln('#undef _HAS_EXCEPTIONS');
-    indent.addln('');
-  }
-
-  /// Writes Cpp source file imports to sink.
-  void writeCppSourceImports(
-      CppOptions options, Root root, StringSink sink, Indent indent) {
-    indent.writeln('#include "${options.headerIncludePath}"');
-    indent.addln('');
-    _writeSystemHeaderIncludeBlock(indent, <String>[
-      'flutter/basic_message_channel.h',
-      'flutter/binary_messenger.h',
-      'flutter/encodable_value.h',
-      'flutter/standard_message_codec.h',
-    ]);
-    indent.addln('');
-    _writeSystemHeaderIncludeBlock(indent, <String>[
-      'map',
-      'string',
-      'optional',
-    ]);
-    indent.addln('');
-
-    if (options.namespace != null) {
-      indent.writeln('namespace ${options.namespace} {');
-    }
-  }
 }
 
 String _getCodecSerializerName(Api api) => '${api.name}CodecSerializer';
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 3cf8021c002..ce267e135b3 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -115,9 +115,9 @@ class ObjcGenerator extends Generator<ObjcOptions> {
   void writeHeaders(ObjcOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
     if (fileType == FileType.header) {
-      writeObjcHeaderHeader(languageOptions, root, sink, indent);
+      _writeObjcHeaderHeader(languageOptions, root, sink, indent);
     } else {
-      writeObjcSourceHeader(languageOptions, root, sink, indent);
+      _writeObjcSourceHeader(languageOptions, root, sink, indent);
     }
   }
 
@@ -125,9 +125,9 @@ class ObjcGenerator extends Generator<ObjcOptions> {
   void writeImports(ObjcOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType) {
     if (fileType == FileType.header) {
-      writeObjcHeaderImports(languageOptions, root, sink, indent);
+      _writeObjcHeaderImports(languageOptions, root, sink, indent);
     } else {
-      writeObjcSourceImports(languageOptions, root, sink, indent);
+      _writeObjcSourceImports(languageOptions, root, sink, indent);
     }
   }
 
@@ -135,7 +135,7 @@ class ObjcGenerator extends Generator<ObjcOptions> {
   void writeEnum(ObjcOptions languageOptions, Root root, StringSink sink,
       Indent indent, FileType fileType, Enum anEnum) {
     if (fileType == FileType.header) {
-      writeObjcHeaderEnum(languageOptions, root, sink, indent, anEnum);
+      _writeObjcHeaderEnum(languageOptions, root, sink, indent, anEnum);
     }
   }
 
@@ -191,6 +191,49 @@ class ObjcGenerator extends Generator<ObjcOptions> {
 
   // Header File Methods.
 
+  /// Writes Objc header file header to sink.
+  void _writeObjcHeaderHeader(
+      ObjcOptions options, Root root, StringSink sink, Indent indent) {
+    if (options.copyrightHeader != null) {
+      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('// $generatedCodeWarning');
+    indent.writeln('// $seeAlsoWarning');
+    indent.addln('');
+  }
+
+  /// Writes Objc header file imports to sink.
+  void _writeObjcHeaderImports(
+      ObjcOptions options, Root root, StringSink sink, Indent indent) {
+    indent.writeln('#import <Foundation/Foundation.h>');
+    indent.addln('');
+
+    indent.writeln('@protocol FlutterBinaryMessenger;');
+    indent.writeln('@protocol FlutterMessageCodec;');
+    indent.writeln('@class FlutterError;');
+    indent.writeln('@class FlutterStandardTypedData;');
+    indent.addln('');
+  }
+
+  /// Writes single Objc header enum.
+  void _writeObjcHeaderEnum(ObjcOptions options, Root root, StringSink sink,
+      Indent indent, Enum anEnum) {
+    final String enumName = _className(options.prefix, anEnum.name);
+    addDocumentationComments(
+        indent, anEnum.documentationComments, _docCommentSpec);
+
+    indent.write('typedef NS_ENUM(NSUInteger, $enumName) ');
+    indent.scoped('{', '};', () {
+      enumerate(anEnum.members, (int index, final EnumMember member) {
+        addDocumentationComments(
+            indent, member.documentationComments, _docCommentSpec);
+        // Capitalized first letter to ensure Swift compatibility
+        indent.writeln(
+            '$enumName${member.name[0].toUpperCase()}${member.name.substring(1)} = $index,');
+      });
+    });
+  }
+
   /// Writes the class declaration for a data class.
   ///
   /// Example:
@@ -246,53 +289,10 @@ class ObjcGenerator extends Generator<ObjcOptions> {
     indent.writeln('');
   }
 
-  /// Writes Objc header file header to sink.
-  void writeObjcHeaderHeader(
-      ObjcOptions options, Root root, StringSink sink, Indent indent) {
-    if (options.copyrightHeader != null) {
-      addLines(indent, options.copyrightHeader!, linePrefix: '// ');
-    }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-    indent.addln('');
-  }
-
-  /// Writes Objc header file imports to sink.
-  void writeObjcHeaderImports(
-      ObjcOptions options, Root root, StringSink sink, Indent indent) {
-    indent.writeln('#import <Foundation/Foundation.h>');
-    indent.addln('');
-
-    indent.writeln('@protocol FlutterBinaryMessenger;');
-    indent.writeln('@protocol FlutterMessageCodec;');
-    indent.writeln('@class FlutterError;');
-    indent.writeln('@class FlutterStandardTypedData;');
-    indent.addln('');
-  }
-
-  /// Writes single Objc header enum.
-  void writeObjcHeaderEnum(ObjcOptions options, Root root, StringSink sink,
-      Indent indent, Enum anEnum) {
-    final String enumName = _className(options.prefix, anEnum.name);
-    addDocumentationComments(
-        indent, anEnum.documentationComments, _docCommentSpec);
-
-    indent.write('typedef NS_ENUM(NSUInteger, $enumName) ');
-    indent.scoped('{', '};', () {
-      enumerate(anEnum.members, (int index, final EnumMember member) {
-        addDocumentationComments(
-            indent, member.documentationComments, _docCommentSpec);
-        // Capitalized first letter to ensure Swift compatibility
-        indent.writeln(
-            '$enumName${member.name[0].toUpperCase()}${member.name.substring(1)} = $index,');
-      });
-    });
-  }
-
   // Source File Methods.
 
   /// Writes Objc Source file header to sink.
-  void writeObjcSourceHeader(
+  void _writeObjcSourceHeader(
       ObjcOptions options, Root root, StringSink sink, Indent indent) {
     if (options.copyrightHeader != null) {
       addLines(indent, options.copyrightHeader!, linePrefix: '// ');
@@ -303,7 +303,7 @@ class ObjcGenerator extends Generator<ObjcOptions> {
   }
 
   /// Writes Objc source file imports to sink.
-  void writeObjcSourceImports(
+  void _writeObjcSourceImports(
       ObjcOptions options, Root root, StringSink sink, Indent indent) {
     indent.writeln('#import "${options.headerIncludePath}"');
     indent.writeln('#import <Flutter/Flutter.h>');
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index bfd7dab1009..ec76b562999 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -145,16 +145,6 @@ import FlutterMacOS
     });
   }
 
-  void _writeClassField(Indent indent, NamedType field) {
-    addDocumentationComments(
-        indent, field.documentationComments, _docCommentSpec);
-
-    indent.write(
-        'var ${field.name}: ${_nullsafeSwiftTypeForDartType(field.type)}');
-    final String defaultNil = field.type.isNullable ? ' = nil' : '';
-    indent.addln(defaultNil);
-  }
-
   @override
   void writeClassEncode(
     SwiftOptions languageOptions,
@@ -260,6 +250,16 @@ import FlutterMacOS
     });
   }
 
+  void _writeClassField(Indent indent, NamedType field) {
+    addDocumentationComments(
+        indent, field.documentationComments, _docCommentSpec);
+
+    indent.write(
+        'var ${field.name}: ${_nullsafeSwiftTypeForDartType(field.type)}');
+    final String defaultNil = field.type.isNullable ? ' = nil' : '';
+    indent.addln(defaultNil);
+  }
+
   HostDatatype _getHostDatatype(Root root, NamedType field) {
     return getFieldHostDatatype(field, root.classes, root.enums,
         (TypeDeclaration x) => _swiftTypeForBuiltinDartType(x));

From 3a01adec3b3fc6ec607d9dad820c66e1c560af77 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 16:43:18 -0800
Subject: [PATCH 57/87] changelog

---
 packages/pigeon/CHANGELOG.md             | 4 ++++
 packages/pigeon/lib/generator_tools.dart | 2 +-
 packages/pigeon/pubspec.yaml             | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index 394a84a7f80..235f434d9cf 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 5.0.2
+
+* Adds writeImports method to Generator classes.
+
 ## 5.0.1
 
 * Adds writeHeaders method to Generator classes and updates tests to use new Generators.
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 577bf8216de..e3016ad19af 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -9,7 +9,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon. This must match the version in pubspec.yaml.
-const String pigeonVersion = '5.0.1';
+const String pigeonVersion = '5.0.2';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index f2a5a9a6639..3e1b364ac62 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 5.0.1 # This must match the version in lib/generator_tools.dart
+version: 5.0.2 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

From 91ffeb4adce02f297bb0b911266461aeec4cca9e Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 16:44:58 -0800
Subject: [PATCH 58/87] changelog

---
 packages/pigeon/CHANGELOG.md             | 4 ++++
 packages/pigeon/lib/generator_tools.dart | 2 +-
 packages/pigeon/pubspec.yaml             | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index 235f434d9cf..f3328922108 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 5.0.3
+
+* Adds writeEnum method to Generator classes.
+
 ## 5.0.2
 
 * Adds writeImports method to Generator classes.
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index e3016ad19af..73c1fd36272 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -9,7 +9,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon. This must match the version in pubspec.yaml.
-const String pigeonVersion = '5.0.2';
+const String pigeonVersion = '5.0.3';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index 3e1b364ac62..a72557dab8a 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 5.0.2 # This must match the version in lib/generator_tools.dart
+version: 5.0.3 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

From 1bbfa53b3b8aa3cb8abe67e28200d4afe1788fd6 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 16:46:00 -0800
Subject: [PATCH 59/87] changelog

---
 packages/pigeon/CHANGELOG.md             | 4 ++++
 packages/pigeon/lib/generator_tools.dart | 2 +-
 packages/pigeon/pubspec.yaml             | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index f3328922108..33c5fabb787 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 5.0.4
+
+* Adds writeEnum method to Generator classes.
+
 ## 5.0.3
 
 * Adds writeEnum method to Generator classes.
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 73c1fd36272..d6ef9703cf4 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -9,7 +9,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon. This must match the version in pubspec.yaml.
-const String pigeonVersion = '5.0.3';
+const String pigeonVersion = '5.0.4';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index a72557dab8a..1740c655da9 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 5.0.3 # This must match the version in lib/generator_tools.dart
+version: 5.0.4 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

From c92b944787d6a28448caf45282b1d8868ecb9cf0 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 16:49:10 -0800
Subject: [PATCH 60/87] changelog

---
 packages/pigeon/CHANGELOG.md             | 4 ++++
 packages/pigeon/lib/generator_tools.dart | 2 +-
 packages/pigeon/pubspec.yaml             | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index 33c5fabb787..bda54aef371 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 5.0.5
+
+* Adds writeApi method to Generator classes.
+
 ## 5.0.4
 
 * Adds writeEnum method to Generator classes.
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index d6ef9703cf4..07eac70ad9b 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -9,7 +9,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon. This must match the version in pubspec.yaml.
-const String pigeonVersion = '5.0.4';
+const String pigeonVersion = '5.0.5';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index 1740c655da9..e4feca00cb9 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 5.0.4 # This must match the version in lib/generator_tools.dart
+version: 5.0.5 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

From 02fd734a60a6588ba410e6fcdea67b492306cc15 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 17:22:40 -0800
Subject: [PATCH 61/87] prologue

---
 packages/pigeon/lib/cpp_generator.dart    | 14 +++++++-------
 packages/pigeon/lib/dart_generator.dart   |  8 ++++----
 packages/pigeon/lib/generator.dart        |  2 +-
 packages/pigeon/lib/java_generator.dart   |  8 ++++----
 packages/pigeon/lib/kotlin_generator.dart |  8 ++++----
 packages/pigeon/lib/objc_generator.dart   | 14 +++++++-------
 packages/pigeon/lib/swift_generator.dart  |  8 ++++----
 7 files changed, 31 insertions(+), 31 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 82fb8bf62b7..d2cd209c0d9 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -84,23 +84,23 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
 
     final Indent indent = Indent(sink);
     if (fileType == FileType.header) {
-      writeFileHeaders(generatorOptions, root, sink, indent);
+      writeFilePrologue(generatorOptions, root, sink, indent);
       generateCppHeader(generatorOptions.languageOptions, root, sink, indent);
     } else {
-      writeFileHeaders(generatorOptions, root, sink, indent);
+      writeFilePrologue(generatorOptions, root, sink, indent);
       generateCppSource(generatorOptions.languageOptions, root, sink, indent);
     }
   }
 
   @override
-  void writeFileHeaders(OutputFileOptions<CppOptions> generatorOptions,
+  void writeFilePrologue(OutputFileOptions<CppOptions> generatorOptions,
       Root root, StringSink sink, Indent indent) {
     final FileType fileType = generatorOptions.fileType;
     if (fileType == FileType.header) {
-      writeCppHeaderHeader(
+      writeCppHeaderPrologue(
           generatorOptions.languageOptions, root, sink, indent);
     } else {
-      writeCppSourceHeader(
+      writeCppSourcePrologue(
           generatorOptions.languageOptions, root, sink, indent);
     }
   }
@@ -1067,7 +1067,7 @@ void _writeSystemHeaderIncludeBlock(Indent indent, List<String> headers) {
 }
 
 /// Writes Cpp header file header to sink.
-void writeCppHeaderHeader(
+void writeCppHeaderPrologue(
     CppOptions options, Root root, StringSink sink, Indent indent) {
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
@@ -1163,7 +1163,7 @@ void generateCppHeader(
 }
 
 /// Writes Cpp source file header to sink.
-void writeCppSourceHeader(
+void writeCppSourcePrologue(
     CppOptions options, Root root, StringSink sink, Indent indent) {
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index daf4171754b..724a1dfc1a8 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -80,14 +80,14 @@ class DartGenerator extends Generator<DartOptions> {
   void generate(DartOptions generatorOptions, Root root, StringSink sink) {
     final Indent indent = Indent(sink);
 
-    writeFileHeaders(generatorOptions, root, sink, indent);
+    writeFilePrologue(generatorOptions, root, sink, indent);
     generateDart(generatorOptions, root, sink, indent);
   }
 
   @override
-  void writeFileHeaders(
+  void writeFilePrologue(
       DartOptions generatorOptions, Root root, StringSink sink, Indent indent) {
-    writeHeader(generatorOptions, root, sink, indent);
+    writePrologue(generatorOptions, root, sink, indent);
   }
 
   /// Generates Dart files for testing with specified [DartOptions]
@@ -512,7 +512,7 @@ String _addGenericTypesNullable(TypeDeclaration type) {
 }
 
 /// Writes file header to sink.
-void writeHeader(DartOptions opt, Root root, StringSink sink, Indent indent) {
+void writePrologue(DartOptions opt, Root root, StringSink sink, Indent indent) {
   if (opt.copyrightHeader != null) {
     addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
   }
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 473e1a3e46f..67e2fdbd602 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -22,7 +22,7 @@ abstract class Generator<T> {
   );
 
   /// Adds specified file headers.
-  void writeFileHeaders(
+  void writeFilePrologue(
     T generatorOptions,
     Root root,
     StringSink sink,
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 6a18fba04aa..84357703b15 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -95,14 +95,14 @@ class JavaGenerator extends Generator<JavaOptions> {
   void generate(JavaOptions generatorOptions, Root root, StringSink sink) {
     final Indent indent = Indent(sink);
 
-    writeFileHeaders(generatorOptions, root, sink, indent);
+    writeFilePrologue(generatorOptions, root, sink, indent);
     generateJava(generatorOptions, root, sink, indent);
   }
 
   @override
-  void writeFileHeaders(
+  void writeFilePrologue(
       JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
-    writeHeader(generatorOptions, root, sink, indent);
+    writePrologue(generatorOptions, root, sink, indent);
   }
 }
 
@@ -544,7 +544,7 @@ String _castObject(
 }
 
 /// Writes file header to sink.
-void writeHeader(
+void writePrologue(
     JavaOptions options, Root root, StringSink sink, Indent indent) {
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index eed3e6da387..5e47a152ebc 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -79,14 +79,14 @@ class KotlinGenerator extends Generator<KotlinOptions> {
   ) {
     final Indent indent = Indent(sink);
 
-    writeFileHeaders(generatorOptions, root, sink, indent);
+    writeFilePrologue(generatorOptions, root, sink, indent);
     generateKotlin(generatorOptions, root, sink, indent);
   }
 
   @override
-  void writeFileHeaders(KotlinOptions generatorOptions, Root root,
+  void writeFilePrologue(KotlinOptions generatorOptions, Root root,
       StringSink sink, Indent indent) {
-    writeHeader(generatorOptions, root, sink, indent);
+    writePrologue(generatorOptions, root, sink, indent);
   }
 }
 
@@ -461,7 +461,7 @@ String _nullsafeKotlinTypeForDartType(TypeDeclaration type) {
 }
 
 /// Writes file header to sink.
-void writeHeader(
+void writePrologue(
     KotlinOptions options, Root root, StringSink sink, Indent indent) {
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 33922019d2c..25e06b98f42 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -77,23 +77,23 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
     final Indent indent = Indent(sink);
 
     if (fileType == FileType.header) {
-      writeFileHeaders(generatorOptions, root, sink, indent);
+      writeFilePrologue(generatorOptions, root, sink, indent);
       generateObjcHeader(generatorOptions.languageOptions, root, sink, indent);
     } else {
-      writeFileHeaders(generatorOptions, root, sink, indent);
+      writeFilePrologue(generatorOptions, root, sink, indent);
       generateObjcSource(generatorOptions.languageOptions, root, sink, indent);
     }
   }
 
   @override
-  void writeFileHeaders(OutputFileOptions<ObjcOptions> generatorOptions,
+  void writeFilePrologue(OutputFileOptions<ObjcOptions> generatorOptions,
       Root root, StringSink sink, Indent indent) {
     final FileType fileType = generatorOptions.fileType;
     if (fileType == FileType.header) {
-      writeObjcHeaderHeader(
+      writeObjcHeaderPrologue(
           generatorOptions.languageOptions, root, sink, indent);
     } else {
-      writeObjcSourceHeader(
+      writeObjcSourcePrologue(
           generatorOptions.languageOptions, root, sink, indent);
     }
   }
@@ -567,7 +567,7 @@ void _writeFlutterApiDeclaration(
 }
 
 /// Writes Objc header file header to sink.
-void writeObjcHeaderHeader(
+void writeObjcHeaderPrologue(
     ObjcOptions options, Root root, StringSink sink, Indent indent) {
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
@@ -911,7 +911,7 @@ void _writeFlutterApiSource(
 }
 
 /// Writes Objc Source file header to sink.
-void writeObjcSourceHeader(
+void writeObjcSourcePrologue(
     ObjcOptions options, Root root, StringSink sink, Indent indent) {
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 44532e91f15..a55be7090b8 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -57,14 +57,14 @@ class SwiftGenerator extends Generator<SwiftOptions> {
   @override
   void generate(SwiftOptions generatorOptions, Root root, StringSink sink) {
     final Indent indent = Indent(sink);
-    writeFileHeaders(generatorOptions, root, sink, indent);
+    writeFilePrologue(generatorOptions, root, sink, indent);
     generateSwift(generatorOptions, root, sink, indent);
   }
 
   @override
-  void writeFileHeaders(SwiftOptions generatorOptions, Root root,
+  void writeFilePrologue(SwiftOptions generatorOptions, Root root,
       StringSink sink, Indent indent) {
-    writeHeader(generatorOptions, root, sink, indent);
+    writePrologue(generatorOptions, root, sink, indent);
   }
 }
 
@@ -454,7 +454,7 @@ String _nullsafeSwiftTypeForDartType(TypeDeclaration type) {
 }
 
 /// Writes file header to sink.
-void writeHeader(
+void writePrologue(
     SwiftOptions options, Root root, StringSink sink, Indent indent) {
   if (options.copyrightHeader != null) {
     addLines(indent, options.copyrightHeader!, linePrefix: '// ');

From cdc2da694a840b9c0329fb910d37921217a6f966 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 17:53:01 -0800
Subject: [PATCH 62/87] gen

---
 packages/pigeon/mock_handler_tester/test/message.dart           | 2 +-
 packages/pigeon/mock_handler_tester/test/test.dart              | 2 +-
 .../com/example/alternate_language_test_plugin/CoreTests.java   | 2 +-
 .../alternate_language_test_plugin/ios/Classes/CoreTests.gen.h  | 2 +-
 .../alternate_language_test_plugin/ios/Classes/CoreTests.gen.m  | 2 +-
 .../flutter_null_safe_unit_tests/lib/core_tests.gen.dart        | 2 +-
 .../flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart    | 2 +-
 .../flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart   | 2 +-
 .../flutter_null_safe_unit_tests/lib/null_fields.gen.dart       | 2 +-
 .../flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart      | 2 +-
 .../flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart  | 2 +-
 .../flutter_null_safe_unit_tests/lib/primitive.dart             | 2 +-
 .../lib/src/generated/core_tests.gen.dart                       | 2 +-
 .../src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt    | 2 +-
 .../platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift  | 2 +-
 .../test_plugin/macos/Classes/CoreTests.gen.swift               | 2 +-
 .../test_plugin/windows/pigeon/core_tests.gen.cpp               | 2 +-
 .../platform_tests/test_plugin/windows/pigeon/core_tests.gen.h  | 2 +-
 18 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/packages/pigeon/mock_handler_tester/test/message.dart b/packages/pigeon/mock_handler_tester/test/message.dart
index f621ac645da..1780b3c7504 100644
--- a/packages/pigeon/mock_handler_tester/test/message.dart
+++ b/packages/pigeon/mock_handler_tester/test/message.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/mock_handler_tester/test/test.dart b/packages/pigeon/mock_handler_tester/test/test.dart
index f9be7a1f0c6..075fe0e7ca6 100644
--- a/packages/pigeon/mock_handler_tester/test/test.dart
+++ b/packages/pigeon/mock_handler_tester/test/test.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, unnecessary_import
 // ignore_for_file: avoid_relative_lib_imports
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
index bb5e3ba569a..b95b18fb650 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package com.example.alternate_language_test_plugin;
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
index 99a55d66a71..74c3c2e68f4 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #import <Foundation/Foundation.h>
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
index 1e0bc26defd..c52ea0822e1 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #import "CoreTests.gen.h"
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
index fbdca3b2ed4..e681a886aaf 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
index 692de832122..aa2c80d3824 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/multiple_arity.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
index 605a5f2c8c5..d60b52646b1 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
index cd6273f8d65..6d2d1d41f03 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_fields.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
index 0999065d1ae..930fccd57fa 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
index 03522dd4cb7..75e73d74eea 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/nullable_returns.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
index 78eee146e5f..f2961e54cca 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/primitive.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
index fbdca3b2ed4..e681a886aaf 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
 
diff --git a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
index 258a4328e98..15d31704b6d 100644
--- a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
+++ b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package com.example.test_plugin
diff --git a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
index a754852b62e..ecd65d85009 100644
--- a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
diff --git a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
index a754852b62e..ecd65d85009 100644
--- a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // 
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
index 5e748c1f154..7cd0f9cec35 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.cpp
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #undef _HAS_EXCEPTIONS
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
index 48092005912..e6e0825cf88 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v5.0.4), do not edit directly.
+// Autogenerated from Pigeon (v5.0.5), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #ifndef PIGEON_CORE_TESTS_GEN_H_CORE_TESTS_PIGEONTEST_H_

From 3464c373779e69b25ee56a1f7e91f986b10e913f Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 23:10:42 -0800
Subject: [PATCH 63/87] dart

---
 packages/pigeon/lib/dart_generator.dart | 741 ++++++++++++------------
 packages/pigeon/lib/generator.dart      |  22 +-
 2 files changed, 380 insertions(+), 383 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index f930979cc8d..9de09227aa2 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -90,7 +90,14 @@ class DartGenerator extends Generator<DartOptions> {
       writeDataClass(generatorOptions, root, sink, indent, klass);
     }
 
-    generateDart(generatorOptions, root, sink, indent);
+    for (final Api api in root.apis) {
+      indent.writeln('');
+      if (api.location == ApiLocation.host) {
+        writeHostApi(generatorOptions, root, sink, indent, api);
+      } else if (api.location == ApiLocation.flutter) {
+        writeFlutterApi(generatorOptions, root, sink, indent, api);
+      }
+    }
   }
 
   @override
@@ -284,21 +291,366 @@ $resultAt != null
     });
   }
 
-  /// Generates Dart files for testing with specified [DartOptions]
+  /// Writes the code for host [Api], [api].
+  /// Example:
+  /// class FooCodec extends StandardMessageCodec {...}
+  ///
+  /// abstract class Foo {
+  ///   static const MessageCodec<Object?> codec = FooCodec();
+  ///   int add(int x, int y);
+  ///   static void setup(Foo api, {BinaryMessenger? binaryMessenger}) {...}
+  /// }
+  @override
+  void writeFlutterApi(
+    DartOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api, {
+    String Function(Method)? channelNameFunc,
+    bool isMockHandler = false,
+  }) {
+    assert(api.location == ApiLocation.flutter);
+    final List<String> customEnumNames =
+        root.enums.map((Enum x) => x.name).toList();
+    String codecName = _standardMessageCodec;
+    if (getCodecClasses(api, root).isNotEmpty) {
+      codecName = _getCodecName(api);
+      _writeCodec(indent, codecName, api, root);
+    }
+    indent.addln('');
+    addDocumentationComments(
+        indent, api.documentationComments, _docCommentSpec);
+
+    indent.write('abstract class ${api.name} ');
+    indent.scoped('{', '}', () {
+      indent
+          .writeln('static const MessageCodec<Object?> codec = $codecName();');
+      indent.addln('');
+      for (final Method func in api.methods) {
+        addDocumentationComments(
+            indent, func.documentationComments, _docCommentSpec);
+
+        final bool isAsync = func.isAsynchronous;
+        final String returnType = isAsync
+            ? 'Future<${_addGenericTypesNullable(func.returnType)}>'
+            : _addGenericTypesNullable(func.returnType);
+        final String argSignature = _getMethodArgumentsSignature(
+          func,
+          _getArgumentName,
+        );
+        indent.writeln('$returnType ${func.name}($argSignature);');
+        indent.writeln('');
+      }
+      indent.write(
+          'static void setup(${api.name}? api, {BinaryMessenger? binaryMessenger}) ');
+      indent.scoped('{', '}', () {
+        for (final Method func in api.methods) {
+          indent.write('');
+          indent.scoped('{', '}', () {
+            indent.writeln(
+              'final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(',
+            );
+            final String channelName = channelNameFunc == null
+                ? makeChannelName(api, func)
+                : channelNameFunc(func);
+            indent.nest(2, () {
+              indent.writeln("'$channelName', codec,");
+              indent.writeln(
+                'binaryMessenger: binaryMessenger);',
+              );
+            });
+            final String messageHandlerSetter =
+                isMockHandler ? 'setMockMessageHandler' : 'setMessageHandler';
+            indent.write('if (api == null) ');
+            indent.scoped('{', '}', () {
+              indent.writeln('channel.$messageHandlerSetter(null);');
+            }, addTrailingNewline: false);
+            indent.add(' else ');
+            indent.scoped('{', '}', () {
+              indent.write(
+                'channel.$messageHandlerSetter((Object? message) async ',
+              );
+              indent.scoped('{', '});', () {
+                final String returnType =
+                    _addGenericTypesNullable(func.returnType);
+                final bool isAsync = func.isAsynchronous;
+                final String emptyReturnStatement = isMockHandler
+                    ? 'return <Object?>[];'
+                    : func.returnType.isVoid
+                        ? 'return;'
+                        : 'return null;';
+                String call;
+                if (func.arguments.isEmpty) {
+                  indent.writeln('// ignore message');
+                  call = 'api.${func.name}()';
+                } else {
+                  indent.writeln('assert(message != null,');
+                  indent.writeln("'Argument for $channelName was null.');");
+                  const String argsArray = 'args';
+                  indent.writeln(
+                      'final List<Object?> $argsArray = (message as List<Object?>?)!;');
+                  String argNameFunc(int index, NamedType type) =>
+                      _getSafeArgumentName(index, type);
+                  enumerate(func.arguments, (int count, NamedType arg) {
+                    final String argType = _addGenericTypes(arg.type);
+                    final String argName = argNameFunc(count, arg);
+                    final String genericArgType =
+                        _makeGenericTypeArguments(arg.type);
+                    final String castCall = _makeGenericCastCall(arg.type);
+
+                    final String leftHandSide = 'final $argType? $argName';
+                    if (customEnumNames.contains(arg.type.baseName)) {
+                      indent.writeln(
+                          '$leftHandSide = $argsArray[$count] == null ? null : $argType.values[$argsArray[$count] as int];');
+                    } else {
+                      indent.writeln(
+                          '$leftHandSide = ($argsArray[$count] as $genericArgType?)${castCall.isEmpty ? '' : '?$castCall'};');
+                    }
+                    if (!arg.type.isNullable) {
+                      indent.writeln(
+                          "assert($argName != null, 'Argument for $channelName was null, expected non-null $argType.');");
+                    }
+                  });
+                  final Iterable<String> argNames =
+                      indexMap(func.arguments, (int index, NamedType field) {
+                    final String name = _getSafeArgumentName(index, field);
+                    return '$name${field.type.isNullable ? '' : '!'}';
+                  });
+                  call = 'api.${func.name}(${argNames.join(', ')})';
+                }
+                if (func.returnType.isVoid) {
+                  if (isAsync) {
+                    indent.writeln('await $call;');
+                  } else {
+                    indent.writeln('$call;');
+                  }
+                  indent.writeln(emptyReturnStatement);
+                } else {
+                  if (isAsync) {
+                    indent.writeln('final $returnType output = await $call;');
+                  } else {
+                    indent.writeln('final $returnType output = $call;');
+                  }
+                  const String returnExpression = 'output';
+                  final String returnStatement = isMockHandler
+                      ? 'return <Object?>[$returnExpression];'
+                      : 'return $returnExpression;';
+                  indent.writeln(returnStatement);
+                }
+              });
+            });
+          });
+        }
+      });
+    });
+  }
+
+  /// Writes the code for host [Api], [api].
+  /// Example:
+  /// class FooCodec extends StandardMessageCodec {...}
+  ///
+  /// class Foo {
+  ///   Foo(BinaryMessenger? binaryMessenger) {}
+  ///   static const MessageCodec<Object?> codec = FooCodec();
+  ///   Future<int> add(int x, int y) async {...}
+  /// }
+  ///
+  /// Messages will be sent and received in a list.
+  ///
+  /// If the message recieved was succesful,
+  /// the result will be contained at the 0'th index.
+  ///
+  /// If the message was a failure, the list will contain 3 items:
+  /// a code, a message, and details in that order.
+  @override
+  void writeHostApi(DartOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Api api) {
+    assert(api.location == ApiLocation.host);
+    String codecName = _standardMessageCodec;
+    if (getCodecClasses(api, root).isNotEmpty) {
+      codecName = _getCodecName(api);
+      _writeCodec(indent, codecName, api, root);
+    }
+    indent.addln('');
+    bool first = true;
+    addDocumentationComments(
+        indent, api.documentationComments, _docCommentSpec);
+    indent.write('class ${api.name} ');
+    indent.scoped('{', '}', () {
+      indent.format('''
+/// Constructor for [${api.name}].  The [binaryMessenger] named argument is
+/// available for dependency injection.  If it is left null, the default
+/// BinaryMessenger will be used which routes to the host platform.
+${api.name}({BinaryMessenger? binaryMessenger})
+\t\t: _binaryMessenger = binaryMessenger;
+final BinaryMessenger? _binaryMessenger;
+''');
+
+      indent
+          .writeln('static const MessageCodec<Object?> codec = $codecName();');
+      indent.addln('');
+      for (final Method func in api.methods) {
+        if (!first) {
+          indent.writeln('');
+        } else {
+          first = false;
+        }
+        addDocumentationComments(
+            indent, func.documentationComments, _docCommentSpec);
+        String argSignature = '';
+        String sendArgument = 'null';
+        if (func.arguments.isNotEmpty) {
+          String argNameFunc(int index, NamedType type) =>
+              _getSafeArgumentName(index, type);
+          final Iterable<String> argExpressions =
+              indexMap(func.arguments, (int index, NamedType type) {
+            final String name = argNameFunc(index, type);
+            if (root.enums
+                .map((Enum e) => e.name)
+                .contains(type.type.baseName)) {
+              return '$name${type.type.isNullable ? '?' : ''}.index';
+            } else {
+              return name;
+            }
+          });
+          sendArgument = '<Object?>[${argExpressions.join(', ')}]';
+          argSignature = _getMethodArgumentsSignature(func, argNameFunc);
+        }
+        indent.write(
+          'Future<${_addGenericTypesNullable(func.returnType)}> ${func.name}($argSignature) async ',
+        );
+        indent.scoped('{', '}', () {
+          final String channelName = makeChannelName(api, func);
+          indent.writeln(
+              'final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(');
+          indent.nest(2, () {
+            indent.writeln("'$channelName', codec,");
+            indent.writeln('binaryMessenger: _binaryMessenger);');
+          });
+          final String returnType = _makeGenericTypeArguments(func.returnType);
+          final String genericCastCall = _makeGenericCastCall(func.returnType);
+          const String accessor = 'replyList[0]';
+          // Avoid warnings from pointlessly casting to `Object?`.
+          final String nullablyTypedAccessor =
+              returnType == 'Object' ? accessor : '($accessor as $returnType?)';
+          final String nullHandler = func.returnType.isNullable
+              ? (genericCastCall.isEmpty ? '' : '?')
+              : '!';
+          final String returnStatement = func.returnType.isVoid
+              ? 'return;'
+              : 'return $nullablyTypedAccessor$nullHandler$genericCastCall;';
+          indent.format('''
+final List<Object?>? replyList =
+\t\tawait channel.send($sendArgument) as List<Object?>?;
+if (replyList == null) {
+\tthrow PlatformException(
+\t\tcode: 'channel-error',
+\t\tmessage: 'Unable to establish connection on channel.',
+\t);
+} else if (replyList.length > 1) {
+\tthrow PlatformException(
+\t\tcode: replyList[0]! as String,
+\t\tmessage: replyList[1] as String?,
+\t\tdetails: replyList[2],
+\t);''');
+          // On iOS we can return nil from functions to accommodate error
+          // handling.  Returning a nil value and not returning an error is an
+          // exception.
+          if (!func.returnType.isNullable && !func.returnType.isVoid) {
+            indent.format('''
+} else if (replyList[0] == null) {
+\tthrow PlatformException(
+\t\tcode: 'null-error',
+\t\tmessage: 'Host platform returned null value for non-null return value.',
+\t);''');
+          }
+          indent.format('''
+} else {
+\t$returnStatement
+}''');
+        });
+      }
+    });
+  }
+
+  /// Generates Dart source code for test support libraries based on the given AST
+  /// represented by [root], outputting the code to [sink]. [sourceOutPath] is the
+  /// path of the generated dart code to be tested. [testOutPath] is where the
+  /// test code will be generated.
   void generateTest(DartOptions generatorOptions, Root root, StringSink sink) {
     final Indent indent = Indent(sink);
     final String sourceOutPath = generatorOptions.sourceOutPath ?? '';
     final String testOutPath = generatorOptions.testOutPath ?? '';
-    writeTestHeader(generatorOptions, root, sink, indent);
-    writeTestImports(generatorOptions, root, sink, indent);
-    generateTestDart(
-      generatorOptions,
-      root,
-      sink,
-      indent,
-      sourceOutPath: sourceOutPath,
-      testOutPath: testOutPath,
+    _writeTestPrologue(generatorOptions, root, sink, indent);
+    _writeTestImports(generatorOptions, root, sink, indent);
+    final String relativeDartPath =
+        path.Context(style: path.Style.posix).relative(
+      _posixify(sourceOutPath),
+      from: _posixify(path.dirname(testOutPath)),
     );
+    late final String? packageName = _deducePackageName(sourceOutPath);
+    if (!relativeDartPath.contains('/lib/') || packageName == null) {
+      // If we can't figure out the package name or the relative path doesn't
+      // include a 'lib' directory, try relative path import which only works in
+      // certain (older) versions of Dart.
+      // TODO(gaaclarke): We should add a command-line parameter to override this import.
+      indent.writeln(
+          "import '${_escapeForDartSingleQuotedString(relativeDartPath)}';");
+    } else {
+      final String path =
+          relativeDartPath.replaceFirst(RegExp(r'^.*/lib/'), '');
+      indent.writeln("import 'package:$packageName/$path';");
+    }
+    for (final Api api in root.apis) {
+      if (api.location == ApiLocation.host && api.dartHostTestHandler != null) {
+        final Api mockApi = Api(
+          name: api.dartHostTestHandler!,
+          methods: api.methods,
+          location: ApiLocation.flutter,
+          dartHostTestHandler: api.dartHostTestHandler,
+          documentationComments: api.documentationComments,
+        );
+        indent.writeln('');
+        writeFlutterApi(
+          generatorOptions,
+          root,
+          sink,
+          indent,
+          mockApi,
+          channelNameFunc: (Method func) => makeChannelName(api, func),
+          isMockHandler: true,
+        );
+      }
+    }
+  }
+
+  /// Writes file header to sink.
+  void _writeTestPrologue(
+      DartOptions opt, Root root, StringSink sink, Indent indent) {
+    if (opt.copyrightHeader != null) {
+      addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('// $generatedCodeWarning');
+    indent.writeln('// $seeAlsoWarning');
+    indent.writeln(
+      '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, unnecessary_import',
+    );
+    indent.writeln('// ignore_for_file: avoid_relative_lib_imports');
+  }
+
+  /// Writes file imports to sink.
+  void _writeTestImports(
+      DartOptions opt, Root root, StringSink sink, Indent indent) {
+    indent.writeln("import 'dart:async';");
+    indent.writeln(
+      "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
+    );
+    indent.writeln(
+        "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;");
+    indent.writeln("import 'package:flutter/services.dart';");
+    indent.writeln("import 'package:flutter_test/flutter_test.dart';");
+    indent.writeln('');
   }
 }
 
@@ -400,279 +752,6 @@ String _getMethodArgumentsSignature(
         }).join(', ');
 }
 
-/// Writes the code for host [Api], [api].
-/// Example:
-/// class FooCodec extends StandardMessageCodec {...}
-///
-/// class Foo {
-///   Foo(BinaryMessenger? binaryMessenger) {}
-///   static const MessageCodec<Object?> codec = FooCodec();
-///   Future<int> add(int x, int y) async {...}
-/// }
-///
-/// Messages will be sent and received in a list.
-///
-/// If the message recieved was succesful,
-/// the result will be contained at the 0'th index.
-///
-/// If the message was a failure, the list will contain 3 items:
-/// a code, a message, and details in that order.
-void _writeHostApi(DartOptions opt, Indent indent, Api api, Root root) {
-  assert(api.location == ApiLocation.host);
-  String codecName = _standardMessageCodec;
-  if (getCodecClasses(api, root).isNotEmpty) {
-    codecName = _getCodecName(api);
-    _writeCodec(indent, codecName, api, root);
-  }
-  indent.addln('');
-  bool first = true;
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec);
-  indent.write('class ${api.name} ');
-  indent.scoped('{', '}', () {
-    indent.format('''
-/// Constructor for [${api.name}].  The [binaryMessenger] named argument is
-/// available for dependency injection.  If it is left null, the default
-/// BinaryMessenger will be used which routes to the host platform.
-${api.name}({BinaryMessenger? binaryMessenger})
-\t\t: _binaryMessenger = binaryMessenger;
-final BinaryMessenger? _binaryMessenger;
-''');
-
-    indent.writeln('static const MessageCodec<Object?> codec = $codecName();');
-    indent.addln('');
-    for (final Method func in api.methods) {
-      if (!first) {
-        indent.writeln('');
-      } else {
-        first = false;
-      }
-      addDocumentationComments(
-          indent, func.documentationComments, _docCommentSpec);
-      String argSignature = '';
-      String sendArgument = 'null';
-      if (func.arguments.isNotEmpty) {
-        String argNameFunc(int index, NamedType type) =>
-            _getSafeArgumentName(index, type);
-        final Iterable<String> argExpressions =
-            indexMap(func.arguments, (int index, NamedType type) {
-          final String name = argNameFunc(index, type);
-          if (root.enums.map((Enum e) => e.name).contains(type.type.baseName)) {
-            return '$name${type.type.isNullable ? '?' : ''}.index';
-          } else {
-            return name;
-          }
-        });
-        sendArgument = '<Object?>[${argExpressions.join(', ')}]';
-        argSignature = _getMethodArgumentsSignature(func, argNameFunc);
-      }
-      indent.write(
-        'Future<${_addGenericTypesNullable(func.returnType)}> ${func.name}($argSignature) async ',
-      );
-      indent.scoped('{', '}', () {
-        final String channelName = makeChannelName(api, func);
-        indent.writeln(
-            'final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(');
-        indent.nest(2, () {
-          indent.writeln("'$channelName', codec,");
-          indent.writeln('binaryMessenger: _binaryMessenger);');
-        });
-        final String returnType = _makeGenericTypeArguments(func.returnType);
-        final String genericCastCall = _makeGenericCastCall(func.returnType);
-        const String accessor = 'replyList[0]';
-        // Avoid warnings from pointlessly casting to `Object?`.
-        final String nullablyTypedAccessor =
-            returnType == 'Object' ? accessor : '($accessor as $returnType?)';
-        final String nullHandler = func.returnType.isNullable
-            ? (genericCastCall.isEmpty ? '' : '?')
-            : '!';
-        final String returnStatement = func.returnType.isVoid
-            ? 'return;'
-            : 'return $nullablyTypedAccessor$nullHandler$genericCastCall;';
-        indent.format('''
-final List<Object?>? replyList =
-\t\tawait channel.send($sendArgument) as List<Object?>?;
-if (replyList == null) {
-\tthrow PlatformException(
-\t\tcode: 'channel-error',
-\t\tmessage: 'Unable to establish connection on channel.',
-\t);
-} else if (replyList.length > 1) {
-\tthrow PlatformException(
-\t\tcode: replyList[0]! as String,
-\t\tmessage: replyList[1] as String?,
-\t\tdetails: replyList[2],
-\t);''');
-        // On iOS we can return nil from functions to accommodate error
-        // handling.  Returning a nil value and not returning an error is an
-        // exception.
-        if (!func.returnType.isNullable && !func.returnType.isVoid) {
-          indent.format('''
-} else if (replyList[0] == null) {
-\tthrow PlatformException(
-\t\tcode: 'null-error',
-\t\tmessage: 'Host platform returned null value for non-null return value.',
-\t);''');
-        }
-        indent.format('''
-} else {
-\t$returnStatement
-}''');
-      });
-    }
-  });
-}
-
-/// Writes the code for host [Api], [api].
-/// Example:
-/// class FooCodec extends StandardMessageCodec {...}
-///
-/// abstract class Foo {
-///   static const MessageCodec<Object?> codec = FooCodec();
-///   int add(int x, int y);
-///   static void setup(Foo api, {BinaryMessenger? binaryMessenger}) {...}
-/// }
-void _writeFlutterApi(
-  DartOptions opt,
-  Indent indent,
-  Api api,
-  Root root, {
-  String Function(Method)? channelNameFunc,
-  bool isMockHandler = false,
-}) {
-  assert(api.location == ApiLocation.flutter);
-  final List<String> customEnumNames =
-      root.enums.map((Enum x) => x.name).toList();
-  String codecName = _standardMessageCodec;
-  if (getCodecClasses(api, root).isNotEmpty) {
-    codecName = _getCodecName(api);
-    _writeCodec(indent, codecName, api, root);
-  }
-  indent.addln('');
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec);
-
-  indent.write('abstract class ${api.name} ');
-  indent.scoped('{', '}', () {
-    indent.writeln('static const MessageCodec<Object?> codec = $codecName();');
-    indent.addln('');
-    for (final Method func in api.methods) {
-      addDocumentationComments(
-          indent, func.documentationComments, _docCommentSpec);
-
-      final bool isAsync = func.isAsynchronous;
-      final String returnType = isAsync
-          ? 'Future<${_addGenericTypesNullable(func.returnType)}>'
-          : _addGenericTypesNullable(func.returnType);
-      final String argSignature = _getMethodArgumentsSignature(
-        func,
-        _getArgumentName,
-      );
-      indent.writeln('$returnType ${func.name}($argSignature);');
-      indent.writeln('');
-    }
-    indent.write(
-        'static void setup(${api.name}? api, {BinaryMessenger? binaryMessenger}) ');
-    indent.scoped('{', '}', () {
-      for (final Method func in api.methods) {
-        indent.write('');
-        indent.scoped('{', '}', () {
-          indent.writeln(
-            'final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(',
-          );
-          final String channelName = channelNameFunc == null
-              ? makeChannelName(api, func)
-              : channelNameFunc(func);
-          indent.nest(2, () {
-            indent.writeln("'$channelName', codec,");
-            indent.writeln(
-              'binaryMessenger: binaryMessenger);',
-            );
-          });
-          final String messageHandlerSetter =
-              isMockHandler ? 'setMockMessageHandler' : 'setMessageHandler';
-          indent.write('if (api == null) ');
-          indent.scoped('{', '}', () {
-            indent.writeln('channel.$messageHandlerSetter(null);');
-          }, addTrailingNewline: false);
-          indent.add(' else ');
-          indent.scoped('{', '}', () {
-            indent.write(
-              'channel.$messageHandlerSetter((Object? message) async ',
-            );
-            indent.scoped('{', '});', () {
-              final String returnType =
-                  _addGenericTypesNullable(func.returnType);
-              final bool isAsync = func.isAsynchronous;
-              final String emptyReturnStatement = isMockHandler
-                  ? 'return <Object?>[];'
-                  : func.returnType.isVoid
-                      ? 'return;'
-                      : 'return null;';
-              String call;
-              if (func.arguments.isEmpty) {
-                indent.writeln('// ignore message');
-                call = 'api.${func.name}()';
-              } else {
-                indent.writeln('assert(message != null,');
-                indent.writeln("'Argument for $channelName was null.');");
-                const String argsArray = 'args';
-                indent.writeln(
-                    'final List<Object?> $argsArray = (message as List<Object?>?)!;');
-                String argNameFunc(int index, NamedType type) =>
-                    _getSafeArgumentName(index, type);
-                enumerate(func.arguments, (int count, NamedType arg) {
-                  final String argType = _addGenericTypes(arg.type);
-                  final String argName = argNameFunc(count, arg);
-                  final String genericArgType =
-                      _makeGenericTypeArguments(arg.type);
-                  final String castCall = _makeGenericCastCall(arg.type);
-
-                  final String leftHandSide = 'final $argType? $argName';
-                  if (customEnumNames.contains(arg.type.baseName)) {
-                    indent.writeln(
-                        '$leftHandSide = $argsArray[$count] == null ? null : $argType.values[$argsArray[$count] as int];');
-                  } else {
-                    indent.writeln(
-                        '$leftHandSide = ($argsArray[$count] as $genericArgType?)${castCall.isEmpty ? '' : '?$castCall'};');
-                  }
-                  if (!arg.type.isNullable) {
-                    indent.writeln(
-                        "assert($argName != null, 'Argument for $channelName was null, expected non-null $argType.');");
-                  }
-                });
-                final Iterable<String> argNames =
-                    indexMap(func.arguments, (int index, NamedType field) {
-                  final String name = _getSafeArgumentName(index, field);
-                  return '$name${field.type.isNullable ? '' : '!'}';
-                });
-                call = 'api.${func.name}(${argNames.join(', ')})';
-              }
-              if (func.returnType.isVoid) {
-                if (isAsync) {
-                  indent.writeln('await $call;');
-                } else {
-                  indent.writeln('$call;');
-                }
-                indent.writeln(emptyReturnStatement);
-              } else {
-                if (isAsync) {
-                  indent.writeln('final $returnType output = await $call;');
-                } else {
-                  indent.writeln('final $returnType output = $call;');
-                }
-                const String returnExpression = 'output';
-                final String returnStatement = isMockHandler
-                    ? 'return <Object?>[$returnExpression];'
-                    : 'return $returnExpression;';
-                indent.writeln(returnStatement);
-              }
-            });
-          });
-        });
-      }
-    });
-  });
-}
-
 /// Converts a [List] of [TypeDeclaration]s to a comma separated [String] to be
 /// used in Dart code.
 String _flattenTypeArguments(List<TypeDeclaration> args) {
@@ -708,20 +787,7 @@ String _addGenericTypesNullable(TypeDeclaration type) {
 
 /// Generates Dart source code for the given AST represented by [root],
 /// outputting the code to [sink].
-void generateDart(DartOptions opt, Root root, StringSink sink, Indent indent) {
-  void writeApi(Api api) {
-    if (api.location == ApiLocation.host) {
-      _writeHostApi(opt, indent, api, root);
-    } else if (api.location == ApiLocation.flutter) {
-      _writeFlutterApi(opt, indent, api, root);
-    }
-  }
-
-  for (final Api api in root.apis) {
-    indent.writeln('');
-    writeApi(api);
-  }
-}
+void generateDart(DartOptions opt, Root root, StringSink sink, Indent indent) {}
 
 /// Crawls up the path of [dartFilePath] until it finds a pubspec.yaml in a
 /// parent directory and returns its path.
@@ -771,82 +837,3 @@ String _posixify(String inputPath) {
   final path.Context context = path.Context(style: path.Style.posix);
   return context.fromUri(path.toUri(path.absolute(inputPath)));
 }
-
-/// Writes file header to sink.
-void writeTestHeader(
-    DartOptions opt, Root root, StringSink sink, Indent indent) {
-  if (opt.copyrightHeader != null) {
-    addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
-  }
-  indent.writeln('// $generatedCodeWarning');
-  indent.writeln('// $seeAlsoWarning');
-  indent.writeln(
-    '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, unnecessary_import',
-  );
-  indent.writeln('// ignore_for_file: avoid_relative_lib_imports');
-}
-
-/// Writes file imports to sink.
-void writeTestImports(
-    DartOptions opt, Root root, StringSink sink, Indent indent) {
-  indent.writeln("import 'dart:async';");
-  indent.writeln(
-    "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
-  );
-  indent.writeln(
-      "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;");
-  indent.writeln("import 'package:flutter/services.dart';");
-  indent.writeln("import 'package:flutter_test/flutter_test.dart';");
-  indent.writeln('');
-}
-
-/// Generates Dart source code for test support libraries based on the given AST
-/// represented by [root], outputting the code to [sink]. [dartOutPath] is the
-/// path of the generated dart code to be tested. [testOutPath] is where the
-/// test code will be generated.
-void generateTestDart(
-  DartOptions opt,
-  Root root,
-  StringSink sink,
-  Indent indent, {
-  required String sourceOutPath,
-  required String testOutPath,
-}) {
-  final String relativeDartPath =
-      path.Context(style: path.Style.posix).relative(
-    _posixify(sourceOutPath),
-    from: _posixify(path.dirname(testOutPath)),
-  );
-  late final String? packageName = _deducePackageName(sourceOutPath);
-  if (!relativeDartPath.contains('/lib/') || packageName == null) {
-    // If we can't figure out the package name or the relative path doesn't
-    // include a 'lib' directory, try relative path import which only works in
-    // certain (older) versions of Dart.
-    // TODO(gaaclarke): We should add a command-line parameter to override this import.
-    indent.writeln(
-        "import '${_escapeForDartSingleQuotedString(relativeDartPath)}';");
-  } else {
-    final String path = relativeDartPath.replaceFirst(RegExp(r'^.*/lib/'), '');
-    indent.writeln("import 'package:$packageName/$path';");
-  }
-  for (final Api api in root.apis) {
-    if (api.location == ApiLocation.host && api.dartHostTestHandler != null) {
-      final Api mockApi = Api(
-        name: api.dartHostTestHandler!,
-        methods: api.methods,
-        location: ApiLocation.flutter,
-        dartHostTestHandler: api.dartHostTestHandler,
-        documentationComments: api.documentationComments,
-      );
-      indent.writeln('');
-      _writeFlutterApi(
-        opt,
-        indent,
-        mockApi,
-        root,
-        channelNameFunc: (Method func) => makeChannelName(api, func),
-        isMockHandler: true,
-      );
-    }
-  }
-}
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 55356611f1b..981fcc8dfbe 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -80,11 +80,21 @@ abstract class Generator<T> {
     Set<String> customEnumNames,
   );
 
-  // /// Writes a single Flutter Api to file.
-  // void writeFlutterApi(T generatorOptions, Root root, StringSink sink,
-  //     Indent indent, FileType fileType, Api api,);
+  /// Writes a single Flutter Api to file.
+  void writeFlutterApi(
+    T generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  );
 
-  // /// Writes a single Host Api to file.
-  // void writeHostApi(T generatorOptions, Root root, StringSink sink,
-  //     Indent indent, FileType fileType, Api api,);
+  /// Writes a single Host Api to file.
+  void writeHostApi(
+    T generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  );
 }

From 0e36e5b49597cbfa537a4c550f1d64752845b573 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 23:10:50 -0800
Subject: [PATCH 64/87] java

---
 packages/pigeon/lib/java_generator.dart | 479 ++++++++++++------------
 1 file changed, 242 insertions(+), 237 deletions(-)

diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index f3a4a9f1629..5c541aaf27b 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -90,7 +90,8 @@ class JavaGenerator extends Generator<JavaOptions> {
   /// Instantiates a Java Generator.
   JavaGenerator();
 
-  /// Generates Java files with specified [JavaOptions]
+  /// Generates the ".java" file for the AST represented by [root] to [sink] with the
+  /// provided [generatorOptions].
   @override
   void generate(JavaOptions generatorOptions, Root root, StringSink sink) {
     final Indent indent = Indent(sink);
@@ -114,7 +115,24 @@ class JavaGenerator extends Generator<JavaOptions> {
         indent.addln('');
         writeDataClass(generatorOptions, root, sink, indent, klass);
       }
-      generateJava(generatorOptions, root, sink, indent);
+      if (root.apis.any((Api api) =>
+          api.location == ApiLocation.host &&
+          api.methods.any((Method it) => it.isAsynchronous))) {
+        indent.addln('');
+        _writeResultInterface(indent);
+      }
+      for (final Api api in root.apis) {
+        if (getCodecClasses(api, root).isNotEmpty) {
+          _writeCodec(indent, api, root);
+          indent.addln('');
+        }
+        if (api.location == ApiLocation.host) {
+          writeHostApi(generatorOptions, root, sink, indent, api);
+        } else if (api.location == ApiLocation.flutter) {
+          writeFlutterApi(generatorOptions, root, sink, indent, api);
+        }
+      }
+      _writeWrapError(indent);
     });
   }
 
@@ -352,83 +370,168 @@ class JavaGenerator extends Generator<JavaOptions> {
       indent.writeln('return $result;');
     });
   }
-}
 
-/// Calculates the name of the codec that will be generated for [api].
-String _getCodecName(Api api) => '${api.name}Codec';
-
-/// Converts an expression that evaluates to an nullable int to an expression
-/// that evaluates to a nullable enum.
-String _intToEnum(String expression, String enumName) =>
-    '$expression == null ? null : $enumName.values()[(int)$expression]';
+  /// Writes the code for a flutter [Api], [api].
+  /// Example:
+  /// public static class Foo {
+  ///   public Foo(BinaryMessenger argBinaryMessenger) {...}
+  ///   public interface Reply<T> {
+  ///     void reply(T reply);
+  ///   }
+  ///   public int add(int x, int y, Reply<int> callback) {...}
+  /// }
+  @override
+  void writeFlutterApi(
+    JavaOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    assert(api.location == ApiLocation.flutter);
+    const List<String> generatedMessages = <String>[
+      ' Generated class from Pigeon that represents Flutter messages that can be called from Java.'
+    ];
+    addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
+        generatorComments: generatedMessages);
 
-/// Writes the codec class that will be used by [api].
-/// Example:
-/// private static class FooCodec extends StandardMessageCodec {...}
-void _writeCodec(Indent indent, Api api, Root root) {
-  assert(getCodecClasses(api, root).isNotEmpty);
-  final Iterable<EnumeratedClass> codecClasses = getCodecClasses(api, root);
-  final String codecName = _getCodecName(api);
-  indent
-      .write('private static class $codecName extends $_standardMessageCodec ');
-  indent.scoped('{', '}', () {
-    indent
-        .writeln('public static final $codecName INSTANCE = new $codecName();');
-    indent.writeln('private $codecName() {}');
-    indent.writeln('@Override');
-    indent.write(
-        'protected Object readValueOfType(byte type, @NonNull ByteBuffer buffer) ');
+    indent.write('public static class ${api.name} ');
     indent.scoped('{', '}', () {
-      indent.write('switch (type) ');
+      indent.writeln('private final BinaryMessenger binaryMessenger;');
+      indent.write('public ${api.name}(BinaryMessenger argBinaryMessenger)');
       indent.scoped('{', '}', () {
-        for (final EnumeratedClass customClass in codecClasses) {
-          indent.write('case (byte)${customClass.enumeration}: ');
-          indent.writeScoped('', '', () {
-            indent.writeln(
-                'return ${customClass.name}.fromList((ArrayList<Object>) readValue(buffer));');
-          });
+        indent.writeln('this.binaryMessenger = argBinaryMessenger;');
+      });
+      indent.write('public interface Reply<T> ');
+      indent.scoped('{', '}', () {
+        indent.writeln('void reply(T reply);');
+      });
+      final String codecName = _getCodecName(api);
+      indent.writeln('/** The codec used by ${api.name}. */');
+      indent.write('static MessageCodec<Object> getCodec() ');
+      indent.scoped('{', '}', () {
+        indent.write('return ');
+        if (getCodecClasses(api, root).isNotEmpty) {
+          indent.writeln('$codecName.INSTANCE;');
+        } else {
+          indent.writeln('new $_standardMessageCodec();');
         }
-        indent.write('default:');
-        indent.writeScoped('', '', () {
-          indent.writeln('return super.readValueOfType(type, buffer);');
-        });
       });
-    });
-    indent.writeln('@Override');
-    indent.write(
-        'protected void writeValue(@NonNull ByteArrayOutputStream stream, Object value) ');
-    indent.writeScoped('{', '}', () {
-      for (final EnumeratedClass customClass in codecClasses) {
-        indent.write('if (value instanceof ${customClass.name}) ');
-        indent.scoped('{', '} else ', () {
-          indent.writeln('stream.write(${customClass.enumeration});');
+
+      for (final Method func in api.methods) {
+        final String channelName = makeChannelName(api, func);
+        final String returnType = func.returnType.isVoid
+            ? 'Void'
+            : _javaTypeForDartType(func.returnType);
+        String sendArgument;
+        addDocumentationComments(
+            indent, func.documentationComments, _docCommentSpec);
+        if (func.arguments.isEmpty) {
+          indent
+              .write('public void ${func.name}(Reply<$returnType> callback) ');
+          sendArgument = 'null';
+        } else {
+          final Iterable<String> argTypes = func.arguments
+              .map((NamedType e) => _nullsafeJavaTypeForDartType(e.type));
+          final Iterable<String> argNames =
+              indexMap(func.arguments, _getSafeArgumentName);
+          if (func.arguments.length == 1) {
+            sendArgument =
+                'new ArrayList<Object>(Collections.singletonList(${argNames.first}))';
+          } else {
+            sendArgument =
+                'new ArrayList<Object>(Arrays.asList(${argNames.join(', ')}))';
+          }
+          final String argsSignature =
+              map2(argTypes, argNames, (String x, String y) => '$x $y')
+                  .join(', ');
+          indent.write(
+              'public void ${func.name}($argsSignature, Reply<$returnType> callback) ');
+        }
+        indent.scoped('{', '}', () {
+          const String channel = 'channel';
+          indent.writeln('BasicMessageChannel<Object> $channel =');
+          indent.inc();
+          indent.inc();
           indent.writeln(
-              'writeValue(stream, ((${customClass.name}) value).toList());');
+              'new BasicMessageChannel<>(binaryMessenger, "$channelName", getCodec());');
+          indent.dec();
+          indent.dec();
+          indent.write('$channel.send($sendArgument, channelReply -> ');
+          indent.scoped('{', '});', () {
+            if (func.returnType.isVoid) {
+              indent.writeln('callback.reply(null);');
+            } else {
+              const String output = 'output';
+              indent.writeln('@SuppressWarnings("ConstantConditions")');
+              if (func.returnType.baseName == 'int') {
+                indent.writeln(
+                    '$returnType $output = channelReply == null ? null : ((Number)channelReply).longValue();');
+              } else {
+                indent.writeln(
+                    '$returnType $output = ($returnType)channelReply;');
+              }
+              indent.writeln('callback.reply($output);');
+            }
+          });
         });
       }
-      indent.scoped('{', '}', () {
-        indent.writeln('super.writeValue(stream, value);');
-      });
     });
-  });
-}
+  }
 
-/// Write the java code that represents a host [Api], [api].
-/// Example:
-/// public interface Foo {
-///   int add(int x, int y);
-///   static void setup(BinaryMessenger binaryMessenger, Foo api) {...}
-/// }
-void _writeHostApi(Indent indent, Api api, Root root) {
-  assert(api.location == ApiLocation.host);
+  /// Write the java code that represents a host [Api], [api].
+  /// Example:
+  /// public interface Foo {
+  ///   int add(int x, int y);
+  ///   static void setup(BinaryMessenger binaryMessenger, Foo api) {...}
+  /// }
+  @override
+  void writeHostApi(JavaOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Api api) {
+    assert(api.location == ApiLocation.host);
 
-  bool isEnum(TypeDeclaration type) =>
-      root.enums.map((Enum e) => e.name).contains(type.baseName);
+    const List<String> generatedMessages = <String>[
+      ' Generated interface from Pigeon that represents a handler of messages from Flutter.'
+    ];
+    addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
+        generatorComments: generatedMessages);
+
+    indent.write('public interface ${api.name} ');
+    indent.scoped('{', '}', () {
+      for (final Method method in api.methods) {
+        _writeInterfaceMethod(
+            generatorOptions, root, sink, indent, api, method);
+      }
+      indent.addln('');
+      final String codecName = _getCodecName(api);
+      indent.writeln('/** The codec used by ${api.name}. */');
+      indent.write('static MessageCodec<Object> getCodec() ');
+      indent.scoped('{', '}', () {
+        indent.write('return ');
+        if (getCodecClasses(api, root).isNotEmpty) {
+          indent.write('$codecName.INSTANCE;');
+        } else {
+          indent.write('new $_standardMessageCodec();');
+        }
+      });
+
+      indent.writeln(
+          '${_docCommentPrefix}Sets up an instance of `${api.name}` to handle messages through the `binaryMessenger`.$_docCommentSuffix');
+      indent.write(
+          'static void setup(BinaryMessenger binaryMessenger, ${api.name} api) ');
+      indent.scoped('{', '}', () {
+        for (final Method method in api.methods) {
+          _writeMethodSetup(generatorOptions, root, sink, indent, api, method);
+        }
+      });
+    });
+  }
 
   /// Write a method in the interface.
   /// Example:
   ///   int add(int x, int y);
-  void writeInterfaceMethod(final Method method) {
+  void _writeInterfaceMethod(JavaOptions generatorOptions, Root root,
+      StringSink sink, Indent indent, Api api, final Method method) {
     final String returnType = method.isAsynchronous
         ? 'void'
         : _nullsafeJavaTypeForDartType(method.returnType);
@@ -458,7 +561,11 @@ void _writeHostApi(Indent indent, Api api, Root root) {
   /// Write a static setup function in the interface.
   /// Example:
   ///   static void setup(BinaryMessenger binaryMessenger, Foo api) {...}
-  void writeMethodSetup(final Method method) {
+  void _writeMethodSetup(JavaOptions generatorOptions, Root root,
+      StringSink sink, Indent indent, Api api, final Method method) {
+    //TODO(tarrinneal): See if this is needed or if generator_tools is enough
+    bool isEnum(TypeDeclaration type) =>
+        root.enums.map((Enum e) => e.name).contains(type.baseName);
     final String channelName = makeChannelName(api, method);
     indent.write('');
     indent.scoped('{', '}', () {
@@ -574,38 +681,85 @@ Result<$returnType> $resultName = new Result<$returnType>() {
     });
   }
 
-  const List<String> generatedMessages = <String>[
-    ' Generated interface from Pigeon that represents a handler of messages from Flutter.'
-  ];
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
-      generatorComments: generatedMessages);
-
-  indent.write('public interface ${api.name} ');
-  indent.scoped('{', '}', () {
-    api.methods.forEach(writeInterfaceMethod);
-    indent.addln('');
+  /// Writes the codec class that will be used by [api].
+  /// Example:
+  /// private static class FooCodec extends StandardMessageCodec {...}
+  void _writeCodec(Indent indent, Api api, Root root) {
+    assert(getCodecClasses(api, root).isNotEmpty);
+    final Iterable<EnumeratedClass> codecClasses = getCodecClasses(api, root);
     final String codecName = _getCodecName(api);
-    indent.writeln('/** The codec used by ${api.name}. */');
-    indent.write('static MessageCodec<Object> getCodec() ');
+    indent.write(
+        'private static class $codecName extends $_standardMessageCodec ');
     indent.scoped('{', '}', () {
-      indent.write('return ');
-      if (getCodecClasses(api, root).isNotEmpty) {
-        indent.write('$codecName.INSTANCE;');
-      } else {
-        indent.write('new $_standardMessageCodec();');
-      }
+      indent.writeln(
+          'public static final $codecName INSTANCE = new $codecName();');
+      indent.writeln('private $codecName() {}');
+      indent.writeln('@Override');
+      indent.write(
+          'protected Object readValueOfType(byte type, @NonNull ByteBuffer buffer) ');
+      indent.scoped('{', '}', () {
+        indent.write('switch (type) ');
+        indent.scoped('{', '}', () {
+          for (final EnumeratedClass customClass in codecClasses) {
+            indent.write('case (byte)${customClass.enumeration}: ');
+            indent.writeScoped('', '', () {
+              indent.writeln(
+                  'return ${customClass.name}.fromList((ArrayList<Object>) readValue(buffer));');
+            });
+          }
+          indent.write('default:');
+          indent.writeScoped('', '', () {
+            indent.writeln('return super.readValueOfType(type, buffer);');
+          });
+        });
+      });
+      indent.writeln('@Override');
+      indent.write(
+          'protected void writeValue(@NonNull ByteArrayOutputStream stream, Object value) ');
+      indent.writeScoped('{', '}', () {
+        for (final EnumeratedClass customClass in codecClasses) {
+          indent.write('if (value instanceof ${customClass.name}) ');
+          indent.scoped('{', '} else ', () {
+            indent.writeln('stream.write(${customClass.enumeration});');
+            indent.writeln(
+                'writeValue(stream, ((${customClass.name}) value).toList());');
+          });
+        }
+        indent.scoped('{', '}', () {
+          indent.writeln('super.writeValue(stream, value);');
+        });
+      });
     });
+  }
 
-    indent.writeln(
-        '${_docCommentPrefix}Sets up an instance of `${api.name}` to handle messages through the `binaryMessenger`.$_docCommentSuffix');
-    indent.write(
-        'static void setup(BinaryMessenger binaryMessenger, ${api.name} api) ');
+  void _writeResultInterface(Indent indent) {
+    indent.write('public interface Result<T> ');
     indent.scoped('{', '}', () {
-      api.methods.forEach(writeMethodSetup);
+      indent.writeln('void success(T result);');
+      indent.writeln('void error(Throwable error);');
     });
-  });
+  }
+
+  void _writeWrapError(Indent indent) {
+    indent.format('''
+@NonNull private static ArrayList<Object> wrapError(@NonNull Throwable exception) {
+\tArrayList<Object> errorList = new ArrayList<>(3);
+\terrorList.add(exception.toString());
+\terrorList.add(exception.getClass().getSimpleName());
+\terrorList.add("Cause: " + exception.getCause() + ", Stacktrace: " + Log.getStackTraceString(exception));
+\treturn errorList;
+}''');
+  }
 }
 
+/// Calculates the name of the codec that will be generated for [api].
+String _getCodecName(Api api) => '${api.name}Codec';
+
+/// Converts an expression that evaluates to an nullable int to an expression
+/// that evaluates to a nullable enum.
+String _intToEnum(String expression, String enumName) =>
+    '$expression == null ? null : $enumName.values()[(int)$expression]';
+
 String _getArgumentName(int count, NamedType argument) =>
     argument.name.isEmpty ? 'arg$count' : argument.name;
 
@@ -613,106 +767,6 @@ String _getArgumentName(int count, NamedType argument) =>
 String _getSafeArgumentName(int count, NamedType argument) =>
     '${_getArgumentName(count, argument)}Arg';
 
-/// Writes the code for a flutter [Api], [api].
-/// Example:
-/// public static class Foo {
-///   public Foo(BinaryMessenger argBinaryMessenger) {...}
-///   public interface Reply<T> {
-///     void reply(T reply);
-///   }
-///   public int add(int x, int y, Reply<int> callback) {...}
-/// }
-void _writeFlutterApi(Indent indent, Api api, Root root) {
-  assert(api.location == ApiLocation.flutter);
-  const List<String> generatedMessages = <String>[
-    ' Generated class from Pigeon that represents Flutter messages that can be called from Java.'
-  ];
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
-      generatorComments: generatedMessages);
-
-  indent.write('public static class ${api.name} ');
-  indent.scoped('{', '}', () {
-    indent.writeln('private final BinaryMessenger binaryMessenger;');
-    indent.write('public ${api.name}(BinaryMessenger argBinaryMessenger)');
-    indent.scoped('{', '}', () {
-      indent.writeln('this.binaryMessenger = argBinaryMessenger;');
-    });
-    indent.write('public interface Reply<T> ');
-    indent.scoped('{', '}', () {
-      indent.writeln('void reply(T reply);');
-    });
-    final String codecName = _getCodecName(api);
-    indent.writeln('/** The codec used by ${api.name}. */');
-    indent.write('static MessageCodec<Object> getCodec() ');
-    indent.scoped('{', '}', () {
-      indent.write('return ');
-      if (getCodecClasses(api, root).isNotEmpty) {
-        indent.writeln('$codecName.INSTANCE;');
-      } else {
-        indent.writeln('new $_standardMessageCodec();');
-      }
-    });
-
-    for (final Method func in api.methods) {
-      final String channelName = makeChannelName(api, func);
-      final String returnType = func.returnType.isVoid
-          ? 'Void'
-          : _javaTypeForDartType(func.returnType);
-      String sendArgument;
-      addDocumentationComments(
-          indent, func.documentationComments, _docCommentSpec);
-      if (func.arguments.isEmpty) {
-        indent.write('public void ${func.name}(Reply<$returnType> callback) ');
-        sendArgument = 'null';
-      } else {
-        final Iterable<String> argTypes = func.arguments
-            .map((NamedType e) => _nullsafeJavaTypeForDartType(e.type));
-        final Iterable<String> argNames =
-            indexMap(func.arguments, _getSafeArgumentName);
-        if (func.arguments.length == 1) {
-          sendArgument =
-              'new ArrayList<Object>(Collections.singletonList(${argNames.first}))';
-        } else {
-          sendArgument =
-              'new ArrayList<Object>(Arrays.asList(${argNames.join(', ')}))';
-        }
-        final String argsSignature =
-            map2(argTypes, argNames, (String x, String y) => '$x $y')
-                .join(', ');
-        indent.write(
-            'public void ${func.name}($argsSignature, Reply<$returnType> callback) ');
-      }
-      indent.scoped('{', '}', () {
-        const String channel = 'channel';
-        indent.writeln('BasicMessageChannel<Object> $channel =');
-        indent.inc();
-        indent.inc();
-        indent.writeln(
-            'new BasicMessageChannel<>(binaryMessenger, "$channelName", getCodec());');
-        indent.dec();
-        indent.dec();
-        indent.write('$channel.send($sendArgument, channelReply -> ');
-        indent.scoped('{', '});', () {
-          if (func.returnType.isVoid) {
-            indent.writeln('callback.reply(null);');
-          } else {
-            const String output = 'output';
-            indent.writeln('@SuppressWarnings("ConstantConditions")');
-            if (func.returnType.baseName == 'int') {
-              indent.writeln(
-                  '$returnType $output = channelReply == null ? null : ((Number)channelReply).longValue();');
-            } else {
-              indent
-                  .writeln('$returnType $output = ($returnType)channelReply;');
-            }
-            indent.writeln('callback.reply($output);');
-          }
-        });
-      });
-    }
-  });
-}
-
 String _makeGetter(NamedType field) {
   final String uppercased =
       field.name.substring(0, 1).toUpperCase() + field.name.substring(1);
@@ -790,52 +844,3 @@ String _castObject(
     return '(${hostDatatype.datatype})$varName';
   }
 }
-
-/// Generates the ".java" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateJava(
-    JavaOptions options, Root root, StringSink sink, Indent indent) {
-  void writeResultInterface() {
-    indent.write('public interface Result<T> ');
-    indent.scoped('{', '}', () {
-      indent.writeln('void success(T result);');
-      indent.writeln('void error(Throwable error);');
-    });
-  }
-
-  void writeApi(Api api) {
-    if (api.location == ApiLocation.host) {
-      _writeHostApi(indent, api, root);
-    } else if (api.location == ApiLocation.flutter) {
-      _writeFlutterApi(indent, api, root);
-    }
-  }
-
-  void writeWrapError() {
-    indent.format('''
-@NonNull private static ArrayList<Object> wrapError(@NonNull Throwable exception) {
-\tArrayList<Object> errorList = new ArrayList<>(3);
-\terrorList.add(exception.toString());
-\terrorList.add(exception.getClass().getSimpleName());
-\terrorList.add("Cause: " + exception.getCause() + ", Stacktrace: " + Log.getStackTraceString(exception));
-\treturn errorList;
-}''');
-  }
-
-  if (root.apis.any((Api api) =>
-      api.location == ApiLocation.host &&
-      api.methods.any((Method it) => it.isAsynchronous))) {
-    indent.addln('');
-    writeResultInterface();
-  }
-
-  for (final Api api in root.apis) {
-    if (getCodecClasses(api, root).isNotEmpty) {
-      _writeCodec(indent, api, root);
-      indent.addln('');
-    }
-    writeApi(api);
-  }
-
-  writeWrapError();
-}

From 8d6c4350bd45e756aa61b1237fe5f631a2e97354 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 23:18:40 -0800
Subject: [PATCH 65/87] kotlin

---
 packages/pigeon/lib/kotlin_generator.dart | 629 +++++++++++-----------
 1 file changed, 317 insertions(+), 312 deletions(-)

diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index f324662a884..c0b5ae19a60 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -70,7 +70,8 @@ class KotlinGenerator extends Generator<KotlinOptions> {
   /// Instantiates a Kotlin Generator.
   KotlinGenerator();
 
-  /// Generates Kotlin files with specified [KotlinOptions]
+  /// Generates the ".kotlin" file for the AST represented by [root] to [sink] with the
+  /// provided [KotlinOptions].
   @override
   void generate(KotlinOptions generatorOptions, Root root, StringSink sink) {
     final Indent indent = Indent(sink);
@@ -86,7 +87,28 @@ class KotlinGenerator extends Generator<KotlinOptions> {
       indent.addln('');
       writeDataClass(generatorOptions, root, sink, indent, klass);
     }
-    generateKotlin(generatorOptions, root, sink, indent);
+    if (root.apis.any((Api api) =>
+        api.location == ApiLocation.host &&
+        api.methods.any((Method it) => it.isAsynchronous))) {
+      indent.addln('');
+    }
+
+    for (final Api api in root.apis) {
+      if (getCodecClasses(api, root).isNotEmpty) {
+        _writeCodec(indent, api, root);
+        indent.addln('');
+      }
+      if (api.location == ApiLocation.host) {
+        writeHostApi(generatorOptions, root, sink, indent, api);
+      } else if (api.location == ApiLocation.flutter) {
+        writeFlutterApi(generatorOptions, root, sink, indent, api);
+      }
+    }
+
+    indent.addln('');
+    _writeWrapResult(indent);
+    indent.addln('');
+    _writeWrapError(indent);
   }
 
   @override
@@ -302,302 +324,337 @@ class KotlinGenerator extends Generator<KotlinOptions> {
     indent.add(defaultNil);
   }
 
-  HostDatatype _getHostDatatype(Root root, NamedType field) {
-    return getFieldHostDatatype(field, root.classes, root.enums,
-        (TypeDeclaration x) => _kotlinTypeForBuiltinDartType(x));
-  }
-}
+  /// Writes the code for a flutter [Api], [api].
+  /// Example:
+  /// class Foo(private val binaryMessenger: BinaryMessenger) {
+  ///   fun add(x: Int, y: Int, callback: (Int?) -> Unit) {...}
+  /// }
+  @override
+  void writeFlutterApi(
+    KotlinOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    assert(api.location == ApiLocation.flutter);
+    final bool isCustomCodec = getCodecClasses(api, root).isNotEmpty;
 
-/// Calculates the name of the codec that will be generated for [api].
-String _getCodecName(Api api) => '${api.name}Codec';
+    const List<String> generatedMessages = <String>[
+      ' Generated class from Pigeon that represents Flutter messages that can be called from Kotlin.'
+    ];
+    addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
+        generatorComments: generatedMessages);
 
-/// Writes the codec class that will be used by [api].
-/// Example:
-/// private static class FooCodec extends StandardMessageCodec {...}
-void _writeCodec(Indent indent, Api api, Root root) {
-  assert(getCodecClasses(api, root).isNotEmpty);
-  final Iterable<EnumeratedClass> codecClasses = getCodecClasses(api, root);
-  final String codecName = _getCodecName(api);
-  indent.writeln('@Suppress("UNCHECKED_CAST")');
-  indent.write('private object $codecName : StandardMessageCodec() ');
-  indent.scoped('{', '}', () {
-    indent.write(
-        'override fun readValueOfType(type: Byte, buffer: ByteBuffer): Any? ');
+    final String apiName = api.name;
+    indent.writeln('@Suppress("UNCHECKED_CAST")');
+    indent
+        .write('class $apiName(private val binaryMessenger: BinaryMessenger) ');
     indent.scoped('{', '}', () {
-      indent.write('return when (type) ');
+      indent.write('companion object ');
       indent.scoped('{', '}', () {
-        for (final EnumeratedClass customClass in codecClasses) {
-          indent.write('${customClass.enumeration}.toByte() -> ');
-          indent.scoped('{', '}', () {
-            indent.write('return (readValue(buffer) as? List<Any?>)?.let ');
-            indent.scoped('{', '}', () {
-              indent.writeln('${customClass.name}.fromList(it)');
-            });
-          });
-        }
-        indent.writeln('else -> super.readValueOfType(type, buffer)');
+        indent.writeln('/** The codec used by $apiName. */');
+        indent.write('val codec: MessageCodec<Any?> by lazy ');
+        indent.scoped('{', '}', () {
+          if (isCustomCodec) {
+            indent.writeln(_getCodecName(api));
+          } else {
+            indent.writeln('StandardMessageCodec()');
+          }
+        });
       });
-    });
 
-    indent.write(
-        'override fun writeValue(stream: ByteArrayOutputStream, value: Any?) ');
-    indent.writeScoped('{', '}', () {
-      indent.write('when (value) ');
-      indent.scoped('{', '}', () {
-        for (final EnumeratedClass customClass in codecClasses) {
-          indent.write('is ${customClass.name} -> ');
-          indent.scoped('{', '}', () {
-            indent.writeln('stream.write(${customClass.enumeration})');
-            indent.writeln('writeValue(stream, value.toList())');
-          });
+      for (final Method func in api.methods) {
+        final String channelName = makeChannelName(api, func);
+        final String returnType = func.returnType.isVoid
+            ? ''
+            : _nullsafeKotlinTypeForDartType(func.returnType);
+        String sendArgument;
+
+        addDocumentationComments(
+            indent, func.documentationComments, _docCommentSpec);
+
+        if (func.arguments.isEmpty) {
+          indent.write('fun ${func.name}(callback: ($returnType) -> Unit) ');
+          sendArgument = 'null';
+        } else {
+          final Iterable<String> argTypes = func.arguments
+              .map((NamedType e) => _nullsafeKotlinTypeForDartType(e.type));
+          final Iterable<String> argNames =
+              indexMap(func.arguments, _getSafeArgumentName);
+          sendArgument = 'listOf(${argNames.join(', ')})';
+          final String argsSignature = map2(argTypes, argNames,
+              (String type, String name) => '$name: $type').join(', ');
+          if (func.returnType.isVoid) {
+            indent.write(
+                'fun ${func.name}($argsSignature, callback: () -> Unit) ');
+          } else {
+            indent.write(
+                'fun ${func.name}($argsSignature, callback: ($returnType) -> Unit) ');
+          }
         }
-        indent.writeln('else -> super.writeValue(stream, value)');
-      });
+        indent.scoped('{', '}', () {
+          const String channel = 'channel';
+          indent.writeln(
+              'val $channel = BasicMessageChannel<Any?>(binaryMessenger, "$channelName", codec)');
+          indent.write('$channel.send($sendArgument) ');
+          if (func.returnType.isVoid) {
+            indent.scoped('{', '}', () {
+              indent.writeln('callback()');
+            });
+          } else {
+            final String forceUnwrap = func.returnType.isNullable ? '?' : '';
+            indent.scoped('{', '}', () {
+              indent.writeln('val result = it as$forceUnwrap $returnType');
+              indent.writeln('callback(result)');
+            });
+          }
+        });
+      }
     });
-  });
-}
+  }
 
-/// Write the kotlin code that represents a host [Api], [api].
-/// Example:
-/// interface Foo {
-///   Int add(x: Int, y: Int);
-///   companion object {
-///     fun setUp(binaryMessenger: BinaryMessenger, api: Api) {...}
-///   }
-/// }
-void _writeHostApi(Indent indent, Api api, Root root) {
-  assert(api.location == ApiLocation.host);
-
-  final String apiName = api.name;
-
-  final bool isCustomCodec = getCodecClasses(api, root).isNotEmpty;
-
-  const List<String> generatedMessages = <String>[
-    ' Generated interface from Pigeon that represents a handler of messages from Flutter.'
-  ];
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
-      generatorComments: generatedMessages);
-
-  indent.write('interface $apiName ');
-  indent.scoped('{', '}', () {
-    for (final Method method in api.methods) {
-      final List<String> argSignature = <String>[];
-      if (method.arguments.isNotEmpty) {
-        final Iterable<String> argTypes = method.arguments
-            .map((NamedType e) => _nullsafeKotlinTypeForDartType(e.type));
-        final Iterable<String> argNames =
-            method.arguments.map((NamedType e) => e.name);
-        argSignature
-            .addAll(map2(argTypes, argNames, (String argType, String argName) {
-          return '$argName: $argType';
-        }));
-      }
+  /// Write the kotlin code that represents a host [Api], [api].
+  /// Example:
+  /// interface Foo {
+  ///   Int add(x: Int, y: Int);
+  ///   companion object {
+  ///     fun setUp(binaryMessenger: BinaryMessenger, api: Api) {...}
+  ///   }
+  /// }
+  @override
+  void writeHostApi(
+    KotlinOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    assert(api.location == ApiLocation.host);
 
-      final String returnType = method.returnType.isVoid
-          ? ''
-          : _nullsafeKotlinTypeForDartType(method.returnType);
+    final String apiName = api.name;
 
-      addDocumentationComments(
-          indent, method.documentationComments, _docCommentSpec);
+    final bool isCustomCodec = getCodecClasses(api, root).isNotEmpty;
 
-      if (method.isAsynchronous) {
-        argSignature.add('callback: ($returnType) -> Unit');
-        indent.writeln('fun ${method.name}(${argSignature.join(', ')})');
-      } else if (method.returnType.isVoid) {
-        indent.writeln('fun ${method.name}(${argSignature.join(', ')})');
-      } else {
-        indent.writeln(
-            'fun ${method.name}(${argSignature.join(', ')}): $returnType');
-      }
-    }
+    const List<String> generatedMessages = <String>[
+      ' Generated interface from Pigeon that represents a handler of messages from Flutter.'
+    ];
+    addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
+        generatorComments: generatedMessages);
 
-    indent.addln('');
-    indent.write('companion object ');
+    indent.write('interface $apiName ');
     indent.scoped('{', '}', () {
-      indent.writeln('/** The codec used by $apiName. */');
-      indent.write('val codec: MessageCodec<Any?> by lazy ');
-      indent.scoped('{', '}', () {
-        if (isCustomCodec) {
-          indent.writeln(_getCodecName(api));
+      for (final Method method in api.methods) {
+        final List<String> argSignature = <String>[];
+        if (method.arguments.isNotEmpty) {
+          final Iterable<String> argTypes = method.arguments
+              .map((NamedType e) => _nullsafeKotlinTypeForDartType(e.type));
+          final Iterable<String> argNames =
+              method.arguments.map((NamedType e) => e.name);
+          argSignature.addAll(
+              map2(argTypes, argNames, (String argType, String argName) {
+            return '$argName: $argType';
+          }));
+        }
+
+        final String returnType = method.returnType.isVoid
+            ? ''
+            : _nullsafeKotlinTypeForDartType(method.returnType);
+
+        addDocumentationComments(
+            indent, method.documentationComments, _docCommentSpec);
+
+        if (method.isAsynchronous) {
+          argSignature.add('callback: ($returnType) -> Unit');
+          indent.writeln('fun ${method.name}(${argSignature.join(', ')})');
+        } else if (method.returnType.isVoid) {
+          indent.writeln('fun ${method.name}(${argSignature.join(', ')})');
         } else {
-          indent.writeln('StandardMessageCodec()');
+          indent.writeln(
+              'fun ${method.name}(${argSignature.join(', ')}): $returnType');
         }
-      });
-      indent.writeln(
-          '/** Sets up an instance of `$apiName` to handle messages through the `binaryMessenger`. */');
-      indent.writeln('@Suppress("UNCHECKED_CAST")');
-      indent.write(
-          'fun setUp(binaryMessenger: BinaryMessenger, api: $apiName?) ');
+      }
+
+      indent.addln('');
+      indent.write('companion object ');
       indent.scoped('{', '}', () {
-        for (final Method method in api.methods) {
-          indent.write('run ');
-          indent.scoped('{', '}', () {
-            String? taskQueue;
-            if (method.taskQueueType != TaskQueueType.serial) {
-              taskQueue = 'taskQueue';
-              indent.writeln(
-                  'val $taskQueue = binaryMessenger.makeBackgroundTaskQueue()');
-            }
+        indent.writeln('/** The codec used by $apiName. */');
+        indent.write('val codec: MessageCodec<Any?> by lazy ');
+        indent.scoped('{', '}', () {
+          if (isCustomCodec) {
+            indent.writeln(_getCodecName(api));
+          } else {
+            indent.writeln('StandardMessageCodec()');
+          }
+        });
+        indent.writeln(
+            '/** Sets up an instance of `$apiName` to handle messages through the `binaryMessenger`. */');
+        indent.writeln('@Suppress("UNCHECKED_CAST")');
+        indent.write(
+            'fun setUp(binaryMessenger: BinaryMessenger, api: $apiName?) ');
+        indent.scoped('{', '}', () {
+          for (final Method method in api.methods) {
+            indent.write('run ');
+            indent.scoped('{', '}', () {
+              String? taskQueue;
+              if (method.taskQueueType != TaskQueueType.serial) {
+                taskQueue = 'taskQueue';
+                indent.writeln(
+                    'val $taskQueue = binaryMessenger.makeBackgroundTaskQueue()');
+              }
 
-            final String channelName = makeChannelName(api, method);
+              final String channelName = makeChannelName(api, method);
 
-            indent.write(
-                'val channel = BasicMessageChannel<Any?>(binaryMessenger, "$channelName", codec');
+              indent.write(
+                  'val channel = BasicMessageChannel<Any?>(binaryMessenger, "$channelName", codec');
 
-            if (taskQueue != null) {
-              indent.addln(', $taskQueue)');
-            } else {
-              indent.addln(')');
-            }
+              if (taskQueue != null) {
+                indent.addln(', $taskQueue)');
+              } else {
+                indent.addln(')');
+              }
 
-            indent.write('if (api != null) ');
-            indent.scoped('{', '}', () {
-              final String messageVarName =
-                  method.arguments.isNotEmpty ? 'message' : '_';
-
-              indent.write('channel.setMessageHandler ');
-              indent.scoped('{ $messageVarName, reply ->', '}', () {
-                indent.writeln('var wrapped = listOf<Any?>()');
-                indent.write('try ');
-                indent.scoped('{', '}', () {
-                  final List<String> methodArgument = <String>[];
-                  if (method.arguments.isNotEmpty) {
-                    indent.writeln('val args = message as List<Any?>');
-                    enumerate(method.arguments, (int index, NamedType arg) {
-                      final String argName = _getSafeArgumentName(index, arg);
-                      final String argIndex = 'args[$index]';
-                      indent.writeln(
-                          'val $argName = ${_castForceUnwrap(argIndex, arg.type, root)}');
-                      methodArgument.add(argName);
-                    });
-                  }
-                  final String call =
-                      'api.${method.name}(${methodArgument.join(', ')})';
-                  if (method.isAsynchronous) {
-                    indent.write('$call ');
-                    final String resultValue =
-                        method.returnType.isVoid ? 'null' : 'it';
-                    indent.scoped('{', '}', () {
-                      indent.writeln('reply.reply(wrapResult($resultValue))');
-                    });
-                  } else if (method.returnType.isVoid) {
-                    indent.writeln(call);
-                    indent.writeln('wrapped = listOf<Any?>(null)');
-                  } else {
-                    indent.writeln('wrapped = listOf<Any?>($call)');
-                  }
-                }, addTrailingNewline: false);
-                indent.add(' catch (exception: Error) ');
-                indent.scoped('{', '}', () {
-                  indent.writeln('wrapped = wrapError(exception)');
-                  if (method.isAsynchronous) {
+              indent.write('if (api != null) ');
+              indent.scoped('{', '}', () {
+                final String messageVarName =
+                    method.arguments.isNotEmpty ? 'message' : '_';
+
+                indent.write('channel.setMessageHandler ');
+                indent.scoped('{ $messageVarName, reply ->', '}', () {
+                  indent.writeln('var wrapped = listOf<Any?>()');
+                  indent.write('try ');
+                  indent.scoped('{', '}', () {
+                    final List<String> methodArgument = <String>[];
+                    if (method.arguments.isNotEmpty) {
+                      indent.writeln('val args = message as List<Any?>');
+                      enumerate(method.arguments, (int index, NamedType arg) {
+                        final String argName = _getSafeArgumentName(index, arg);
+                        final String argIndex = 'args[$index]';
+                        indent.writeln(
+                            'val $argName = ${_castForceUnwrap(argIndex, arg.type, root)}');
+                        methodArgument.add(argName);
+                      });
+                    }
+                    final String call =
+                        'api.${method.name}(${methodArgument.join(', ')})';
+                    if (method.isAsynchronous) {
+                      indent.write('$call ');
+                      final String resultValue =
+                          method.returnType.isVoid ? 'null' : 'it';
+                      indent.scoped('{', '}', () {
+                        indent.writeln('reply.reply(wrapResult($resultValue))');
+                      });
+                    } else if (method.returnType.isVoid) {
+                      indent.writeln(call);
+                      indent.writeln('wrapped = listOf<Any?>(null)');
+                    } else {
+                      indent.writeln('wrapped = listOf<Any?>($call)');
+                    }
+                  }, addTrailingNewline: false);
+                  indent.add(' catch (exception: Error) ');
+                  indent.scoped('{', '}', () {
+                    indent.writeln('wrapped = wrapError(exception)');
+                    if (method.isAsynchronous) {
+                      indent.writeln('reply.reply(wrapped)');
+                    }
+                  });
+                  if (!method.isAsynchronous) {
                     indent.writeln('reply.reply(wrapped)');
                   }
                 });
-                if (!method.isAsynchronous) {
-                  indent.writeln('reply.reply(wrapped)');
-                }
+              }, addTrailingNewline: false);
+              indent.scoped(' else {', '}', () {
+                indent.writeln('channel.setMessageHandler(null)');
               });
-            }, addTrailingNewline: false);
-            indent.scoped(' else {', '}', () {
-              indent.writeln('channel.setMessageHandler(null)');
             });
-          });
-        }
+          }
+        });
       });
     });
-  });
-}
-
-String _getArgumentName(int count, NamedType argument) =>
-    argument.name.isEmpty ? 'arg$count' : argument.name;
-
-/// Returns an argument name that can be used in a context where it is possible to collide.
-String _getSafeArgumentName(int count, NamedType argument) =>
-    '${_getArgumentName(count, argument)}Arg';
+  }
 
-/// Writes the code for a flutter [Api], [api].
-/// Example:
-/// class Foo(private val binaryMessenger: BinaryMessenger) {
-///   fun add(x: Int, y: Int, callback: (Int?) -> Unit) {...}
-/// }
-void _writeFlutterApi(Indent indent, Api api, Root root) {
-  assert(api.location == ApiLocation.flutter);
-  final bool isCustomCodec = getCodecClasses(api, root).isNotEmpty;
-
-  const List<String> generatedMessages = <String>[
-    ' Generated class from Pigeon that represents Flutter messages that can be called from Kotlin.'
-  ];
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
-      generatorComments: generatedMessages);
-
-  final String apiName = api.name;
-  indent.writeln('@Suppress("UNCHECKED_CAST")');
-  indent.write('class $apiName(private val binaryMessenger: BinaryMessenger) ');
-  indent.scoped('{', '}', () {
-    indent.write('companion object ');
+  /// Writes the codec class that will be used by [api].
+  /// Example:
+  /// private static class FooCodec extends StandardMessageCodec {...}
+  void _writeCodec(Indent indent, Api api, Root root) {
+    assert(getCodecClasses(api, root).isNotEmpty);
+    final Iterable<EnumeratedClass> codecClasses = getCodecClasses(api, root);
+    final String codecName = _getCodecName(api);
+    indent.writeln('@Suppress("UNCHECKED_CAST")');
+    indent.write('private object $codecName : StandardMessageCodec() ');
     indent.scoped('{', '}', () {
-      indent.writeln('/** The codec used by $apiName. */');
-      indent.write('val codec: MessageCodec<Any?> by lazy ');
+      indent.write(
+          'override fun readValueOfType(type: Byte, buffer: ByteBuffer): Any? ');
       indent.scoped('{', '}', () {
-        if (isCustomCodec) {
-          indent.writeln(_getCodecName(api));
-        } else {
-          indent.writeln('StandardMessageCodec()');
-        }
+        indent.write('return when (type) ');
+        indent.scoped('{', '}', () {
+          for (final EnumeratedClass customClass in codecClasses) {
+            indent.write('${customClass.enumeration}.toByte() -> ');
+            indent.scoped('{', '}', () {
+              indent.write('return (readValue(buffer) as? List<Any?>)?.let ');
+              indent.scoped('{', '}', () {
+                indent.writeln('${customClass.name}.fromList(it)');
+              });
+            });
+          }
+          indent.writeln('else -> super.readValueOfType(type, buffer)');
+        });
+      });
+
+      indent.write(
+          'override fun writeValue(stream: ByteArrayOutputStream, value: Any?) ');
+      indent.writeScoped('{', '}', () {
+        indent.write('when (value) ');
+        indent.scoped('{', '}', () {
+          for (final EnumeratedClass customClass in codecClasses) {
+            indent.write('is ${customClass.name} -> ');
+            indent.scoped('{', '}', () {
+              indent.writeln('stream.write(${customClass.enumeration})');
+              indent.writeln('writeValue(stream, value.toList())');
+            });
+          }
+          indent.writeln('else -> super.writeValue(stream, value)');
+        });
       });
     });
+  }
 
-    for (final Method func in api.methods) {
-      final String channelName = makeChannelName(api, func);
-      final String returnType = func.returnType.isVoid
-          ? ''
-          : _nullsafeKotlinTypeForDartType(func.returnType);
-      String sendArgument;
-
-      addDocumentationComments(
-          indent, func.documentationComments, _docCommentSpec);
-
-      if (func.arguments.isEmpty) {
-        indent.write('fun ${func.name}(callback: ($returnType) -> Unit) ');
-        sendArgument = 'null';
-      } else {
-        final Iterable<String> argTypes = func.arguments
-            .map((NamedType e) => _nullsafeKotlinTypeForDartType(e.type));
-        final Iterable<String> argNames =
-            indexMap(func.arguments, _getSafeArgumentName);
-        sendArgument = 'listOf(${argNames.join(', ')})';
-        final String argsSignature = map2(argTypes, argNames,
-            (String type, String name) => '$name: $type').join(', ');
-        if (func.returnType.isVoid) {
-          indent
-              .write('fun ${func.name}($argsSignature, callback: () -> Unit) ');
-        } else {
-          indent.write(
-              'fun ${func.name}($argsSignature, callback: ($returnType) -> Unit) ');
-        }
-      }
-      indent.scoped('{', '}', () {
-        const String channel = 'channel';
+  void _writeWrapResult(Indent indent) {
+    indent.write('private fun wrapResult(result: Any?): List<Any?> ');
+    indent.scoped('{', '}', () {
+      indent.writeln('return listOf(result)');
+    });
+  }
+
+  void _writeWrapError(Indent indent) {
+    indent.write('private fun wrapError(exception: Throwable): List<Any> ');
+    indent.scoped('{', '}', () {
+      indent.write('return ');
+      indent.scoped('listOf<Any>(', ')', () {
+        indent.writeln('exception.javaClass.simpleName,');
+        indent.writeln('exception.toString(),');
         indent.writeln(
-            'val $channel = BasicMessageChannel<Any?>(binaryMessenger, "$channelName", codec)');
-        indent.write('$channel.send($sendArgument) ');
-        if (func.returnType.isVoid) {
-          indent.scoped('{', '}', () {
-            indent.writeln('callback()');
-          });
-        } else {
-          final String forceUnwrap = func.returnType.isNullable ? '?' : '';
-          indent.scoped('{', '}', () {
-            indent.writeln('val result = it as$forceUnwrap $returnType');
-            indent.writeln('callback(result)');
-          });
-        }
+            '"Cause: " + exception.cause + ", Stacktrace: " + Log.getStackTraceString(exception)');
       });
-    }
-  });
+    });
+  }
 }
 
+HostDatatype _getHostDatatype(Root root, NamedType field) {
+  return getFieldHostDatatype(field, root.classes, root.enums,
+      (TypeDeclaration x) => _kotlinTypeForBuiltinDartType(x));
+}
+
+/// Calculates the name of the codec that will be generated for [api].
+String _getCodecName(Api api) => '${api.name}Codec';
+
+String _getArgumentName(int count, NamedType argument) =>
+    argument.name.isEmpty ? 'arg$count' : argument.name;
+
+/// Returns an argument name that can be used in a context where it is possible to collide.
+String _getSafeArgumentName(int count, NamedType argument) =>
+    '${_getArgumentName(count, argument)}Arg';
+
 String _castForceUnwrap(String value, TypeDeclaration type, Root root) {
   if (isEnum(root, type)) {
     final String forceUnwrap = type.isNullable ? '' : '!!';
@@ -677,55 +734,3 @@ String _nullsafeKotlinTypeForDartType(TypeDeclaration type) {
   final String nullSafe = type.isNullable ? '?' : '';
   return '${_kotlinTypeForDartType(type)}$nullSafe';
 }
-
-/// Generates the ".kotlin" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateKotlin(
-    KotlinOptions options, Root root, StringSink sink, Indent indent) {
-  void writeApi(Api api) {
-    if (api.location == ApiLocation.host) {
-      _writeHostApi(indent, api, root);
-    } else if (api.location == ApiLocation.flutter) {
-      _writeFlutterApi(indent, api, root);
-    }
-  }
-
-  void writeWrapResult() {
-    indent.write('private fun wrapResult(result: Any?): List<Any?> ');
-    indent.scoped('{', '}', () {
-      indent.writeln('return listOf(result)');
-    });
-  }
-
-  void writeWrapError() {
-    indent.write('private fun wrapError(exception: Throwable): List<Any> ');
-    indent.scoped('{', '}', () {
-      indent.write('return ');
-      indent.scoped('listOf<Any>(', ')', () {
-        indent.writeln('exception.javaClass.simpleName,');
-        indent.writeln('exception.toString(),');
-        indent.writeln(
-            '"Cause: " + exception.cause + ", Stacktrace: " + Log.getStackTraceString(exception)');
-      });
-    });
-  }
-
-  if (root.apis.any((Api api) =>
-      api.location == ApiLocation.host &&
-      api.methods.any((Method it) => it.isAsynchronous))) {
-    indent.addln('');
-  }
-
-  for (final Api api in root.apis) {
-    if (getCodecClasses(api, root).isNotEmpty) {
-      _writeCodec(indent, api, root);
-      indent.addln('');
-    }
-    writeApi(api);
-  }
-
-  indent.addln('');
-  writeWrapResult();
-  indent.addln('');
-  writeWrapError();
-}

From 434c98fa8abf8a063f7d962ba3488daa9aff2b26 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 23:25:07 -0800
Subject: [PATCH 66/87] swift

---
 packages/pigeon/lib/swift_generator.dart | 655 ++++++++++++-----------
 1 file changed, 333 insertions(+), 322 deletions(-)

diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index ed7db3685dd..15c5b51250a 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -68,7 +68,29 @@ class SwiftGenerator extends Generator<SwiftOptions> {
       indent.addln('');
       writeDataClass(generatorOptions, root, sink, indent, klass);
     }
-    generateSwift(generatorOptions, root, sink, indent);
+
+    if (root.apis.any((Api api) =>
+        api.location == ApiLocation.host &&
+        api.methods.any((Method it) => it.isAsynchronous))) {
+      indent.addln('');
+    }
+
+    for (final Api api in root.apis) {
+      if (getCodecClasses(api, root).isNotEmpty) {
+        _writeCodec(indent, api, root);
+        indent.addln('');
+      }
+      if (api.location == ApiLocation.host) {
+        writeHostApi(generatorOptions, root, sink, indent, api);
+      } else if (api.location == ApiLocation.flutter) {
+        writeFlutterApi(generatorOptions, root, sink, indent, api);
+      }
+    }
+
+    indent.addln('');
+    _writeWrapResult(indent);
+    indent.addln('');
+    _writeWrapError(indent);
   }
 
   @override
@@ -256,223 +278,345 @@ import FlutterMacOS
     indent.addln(defaultNil);
   }
 
-  HostDatatype _getHostDatatype(Root root, NamedType field) {
-    return getFieldHostDatatype(field, root.classes, root.enums,
-        (TypeDeclaration x) => _swiftTypeForBuiltinDartType(x));
-  }
-}
-
-/// Calculates the name of the codec that will be generated for [api].
-String _getCodecName(Api api) => '${api.name}Codec';
+  /// Writes the code for a flutter [Api], [api].
+  /// Example:
+  /// class Foo {
+  ///   private let binaryMessenger: FlutterBinaryMessenger
+  ///   init(binaryMessenger: FlutterBinaryMessenger) {...}
+  ///   func add(x: Int32, y: Int32, completion: @escaping (Int32?) -> Void) {...}
+  /// }
+  @override
+  void writeFlutterApi(
+    SwiftOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    assert(api.location == ApiLocation.flutter);
+    const List<String> generatedComments = <String>[
+      ' Generated class from Pigeon that represents Flutter messages that can be called from Swift.'
+    ];
+    addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
+        generatorComments: generatedComments);
 
-/// Writes the codec classwill be used for encoding messages for the [api].
-/// Example:
-/// private class FooHostApiCodecReader: FlutterStandardReader {...}
-/// private class FooHostApiCodecWriter: FlutterStandardWriter {...}
-/// private class FooHostApiCodecReaderWriter: FlutterStandardReaderWriter {...}
-void _writeCodec(Indent indent, Api api, Root root) {
-  assert(getCodecClasses(api, root).isNotEmpty);
-  final String codecName = _getCodecName(api);
-  final String readerWriterName = '${codecName}ReaderWriter';
-  final String readerName = '${codecName}Reader';
-  final String writerName = '${codecName}Writer';
-
-  // Generate Reader
-  indent.write('private class $readerName: FlutterStandardReader ');
-  indent.scoped('{', '}', () {
-    if (getCodecClasses(api, root).isNotEmpty) {
-      indent.write('override func readValue(ofType type: UInt8) -> Any? ');
+    indent.write('class ${api.name} ');
+    indent.scoped('{', '}', () {
+      indent.writeln('private let binaryMessenger: FlutterBinaryMessenger');
+      indent.write('init(binaryMessenger: FlutterBinaryMessenger)');
       indent.scoped('{', '}', () {
-        indent.write('switch type ');
+        indent.writeln('self.binaryMessenger = binaryMessenger');
+      });
+      final String codecName = _getCodecName(api);
+      String codecArgumentString = '';
+      if (getCodecClasses(api, root).isNotEmpty) {
+        codecArgumentString = ', codec: codec';
+        indent.write('var codec: FlutterStandardMessageCodec ');
         indent.scoped('{', '}', () {
-          for (final EnumeratedClass customClass
-              in getCodecClasses(api, root)) {
-            indent.write('case ${customClass.enumeration}:');
-            indent.scoped('', '', () {
-              indent.write(
-                  'return ${customClass.name}.fromList(self.readValue() as! [Any])');
-            });
-          }
-          indent.write('default:');
-          indent.scoped('', '', () {
-            indent.writeln('return super.readValue(ofType: type)');
-          });
+          indent.writeln('return $codecName.shared');
         });
-      });
-    }
-  });
+      }
+      for (final Method func in api.methods) {
+        final String channelName = makeChannelName(api, func);
+        final String returnType = func.returnType.isVoid
+            ? ''
+            : _nullsafeSwiftTypeForDartType(func.returnType);
+        String sendArgument;
+        addDocumentationComments(
+            indent, func.documentationComments, _docCommentSpec);
 
-  // Generate Writer
-  indent.write('private class $writerName: FlutterStandardWriter ');
-  indent.scoped('{', '}', () {
-    if (getCodecClasses(api, root).isNotEmpty) {
-      indent.write('override func writeValue(_ value: Any) ');
-      indent.scoped('{', '}', () {
-        indent.write('');
-        for (final EnumeratedClass customClass in getCodecClasses(api, root)) {
-          indent.add('if let value = value as? ${customClass.name} ');
-          indent.scoped('{', '} else ', () {
-            indent.writeln('super.writeByte(${customClass.enumeration})');
-            indent.writeln('super.writeValue(value.toList())');
-          }, addTrailingNewline: false);
+        if (func.arguments.isEmpty) {
+          indent.write(
+              'func ${func.name}(completion: @escaping ($returnType) -> Void) ');
+          sendArgument = 'nil';
+        } else {
+          final Iterable<String> argTypes = func.arguments
+              .map((NamedType e) => _nullsafeSwiftTypeForDartType(e.type));
+          final Iterable<String> argLabels =
+              indexMap(func.arguments, _getArgumentName);
+          final Iterable<String> argNames =
+              indexMap(func.arguments, _getSafeArgumentName);
+          sendArgument = '[${argNames.join(', ')}]';
+          final String argsSignature = map3(
+              argTypes,
+              argLabels,
+              argNames,
+              (String type, String label, String name) =>
+                  '$label $name: $type').join(', ');
+          if (func.returnType.isVoid) {
+            indent.write(
+                'func ${func.name}($argsSignature, completion: @escaping () -> Void) ');
+          } else {
+            indent.write(
+                'func ${func.name}($argsSignature, completion: @escaping ($returnType) -> Void) ');
+          }
         }
         indent.scoped('{', '}', () {
-          indent.writeln('super.writeValue(value)');
+          const String channel = 'channel';
+          indent.writeln(
+              'let $channel = FlutterBasicMessageChannel(name: "$channelName", binaryMessenger: binaryMessenger$codecArgumentString)');
+          indent.write('$channel.sendMessage($sendArgument) ');
+          if (func.returnType.isVoid) {
+            indent.scoped('{ _ in', '}', () {
+              indent.writeln('completion()');
+            });
+          } else {
+            indent.scoped('{ response in', '}', () {
+              indent.writeln(
+                  'let result = ${_castForceUnwrap("response", func.returnType, root)}');
+              indent.writeln('completion(result)');
+            });
+          }
         });
-      });
-    }
-  });
-  indent.writeln('');
-
-  // Generate ReaderWriter
-  indent.write('private class $readerWriterName: FlutterStandardReaderWriter ');
-  indent.scoped('{', '}', () {
-    indent.write(
-        'override func reader(with data: Data) -> FlutterStandardReader ');
-    indent.scoped('{', '}', () {
-      indent.writeln('return $readerName(data: data)');
-    });
-    indent.writeln('');
-    indent.write(
-        'override func writer(with data: NSMutableData) -> FlutterStandardWriter ');
-    indent.scoped('{', '}', () {
-      indent.writeln('return $writerName(data: data)');
+      }
     });
-  });
-  indent.writeln('');
+  }
 
-  // Generate Codec
-  indent.write('class $codecName: FlutterStandardMessageCodec ');
-  indent.scoped('{', '}', () {
-    indent.writeln(
-        'static let shared = $codecName(readerWriter: $readerWriterName())');
-  });
-}
+  /// Write the swift code that represents a host [Api], [api].
+  /// Example:
+  /// protocol Foo {
+  ///   Int32 add(x: Int32, y: Int32)
+  /// }
+  @override
+  void writeHostApi(
+    SwiftOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    assert(api.location == ApiLocation.host);
 
-/// Write the swift code that represents a host [Api], [api].
-/// Example:
-/// protocol Foo {
-///   Int32 add(x: Int32, y: Int32)
-/// }
-void _writeHostApi(Indent indent, Api api, Root root) {
-  assert(api.location == ApiLocation.host);
-
-  final String apiName = api.name;
-
-  const List<String> generatedComments = <String>[
-    ' Generated protocol from Pigeon that represents a handler of messages from Flutter.'
-  ];
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
-      generatorComments: generatedComments);
-
-  indent.write('protocol $apiName ');
-  indent.scoped('{', '}', () {
-    for (final Method method in api.methods) {
-      final List<String> argSignature = <String>[];
-      if (method.arguments.isNotEmpty) {
-        final Iterable<String> argTypes = method.arguments
-            .map((NamedType e) => _nullsafeSwiftTypeForDartType(e.type));
-        final Iterable<String> argNames =
-            method.arguments.map((NamedType e) => e.name);
-        argSignature
-            .addAll(map2(argTypes, argNames, (String argType, String argName) {
-          return '$argName: $argType';
-        }));
-      }
+    final String apiName = api.name;
 
-      final String returnType = method.returnType.isVoid
-          ? ''
-          : _nullsafeSwiftTypeForDartType(method.returnType);
-      addDocumentationComments(
-          indent, method.documentationComments, _docCommentSpec);
-
-      if (method.isAsynchronous) {
-        argSignature.add('completion: @escaping ($returnType) -> Void');
-        indent.writeln('func ${method.name}(${argSignature.join(', ')})');
-      } else if (method.returnType.isVoid) {
-        indent.writeln('func ${method.name}(${argSignature.join(', ')})');
-      } else {
-        indent.writeln(
-            'func ${method.name}(${argSignature.join(', ')}) -> $returnType');
-      }
-    }
-  });
+    const List<String> generatedComments = <String>[
+      ' Generated protocol from Pigeon that represents a handler of messages from Flutter.'
+    ];
+    addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
+        generatorComments: generatedComments);
 
-  indent.addln('');
-  indent.writeln(
-      '$_docCommentPrefix Generated setup class from Pigeon to handle messages through the `binaryMessenger`.');
-  indent.write('class ${apiName}Setup ');
-  indent.scoped('{', '}', () {
-    final String codecName = _getCodecName(api);
-    indent.writeln('$_docCommentPrefix The codec used by $apiName.');
-    String codecArgumentString = '';
-    if (getCodecClasses(api, root).isNotEmpty) {
-      codecArgumentString = ', codec: codec';
-      indent.writeln(
-          'static var codec: FlutterStandardMessageCodec { $codecName.shared }');
-    }
-    indent.writeln(
-        '$_docCommentPrefix Sets up an instance of `$apiName` to handle messages through the `binaryMessenger`.');
-    indent.write(
-        'static func setUp(binaryMessenger: FlutterBinaryMessenger, api: $apiName?) ');
+    indent.write('protocol $apiName ');
     indent.scoped('{', '}', () {
       for (final Method method in api.methods) {
-        final String channelName = makeChannelName(api, method);
-        final String varChannelName = '${method.name}Channel';
+        final List<String> argSignature = <String>[];
+        if (method.arguments.isNotEmpty) {
+          final Iterable<String> argTypes = method.arguments
+              .map((NamedType e) => _nullsafeSwiftTypeForDartType(e.type));
+          final Iterable<String> argNames =
+              method.arguments.map((NamedType e) => e.name);
+          argSignature.addAll(
+              map2(argTypes, argNames, (String argType, String argName) {
+            return '$argName: $argType';
+          }));
+        }
+
+        final String returnType = method.returnType.isVoid
+            ? ''
+            : _nullsafeSwiftTypeForDartType(method.returnType);
         addDocumentationComments(
             indent, method.documentationComments, _docCommentSpec);
 
+        if (method.isAsynchronous) {
+          argSignature.add('completion: @escaping ($returnType) -> Void');
+          indent.writeln('func ${method.name}(${argSignature.join(', ')})');
+        } else if (method.returnType.isVoid) {
+          indent.writeln('func ${method.name}(${argSignature.join(', ')})');
+        } else {
+          indent.writeln(
+              'func ${method.name}(${argSignature.join(', ')}) -> $returnType');
+        }
+      }
+    });
+
+    indent.addln('');
+    indent.writeln(
+        '$_docCommentPrefix Generated setup class from Pigeon to handle messages through the `binaryMessenger`.');
+    indent.write('class ${apiName}Setup ');
+    indent.scoped('{', '}', () {
+      final String codecName = _getCodecName(api);
+      indent.writeln('$_docCommentPrefix The codec used by $apiName.');
+      String codecArgumentString = '';
+      if (getCodecClasses(api, root).isNotEmpty) {
+        codecArgumentString = ', codec: codec';
         indent.writeln(
-            'let $varChannelName = FlutterBasicMessageChannel(name: "$channelName", binaryMessenger: binaryMessenger$codecArgumentString)');
-        indent.write('if let api = api ');
-        indent.scoped('{', '}', () {
-          indent.write('$varChannelName.setMessageHandler ');
-          final String messageVarName =
-              method.arguments.isNotEmpty ? 'message' : '_';
-          indent.scoped('{ $messageVarName, reply in', '}', () {
-            final List<String> methodArgument = <String>[];
-            if (method.arguments.isNotEmpty) {
-              indent.writeln('let args = message as! [Any?]');
-              enumerate(method.arguments, (int index, NamedType arg) {
-                final String argName = _getSafeArgumentName(index, arg);
-                final String argIndex = 'args[$index]';
-                indent.writeln(
-                    'let $argName = ${_castForceUnwrap(argIndex, arg.type, root)}');
-                methodArgument.add('${arg.name}: $argName');
-              });
-            }
-            final String call =
-                'api.${method.name}(${methodArgument.join(', ')})';
-            if (method.isAsynchronous) {
-              indent.write('$call ');
-              if (method.returnType.isVoid) {
-                indent.scoped('{', '}', () {
-                  indent.writeln('reply(wrapResult(nil))');
-                });
-              } else {
-                indent.scoped('{ result in', '}', () {
-                  indent.writeln('reply(wrapResult(result))');
+            'static var codec: FlutterStandardMessageCodec { $codecName.shared }');
+      }
+      indent.writeln(
+          '$_docCommentPrefix Sets up an instance of `$apiName` to handle messages through the `binaryMessenger`.');
+      indent.write(
+          'static func setUp(binaryMessenger: FlutterBinaryMessenger, api: $apiName?) ');
+      indent.scoped('{', '}', () {
+        for (final Method method in api.methods) {
+          final String channelName = makeChannelName(api, method);
+          final String varChannelName = '${method.name}Channel';
+          addDocumentationComments(
+              indent, method.documentationComments, _docCommentSpec);
+
+          indent.writeln(
+              'let $varChannelName = FlutterBasicMessageChannel(name: "$channelName", binaryMessenger: binaryMessenger$codecArgumentString)');
+          indent.write('if let api = api ');
+          indent.scoped('{', '}', () {
+            indent.write('$varChannelName.setMessageHandler ');
+            final String messageVarName =
+                method.arguments.isNotEmpty ? 'message' : '_';
+            indent.scoped('{ $messageVarName, reply in', '}', () {
+              final List<String> methodArgument = <String>[];
+              if (method.arguments.isNotEmpty) {
+                indent.writeln('let args = message as! [Any?]');
+                enumerate(method.arguments, (int index, NamedType arg) {
+                  final String argName = _getSafeArgumentName(index, arg);
+                  final String argIndex = 'args[$index]';
+                  indent.writeln(
+                      'let $argName = ${_castForceUnwrap(argIndex, arg.type, root)}');
+                  methodArgument.add('${arg.name}: $argName');
                 });
               }
-            } else {
-              if (method.returnType.isVoid) {
-                indent.writeln(call);
-                indent.writeln('reply(wrapResult(nil))');
+              final String call =
+                  'api.${method.name}(${methodArgument.join(', ')})';
+              if (method.isAsynchronous) {
+                indent.write('$call ');
+                if (method.returnType.isVoid) {
+                  indent.scoped('{', '}', () {
+                    indent.writeln('reply(wrapResult(nil))');
+                  });
+                } else {
+                  indent.scoped('{ result in', '}', () {
+                    indent.writeln('reply(wrapResult(result))');
+                  });
+                }
               } else {
-                indent.writeln('let result = $call');
-                indent.writeln('reply(wrapResult(result))');
+                if (method.returnType.isVoid) {
+                  indent.writeln(call);
+                  indent.writeln('reply(wrapResult(nil))');
+                } else {
+                  indent.writeln('let result = $call');
+                  indent.writeln('reply(wrapResult(result))');
+                }
               }
+            });
+          }, addTrailingNewline: false);
+          indent.scoped(' else {', '}', () {
+            indent.writeln('$varChannelName.setMessageHandler(nil)');
+          });
+        }
+      });
+    });
+  }
+
+  /// Writes the codec classwill be used for encoding messages for the [api].
+  /// Example:
+  /// private class FooHostApiCodecReader: FlutterStandardReader {...}
+  /// private class FooHostApiCodecWriter: FlutterStandardWriter {...}
+  /// private class FooHostApiCodecReaderWriter: FlutterStandardReaderWriter {...}
+  void _writeCodec(Indent indent, Api api, Root root) {
+    assert(getCodecClasses(api, root).isNotEmpty);
+    final String codecName = _getCodecName(api);
+    final String readerWriterName = '${codecName}ReaderWriter';
+    final String readerName = '${codecName}Reader';
+    final String writerName = '${codecName}Writer';
+
+    // Generate Reader
+    indent.write('private class $readerName: FlutterStandardReader ');
+    indent.scoped('{', '}', () {
+      if (getCodecClasses(api, root).isNotEmpty) {
+        indent.write('override func readValue(ofType type: UInt8) -> Any? ');
+        indent.scoped('{', '}', () {
+          indent.write('switch type ');
+          indent.scoped('{', '}', () {
+            for (final EnumeratedClass customClass
+                in getCodecClasses(api, root)) {
+              indent.write('case ${customClass.enumeration}:');
+              indent.scoped('', '', () {
+                indent.write(
+                    'return ${customClass.name}.fromList(self.readValue() as! [Any])');
+              });
             }
+            indent.write('default:');
+            indent.scoped('', '', () {
+              indent.writeln('return super.readValue(ofType: type)');
+            });
           });
-        }, addTrailingNewline: false);
-        indent.scoped(' else {', '}', () {
-          indent.writeln('$varChannelName.setMessageHandler(nil)');
         });
       }
     });
-  });
+
+    // Generate Writer
+    indent.write('private class $writerName: FlutterStandardWriter ');
+    indent.scoped('{', '}', () {
+      if (getCodecClasses(api, root).isNotEmpty) {
+        indent.write('override func writeValue(_ value: Any) ');
+        indent.scoped('{', '}', () {
+          indent.write('');
+          for (final EnumeratedClass customClass
+              in getCodecClasses(api, root)) {
+            indent.add('if let value = value as? ${customClass.name} ');
+            indent.scoped('{', '} else ', () {
+              indent.writeln('super.writeByte(${customClass.enumeration})');
+              indent.writeln('super.writeValue(value.toList())');
+            }, addTrailingNewline: false);
+          }
+          indent.scoped('{', '}', () {
+            indent.writeln('super.writeValue(value)');
+          });
+        });
+      }
+    });
+    indent.writeln('');
+
+    // Generate ReaderWriter
+    indent
+        .write('private class $readerWriterName: FlutterStandardReaderWriter ');
+    indent.scoped('{', '}', () {
+      indent.write(
+          'override func reader(with data: Data) -> FlutterStandardReader ');
+      indent.scoped('{', '}', () {
+        indent.writeln('return $readerName(data: data)');
+      });
+      indent.writeln('');
+      indent.write(
+          'override func writer(with data: NSMutableData) -> FlutterStandardWriter ');
+      indent.scoped('{', '}', () {
+        indent.writeln('return $writerName(data: data)');
+      });
+    });
+    indent.writeln('');
+
+    // Generate Codec
+    indent.write('class $codecName: FlutterStandardMessageCodec ');
+    indent.scoped('{', '}', () {
+      indent.writeln(
+          'static let shared = $codecName(readerWriter: $readerWriterName())');
+    });
+  }
+
+  void _writeWrapResult(Indent indent) {
+    indent.write('private func wrapResult(_ result: Any?) -> [Any?] ');
+    indent.scoped('{', '}', () {
+      indent.writeln('return [result]');
+    });
+  }
+
+  void _writeWrapError(Indent indent) {
+    indent.write('private func wrapError(_ error: FlutterError) -> [Any?] ');
+    indent.scoped('{', '}', () {
+      indent.write('return ');
+      indent.scoped('[', ']', () {
+        indent.writeln('error.code,');
+        indent.writeln('error.message,');
+        indent.writeln('error.details');
+      });
+    });
+  }
+}
+
+HostDatatype _getHostDatatype(Root root, NamedType field) {
+  return getFieldHostDatatype(field, root.classes, root.enums,
+      (TypeDeclaration x) => _swiftTypeForBuiltinDartType(x));
 }
 
+/// Calculates the name of the codec that will be generated for [api].
+String _getCodecName(Api api) => '${api.name}Codec';
+
 String _getArgumentName(int count, NamedType argument) =>
     argument.name.isEmpty ? 'arg$count' : argument.name;
 
@@ -487,93 +631,6 @@ String _camelCase(String text) {
   return pascal[0].toLowerCase() + pascal.substring(1);
 }
 
-/// Writes the code for a flutter [Api], [api].
-/// Example:
-/// class Foo {
-///   private let binaryMessenger: FlutterBinaryMessenger
-///   init(binaryMessenger: FlutterBinaryMessenger) {...}
-///   func add(x: Int32, y: Int32, completion: @escaping (Int32?) -> Void) {...}
-/// }
-void _writeFlutterApi(Indent indent, Api api, Root root) {
-  assert(api.location == ApiLocation.flutter);
-  const List<String> generatedComments = <String>[
-    ' Generated class from Pigeon that represents Flutter messages that can be called from Swift.'
-  ];
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
-      generatorComments: generatedComments);
-
-  indent.write('class ${api.name} ');
-  indent.scoped('{', '}', () {
-    indent.writeln('private let binaryMessenger: FlutterBinaryMessenger');
-    indent.write('init(binaryMessenger: FlutterBinaryMessenger)');
-    indent.scoped('{', '}', () {
-      indent.writeln('self.binaryMessenger = binaryMessenger');
-    });
-    final String codecName = _getCodecName(api);
-    String codecArgumentString = '';
-    if (getCodecClasses(api, root).isNotEmpty) {
-      codecArgumentString = ', codec: codec';
-      indent.write('var codec: FlutterStandardMessageCodec ');
-      indent.scoped('{', '}', () {
-        indent.writeln('return $codecName.shared');
-      });
-    }
-    for (final Method func in api.methods) {
-      final String channelName = makeChannelName(api, func);
-      final String returnType = func.returnType.isVoid
-          ? ''
-          : _nullsafeSwiftTypeForDartType(func.returnType);
-      String sendArgument;
-      addDocumentationComments(
-          indent, func.documentationComments, _docCommentSpec);
-
-      if (func.arguments.isEmpty) {
-        indent.write(
-            'func ${func.name}(completion: @escaping ($returnType) -> Void) ');
-        sendArgument = 'nil';
-      } else {
-        final Iterable<String> argTypes = func.arguments
-            .map((NamedType e) => _nullsafeSwiftTypeForDartType(e.type));
-        final Iterable<String> argLabels =
-            indexMap(func.arguments, _getArgumentName);
-        final Iterable<String> argNames =
-            indexMap(func.arguments, _getSafeArgumentName);
-        sendArgument = '[${argNames.join(', ')}]';
-        final String argsSignature = map3(
-            argTypes,
-            argLabels,
-            argNames,
-            (String type, String label, String name) =>
-                '$label $name: $type').join(', ');
-        if (func.returnType.isVoid) {
-          indent.write(
-              'func ${func.name}($argsSignature, completion: @escaping () -> Void) ');
-        } else {
-          indent.write(
-              'func ${func.name}($argsSignature, completion: @escaping ($returnType) -> Void) ');
-        }
-      }
-      indent.scoped('{', '}', () {
-        const String channel = 'channel';
-        indent.writeln(
-            'let $channel = FlutterBasicMessageChannel(name: "$channelName", binaryMessenger: binaryMessenger$codecArgumentString)');
-        indent.write('$channel.sendMessage($sendArgument) ');
-        if (func.returnType.isVoid) {
-          indent.scoped('{ _ in', '}', () {
-            indent.writeln('completion()');
-          });
-        } else {
-          indent.scoped('{ response in', '}', () {
-            indent.writeln(
-                'let result = ${_castForceUnwrap("response", func.returnType, root)}');
-            indent.writeln('completion(result)');
-          });
-        }
-      });
-    }
-  });
-}
-
 String _castForceUnwrap(String value, TypeDeclaration type, Root root) {
   if (isEnum(root, type)) {
     final String forceUnwrap = type.isNullable ? '' : '!';
@@ -650,50 +707,4 @@ String _nullsafeSwiftTypeForDartType(TypeDeclaration type) {
 /// Generates the ".swift" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateSwift(
-    SwiftOptions options, Root root, StringSink sink, Indent indent) {
-  void writeApi(Api api, Root root) {
-    if (api.location == ApiLocation.host) {
-      _writeHostApi(indent, api, root);
-    } else if (api.location == ApiLocation.flutter) {
-      _writeFlutterApi(indent, api, root);
-    }
-  }
-
-  void writeWrapResult() {
-    indent.write('private func wrapResult(_ result: Any?) -> [Any?] ');
-    indent.scoped('{', '}', () {
-      indent.writeln('return [result]');
-    });
-  }
-
-  void writeWrapError() {
-    indent.write('private func wrapError(_ error: FlutterError) -> [Any?] ');
-    indent.scoped('{', '}', () {
-      indent.write('return ');
-      indent.scoped('[', ']', () {
-        indent.writeln('error.code,');
-        indent.writeln('error.message,');
-        indent.writeln('error.details');
-      });
-    });
-  }
-
-  if (root.apis.any((Api api) =>
-      api.location == ApiLocation.host &&
-      api.methods.any((Method it) => it.isAsynchronous))) {
-    indent.addln('');
-  }
-
-  for (final Api api in root.apis) {
-    if (getCodecClasses(api, root).isNotEmpty) {
-      _writeCodec(indent, api, root);
-      indent.addln('');
-    }
-    writeApi(api, root);
-  }
-
-  indent.addln('');
-  writeWrapResult();
-  indent.addln('');
-  writeWrapError();
-}
+    SwiftOptions options, Root root, StringSink sink, Indent indent) {}

From 1e1f7130ff584b64fddf03e94efd6b9092f82d6a Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 6 Jan 2023 23:50:29 -0800
Subject: [PATCH 67/87] cpp

---
 packages/pigeon/lib/cpp_generator.dart | 1195 ++++++++++++------------
 1 file changed, 614 insertions(+), 581 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 4c5ca20c0c4..71e02b42191 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -98,10 +98,31 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
     for (final Class klass in root.classes) {
       writeDataClass(generatorOptions, root, sink, indent, klass);
     }
+
+    for (final Api api in root.apis) {
+      _writeCodec(generatorOptions, root, sink, indent, api);
+      indent.addln('');
+      if (api.location == ApiLocation.host) {
+        writeHostApi(generatorOptions, root, sink, indent, api);
+      } else if (api.location == ApiLocation.flutter) {
+        writeFlutterApi(generatorOptions, root, sink, indent, api);
+      }
+    }
+
     if (generatorOptions.fileType == FileType.header) {
-      generateCppHeader(generatorOptions.languageOptions, root, sink, indent);
+      if (generatorOptions.languageOptions.namespace != null) {
+        indent.writeln(
+            '}  // namespace ${generatorOptions.languageOptions.namespace}');
+      }
+      final String guardName = _getGuardName(
+          generatorOptions.languageOptions.headerIncludePath,
+          generatorOptions.languageOptions.namespace);
+      indent.writeln('#endif  // $guardName');
     } else {
-      generateCppSource(generatorOptions.languageOptions, root, sink, indent);
+      if (generatorOptions.languageOptions.namespace != null) {
+        indent.writeln(
+            '}  // namespace ${generatorOptions.languageOptions.namespace}');
+      }
     }
   }
 
@@ -166,6 +187,7 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
     Set<String> customClassNames,
     Set<String> customEnumNames,
   ) {
+    assert(generatorOptions.fileType == FileType.source);
     _writeCppSourceClassEncode(generatorOptions.languageOptions, root, sink,
         indent, klass, customClassNames, customEnumNames);
   }
@@ -180,10 +202,57 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
     Set<String> customClassNames,
     Set<String> customEnumNames,
   ) {
+    assert(generatorOptions.fileType == FileType.source);
     _writeCppSourceClassDecode(generatorOptions, root, sink, indent, klass,
         customClassNames, customEnumNames);
   }
 
+  @override
+  void writeFlutterApi(
+    OutputFileOptions<CppOptions> generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    if (generatorOptions.fileType == FileType.header) {
+      _writeFlutterApiHeader(indent, api, root);
+    } else {
+      _writeFlutterApiSource(indent, api, root);
+    }
+  }
+
+  @override
+  void writeHostApi(
+    OutputFileOptions<CppOptions> generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    if (generatorOptions.fileType == FileType.header) {
+      _writeHostApiHeader(indent, api, root);
+    } else {
+      _writeHostApiSource(indent, api, root);
+    }
+  }
+
+  void _writeCodec(
+    OutputFileOptions<CppOptions> generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    if (generatorOptions.fileType == FileType.header) {
+      _writeCodecHeader(indent, api, root);
+    } else {
+      _writeCodecSource(indent, api, root);
+    }
+  }
+
+  // Header methods.
+
   /// Writes Cpp header file header to sink.
   void _writeCppHeaderPrologue(OutputFileOptions<CppOptions> generatorOptions,
       Root root, StringSink sink, Indent indent) {
@@ -329,6 +398,199 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
     indent.writeln('');
   }
 
+  void _writeCodecHeader(Indent indent, Api api, Root root) {
+    assert(getCodecClasses(api, root).isNotEmpty);
+    final String codeSerializerName = _getCodecSerializerName(api);
+    indent
+        .write('class $codeSerializerName : public $_defaultCodecSerializer ');
+    indent.scoped('{', '};', () {
+      indent.scoped(' public:', '', () {
+        indent.writeln('');
+        indent.format('''
+inline static $codeSerializerName& GetInstance() {
+\tstatic $codeSerializerName sInstance;
+\treturn sInstance;
+}
+''');
+        indent.writeln('$codeSerializerName();');
+      });
+      indent.writeScoped(' public:', '', () {
+        indent.writeln(
+            'void WriteValue(const flutter::EncodableValue& value, flutter::ByteStreamWriter* stream) const override;');
+      });
+      indent.writeScoped(' protected:', '', () {
+        indent.writeln(
+            'flutter::EncodableValue ReadValueOfType(uint8_t type, flutter::ByteStreamReader* stream) const override;');
+      });
+    }, nestCount: 0);
+  }
+
+  void _writeErrorOr(Indent indent,
+      {Iterable<String> friends = const <String>[]}) {
+    final String friendLines = friends
+        .map((String className) => '\tfriend class $className;')
+        .join('\n');
+    indent.format('''
+class FlutterError {
+ public:
+\texplicit FlutterError(const std::string& code)
+\t\t: code_(code) {}
+\texplicit FlutterError(const std::string& code, const std::string& message)
+\t\t: code_(code), message_(message) {}
+\texplicit FlutterError(const std::string& code, const std::string& message, const flutter::EncodableValue& details)
+\t\t: code_(code), message_(message), details_(details) {}
+
+\tconst std::string& code() const { return code_; }
+\tconst std::string& message() const { return message_; }
+\tconst flutter::EncodableValue& details() const { return details_; }
+
+ private:
+\tstd::string code_;
+\tstd::string message_;
+\tflutter::EncodableValue details_;
+};
+
+template<class T> class ErrorOr {
+ public:
+\tErrorOr(const T& rhs) { new(&v_) T(rhs); }
+\tErrorOr(const T&& rhs) { v_ = std::move(rhs); }
+\tErrorOr(const FlutterError& rhs) {
+\t\tnew(&v_) FlutterError(rhs);
+\t}
+\tErrorOr(const FlutterError&& rhs) { v_ = std::move(rhs); }
+
+\tbool has_error() const { return std::holds_alternative<FlutterError>(v_); }
+\tconst T& value() const { return std::get<T>(v_); };
+\tconst FlutterError& error() const { return std::get<FlutterError>(v_); };
+
+ private:
+$friendLines
+\tErrorOr() = default;
+\tT TakeValue() && { return std::get<T>(std::move(v_)); }
+
+\tstd::variant<T, FlutterError> v_;
+};
+''');
+  }
+
+  void _writeHostApiHeader(Indent indent, Api api, Root root) {
+    assert(api.location == ApiLocation.host);
+
+    const List<String> generatedMessages = <String>[
+      ' Generated interface from Pigeon that represents a handler of messages from Flutter.'
+    ];
+    addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
+        generatorComments: generatedMessages);
+    indent.write('class ${api.name} ');
+    indent.scoped('{', '};', () {
+      indent.scoped(' public:', '', () {
+        indent.writeln('${api.name}(const ${api.name}&) = delete;');
+        indent.writeln('${api.name}& operator=(const ${api.name}&) = delete;');
+        indent.writeln('virtual ~${api.name}() { };');
+        for (final Method method in api.methods) {
+          final HostDatatype returnType = getHostDatatype(
+              method.returnType,
+              root.classes,
+              root.enums,
+              (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
+          final String returnTypeName = _apiReturnType(returnType);
+
+          final List<String> argSignature = <String>[];
+          if (method.arguments.isNotEmpty) {
+            final Iterable<String> argTypes =
+                method.arguments.map((NamedType arg) {
+              final HostDatatype hostType = getFieldHostDatatype(
+                  arg,
+                  root.classes,
+                  root.enums,
+                  (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
+              return _hostApiArgumentType(hostType);
+            });
+            final Iterable<String> argNames =
+                method.arguments.map((NamedType e) => _makeVariableName(e));
+            argSignature.addAll(
+                map2(argTypes, argNames, (String argType, String argName) {
+              return '$argType $argName';
+            }));
+          }
+
+          addDocumentationComments(
+              indent, method.documentationComments, _docCommentSpec);
+
+          if (method.isAsynchronous) {
+            argSignature
+                .add('std::function<void($returnTypeName reply)> result');
+            indent.writeln(
+                'virtual void ${_makeMethodName(method)}(${argSignature.join(', ')}) = 0;');
+          } else {
+            indent.writeln(
+                'virtual $returnTypeName ${_makeMethodName(method)}(${argSignature.join(', ')}) = 0;');
+          }
+        }
+        indent.addln('');
+        indent.writeln('$_commentPrefix The codec used by ${api.name}.');
+        indent
+            .writeln('static const flutter::StandardMessageCodec& GetCodec();');
+        indent.writeln(
+            '$_commentPrefix Sets up an instance of `${api.name}` to handle messages through the `binary_messenger`.');
+        indent.writeln(
+            'static void SetUp(flutter::BinaryMessenger* binary_messenger, ${api.name}* api);');
+        indent.writeln(
+            'static flutter::EncodableList WrapError(std::string_view error_message);');
+        indent.writeln(
+            'static flutter::EncodableList WrapError(const FlutterError& error);');
+      });
+      indent.scoped(' protected:', '', () {
+        indent.writeln('${api.name}() = default;');
+      });
+    }, nestCount: 0);
+  }
+
+  void _writeFlutterApiHeader(Indent indent, Api api, Root root) {
+    assert(api.location == ApiLocation.flutter);
+
+    const List<String> generatedMessages = <String>[
+      ' Generated class from Pigeon that represents Flutter messages that can be called from C++.'
+    ];
+    addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
+        generatorComments: generatedMessages);
+    indent.write('class ${api.name} ');
+    indent.scoped('{', '};', () {
+      indent.scoped(' private:', '', () {
+        indent.writeln('flutter::BinaryMessenger* binary_messenger_;');
+      });
+      indent.scoped(' public:', '', () {
+        indent
+            .write('${api.name}(flutter::BinaryMessenger* binary_messenger);');
+        indent.writeln('');
+        indent
+            .writeln('static const flutter::StandardMessageCodec& GetCodec();');
+        for (final Method func in api.methods) {
+          final String returnType = func.returnType.isVoid
+              ? 'void'
+              : _nullSafeCppTypeForDartType(func.returnType);
+          final String callback = 'std::function<void($returnType)>&& callback';
+          addDocumentationComments(
+              indent, func.documentationComments, _docCommentSpec);
+          if (func.arguments.isEmpty) {
+            indent.writeln('void ${func.name}($callback);');
+          } else {
+            final Iterable<String> argTypes = func.arguments
+                .map((NamedType e) => _nullSafeCppTypeForDartType(e.type));
+            final Iterable<String> argNames =
+                indexMap(func.arguments, _getSafeArgumentName);
+            final String argsSignature =
+                map2(argTypes, argNames, (String x, String y) => '$x $y')
+                    .join(', ');
+            indent.writeln('void ${func.name}($argsSignature, $callback);');
+          }
+        }
+      });
+    }, nestCount: 0);
+  }
+
+  // Source methods.
+
   /// Writes Cpp source file header to sink.
   void _writeCppSourcePrologue(OutputFileOptions<CppOptions> generatorOptions,
       Root root, StringSink sink, Indent indent) {
@@ -549,569 +811,403 @@ else if (const int64_t* ${pointerFieldName}_64 = std::get_if<int64_t>(&$encodabl
     writeClassDecode(generatorOptions, root, sink, indent, klass,
         customClassNames, customEnumNames);
   }
-}
-
-String _getCodecSerializerName(Api api) => '${api.name}CodecSerializer';
-
-const String _pointerPrefix = 'pointer';
-const String _encodablePrefix = 'encodable';
-
-void _writeCodecHeader(Indent indent, Api api, Root root) {
-  assert(getCodecClasses(api, root).isNotEmpty);
-  final String codeSerializerName = _getCodecSerializerName(api);
-  indent.write('class $codeSerializerName : public $_defaultCodecSerializer ');
-  indent.scoped('{', '};', () {
-    indent.scoped(' public:', '', () {
-      indent.writeln('');
-      indent.format('''
-inline static $codeSerializerName& GetInstance() {
-\tstatic $codeSerializerName sInstance;
-\treturn sInstance;
-}
-''');
-      indent.writeln('$codeSerializerName();');
-    });
-    indent.writeScoped(' public:', '', () {
-      indent.writeln(
-          'void WriteValue(const flutter::EncodableValue& value, flutter::ByteStreamWriter* stream) const override;');
-    });
-    indent.writeScoped(' protected:', '', () {
-      indent.writeln(
-          'flutter::EncodableValue ReadValueOfType(uint8_t type, flutter::ByteStreamReader* stream) const override;');
-    });
-  }, nestCount: 0);
-}
 
-void _writeCodecSource(Indent indent, Api api, Root root) {
-  assert(getCodecClasses(api, root).isNotEmpty);
-  final String codeSerializerName = _getCodecSerializerName(api);
-  indent.writeln('$codeSerializerName::$codeSerializerName() {}');
-  indent.write(
-      'flutter::EncodableValue $codeSerializerName::ReadValueOfType(uint8_t type, flutter::ByteStreamReader* stream) const ');
-  indent.scoped('{', '}', () {
-    indent.write('switch (type) ');
+  void _writeCodecSource(Indent indent, Api api, Root root) {
+    assert(getCodecClasses(api, root).isNotEmpty);
+    final String codeSerializerName = _getCodecSerializerName(api);
+    indent.writeln('$codeSerializerName::$codeSerializerName() {}');
+    indent.write(
+        'flutter::EncodableValue $codeSerializerName::ReadValueOfType(uint8_t type, flutter::ByteStreamReader* stream) const ');
     indent.scoped('{', '}', () {
-      for (final EnumeratedClass customClass in getCodecClasses(api, root)) {
-        indent.write('case ${customClass.enumeration}:');
+      indent.write('switch (type) ');
+      indent.scoped('{', '}', () {
+        for (final EnumeratedClass customClass in getCodecClasses(api, root)) {
+          indent.write('case ${customClass.enumeration}:');
+          indent.writeScoped('', '', () {
+            indent.writeln(
+                'return flutter::CustomEncodableValue(${customClass.name}(std::get<flutter::EncodableList>(ReadValue(stream))));');
+          });
+        }
+        indent.write('default:');
         indent.writeScoped('', '', () {
           indent.writeln(
-              'return flutter::CustomEncodableValue(${customClass.name}(std::get<flutter::EncodableList>(ReadValue(stream))));');
-        });
-      }
-      indent.write('default:');
-      indent.writeScoped('', '', () {
-        indent.writeln(
-            'return $_defaultCodecSerializer::ReadValueOfType(type, stream);');
-      }, addTrailingNewline: false);
+              'return $_defaultCodecSerializer::ReadValueOfType(type, stream);');
+        }, addTrailingNewline: false);
+      });
     });
-  });
-  indent.writeln('');
-  indent.write(
-      'void $codeSerializerName::WriteValue(const flutter::EncodableValue& value, flutter::ByteStreamWriter* stream) const ');
-  indent.writeScoped('{', '}', () {
+    indent.writeln('');
     indent.write(
-        'if (const flutter::CustomEncodableValue* custom_value = std::get_if<flutter::CustomEncodableValue>(&value)) ');
-    indent.scoped('{', '}', () {
-      for (final EnumeratedClass customClass in getCodecClasses(api, root)) {
-        indent
-            .write('if (custom_value->type() == typeid(${customClass.name})) ');
-        indent.scoped('{', '}', () {
-          indent.writeln('stream->WriteByte(${customClass.enumeration});');
-          indent.writeln(
-              'WriteValue(flutter::EncodableValue(std::any_cast<${customClass.name}>(*custom_value).ToEncodableList()), stream);');
-          indent.writeln('return;');
-        });
-      }
-    });
-    indent.writeln('$_defaultCodecSerializer::WriteValue(value, stream);');
-  });
-}
-
-void _writeErrorOr(Indent indent,
-    {Iterable<String> friends = const <String>[]}) {
-  final String friendLines = friends
-      .map((String className) => '\tfriend class $className;')
-      .join('\n');
-  indent.format('''
-class FlutterError {
- public:
-\texplicit FlutterError(const std::string& code)
-\t\t: code_(code) {}
-\texplicit FlutterError(const std::string& code, const std::string& message)
-\t\t: code_(code), message_(message) {}
-\texplicit FlutterError(const std::string& code, const std::string& message, const flutter::EncodableValue& details)
-\t\t: code_(code), message_(message), details_(details) {}
-
-\tconst std::string& code() const { return code_; }
-\tconst std::string& message() const { return message_; }
-\tconst flutter::EncodableValue& details() const { return details_; }
-
- private:
-\tstd::string code_;
-\tstd::string message_;
-\tflutter::EncodableValue details_;
-};
-
-template<class T> class ErrorOr {
- public:
-\tErrorOr(const T& rhs) { new(&v_) T(rhs); }
-\tErrorOr(const T&& rhs) { v_ = std::move(rhs); }
-\tErrorOr(const FlutterError& rhs) {
-\t\tnew(&v_) FlutterError(rhs);
-\t}
-\tErrorOr(const FlutterError&& rhs) { v_ = std::move(rhs); }
-
-\tbool has_error() const { return std::holds_alternative<FlutterError>(v_); }
-\tconst T& value() const { return std::get<T>(v_); };
-\tconst FlutterError& error() const { return std::get<FlutterError>(v_); };
-
- private:
-$friendLines
-\tErrorOr() = default;
-\tT TakeValue() && { return std::get<T>(std::move(v_)); }
-
-\tstd::variant<T, FlutterError> v_;
-};
-''');
-}
-
-void _writeHostApiHeader(Indent indent, Api api, Root root) {
-  assert(api.location == ApiLocation.host);
-
-  const List<String> generatedMessages = <String>[
-    ' Generated interface from Pigeon that represents a handler of messages from Flutter.'
-  ];
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
-      generatorComments: generatedMessages);
-  indent.write('class ${api.name} ');
-  indent.scoped('{', '};', () {
-    indent.scoped(' public:', '', () {
-      indent.writeln('${api.name}(const ${api.name}&) = delete;');
-      indent.writeln('${api.name}& operator=(const ${api.name}&) = delete;');
-      indent.writeln('virtual ~${api.name}() { };');
-      for (final Method method in api.methods) {
-        final HostDatatype returnType = getHostDatatype(
-            method.returnType,
-            root.classes,
-            root.enums,
-            (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-        final String returnTypeName = _apiReturnType(returnType);
-
-        final List<String> argSignature = <String>[];
-        if (method.arguments.isNotEmpty) {
-          final Iterable<String> argTypes =
-              method.arguments.map((NamedType arg) {
-            final HostDatatype hostType = getFieldHostDatatype(
-                arg,
-                root.classes,
-                root.enums,
-                (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-            return _hostApiArgumentType(hostType);
+        'void $codeSerializerName::WriteValue(const flutter::EncodableValue& value, flutter::ByteStreamWriter* stream) const ');
+    indent.writeScoped('{', '}', () {
+      indent.write(
+          'if (const flutter::CustomEncodableValue* custom_value = std::get_if<flutter::CustomEncodableValue>(&value)) ');
+      indent.scoped('{', '}', () {
+        for (final EnumeratedClass customClass in getCodecClasses(api, root)) {
+          indent.write(
+              'if (custom_value->type() == typeid(${customClass.name})) ');
+          indent.scoped('{', '}', () {
+            indent.writeln('stream->WriteByte(${customClass.enumeration});');
+            indent.writeln(
+                'WriteValue(flutter::EncodableValue(std::any_cast<${customClass.name}>(*custom_value).ToEncodableList()), stream);');
+            indent.writeln('return;');
           });
-          final Iterable<String> argNames =
-              method.arguments.map((NamedType e) => _makeVariableName(e));
-          argSignature.addAll(
-              map2(argTypes, argNames, (String argType, String argName) {
-            return '$argType $argName';
-          }));
-        }
-
-        addDocumentationComments(
-            indent, method.documentationComments, _docCommentSpec);
-
-        if (method.isAsynchronous) {
-          argSignature.add('std::function<void($returnTypeName reply)> result');
-          indent.writeln(
-              'virtual void ${_makeMethodName(method)}(${argSignature.join(', ')}) = 0;');
-        } else {
-          indent.writeln(
-              'virtual $returnTypeName ${_makeMethodName(method)}(${argSignature.join(', ')}) = 0;');
         }
-      }
-      indent.addln('');
-      indent.writeln('$_commentPrefix The codec used by ${api.name}.');
-      indent.writeln('static const flutter::StandardMessageCodec& GetCodec();');
-      indent.writeln(
-          '$_commentPrefix Sets up an instance of `${api.name}` to handle messages through the `binary_messenger`.');
-      indent.writeln(
-          'static void SetUp(flutter::BinaryMessenger* binary_messenger, ${api.name}* api);');
-      indent.writeln(
-          'static flutter::EncodableList WrapError(std::string_view error_message);');
-      indent.writeln(
-          'static flutter::EncodableList WrapError(const FlutterError& error);');
-    });
-    indent.scoped(' protected:', '', () {
-      indent.writeln('${api.name}() = default;');
+      });
+      indent.writeln('$_defaultCodecSerializer::WriteValue(value, stream);');
     });
-  }, nestCount: 0);
-}
+  }
 
-void _writeHostApiSource(Indent indent, Api api, Root root) {
-  assert(api.location == ApiLocation.host);
+  void _writeHostApiSource(Indent indent, Api api, Root root) {
+    assert(api.location == ApiLocation.host);
 
-  final String codeSerializerName = getCodecClasses(api, root).isNotEmpty
-      ? _getCodecSerializerName(api)
-      : _defaultCodecSerializer;
-  indent.format('''
+    final String codeSerializerName = getCodecClasses(api, root).isNotEmpty
+        ? _getCodecSerializerName(api)
+        : _defaultCodecSerializer;
+    indent.format('''
 /// The codec used by ${api.name}.
 const flutter::StandardMessageCodec& ${api.name}::GetCodec() {
 \treturn flutter::StandardMessageCodec::GetInstance(&$codeSerializerName::GetInstance());
 }
 ''');
-  indent.writeln(
-      '$_commentPrefix Sets up an instance of `${api.name}` to handle messages through the `binary_messenger`.');
-  indent.write(
-      'void ${api.name}::SetUp(flutter::BinaryMessenger* binary_messenger, ${api.name}* api) ');
-  indent.scoped('{', '}', () {
-    for (final Method method in api.methods) {
-      final String channelName = makeChannelName(api, method);
-      indent.write('');
-      indent.scoped('{', '}', () {
-        indent.writeln(
-            'auto channel = std::make_unique<flutter::BasicMessageChannel<flutter::EncodableValue>>(');
-        indent.inc();
-        indent.inc();
-        indent.writeln('binary_messenger, "$channelName", &GetCodec());');
-        indent.dec();
-        indent.dec();
-        indent.write('if (api != nullptr) ');
-        indent.scoped('{', '} else {', () {
-          indent.write(
-              'channel->SetMessageHandler([api](const flutter::EncodableValue& message, const flutter::MessageReply<flutter::EncodableValue>& reply) ');
-          indent.scoped('{', '});', () {
-            indent.writeln('flutter::EncodableList wrapped;');
-            indent.write('try ');
-            indent.scoped('{', '}', () {
-              final List<String> methodArgument = <String>[];
-              if (method.arguments.isNotEmpty) {
-                indent.writeln(
-                    'const auto& args = std::get<flutter::EncodableList>(message);');
-
-                // Writes the code to declare and populate a variable called
-                // [argName] to use as a parameter to an API method call from
-                // an existing EncodablValue variable called [encodableArgName]
-                // which corresponds to [arg] in the API definition.
-                void extractEncodedArgument(
-                    String argName,
-                    String encodableArgName,
-                    NamedType arg,
-                    HostDatatype hostType) {
-                  if (arg.type.isNullable) {
-                    // Nullable arguments are always pointers, with nullptr
-                    // corresponding to null.
-                    if (hostType.datatype == 'int64_t') {
-                      // The EncodableValue will either be an int32_t or an
-                      // int64_t depending on the value, but the generated API
-                      // requires an int64_t so that it can handle any case.
-                      // Create a local variable for the 64-bit value...
-                      final String valueVarName = '${argName}_value';
-                      indent.writeln(
-                          'const int64_t $valueVarName = $encodableArgName.IsNull() ? 0 : $encodableArgName.LongValue();');
-                      // ... then declare the arg as a reference to that local.
-                      indent.writeln(
-                          'const auto* $argName = $encodableArgName.IsNull() ? nullptr : &$valueVarName;');
-                    } else if (hostType.datatype == 'flutter::EncodableValue') {
-                      // Generic objects just pass the EncodableValue through
-                      // directly.
-                      indent.writeln(
-                          'const auto* $argName = &$encodableArgName;');
-                    } else if (hostType.isBuiltin) {
-                      indent.writeln(
-                          'const auto* $argName = std::get_if<${hostType.datatype}>(&$encodableArgName);');
-                    } else {
-                      indent.writeln(
-                          'const auto* $argName = &(std::any_cast<const ${hostType.datatype}&>(std::get<flutter::CustomEncodableValue>($encodableArgName)));');
-                    }
-                  } else {
-                    // Non-nullable arguments are either passed by value or
-                    // reference, but the extraction doesn't need to distinguish
-                    // since those are the same at the call site.
-                    if (hostType.datatype == 'int64_t') {
-                      // The EncodableValue will either be an int32_t or an
-                      // int64_t depending on the value, but the generated API
-                      // requires an int64_t so that it can handle any case.
-                      indent.writeln(
-                          'const int64_t $argName = $encodableArgName.LongValue();');
-                    } else if (hostType.datatype == 'flutter::EncodableValue') {
-                      // Generic objects just pass the EncodableValue through
-                      // directly. This creates an alias just to avoid having to
-                      // special-case the argName/encodableArgName distinction
-                      // at a higher level.
-                      indent
-                          .writeln('const auto& $argName = $encodableArgName;');
-                    } else if (hostType.isBuiltin) {
-                      indent.writeln(
-                          'const auto& $argName = std::get<${hostType.datatype}>($encodableArgName);');
+    indent.writeln(
+        '$_commentPrefix Sets up an instance of `${api.name}` to handle messages through the `binary_messenger`.');
+    indent.write(
+        'void ${api.name}::SetUp(flutter::BinaryMessenger* binary_messenger, ${api.name}* api) ');
+    indent.scoped('{', '}', () {
+      for (final Method method in api.methods) {
+        final String channelName = makeChannelName(api, method);
+        indent.write('');
+        indent.scoped('{', '}', () {
+          indent.writeln(
+              'auto channel = std::make_unique<flutter::BasicMessageChannel<flutter::EncodableValue>>(');
+          indent.inc();
+          indent.inc();
+          indent.writeln('binary_messenger, "$channelName", &GetCodec());');
+          indent.dec();
+          indent.dec();
+          indent.write('if (api != nullptr) ');
+          indent.scoped('{', '} else {', () {
+            indent.write(
+                'channel->SetMessageHandler([api](const flutter::EncodableValue& message, const flutter::MessageReply<flutter::EncodableValue>& reply) ');
+            indent.scoped('{', '});', () {
+              indent.writeln('flutter::EncodableList wrapped;');
+              indent.write('try ');
+              indent.scoped('{', '}', () {
+                final List<String> methodArgument = <String>[];
+                if (method.arguments.isNotEmpty) {
+                  indent.writeln(
+                      'const auto& args = std::get<flutter::EncodableList>(message);');
+
+                  // Writes the code to declare and populate a variable called
+                  // [argName] to use as a parameter to an API method call from
+                  // an existing EncodablValue variable called [encodableArgName]
+                  // which corresponds to [arg] in the API definition.
+                  void extractEncodedArgument(
+                      String argName,
+                      String encodableArgName,
+                      NamedType arg,
+                      HostDatatype hostType) {
+                    if (arg.type.isNullable) {
+                      // Nullable arguments are always pointers, with nullptr
+                      // corresponding to null.
+                      if (hostType.datatype == 'int64_t') {
+                        // The EncodableValue will either be an int32_t or an
+                        // int64_t depending on the value, but the generated API
+                        // requires an int64_t so that it can handle any case.
+                        // Create a local variable for the 64-bit value...
+                        final String valueVarName = '${argName}_value';
+                        indent.writeln(
+                            'const int64_t $valueVarName = $encodableArgName.IsNull() ? 0 : $encodableArgName.LongValue();');
+                        // ... then declare the arg as a reference to that local.
+                        indent.writeln(
+                            'const auto* $argName = $encodableArgName.IsNull() ? nullptr : &$valueVarName;');
+                      } else if (hostType.datatype ==
+                          'flutter::EncodableValue') {
+                        // Generic objects just pass the EncodableValue through
+                        // directly.
+                        indent.writeln(
+                            'const auto* $argName = &$encodableArgName;');
+                      } else if (hostType.isBuiltin) {
+                        indent.writeln(
+                            'const auto* $argName = std::get_if<${hostType.datatype}>(&$encodableArgName);');
+                      } else {
+                        indent.writeln(
+                            'const auto* $argName = &(std::any_cast<const ${hostType.datatype}&>(std::get<flutter::CustomEncodableValue>($encodableArgName)));');
+                      }
                     } else {
-                      indent.writeln(
-                          'const auto& $argName = std::any_cast<const ${hostType.datatype}&>(std::get<flutter::CustomEncodableValue>($encodableArgName));');
+                      // Non-nullable arguments are either passed by value or
+                      // reference, but the extraction doesn't need to distinguish
+                      // since those are the same at the call site.
+                      if (hostType.datatype == 'int64_t') {
+                        // The EncodableValue will either be an int32_t or an
+                        // int64_t depending on the value, but the generated API
+                        // requires an int64_t so that it can handle any case.
+                        indent.writeln(
+                            'const int64_t $argName = $encodableArgName.LongValue();');
+                      } else if (hostType.datatype ==
+                          'flutter::EncodableValue') {
+                        // Generic objects just pass the EncodableValue through
+                        // directly. This creates an alias just to avoid having to
+                        // special-case the argName/encodableArgName distinction
+                        // at a higher level.
+                        indent.writeln(
+                            'const auto& $argName = $encodableArgName;');
+                      } else if (hostType.isBuiltin) {
+                        indent.writeln(
+                            'const auto& $argName = std::get<${hostType.datatype}>($encodableArgName);');
+                      } else {
+                        indent.writeln(
+                            'const auto& $argName = std::any_cast<const ${hostType.datatype}&>(std::get<flutter::CustomEncodableValue>($encodableArgName));');
+                      }
                     }
                   }
-                }
 
-                enumerate(method.arguments, (int index, NamedType arg) {
-                  final HostDatatype hostType = getHostDatatype(
-                      arg.type,
-                      root.classes,
-                      root.enums,
-                      (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-                  final String argName = _getSafeArgumentName(index, arg);
-
-                  final String encodableArgName =
-                      '${_encodablePrefix}_$argName';
-                  indent.writeln(
-                      'const auto& $encodableArgName = args.at($index);');
-                  if (!arg.type.isNullable) {
-                    indent.write('if ($encodableArgName.IsNull()) ');
-                    indent.scoped('{', '}', () {
-                      indent.writeln(
-                          'reply(flutter::EncodableValue(WrapError("$argName unexpectedly null.")));');
-                      indent.writeln('return;');
-                    });
-                  }
-                  extractEncodedArgument(
-                      argName, encodableArgName, arg, hostType);
-                  methodArgument.add(argName);
-                });
-              }
+                  enumerate(method.arguments, (int index, NamedType arg) {
+                    final HostDatatype hostType = getHostDatatype(
+                        arg.type,
+                        root.classes,
+                        root.enums,
+                        (TypeDeclaration x) =>
+                            _baseCppTypeForBuiltinDartType(x));
+                    final String argName = _getSafeArgumentName(index, arg);
+
+                    final String encodableArgName =
+                        '${_encodablePrefix}_$argName';
+                    indent.writeln(
+                        'const auto& $encodableArgName = args.at($index);');
+                    if (!arg.type.isNullable) {
+                      indent.write('if ($encodableArgName.IsNull()) ');
+                      indent.scoped('{', '}', () {
+                        indent.writeln(
+                            'reply(flutter::EncodableValue(WrapError("$argName unexpectedly null.")));');
+                        indent.writeln('return;');
+                      });
+                    }
+                    extractEncodedArgument(
+                        argName, encodableArgName, arg, hostType);
+                    methodArgument.add(argName);
+                  });
+                }
 
-              String wrapResponse(String reply, TypeDeclaration returnType) {
-                String elseBody = '';
-                final String ifCondition;
-                final String errorGetter;
-                final String prefix = (reply != '') ? '\t' : '';
-
-                const String nullValue = 'flutter::EncodableValue()';
-                if (returnType.isVoid) {
-                  elseBody =
-                      '$prefix\twrapped.push_back($nullValue);${indent.newline}';
-                  ifCondition = 'output.has_value()';
-                  errorGetter = 'value';
+                final HostDatatype returnType = getHostDatatype(
+                    method.returnType,
+                    root.classes,
+                    root.enums,
+                    (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
+                final String returnTypeName = _apiReturnType(returnType);
+                if (method.isAsynchronous) {
+                  methodArgument.add(
+                    '[&wrapped, &reply]($returnTypeName&& output) {${indent.newline}'
+                    '${_wrapResponse(indent, root, '\treply(flutter::EncodableValue(std::move(wrapped)));${indent.newline}', method.returnType)}'
+                    '}',
+                  );
+                }
+                final String call =
+                    'api->${_makeMethodName(method)}(${methodArgument.join(', ')})';
+                if (method.isAsynchronous) {
+                  indent.format('$call;');
                 } else {
-                  final HostDatatype hostType = getHostDatatype(
-                      returnType,
-                      root.classes,
-                      root.enums,
-                      (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-                  const String extractedValue = 'std::move(output).TakeValue()';
-                  final String wrapperType = hostType.isBuiltin
-                      ? 'flutter::EncodableValue'
-                      : 'flutter::CustomEncodableValue';
-                  if (returnType.isNullable) {
-                    // The value is a std::optional, so needs an extra layer of
-                    // handling.
-                    elseBody = '''
-$prefix\tauto output_optional = $extractedValue;
-$prefix\tif (output_optional) {
-$prefix\t\twrapped.push_back($wrapperType(std::move(output_optional).value()));
-$prefix\t} else {
-$prefix\t\twrapped.push_back($nullValue);
-$prefix\t}${indent.newline}''';
-                  } else {
-                    elseBody =
-                        '$prefix\twrapped.push_back($wrapperType($extractedValue));${indent.newline}';
-                  }
-                  ifCondition = 'output.has_error()';
-                  errorGetter = 'error';
+                  indent.writeln('$returnTypeName output = $call;');
+                  indent.format(
+                      _wrapResponse(indent, root, '', method.returnType));
                 }
-                return '${prefix}if ($ifCondition) {${indent.newline}'
-                    '$prefix\twrapped = WrapError(output.$errorGetter());${indent.newline}'
-                    '$prefix} else {${indent.newline}'
-                    '$elseBody'
-                    '$prefix}'
-                    '$prefix$reply';
-              }
-
-              final HostDatatype returnType = getHostDatatype(
-                  method.returnType,
-                  root.classes,
-                  root.enums,
-                  (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-              final String returnTypeName = _apiReturnType(returnType);
-              if (method.isAsynchronous) {
-                methodArgument.add(
-                  '[&wrapped, &reply]($returnTypeName&& output) {${indent.newline}'
-                  '${wrapResponse('\treply(flutter::EncodableValue(std::move(wrapped)));${indent.newline}', method.returnType)}'
-                  '}',
-                );
-              }
-              final String call =
-                  'api->${_makeMethodName(method)}(${methodArgument.join(', ')})';
-              if (method.isAsynchronous) {
-                indent.format('$call;');
-              } else {
-                indent.writeln('$returnTypeName output = $call;');
-                indent.format(wrapResponse('', method.returnType));
-              }
-            });
-            indent.write('catch (const std::exception& exception) ');
-            indent.scoped('{', '}', () {
-              indent.writeln('wrapped = WrapError(exception.what());');
-              if (method.isAsynchronous) {
+              });
+              indent.write('catch (const std::exception& exception) ');
+              indent.scoped('{', '}', () {
+                indent.writeln('wrapped = WrapError(exception.what());');
+                if (method.isAsynchronous) {
+                  indent.writeln(
+                      'reply(flutter::EncodableValue(std::move(wrapped)));');
+                }
+              });
+              if (!method.isAsynchronous) {
                 indent.writeln(
                     'reply(flutter::EncodableValue(std::move(wrapped)));');
               }
             });
-            if (!method.isAsynchronous) {
-              indent.writeln(
-                  'reply(flutter::EncodableValue(std::move(wrapped)));');
-            }
+          });
+          indent.scoped(null, '}', () {
+            indent.writeln('channel->SetMessageHandler(nullptr);');
           });
         });
-        indent.scoped(null, '}', () {
-          indent.writeln('channel->SetMessageHandler(nullptr);');
-        });
-      });
-    }
-  });
-}
-
-String _getArgumentName(int count, NamedType argument) =>
-    argument.name.isEmpty ? 'arg$count' : _makeVariableName(argument);
-
-/// Returns an argument name that can be used in a context where it is possible to collide.
-String _getSafeArgumentName(int count, NamedType argument) =>
-    '${_getArgumentName(count, argument)}_arg';
-
-void _writeFlutterApiHeader(Indent indent, Api api) {
-  assert(api.location == ApiLocation.flutter);
-
-  const List<String> generatedMessages = <String>[
-    ' Generated class from Pigeon that represents Flutter messages that can be called from C++.'
-  ];
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
-      generatorComments: generatedMessages);
-  indent.write('class ${api.name} ');
-  indent.scoped('{', '};', () {
-    indent.scoped(' private:', '', () {
-      indent.writeln('flutter::BinaryMessenger* binary_messenger_;');
-    });
-    indent.scoped(' public:', '', () {
-      indent.write('${api.name}(flutter::BinaryMessenger* binary_messenger);');
-      indent.writeln('');
-      indent.writeln('static const flutter::StandardMessageCodec& GetCodec();');
-      for (final Method func in api.methods) {
-        final String returnType = func.returnType.isVoid
-            ? 'void'
-            : _nullSafeCppTypeForDartType(func.returnType);
-        final String callback = 'std::function<void($returnType)>&& callback';
-        addDocumentationComments(
-            indent, func.documentationComments, _docCommentSpec);
-        if (func.arguments.isEmpty) {
-          indent.writeln('void ${func.name}($callback);');
-        } else {
-          final Iterable<String> argTypes = func.arguments
-              .map((NamedType e) => _nullSafeCppTypeForDartType(e.type));
-          final Iterable<String> argNames =
-              indexMap(func.arguments, _getSafeArgumentName);
-          final String argsSignature =
-              map2(argTypes, argNames, (String x, String y) => '$x $y')
-                  .join(', ');
-          indent.writeln('void ${func.name}($argsSignature, $callback);');
-        }
       }
     });
-  }, nestCount: 0);
+
+    indent.addln('');
+    indent.format('''
+flutter::EncodableList ${api.name}::WrapError(std::string_view error_message) {
+\treturn flutter::EncodableList({
+\t\tflutter::EncodableValue(std::string(error_message)),
+\t\tflutter::EncodableValue("Error"),
+\t\tflutter::EncodableValue()
+\t});
 }
+flutter::EncodableList ${api.name}::WrapError(const FlutterError& error) {
+\treturn flutter::EncodableList({
+\t\tflutter::EncodableValue(error.message()),
+\t\tflutter::EncodableValue(error.code()),
+\t\terror.details()
+\t});
+}''');
+    indent.addln('');
+  }
 
-void _writeFlutterApiSource(Indent indent, Api api, Root root) {
-  assert(api.location == ApiLocation.flutter);
-  indent.writeln(
-      '$_commentPrefix Generated class from Pigeon that represents Flutter messages that can be called from C++.');
-  indent.write(
-      '${api.name}::${api.name}(flutter::BinaryMessenger* binary_messenger) ');
-  indent.scoped('{', '}', () {
-    indent.writeln('this->binary_messenger_ = binary_messenger;');
-  });
-  indent.writeln('');
-  final String codeSerializerName = getCodecClasses(api, root).isNotEmpty
-      ? _getCodecSerializerName(api)
-      : _defaultCodecSerializer;
-  indent.format('''
+  String _wrapResponse(
+      Indent indent, Root root, String reply, TypeDeclaration returnType) {
+    String elseBody = '';
+    final String ifCondition;
+    final String errorGetter;
+    final String prefix = (reply != '') ? '\t' : '';
+
+    const String nullValue = 'flutter::EncodableValue()';
+    if (returnType.isVoid) {
+      elseBody = '$prefix\twrapped.push_back($nullValue);${indent.newline}';
+      ifCondition = 'output.has_value()';
+      errorGetter = 'value';
+    } else {
+      final HostDatatype hostType = getHostDatatype(returnType, root.classes,
+          root.enums, (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
+      const String extractedValue = 'std::move(output).TakeValue()';
+      final String wrapperType = hostType.isBuiltin
+          ? 'flutter::EncodableValue'
+          : 'flutter::CustomEncodableValue';
+      if (returnType.isNullable) {
+        // The value is a std::optional, so needs an extra layer of
+        // handling.
+        elseBody = '''
+$prefix\tauto output_optional = $extractedValue;
+$prefix\tif (output_optional) {
+$prefix\t\twrapped.push_back($wrapperType(std::move(output_optional).value()));
+$prefix\t} else {
+$prefix\t\twrapped.push_back($nullValue);
+$prefix\t}${indent.newline}''';
+      } else {
+        elseBody =
+            '$prefix\twrapped.push_back($wrapperType($extractedValue));${indent.newline}';
+      }
+      ifCondition = 'output.has_error()';
+      errorGetter = 'error';
+    }
+    return '${prefix}if ($ifCondition) {${indent.newline}'
+        '$prefix\twrapped = WrapError(output.$errorGetter());${indent.newline}'
+        '$prefix} else {${indent.newline}'
+        '$elseBody'
+        '$prefix}'
+        '$prefix$reply';
+  }
+
+  void _writeFlutterApiSource(Indent indent, Api api, Root root) {
+    assert(api.location == ApiLocation.flutter);
+    indent.writeln(
+        '$_commentPrefix Generated class from Pigeon that represents Flutter messages that can be called from C++.');
+    indent.write(
+        '${api.name}::${api.name}(flutter::BinaryMessenger* binary_messenger) ');
+    indent.scoped('{', '}', () {
+      indent.writeln('this->binary_messenger_ = binary_messenger;');
+    });
+    indent.writeln('');
+    final String codeSerializerName = getCodecClasses(api, root).isNotEmpty
+        ? _getCodecSerializerName(api)
+        : _defaultCodecSerializer;
+    indent.format('''
 const flutter::StandardMessageCodec& ${api.name}::GetCodec() {
 \treturn flutter::StandardMessageCodec::GetInstance(&$codeSerializerName::GetInstance());
 }
 ''');
-  for (final Method func in api.methods) {
-    final String channelName = makeChannelName(api, func);
-    final String returnType = func.returnType.isVoid
-        ? 'void'
-        : _nullSafeCppTypeForDartType(func.returnType);
-    String sendArgument;
-    final String callback = 'std::function<void($returnType)>&& callback';
-    if (func.arguments.isEmpty) {
-      indent.write('void ${api.name}::${func.name}($callback) ');
-      sendArgument = 'flutter::EncodableValue()';
-    } else {
-      final Iterable<String> argTypes = func.arguments
-          .map((NamedType e) => _nullSafeCppTypeForDartType(e.type));
-      final Iterable<String> argNames =
-          indexMap(func.arguments, _getSafeArgumentName);
-      sendArgument =
-          'flutter::EncodableList { ${argNames.map((String arg) => 'flutter::CustomEncodableValue($arg)').join(', ')} }';
-      final String argsSignature =
-          map2(argTypes, argNames, (String x, String y) => '$x $y').join(', ');
-      indent
-          .write('void ${api.name}::${func.name}($argsSignature, $callback) ');
-    }
-    indent.scoped('{', '}', () {
-      const String channel = 'channel';
-      indent.writeln(
-          'auto channel = std::make_unique<flutter::BasicMessageChannel<flutter::EncodableValue>>(');
-      indent.inc();
-      indent.inc();
-      indent.writeln('binary_messenger_, "$channelName", &GetCodec());');
-      indent.dec();
-      indent.dec();
-      indent.write(
-          '$channel->Send($sendArgument, [callback](const uint8_t* reply, size_t reply_size) ');
-      indent.scoped('{', '});', () {
-        if (func.returnType.isVoid) {
-          indent.writeln('callback();');
-        } else {
-          indent.writeln(
-              'std::unique_ptr<flutter::EncodableValue> decoded_reply = GetCodec().DecodeMessage(reply, reply_size);');
-          indent.writeln(
-              'flutter::EncodableValue args = *(flutter::EncodableValue*)(decoded_reply.release());');
-          const String output = 'output';
-
-          final bool isBuiltin =
-              _baseCppTypeForBuiltinDartType(func.returnType) != null;
-          final String returnTypeName =
-              _baseCppTypeForDartType(func.returnType);
-          if (func.returnType.isNullable) {
-            indent.writeln('$returnType $output{};');
+    for (final Method func in api.methods) {
+      final String channelName = makeChannelName(api, func);
+      final String returnType = func.returnType.isVoid
+          ? 'void'
+          : _nullSafeCppTypeForDartType(func.returnType);
+      String sendArgument;
+      final String callback = 'std::function<void($returnType)>&& callback';
+      if (func.arguments.isEmpty) {
+        indent.write('void ${api.name}::${func.name}($callback) ');
+        sendArgument = 'flutter::EncodableValue()';
+      } else {
+        final Iterable<String> argTypes = func.arguments
+            .map((NamedType e) => _nullSafeCppTypeForDartType(e.type));
+        final Iterable<String> argNames =
+            indexMap(func.arguments, _getSafeArgumentName);
+        sendArgument =
+            'flutter::EncodableList { ${argNames.map((String arg) => 'flutter::CustomEncodableValue($arg)').join(', ')} }';
+        final String argsSignature =
+            map2(argTypes, argNames, (String x, String y) => '$x $y')
+                .join(', ');
+        indent.write(
+            'void ${api.name}::${func.name}($argsSignature, $callback) ');
+      }
+      indent.scoped('{', '}', () {
+        const String channel = 'channel';
+        indent.writeln(
+            'auto channel = std::make_unique<flutter::BasicMessageChannel<flutter::EncodableValue>>(');
+        indent.inc();
+        indent.inc();
+        indent.writeln('binary_messenger_, "$channelName", &GetCodec());');
+        indent.dec();
+        indent.dec();
+        indent.write(
+            '$channel->Send($sendArgument, [callback](const uint8_t* reply, size_t reply_size) ');
+        indent.scoped('{', '});', () {
+          if (func.returnType.isVoid) {
+            indent.writeln('callback();');
           } else {
-            indent.writeln('$returnTypeName $output{};');
-          }
-          const String pointerVariable = '${_pointerPrefix}_$output';
-          if (func.returnType.baseName == 'int') {
-            indent.format('''
+            indent.writeln(
+                'std::unique_ptr<flutter::EncodableValue> decoded_reply = GetCodec().DecodeMessage(reply, reply_size);');
+            indent.writeln(
+                'flutter::EncodableValue args = *(flutter::EncodableValue*)(decoded_reply.release());');
+            const String output = 'output';
+
+            final bool isBuiltin =
+                _baseCppTypeForBuiltinDartType(func.returnType) != null;
+            final String returnTypeName =
+                _baseCppTypeForDartType(func.returnType);
+            if (func.returnType.isNullable) {
+              indent.writeln('$returnType $output{};');
+            } else {
+              indent.writeln('$returnTypeName $output{};');
+            }
+            const String pointerVariable = '${_pointerPrefix}_$output';
+            if (func.returnType.baseName == 'int') {
+              indent.format('''
 if (const int32_t* $pointerVariable = std::get_if<int32_t>(&args))
 \t$output = *$pointerVariable;
 else if (const int64_t* ${pointerVariable}_64 = std::get_if<int64_t>(&args))
 \t$output = *${pointerVariable}_64;''');
-          } else if (!isBuiltin) {
-            indent.write(
-                'if (const flutter::EncodableList* $pointerVariable = std::get_if<flutter::EncodableList>(&args)) ');
-            indent.scoped('{', '}', () {
-              indent.writeln('$output = $returnTypeName(*$pointerVariable);');
-            });
-          } else {
-            indent.write(
-                'if (const $returnTypeName* $pointerVariable = std::get_if<$returnTypeName>(&args)) ');
-            indent.scoped('{', '}', () {
-              indent.writeln('$output = *$pointerVariable;');
-            });
-          }
+            } else if (!isBuiltin) {
+              indent.write(
+                  'if (const flutter::EncodableList* $pointerVariable = std::get_if<flutter::EncodableList>(&args)) ');
+              indent.scoped('{', '}', () {
+                indent.writeln('$output = $returnTypeName(*$pointerVariable);');
+              });
+            } else {
+              indent.write(
+                  'if (const $returnTypeName* $pointerVariable = std::get_if<$returnTypeName>(&args)) ');
+              indent.scoped('{', '}', () {
+                indent.writeln('$output = *$pointerVariable;');
+              });
+            }
 
-          indent.writeln('callback($output);');
-        }
+            indent.writeln('callback($output);');
+          }
+        });
       });
-    });
+    }
   }
 }
 
+String _getCodecSerializerName(Api api) => '${api.name}CodecSerializer';
+
+const String _pointerPrefix = 'pointer';
+const String _encodablePrefix = 'encodable';
+
+String _getArgumentName(int count, NamedType argument) =>
+    argument.name.isEmpty ? 'arg$count' : _makeVariableName(argument);
+
+/// Returns an argument name that can be used in a context where it is possible to collide.
+String _getSafeArgumentName(int count, NamedType argument) =>
+    '${_getArgumentName(count, argument)}_arg';
+
 /// Returns a non-nullable variant of [type].
 HostDatatype _nonNullableType(HostDatatype type) {
   return HostDatatype(
@@ -1287,69 +1383,6 @@ void _writeSystemHeaderIncludeBlock(Indent indent, List<String> headers) {
   }
 }
 
-/// Generates the ".h" file for the AST represented by [root] to [sink] with the
-/// provided [options] and [headerFileName].
-void generateCppHeader(
-    CppOptions options, Root root, StringSink sink, Indent indent) {
-  for (final Api api in root.apis) {
-    if (getCodecClasses(api, root).isNotEmpty) {
-      _writeCodecHeader(indent, api, root);
-    }
-    indent.addln('');
-    if (api.location == ApiLocation.host) {
-      _writeHostApiHeader(indent, api, root);
-    } else if (api.location == ApiLocation.flutter) {
-      _writeFlutterApiHeader(indent, api);
-    }
-  }
-
-  if (options.namespace != null) {
-    indent.writeln('}  // namespace ${options.namespace}');
-  }
-  final String guardName =
-      _getGuardName(options.headerIncludePath, options.namespace);
-  indent.writeln('#endif  // $guardName');
-}
-
-/// Generates the ".cpp" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateCppSource(
-    CppOptions options, Root root, StringSink sink, Indent indent) {
-  for (final Api api in root.apis) {
-    if (getCodecClasses(api, root).isNotEmpty) {
-      _writeCodecSource(indent, api, root);
-      indent.addln('');
-    }
-    if (api.location == ApiLocation.host) {
-      _writeHostApiSource(indent, api, root);
-
-      indent.addln('');
-      indent.format('''
-flutter::EncodableList ${api.name}::WrapError(std::string_view error_message) {
-\treturn flutter::EncodableList({
-\t\tflutter::EncodableValue(std::string(error_message)),
-\t\tflutter::EncodableValue("Error"),
-\t\tflutter::EncodableValue()
-\t});
-}
-flutter::EncodableList ${api.name}::WrapError(const FlutterError& error) {
-\treturn flutter::EncodableList({
-\t\tflutter::EncodableValue(error.message()),
-\t\tflutter::EncodableValue(error.code()),
-\t\terror.details()
-\t});
-}''');
-      indent.addln('');
-    } else if (api.location == ApiLocation.flutter) {
-      _writeFlutterApiSource(indent, api, root);
-    }
-  }
-
-  if (options.namespace != null) {
-    indent.writeln('}  // namespace ${options.namespace}');
-  }
-}
-
 /// Validates an AST to make sure the cpp generator supports everything.
 List<Error> validateCpp(CppOptions options, Root root) {
   final List<Error> result = <Error>[];

From 3038ae0f33b6f15347b4d24679876d0324ee751d Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Sat, 7 Jan 2023 01:06:14 -0800
Subject: [PATCH 68/87] objc

---
 packages/pigeon/lib/cpp_generator.dart  |   8 +-
 packages/pigeon/lib/objc_generator.dart | 714 ++++++++++++------------
 2 files changed, 377 insertions(+), 345 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 71e02b42191..313c993ed64 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -79,7 +79,6 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
   @override
   void generate(OutputFileOptions<CppOptions> generatorOptions, Root root,
       StringSink sink) {
-    final FileType fileType = generatorOptions.fileType;
     assert(generatorOptions.fileType == FileType.header ||
         generatorOptions.fileType == FileType.source);
 
@@ -100,8 +99,10 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
     }
 
     for (final Api api in root.apis) {
-      _writeCodec(generatorOptions, root, sink, indent, api);
-      indent.addln('');
+      if (getCodecClasses(api, root).isNotEmpty) {
+        _writeCodec(generatorOptions, root, sink, indent, api);
+        indent.addln('');
+      }
       if (api.location == ApiLocation.host) {
         writeHostApi(generatorOptions, root, sink, indent, api);
       } else if (api.location == ApiLocation.flutter) {
@@ -587,6 +588,7 @@ $friendLines
         }
       });
     }, nestCount: 0);
+    indent.writeln('');
   }
 
   // Source methods.
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 766917e1b1b..e09e3dbe2e8 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -105,10 +105,29 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
       writeDataClass(generatorOptions, root, sink, indent, klass);
     }
 
+    indent.writeln('');
+
+    for (final Api api in root.apis) {
+      if (generatorOptions.fileType == FileType.source) {
+        final String codecName =
+            _getCodecName(generatorOptions.languageOptions.prefix, api.name);
+        if (getCodecClasses(api, root).isNotEmpty) {
+          _writeCodec(
+              indent, codecName, generatorOptions.languageOptions, api, root);
+          indent.addln('');
+        }
+        _writeCodecGetter(
+            indent, codecName, generatorOptions.languageOptions, api, root);
+        indent.addln('');
+      }
+      if (api.location == ApiLocation.host) {
+        writeHostApi(generatorOptions, root, sink, indent, api);
+      } else if (api.location == ApiLocation.flutter) {
+        writeFlutterApi(generatorOptions, root, sink, indent, api);
+      }
+    }
     if (generatorOptions.fileType == FileType.header) {
-      generateObjcHeader(generatorOptions.languageOptions, root, sink, indent);
-    } else {
-      generateObjcSource(generatorOptions.languageOptions, root, sink, indent);
+      indent.writeln('NS_ASSUME_NONNULL_END');
     }
   }
 
@@ -196,6 +215,39 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
     }
   }
 
+  @override
+  void writeFlutterApi(
+    OutputFileOptions<ObjcOptions> generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    if (generatorOptions.fileType == FileType.header) {
+      _writeFlutterApiDeclaration(
+          indent, api, generatorOptions.languageOptions, root);
+    } else {
+      _writeFlutterApiSource(
+          indent, generatorOptions.languageOptions, api, root);
+    }
+  }
+
+  @override
+  void writeHostApi(
+    OutputFileOptions<ObjcOptions> generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    if (generatorOptions.fileType == FileType.header) {
+      _writeHostApiDeclaration(
+          indent, api, generatorOptions.languageOptions, root);
+    } else {
+      _writeHostApiSource(indent, generatorOptions.languageOptions, api, root);
+    }
+  }
+
   // Header File Methods.
 
   /// Writes Objc header file header to sink.
@@ -296,6 +348,118 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
     indent.writeln('');
   }
 
+  /// Writes the declaration for an host [Api].
+  ///
+  /// Example:
+  /// @protocol Foo
+  /// - (NSInteger)add:(NSInteger)x to:(NSInteger)y error:(NSError**)error;
+  /// @end
+  ///
+  /// extern void FooSetup(id<FlutterBinaryMessenger> binaryMessenger, NSObject<Foo> *_Nullable api);
+  void _writeHostApiDeclaration(
+      Indent indent, Api api, ObjcOptions options, Root root) {
+    indent.writeln(
+        '$_docCommentPrefix The codec used by ${_className(options.prefix, api.name)}.');
+    indent.writeln(
+        'NSObject<FlutterMessageCodec> *${_getCodecGetterName(options.prefix, api.name)}(void);');
+    indent.addln('');
+    final String apiName = _className(options.prefix, api.name);
+    addDocumentationComments(
+        indent, api.documentationComments, _docCommentSpec);
+
+    indent.writeln('@protocol $apiName');
+    for (final Method func in api.methods) {
+      final _ObjcPtr returnTypeName =
+          _objcTypeForDartType(options.prefix, func.returnType);
+
+      String? lastArgName;
+      String? lastArgType;
+      String? returnType;
+      if (func.isAsynchronous) {
+        returnType = 'void';
+        if (func.returnType.isVoid) {
+          lastArgType = 'void(^)(FlutterError *_Nullable)';
+          lastArgName = 'completion';
+        } else {
+          lastArgType =
+              'void(^)(${returnTypeName.ptr}_Nullable, FlutterError *_Nullable)';
+          lastArgName = 'completion';
+        }
+      } else {
+        returnType = func.returnType.isVoid
+            ? 'void'
+            : 'nullable ${returnTypeName.ptr.trim()}';
+        lastArgType = 'FlutterError *_Nullable *_Nonnull';
+        lastArgName = 'error';
+      }
+      final List<String> generatorComments = <String>[];
+      if (!func.returnType.isNullable &&
+          !func.returnType.isVoid &&
+          !func.isAsynchronous) {
+        generatorComments.add(' @return `nil` only when `error != nil`.');
+      }
+      addDocumentationComments(
+          indent, func.documentationComments, _docCommentSpec,
+          generatorComments: generatorComments);
+
+      final String signature = _makeObjcSignature(
+        func: func,
+        options: options,
+        returnType: returnType,
+        lastArgName: lastArgName,
+        lastArgType: lastArgType,
+        isEnum: (TypeDeclaration t) => isEnum(root, t),
+      );
+      indent.writeln('$signature;');
+    }
+    indent.writeln('@end');
+    indent.writeln('');
+    indent.writeln(
+        'extern void ${apiName}Setup(id<FlutterBinaryMessenger> binaryMessenger, NSObject<$apiName> *_Nullable api);');
+    indent.writeln('');
+  }
+
+  /// Writes the declaration for an flutter [Api].
+  ///
+  /// Example:
+  ///
+  /// @interface Foo : NSObject
+  /// - (instancetype)initWithBinaryMessenger:(id<FlutterBinaryMessenger>)binaryMessenger;
+  /// - (void)add:(NSInteger)x to:(NSInteger)y completion:(void(^)(NSError *, NSInteger result)completion;
+  /// @end
+  void _writeFlutterApiDeclaration(
+      Indent indent, Api api, ObjcOptions options, Root root) {
+    indent.writeln(
+        '$_docCommentPrefix The codec used by ${_className(options.prefix, api.name)}.');
+    indent.writeln(
+        'NSObject<FlutterMessageCodec> *${_getCodecGetterName(options.prefix, api.name)}(void);');
+    indent.addln('');
+    final String apiName = _className(options.prefix, api.name);
+    addDocumentationComments(
+        indent, api.documentationComments, _docCommentSpec);
+
+    indent.writeln('@interface $apiName : NSObject');
+    indent.writeln(
+        '- (instancetype)initWithBinaryMessenger:(id<FlutterBinaryMessenger>)binaryMessenger;');
+    for (final Method func in api.methods) {
+      final _ObjcPtr returnType =
+          _objcTypeForDartType(options.prefix, func.returnType);
+      final String callbackType = _callbackForType(func.returnType, returnType);
+      addDocumentationComments(
+          indent, func.documentationComments, _docCommentSpec);
+
+      indent.writeln('${_makeObjcSignature(
+        func: func,
+        options: options,
+        returnType: 'void',
+        lastArgName: 'completion',
+        lastArgType: callbackType,
+        isEnum: (TypeDeclaration t) => isEnum(root, t),
+      )};');
+    }
+    indent.writeln('@end');
+  }
+
   // Source File Methods.
 
   /// Writes Objc Source file header to sink.
@@ -453,6 +617,138 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
       });
     });
   }
+
+  /// Writes the method declaration for the initializer.
+  ///
+  /// Example '+ (instancetype)makeWithFoo:(NSString *)foo'
+  void _writeObjcSourceClassInitializerDeclaration(Indent indent, Class klass,
+      List<Class> classes, List<Enum> enums, String? prefix) {
+    final List<String> customEnumNames = enums.map((Enum x) => x.name).toList();
+    indent.write('+ (instancetype)makeWith');
+    bool isFirst = true;
+    indent.nest(2, () {
+      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+        final String label = isFirst ? _capitalize(field.name) : field.name;
+        final void Function(String) printer = isFirst
+            ? indent.add
+            : (String x) {
+                indent.addln('');
+                indent.write(x);
+              };
+        isFirst = false;
+        final HostDatatype hostDatatype = getFieldHostDatatype(
+            field,
+            classes,
+            enums,
+            (TypeDeclaration x) => _objcTypePtrForPrimitiveDartType(prefix, x),
+            customResolver: customEnumNames.contains(field.type.baseName)
+                ? (String x) => _className(prefix, x)
+                : (String x) => '${_className(prefix, x)} *');
+        final String nullable =
+            _isNullable(hostDatatype, field.type) ? 'nullable ' : '';
+        printer('$label:($nullable${hostDatatype.datatype})${field.name}');
+      }
+    });
+  }
+
+  /// Writes the codec that will be used for encoding messages for the [api].
+  ///
+  /// Example:
+  /// @interface FooHostApiCodecReader : FlutterStandardReader
+  /// ...
+  /// @interface FooHostApiCodecWriter : FlutterStandardWriter
+  /// ...
+  /// @interface FooHostApiCodecReaderWriter : FlutterStandardReaderWriter
+  /// ...
+  /// NSObject<FlutterMessageCodec> *FooHostApiCodecGetCodec() {...}
+  void _writeCodec(
+      Indent indent, String name, ObjcOptions options, Api api, Root root) {
+    assert(getCodecClasses(api, root).isNotEmpty);
+    final Iterable<EnumeratedClass> codecClasses = getCodecClasses(api, root);
+    final String readerWriterName = '${name}ReaderWriter';
+    final String readerName = '${name}Reader';
+    final String writerName = '${name}Writer';
+    indent.writeln('@interface $readerName : FlutterStandardReader');
+    indent.writeln('@end');
+    indent.writeln('@implementation $readerName');
+    indent.writeln('- (nullable id)readValueOfType:(UInt8)type ');
+    indent.scoped('{', '}', () {
+      indent.write('switch (type) ');
+      indent.scoped('{', '}', () {
+        for (final EnumeratedClass customClass in codecClasses) {
+          indent.write('case ${customClass.enumeration}: ');
+          indent.writeScoped('', '', () {
+            indent.writeln(
+                'return [${_className(options.prefix, customClass.name)} fromList:[self readValue]];');
+          });
+        }
+        indent.write('default:');
+        indent.writeScoped('', '', () {
+          indent.writeln('return [super readValueOfType:type];');
+        });
+      });
+    });
+    indent.writeln('@end');
+    indent.addln('');
+    indent.writeln('@interface $writerName : FlutterStandardWriter');
+    indent.writeln('@end');
+    indent.writeln('@implementation $writerName');
+    indent.writeln('- (void)writeValue:(id)value ');
+    indent.scoped('{', '}', () {
+      for (final EnumeratedClass customClass in codecClasses) {
+        indent.write(
+            'if ([value isKindOfClass:[${_className(options.prefix, customClass.name)} class]]) ');
+        indent.scoped('{', '} else ', () {
+          indent.writeln('[self writeByte:${customClass.enumeration}];');
+          indent.writeln('[self writeValue:[value toList]];');
+        });
+      }
+      indent.scoped('{', '}', () {
+        indent.writeln('[super writeValue:value];');
+      });
+    });
+    indent.writeln('@end');
+    indent.addln('');
+    indent.format('''
+@interface $readerWriterName : FlutterStandardReaderWriter
+@end
+@implementation $readerWriterName
+- (FlutterStandardWriter *)writerWithData:(NSMutableData *)data {
+\treturn [[$writerName alloc] initWithData:data];
+}
+- (FlutterStandardReader *)readerWithData:(NSData *)data {
+\treturn [[$readerName alloc] initWithData:data];
+}
+@end
+''');
+  }
+
+  void _writeCodecGetter(
+      Indent indent, String name, ObjcOptions options, Api api, Root root) {
+    final String readerWriterName = '${name}ReaderWriter';
+
+    indent.write(
+        'NSObject<FlutterMessageCodec> *${_getCodecGetterName(options.prefix, api.name)}() ');
+    indent.scoped('{', '}', () {
+      indent
+          .writeln('static FlutterStandardMessageCodec *sSharedObject = nil;');
+      if (getCodecClasses(api, root).isNotEmpty) {
+        indent.writeln('static dispatch_once_t sPred = 0;');
+        indent.write('dispatch_once(&sPred, ^');
+        indent.scoped('{', '});', () {
+          indent.writeln(
+              '$readerWriterName *readerWriter = [[$readerWriterName alloc] init];');
+          indent.writeln(
+              'sSharedObject = [FlutterStandardMessageCodec codecWithReaderWriter:readerWriter];');
+        });
+      } else {
+        indent.writeln(
+            'sSharedObject = [FlutterStandardMessageCodec sharedInstance];');
+      }
+
+      indent.writeln('return sSharedObject;');
+    });
+  }
 }
 
 /// Calculates the ObjC class name, possibly prefixed.
@@ -551,39 +847,6 @@ String _propertyTypeForDartType(NamedType field) {
 bool _isNullable(HostDatatype hostDatatype, TypeDeclaration type) =>
     hostDatatype.datatype.contains('*') && type.isNullable;
 
-/// Writes the method declaration for the initializer.
-///
-/// Example '+ (instancetype)makeWithFoo:(NSString *)foo'
-void _writeObjcSourceClassInitializerDeclaration(Indent indent, Class klass,
-    List<Class> classes, List<Enum> enums, String? prefix) {
-  final List<String> customEnumNames = enums.map((Enum x) => x.name).toList();
-  indent.write('+ (instancetype)makeWith');
-  bool isFirst = true;
-  indent.nest(2, () {
-    for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-      final String label = isFirst ? _capitalize(field.name) : field.name;
-      final void Function(String) printer = isFirst
-          ? indent.add
-          : (String x) {
-              indent.addln('');
-              indent.write(x);
-            };
-      isFirst = false;
-      final HostDatatype hostDatatype = getFieldHostDatatype(
-          field,
-          classes,
-          enums,
-          (TypeDeclaration x) => _objcTypePtrForPrimitiveDartType(prefix, x),
-          customResolver: customEnumNames.contains(field.type.baseName)
-              ? (String x) => _className(prefix, x)
-              : (String x) => '${_className(prefix, x)} *');
-      final String nullable =
-          _isNullable(hostDatatype, field.type) ? 'nullable ' : '';
-      printer('$label:($nullable${hostDatatype.datatype})${field.name}');
-    }
-  });
-}
-
 /// Generates the name of the codec that will be generated.
 String _getCodecName(String? prefix, String className) =>
     '${_className(prefix, className)}Codec';
@@ -593,104 +856,6 @@ String _getCodecName(String? prefix, String className) =>
 String _getCodecGetterName(String? prefix, String className) =>
     '${_className(prefix, className)}GetCodec';
 
-/// Writes the codec that will be used for encoding messages for the [api].
-///
-/// Example:
-/// @interface FooHostApiCodecReader : FlutterStandardReader
-/// ...
-/// @interface FooHostApiCodecWriter : FlutterStandardWriter
-/// ...
-/// @interface FooHostApiCodecReaderWriter : FlutterStandardReaderWriter
-/// ...
-/// NSObject<FlutterMessageCodec> *FooHostApiCodecGetCodec() {...}
-void _writeCodec(
-    Indent indent, String name, ObjcOptions options, Api api, Root root) {
-  assert(getCodecClasses(api, root).isNotEmpty);
-  final Iterable<EnumeratedClass> codecClasses = getCodecClasses(api, root);
-  final String readerWriterName = '${name}ReaderWriter';
-  final String readerName = '${name}Reader';
-  final String writerName = '${name}Writer';
-  indent.writeln('@interface $readerName : FlutterStandardReader');
-  indent.writeln('@end');
-  indent.writeln('@implementation $readerName');
-  indent.writeln('- (nullable id)readValueOfType:(UInt8)type ');
-  indent.scoped('{', '}', () {
-    indent.write('switch (type) ');
-    indent.scoped('{', '}', () {
-      for (final EnumeratedClass customClass in codecClasses) {
-        indent.write('case ${customClass.enumeration}: ');
-        indent.writeScoped('', '', () {
-          indent.writeln(
-              'return [${_className(options.prefix, customClass.name)} fromList:[self readValue]];');
-        });
-      }
-      indent.write('default:');
-      indent.writeScoped('', '', () {
-        indent.writeln('return [super readValueOfType:type];');
-      });
-    });
-  });
-  indent.writeln('@end');
-  indent.addln('');
-  indent.writeln('@interface $writerName : FlutterStandardWriter');
-  indent.writeln('@end');
-  indent.writeln('@implementation $writerName');
-  indent.writeln('- (void)writeValue:(id)value ');
-  indent.scoped('{', '}', () {
-    for (final EnumeratedClass customClass in codecClasses) {
-      indent.write(
-          'if ([value isKindOfClass:[${_className(options.prefix, customClass.name)} class]]) ');
-      indent.scoped('{', '} else ', () {
-        indent.writeln('[self writeByte:${customClass.enumeration}];');
-        indent.writeln('[self writeValue:[value toList]];');
-      });
-    }
-    indent.scoped('{', '}', () {
-      indent.writeln('[super writeValue:value];');
-    });
-  });
-  indent.writeln('@end');
-  indent.addln('');
-  indent.format('''
-@interface $readerWriterName : FlutterStandardReaderWriter
-@end
-@implementation $readerWriterName
-- (FlutterStandardWriter *)writerWithData:(NSMutableData *)data {
-\treturn [[$writerName alloc] initWithData:data];
-}
-- (FlutterStandardReader *)readerWithData:(NSData *)data {
-\treturn [[$readerName alloc] initWithData:data];
-}
-@end
-''');
-}
-
-void _writeCodecGetter(
-    Indent indent, String name, ObjcOptions options, Api api, Root root) {
-  final String readerWriterName = '${name}ReaderWriter';
-
-  indent.write(
-      'NSObject<FlutterMessageCodec> *${_getCodecGetterName(options.prefix, api.name)}() ');
-  indent.scoped('{', '}', () {
-    indent.writeln('static FlutterStandardMessageCodec *sSharedObject = nil;');
-    if (getCodecClasses(api, root).isNotEmpty) {
-      indent.writeln('static dispatch_once_t sPred = 0;');
-      indent.write('dispatch_once(&sPred, ^');
-      indent.scoped('{', '});', () {
-        indent.writeln(
-            '$readerWriterName *readerWriter = [[$readerWriterName alloc] init];');
-        indent.writeln(
-            'sSharedObject = [FlutterStandardMessageCodec codecWithReaderWriter:readerWriter];');
-      });
-    } else {
-      indent.writeln(
-          'sSharedObject = [FlutterStandardMessageCodec sharedInstance];');
-    }
-
-    indent.writeln('return sSharedObject;');
-  });
-}
-
 String _capitalize(String str) =>
     (str.isEmpty) ? '' : str[0].toUpperCase() + str.substring(1);
 
@@ -770,127 +935,10 @@ String _makeObjcSignature({
   return '- ($returnType)$argSignature';
 }
 
-/// Writes the declaration for an host [Api].
-///
-/// Example:
-/// @protocol Foo
-/// - (NSInteger)add:(NSInteger)x to:(NSInteger)y error:(NSError**)error;
-/// @end
-///
-/// extern void FooSetup(id<FlutterBinaryMessenger> binaryMessenger, NSObject<Foo> *_Nullable api);
-void _writeHostApiDeclaration(
-    Indent indent, Api api, ObjcOptions options, Root root) {
-  final String apiName = _className(options.prefix, api.name);
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec);
-
-  indent.writeln('@protocol $apiName');
-  for (final Method func in api.methods) {
-    final _ObjcPtr returnTypeName =
-        _objcTypeForDartType(options.prefix, func.returnType);
-
-    String? lastArgName;
-    String? lastArgType;
-    String? returnType;
-    if (func.isAsynchronous) {
-      returnType = 'void';
-      if (func.returnType.isVoid) {
-        lastArgType = 'void(^)(FlutterError *_Nullable)';
-        lastArgName = 'completion';
-      } else {
-        lastArgType =
-            'void(^)(${returnTypeName.ptr}_Nullable, FlutterError *_Nullable)';
-        lastArgName = 'completion';
-      }
-    } else {
-      returnType = func.returnType.isVoid
-          ? 'void'
-          : 'nullable ${returnTypeName.ptr.trim()}';
-      lastArgType = 'FlutterError *_Nullable *_Nonnull';
-      lastArgName = 'error';
-    }
-    final List<String> generatorComments = <String>[];
-    if (!func.returnType.isNullable &&
-        !func.returnType.isVoid &&
-        !func.isAsynchronous) {
-      generatorComments.add(' @return `nil` only when `error != nil`.');
-    }
-    addDocumentationComments(
-        indent, func.documentationComments, _docCommentSpec,
-        generatorComments: generatorComments);
-
-    final String signature = _makeObjcSignature(
-      func: func,
-      options: options,
-      returnType: returnType,
-      lastArgName: lastArgName,
-      lastArgType: lastArgType,
-      isEnum: (TypeDeclaration t) => isEnum(root, t),
-    );
-    indent.writeln('$signature;');
-  }
-  indent.writeln('@end');
-  indent.writeln('');
-  indent.writeln(
-      'extern void ${apiName}Setup(id<FlutterBinaryMessenger> binaryMessenger, NSObject<$apiName> *_Nullable api);');
-  indent.writeln('');
-}
-
-/// Writes the declaration for an flutter [Api].
-///
-/// Example:
-///
-/// @interface Foo : NSObject
-/// - (instancetype)initWithBinaryMessenger:(id<FlutterBinaryMessenger>)binaryMessenger;
-/// - (void)add:(NSInteger)x to:(NSInteger)y completion:(void(^)(NSError *, NSInteger result)completion;
-/// @end
-void _writeFlutterApiDeclaration(
-    Indent indent, Api api, ObjcOptions options, Root root) {
-  final String apiName = _className(options.prefix, api.name);
-  addDocumentationComments(indent, api.documentationComments, _docCommentSpec);
-
-  indent.writeln('@interface $apiName : NSObject');
-  indent.writeln(
-      '- (instancetype)initWithBinaryMessenger:(id<FlutterBinaryMessenger>)binaryMessenger;');
-  for (final Method func in api.methods) {
-    final _ObjcPtr returnType =
-        _objcTypeForDartType(options.prefix, func.returnType);
-    final String callbackType = _callbackForType(func.returnType, returnType);
-    addDocumentationComments(
-        indent, func.documentationComments, _docCommentSpec);
-
-    indent.writeln('${_makeObjcSignature(
-      func: func,
-      options: options,
-      returnType: 'void',
-      lastArgName: 'completion',
-      lastArgType: callbackType,
-      isEnum: (TypeDeclaration t) => isEnum(root, t),
-    )};');
-  }
-  indent.writeln('@end');
-}
-
 /// Generates the ".h" file for the AST represented by [root] to [sink] with the
 /// provided [options].
 void generateObjcHeader(
-    ObjcOptions options, Root root, StringSink sink, Indent indent) {
-  indent.writeln('');
-
-  for (final Api api in root.apis) {
-    indent.writeln(
-        '$_docCommentPrefix The codec used by ${_className(options.prefix, api.name)}.');
-    indent.writeln(
-        'NSObject<FlutterMessageCodec> *${_getCodecGetterName(options.prefix, api.name)}(void);');
-    indent.addln('');
-    if (api.location == ApiLocation.host) {
-      _writeHostApiDeclaration(indent, api, options, root);
-    } else if (api.location == ApiLocation.flutter) {
-      _writeFlutterApiDeclaration(indent, api, options, root);
-    }
-  }
-
-  indent.writeln('NS_ASSUME_NONNULL_END');
-}
+    ObjcOptions options, Root root, StringSink sink, Indent indent) {}
 
 String _listGetter(Set<String> customClassNames, String list, NamedType field,
     int index, String? prefix) {
@@ -1078,105 +1126,87 @@ void _writeHostApiSource(
 /// Writes the definition code for a flutter [Api].
 /// See also: [_writeFlutterApiDeclaration]
 void _writeFlutterApiSource(
-    Indent indent, ObjcOptions options, Api api, Root root) {
+    Indent indent, ObjcOptions languageOptions, Api api, Root root) {
   assert(api.location == ApiLocation.flutter);
-  final String apiName = _className(options.prefix, api.name);
-
-  void writeExtension() {
-    indent.writeln('@interface $apiName ()');
-    indent.writeln(
-        '@property (nonatomic, strong) NSObject<FlutterBinaryMessenger> *binaryMessenger;');
-    indent.writeln('@end');
-  }
-
-  void writeInitializer() {
-    indent.write(
-        '- (instancetype)initWithBinaryMessenger:(NSObject<FlutterBinaryMessenger> *)binaryMessenger ');
-    indent.scoped('{', '}', () {
-      indent.writeln('self = [super init];');
-      indent.write('if (self) ');
-      indent.scoped('{', '}', () {
-        indent.writeln('_binaryMessenger = binaryMessenger;');
-      });
-      indent.writeln('return self;');
-    });
-  }
+  final String apiName = _className(languageOptions.prefix, api.name);
 
-  void writeMethod(Method func) {
-    final _ObjcPtr returnType =
-        _objcTypeForDartType(options.prefix, func.returnType);
-    final String callbackType = _callbackForType(func.returnType, returnType);
-
-    String argNameFunc(int count, NamedType arg) => _getSafeArgName(count, arg);
-    final Iterable<String> argNames = indexMap(func.arguments, argNameFunc);
-    String sendArgument;
-    if (func.arguments.isEmpty) {
-      sendArgument = 'nil';
-    } else {
-      String makeVarOrNSNullExpression(String x) => '$x ?: [NSNull null]';
-      sendArgument = '@[${argNames.map(makeVarOrNSNullExpression).join(', ')}]';
-    }
-    indent.write(_makeObjcSignature(
-      func: func,
-      options: options,
-      returnType: 'void',
-      lastArgName: 'completion',
-      lastArgType: callbackType,
-      argNameFunc: argNameFunc,
-      isEnum: (TypeDeclaration t) => isEnum(root, t),
-    ));
-    indent.scoped(' {', '}', () {
-      indent.writeln('FlutterBasicMessageChannel *channel =');
-      indent.inc();
-      indent.writeln('[FlutterBasicMessageChannel');
-      indent.inc();
-      indent.writeln('messageChannelWithName:@"${makeChannelName(api, func)}"');
-      indent.writeln('binaryMessenger:self.binaryMessenger');
-      indent.write('codec:${_getCodecGetterName(options.prefix, api.name)}()');
-      indent.addln('];');
-      indent.dec();
-      indent.dec();
-      indent.write('[channel sendMessage:$sendArgument reply:^(id reply) ');
-      indent.scoped('{', '}];', () {
-        if (func.returnType.isVoid) {
-          indent.writeln('completion(nil);');
-        } else {
-          indent.writeln('${returnType.ptr}output = reply;');
-          indent.writeln('completion(output, nil);');
-        }
-      });
-    });
-  }
-
-  writeExtension();
+  _writeExtension(indent, apiName);
   indent.addln('');
   indent.writeln('@implementation $apiName');
   indent.addln('');
-  writeInitializer();
-  api.methods.forEach(writeMethod);
+  _writeInitializer(indent);
+  for (final Method func in api.methods) {
+    _writeMethod(languageOptions, root, indent, api, func);
+  }
   indent.writeln('@end');
 }
 
-/// Generates the ".m" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateObjcSource(
-    ObjcOptions options, Root root, StringSink sink, Indent indent) {
-  void writeApi(Api api) {
-    final String codecName = _getCodecName(options.prefix, api.name);
-    if (getCodecClasses(api, root).isNotEmpty) {
-      _writeCodec(indent, codecName, options, api, root);
-      indent.addln('');
-    }
-    _writeCodecGetter(indent, codecName, options, api, root);
-    indent.addln('');
-    if (api.location == ApiLocation.host) {
-      _writeHostApiSource(indent, options, api, root);
-    } else if (api.location == ApiLocation.flutter) {
-      _writeFlutterApiSource(indent, options, api, root);
-    }
-  }
+void _writeExtension(Indent indent, String apiName) {
+  indent.writeln('@interface $apiName ()');
+  indent.writeln(
+      '@property (nonatomic, strong) NSObject<FlutterBinaryMessenger> *binaryMessenger;');
+  indent.writeln('@end');
+}
+
+void _writeInitializer(Indent indent) {
+  indent.write(
+      '- (instancetype)initWithBinaryMessenger:(NSObject<FlutterBinaryMessenger> *)binaryMessenger ');
+  indent.scoped('{', '}', () {
+    indent.writeln('self = [super init];');
+    indent.write('if (self) ');
+    indent.scoped('{', '}', () {
+      indent.writeln('_binaryMessenger = binaryMessenger;');
+    });
+    indent.writeln('return self;');
+  });
+}
 
-  root.apis.forEach(writeApi);
+void _writeMethod(ObjcOptions languageOptions, Root root, Indent indent,
+    Api api, Method func) {
+  final _ObjcPtr returnType =
+      _objcTypeForDartType(languageOptions.prefix, func.returnType);
+  final String callbackType = _callbackForType(func.returnType, returnType);
+
+  String argNameFunc(int count, NamedType arg) => _getSafeArgName(count, arg);
+  final Iterable<String> argNames = indexMap(func.arguments, argNameFunc);
+  String sendArgument;
+  if (func.arguments.isEmpty) {
+    sendArgument = 'nil';
+  } else {
+    String makeVarOrNSNullExpression(String x) => '$x ?: [NSNull null]';
+    sendArgument = '@[${argNames.map(makeVarOrNSNullExpression).join(', ')}]';
+  }
+  indent.write(_makeObjcSignature(
+    func: func,
+    options: languageOptions,
+    returnType: 'void',
+    lastArgName: 'completion',
+    lastArgType: callbackType,
+    argNameFunc: argNameFunc,
+    isEnum: (TypeDeclaration t) => isEnum(root, t),
+  ));
+  indent.scoped(' {', '}', () {
+    indent.writeln('FlutterBasicMessageChannel *channel =');
+    indent.inc();
+    indent.writeln('[FlutterBasicMessageChannel');
+    indent.inc();
+    indent.writeln('messageChannelWithName:@"${makeChannelName(api, func)}"');
+    indent.writeln('binaryMessenger:self.binaryMessenger');
+    indent.write(
+        'codec:${_getCodecGetterName(languageOptions.prefix, api.name)}()');
+    indent.addln('];');
+    indent.dec();
+    indent.dec();
+    indent.write('[channel sendMessage:$sendArgument reply:^(id reply) ');
+    indent.scoped('{', '}];', () {
+      if (func.returnType.isVoid) {
+        indent.writeln('completion(nil);');
+      } else {
+        indent.writeln('${returnType.ptr}output = reply;');
+        indent.writeln('completion(output, nil);');
+      }
+    });
+  });
 }
 
 /// Looks through the AST for features that aren't supported by the ObjC

From c1e8f667487be1fa2519ae4154d9826994762119 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Sat, 7 Jan 2023 01:15:58 -0800
Subject: [PATCH 69/87] remove unneeded java method

---
 packages/pigeon/lib/java_generator.dart | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 5c541aaf27b..acbc901ab86 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -563,9 +563,6 @@ class JavaGenerator extends Generator<JavaOptions> {
   ///   static void setup(BinaryMessenger binaryMessenger, Foo api) {...}
   void _writeMethodSetup(JavaOptions generatorOptions, Root root,
       StringSink sink, Indent indent, Api api, final Method method) {
-    //TODO(tarrinneal): See if this is needed or if generator_tools is enough
-    bool isEnum(TypeDeclaration type) =>
-        root.enums.map((Enum e) => e.name).contains(type.baseName);
     final String channelName = makeChannelName(api, method);
     indent.write('');
     indent.scoped('{', '}', () {
@@ -614,7 +611,7 @@ class JavaGenerator extends Generator<JavaOptions> {
                     ? '($argName == null) ? null : $argName.longValue()'
                     : argName;
                 String accessor = 'args.get($index)';
-                if (isEnum(arg.type)) {
+                if (isEnum(root, arg.type)) {
                   accessor = _intToEnum(accessor, arg.type.baseName);
                 } else if (argType != 'Object') {
                   accessor = '($argType)$accessor';

From 90960118c1dd875304b8db2d92c7c5715f322161 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Sat, 7 Jan 2023 13:19:14 -0800
Subject: [PATCH 70/87] analyze

---
 packages/pigeon/test/java_generator_test.dart   | 1 -
 packages/pigeon/test/kotlin_generator_test.dart | 1 -
 packages/pigeon/test/swift_generator_test.dart  | 1 -
 3 files changed, 3 deletions(-)

diff --git a/packages/pigeon/test/java_generator_test.dart b/packages/pigeon/test/java_generator_test.dart
index 61cc14d9ed3..f2a25288754 100644
--- a/packages/pigeon/test/java_generator_test.dart
+++ b/packages/pigeon/test/java_generator_test.dart
@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:pigeon/ast.dart';
-import 'package:pigeon/generator_tools.dart';
 import 'package:pigeon/java_generator.dart';
 import 'package:pigeon/pigeon.dart';
 import 'package:test/test.dart';
diff --git a/packages/pigeon/test/kotlin_generator_test.dart b/packages/pigeon/test/kotlin_generator_test.dart
index 2e85079e426..96056c1b1b1 100644
--- a/packages/pigeon/test/kotlin_generator_test.dart
+++ b/packages/pigeon/test/kotlin_generator_test.dart
@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:pigeon/ast.dart';
-import 'package:pigeon/generator_tools.dart';
 import 'package:pigeon/kotlin_generator.dart';
 import 'package:test/test.dart';
 
diff --git a/packages/pigeon/test/swift_generator_test.dart b/packages/pigeon/test/swift_generator_test.dart
index 68c9d91fdad..305ca203fe7 100644
--- a/packages/pigeon/test/swift_generator_test.dart
+++ b/packages/pigeon/test/swift_generator_test.dart
@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:pigeon/ast.dart';
-import 'package:pigeon/generator_tools.dart';
 import 'package:pigeon/swift_generator.dart';
 import 'package:test/test.dart';
 

From 2ed7097172e2467279f78111e4db267fac0cb202 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 10 Jan 2023 22:20:47 -0800
Subject: [PATCH 71/87] single file gens

---
 packages/pigeon/lib/dart_generator.dart       | 49 +++-------
 packages/pigeon/lib/generator.dart            | 94 +++++++++++++++++--
 packages/pigeon/lib/java_generator.dart       | 93 +++++++++++-------
 packages/pigeon/lib/kotlin_generator.dart     | 78 +++++++--------
 packages/pigeon/lib/swift_generator.dart      | 77 +++++++--------
 .../com/example/test_plugin/CoreTests.gen.kt  |  2 -
 .../ios/Classes/CoreTests.gen.swift           |  1 -
 .../macos/Classes/CoreTests.gen.swift         |  1 -
 8 files changed, 226 insertions(+), 169 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 9de09227aa2..ba40f3f0f7e 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -71,35 +71,10 @@ class DartOptions {
 }
 
 /// Class that manages all Dart code generation.
-class DartGenerator extends Generator<DartOptions> {
+class DartGenerator extends StructuredGenerator<DartOptions> {
   /// Instantiates a Dart Generator.
   DartGenerator();
 
-  /// Generates Dart files with specified [DartOptions]
-  @override
-  void generate(DartOptions generatorOptions, Root root, StringSink sink) {
-    final Indent indent = Indent(sink);
-
-    writeFilePrologue(generatorOptions, root, sink, indent);
-    writeFileImports(generatorOptions, root, sink, indent);
-    for (final Enum anEnum in root.enums) {
-      writeEnum(generatorOptions, root, sink, indent, anEnum);
-    }
-    for (final Class klass in root.classes) {
-      indent.writeln('');
-      writeDataClass(generatorOptions, root, sink, indent, klass);
-    }
-
-    for (final Api api in root.apis) {
-      indent.writeln('');
-      if (api.location == ApiLocation.host) {
-        writeHostApi(generatorOptions, root, sink, indent, api);
-      } else if (api.location == ApiLocation.flutter) {
-        writeFlutterApi(generatorOptions, root, sink, indent, api);
-      }
-    }
-  }
-
   @override
   void writeFilePrologue(
       DartOptions generatorOptions, Root root, StringSink sink, Indent indent) {
@@ -150,22 +125,14 @@ class DartGenerator extends Generator<DartOptions> {
         root.classes.map((Class x) => x.name).toSet();
     final Set<String> customEnumNames =
         root.enums.map((Enum x) => x.name).toSet();
-    void writeConstructor() {
-      indent.write(klass.name);
-      indent.scoped('({', '});', () {
-        for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-          final String required = field.type.isNullable ? '' : 'required ';
-          indent.writeln('${required}this.${field.name},');
-        }
-      });
-    }
 
+    indent.writeln('');
     addDocumentationComments(
         indent, klass.documentationComments, _docCommentSpec);
 
     indent.write('class ${klass.name} ');
     indent.scoped('{', '}', () {
-      writeConstructor();
+      _writeConstructor(indent, klass);
       indent.addln('');
       for (final NamedType field in getFieldsInSerializationOrder(klass)) {
         addDocumentationComments(
@@ -183,6 +150,16 @@ class DartGenerator extends Generator<DartOptions> {
     });
   }
 
+  void _writeConstructor(Indent indent, Class klass) {
+    indent.write(klass.name);
+    indent.scoped('({', '});', () {
+      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+        final String required = field.type.isNullable ? '' : 'required ';
+        indent.writeln('${required}this.${field.name},');
+      }
+    });
+  }
+
   @override
   void writeClassEncode(
     DartOptions generatorOptions,
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 981fcc8dfbe..e0a3d6e6f66 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -10,19 +10,57 @@ import 'generator_tools.dart';
 /// This provides the structure that is common across generators for different languages.
 abstract class Generator<T> {
   /// Generates files for specified language with specified [generatorOptions]
-  ///
-  /// This method, when overridden, should follow a generic structure that is currently:
-  /// 1. Create Indent
-  /// 2. Write File Headers
-  /// 3. Write Imports
-  /// 4. Write Enums
-  /// 5. Write Data Classes
-  /// 6. Write Apis
   void generate(
     T generatorOptions,
     Root root,
     StringSink sink,
   );
+}
+
+/// A Superclass that enforces code generation across platforms.
+abstract class StructuredGenerator<T> extends Generator<T> {
+  @override
+  void generate(
+    T generatorOptions,
+    Root root,
+    StringSink sink,
+  ) {
+    final Indent indent = Indent(sink);
+
+    prePrologue(generatorOptions, root, sink, indent);
+    writeFilePrologue(generatorOptions, root, sink, indent);
+    writeFileImports(generatorOptions, root, sink, indent);
+
+    preEnums(generatorOptions, root, sink, indent);
+    for (final Enum anEnum in root.enums) {
+      writeEnum(generatorOptions, root, sink, indent, anEnum);
+    }
+
+    preDataClasses(generatorOptions, root, sink, indent);
+    for (final Class klass in root.classes) {
+      writeDataClass(generatorOptions, root, sink, indent, klass);
+    }
+
+    preApis(generatorOptions, root, sink, indent);
+    for (final Api api in root.apis) {
+      if (api.location == ApiLocation.host) {
+        writeHostApi(generatorOptions, root, sink, indent, api);
+      } else if (api.location == ApiLocation.flutter) {
+        writeFlutterApi(generatorOptions, root, sink, indent, api);
+      }
+    }
+    postWriteFile(generatorOptions, root, sink, indent);
+  }
+
+  /// Pre-process or write before [writeFilePrologue].
+  ///
+  /// This method is not a reqiured method, and does not need to be overriden if not needed.
+  void prePrologue(
+    T generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+  ) {}
 
   /// Adds specified headers to file.
   void writeFilePrologue(
@@ -40,6 +78,16 @@ abstract class Generator<T> {
     Indent indent,
   );
 
+  /// Pre-process for enums or writes before any [writeEnum] calls.
+  ///
+  /// This method is not a reqiured method, and does not need to be overriden if not needed.
+  void preEnums(
+    T generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+  ) {}
+
   /// Writes a single Enum to file.
   void writeEnum(
     T generatorOptions,
@@ -49,6 +97,16 @@ abstract class Generator<T> {
     Enum anEnum,
   );
 
+  /// Pre-process for data classes or writes before any [writeDataClass] calls.
+  ///
+  /// This method is not a reqiured method, and does not need to be overriden if not needed.
+  void preDataClasses(
+    T generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+  ) {}
+
   /// Writes a single data class to file.
   void writeDataClass(
     T generatorOptions,
@@ -80,6 +138,16 @@ abstract class Generator<T> {
     Set<String> customEnumNames,
   );
 
+  /// Pre-process for apis and/or writes before any [writeFlutterApi] or [writeHostApi] calls.
+  ///
+  /// This method is not a reqiured method, and does not need to be overriden if not needed.
+  void preApis(
+    T generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+  ) {}
+
   /// Writes a single Flutter Api to file.
   void writeFlutterApi(
     T generatorOptions,
@@ -97,4 +165,14 @@ abstract class Generator<T> {
     Indent indent,
     Api api,
   );
+
+  /// Post-process for generate and/or writes after all other methods.
+  ///
+  /// This method is not a reqiured method, and does not need to be overriden if not needed.
+  void postWriteFile(
+    T generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+  ) {}
 }
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index acbc901ab86..844695eabe9 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -86,7 +86,7 @@ class JavaOptions {
 }
 
 /// Class that manages all Java code generation.
-class JavaGenerator extends Generator<JavaOptions> {
+class JavaGenerator extends StructuredGenerator<JavaOptions> {
   /// Instantiates a Java Generator.
   JavaGenerator();
 
@@ -98,42 +98,22 @@ class JavaGenerator extends Generator<JavaOptions> {
 
     writeFilePrologue(generatorOptions, root, sink, indent);
     writeFileImports(generatorOptions, root, sink, indent);
-    indent.writeln(
-        '$_docCommentPrefix Generated class from Pigeon.$_docCommentSuffix');
-    indent.writeln(
-        '@SuppressWarnings({"unused", "unchecked", "CodeBlock2Expr", "RedundantSuppression"})');
-    if (generatorOptions.useGeneratedAnnotation ?? false) {
-      indent.writeln('@javax.annotation.Generated("dev.flutter.pigeon")');
+    preEnums(generatorOptions, root, sink, indent);
+    for (final Enum anEnum in root.enums) {
+      writeEnum(generatorOptions, root, sink, indent, anEnum);
     }
-    indent.write('public class ${generatorOptions.className!} ');
-    indent.scoped('{', '}', () {
-      for (final Enum anEnum in root.enums) {
-        indent.writeln('');
-        writeEnum(generatorOptions, root, sink, indent, anEnum);
-      }
-      for (final Class klass in root.classes) {
-        indent.addln('');
-        writeDataClass(generatorOptions, root, sink, indent, klass);
-      }
-      if (root.apis.any((Api api) =>
-          api.location == ApiLocation.host &&
-          api.methods.any((Method it) => it.isAsynchronous))) {
-        indent.addln('');
-        _writeResultInterface(indent);
-      }
-      for (final Api api in root.apis) {
-        if (getCodecClasses(api, root).isNotEmpty) {
-          _writeCodec(indent, api, root);
-          indent.addln('');
-        }
-        if (api.location == ApiLocation.host) {
-          writeHostApi(generatorOptions, root, sink, indent, api);
-        } else if (api.location == ApiLocation.flutter) {
-          writeFlutterApi(generatorOptions, root, sink, indent, api);
-        }
+    for (final Class klass in root.classes) {
+      writeDataClass(generatorOptions, root, sink, indent, klass);
+    }
+    preApis(generatorOptions, root, sink, indent);
+    for (final Api api in root.apis) {
+      if (api.location == ApiLocation.host) {
+        writeHostApi(generatorOptions, root, sink, indent, api);
+      } else if (api.location == ApiLocation.flutter) {
+        writeFlutterApi(generatorOptions, root, sink, indent, api);
       }
-      _writeWrapError(indent);
-    });
+    }
+    postWriteFile(generatorOptions, root, sink, indent);
   }
 
   @override
@@ -171,6 +151,20 @@ class JavaGenerator extends Generator<JavaOptions> {
     indent.addln('');
   }
 
+  @override
+  void preEnums(
+      JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    indent.writeln(
+        '$_docCommentPrefix Generated class from Pigeon.$_docCommentSuffix');
+    indent.writeln(
+        '@SuppressWarnings({"unused", "unchecked", "CodeBlock2Expr", "RedundantSuppression"})');
+    if (generatorOptions.useGeneratedAnnotation ?? false) {
+      indent.writeln('@javax.annotation.Generated("dev.flutter.pigeon")');
+    }
+    indent.writeln('public class ${generatorOptions.className!} {');
+    indent.inc();
+  }
+
   @override
   void writeEnum(JavaOptions generatorOptions, Root root, StringSink sink,
       Indent indent, Enum anEnum) {
@@ -181,6 +175,7 @@ class JavaGenerator extends Generator<JavaOptions> {
           .toUpperCase();
     }
 
+    indent.writeln('');
     addDocumentationComments(
         indent, anEnum.documentationComments, _docCommentSpec);
 
@@ -212,6 +207,7 @@ class JavaGenerator extends Generator<JavaOptions> {
     const List<String> generatedMessages = <String>[
       ' Generated class from Pigeon that represents data sent in messages.'
     ];
+    indent.addln('');
     addDocumentationComments(
         indent, klass.documentationComments, _docCommentSpec,
         generatorComments: generatedMessages);
@@ -389,6 +385,9 @@ class JavaGenerator extends Generator<JavaOptions> {
     Api api,
   ) {
     assert(api.location == ApiLocation.flutter);
+    if (getCodecClasses(api, root).isNotEmpty) {
+      _writeCodec(indent, api, root);
+    }
     const List<String> generatedMessages = <String>[
       ' Generated class from Pigeon that represents Flutter messages that can be called from Java.'
     ];
@@ -479,6 +478,17 @@ class JavaGenerator extends Generator<JavaOptions> {
     });
   }
 
+  @override
+  void preApis(
+      JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    if (root.apis.any((Api api) =>
+        api.location == ApiLocation.host &&
+        api.methods.any((Method it) => it.isAsynchronous))) {
+      indent.addln('');
+      _writeResultInterface(indent);
+    }
+  }
+
   /// Write the java code that represents a host [Api], [api].
   /// Example:
   /// public interface Foo {
@@ -489,7 +499,9 @@ class JavaGenerator extends Generator<JavaOptions> {
   void writeHostApi(JavaOptions generatorOptions, Root root, StringSink sink,
       Indent indent, Api api) {
     assert(api.location == ApiLocation.host);
-
+    if (getCodecClasses(api, root).isNotEmpty) {
+      _writeCodec(indent, api, root);
+    }
     const List<String> generatedMessages = <String>[
       ' Generated interface from Pigeon that represents a handler of messages from Flutter.'
     ];
@@ -727,6 +739,7 @@ Result<$returnType> $resultName = new Result<$returnType>() {
         });
       });
     });
+    indent.addln('');
   }
 
   void _writeResultInterface(Indent indent) {
@@ -747,6 +760,14 @@ Result<$returnType> $resultName = new Result<$returnType>() {
 \treturn errorList;
 }''');
   }
+
+  @override
+  void postWriteFile(
+      JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    _writeWrapError(indent);
+    indent.dec();
+    indent.addln('}');
+  }
 }
 
 /// Calculates the name of the codec that will be generated for [api].
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index c0b5ae19a60..115f55be9f4 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -66,51 +66,10 @@ class KotlinOptions {
 }
 
 /// Class that manages all Kotlin code generation.
-class KotlinGenerator extends Generator<KotlinOptions> {
+class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   /// Instantiates a Kotlin Generator.
   KotlinGenerator();
 
-  /// Generates the ".kotlin" file for the AST represented by [root] to [sink] with the
-  /// provided [KotlinOptions].
-  @override
-  void generate(KotlinOptions generatorOptions, Root root, StringSink sink) {
-    final Indent indent = Indent(sink);
-
-    writeFilePrologue(generatorOptions, root, sink, indent);
-    writeFileImports(generatorOptions, root, sink, indent);
-    indent.writeln('/** Generated class from Pigeon. */');
-    for (final Enum anEnum in root.enums) {
-      indent.writeln('');
-      writeEnum(generatorOptions, root, sink, indent, anEnum);
-    }
-    for (final Class klass in root.classes) {
-      indent.addln('');
-      writeDataClass(generatorOptions, root, sink, indent, klass);
-    }
-    if (root.apis.any((Api api) =>
-        api.location == ApiLocation.host &&
-        api.methods.any((Method it) => it.isAsynchronous))) {
-      indent.addln('');
-    }
-
-    for (final Api api in root.apis) {
-      if (getCodecClasses(api, root).isNotEmpty) {
-        _writeCodec(indent, api, root);
-        indent.addln('');
-      }
-      if (api.location == ApiLocation.host) {
-        writeHostApi(generatorOptions, root, sink, indent, api);
-      } else if (api.location == ApiLocation.flutter) {
-        writeFlutterApi(generatorOptions, root, sink, indent, api);
-      }
-    }
-
-    indent.addln('');
-    _writeWrapResult(indent);
-    indent.addln('');
-    _writeWrapError(indent);
-  }
-
   @override
   void writeFilePrologue(KotlinOptions generatorOptions, Root root,
       StringSink sink, Indent indent) {
@@ -119,12 +78,12 @@ class KotlinGenerator extends Generator<KotlinOptions> {
     }
     indent.writeln('// $generatedCodeWarning');
     indent.writeln('// $seeAlsoWarning');
-    indent.addln('');
   }
 
   @override
   void writeFileImports(KotlinOptions generatorOptions, Root root,
       StringSink sink, Indent indent) {
+    indent.addln('');
     if (generatorOptions.package != null) {
       indent.writeln('package ${generatorOptions.package}');
     }
@@ -136,12 +95,12 @@ class KotlinGenerator extends Generator<KotlinOptions> {
     indent.writeln('import io.flutter.plugin.common.StandardMessageCodec');
     indent.writeln('import java.io.ByteArrayOutputStream');
     indent.writeln('import java.nio.ByteBuffer');
-    indent.addln('');
   }
 
   @override
   void writeEnum(KotlinOptions generatorOptions, Root root, StringSink sink,
       Indent indent, Enum anEnum) {
+    indent.writeln('');
     addDocumentationComments(
         indent, anEnum.documentationComments, _docCommentSpec);
     indent.write('enum class ${anEnum.name}(val raw: Int) ');
@@ -179,6 +138,7 @@ class KotlinGenerator extends Generator<KotlinOptions> {
     const List<String> generatedMessages = <String>[
       ' Generated class from Pigeon that represents data sent in messages.'
     ];
+    indent.addln('');
     addDocumentationComments(
         indent, klass.documentationComments, _docCommentSpec,
         generatorComments: generatedMessages);
@@ -324,6 +284,20 @@ class KotlinGenerator extends Generator<KotlinOptions> {
     indent.add(defaultNil);
   }
 
+  @override
+  void preApis(
+    KotlinOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+  ) {
+    if (root.apis.any((Api api) =>
+        api.location == ApiLocation.host &&
+        api.methods.any((Method it) => it.isAsynchronous))) {
+      indent.addln('');
+    }
+  }
+
   /// Writes the code for a flutter [Api], [api].
   /// Example:
   /// class Foo(private val binaryMessenger: BinaryMessenger) {
@@ -339,6 +313,9 @@ class KotlinGenerator extends Generator<KotlinOptions> {
   ) {
     assert(api.location == ApiLocation.flutter);
     final bool isCustomCodec = getCodecClasses(api, root).isNotEmpty;
+    if (isCustomCodec) {
+      _writeCodec(indent, api, root);
+    }
 
     const List<String> generatedMessages = <String>[
       ' Generated class from Pigeon that represents Flutter messages that can be called from Kotlin.'
@@ -435,6 +412,9 @@ class KotlinGenerator extends Generator<KotlinOptions> {
     final String apiName = api.name;
 
     final bool isCustomCodec = getCodecClasses(api, root).isNotEmpty;
+    if (isCustomCodec) {
+      _writeCodec(indent, api, root);
+    }
 
     const List<String> generatedMessages = <String>[
       ' Generated interface from Pigeon that represents a handler of messages from Flutter.'
@@ -617,9 +597,11 @@ class KotlinGenerator extends Generator<KotlinOptions> {
         });
       });
     });
+    indent.addln('');
   }
 
   void _writeWrapResult(Indent indent) {
+    indent.addln('');
     indent.write('private fun wrapResult(result: Any?): List<Any?> ');
     indent.scoped('{', '}', () {
       indent.writeln('return listOf(result)');
@@ -627,6 +609,7 @@ class KotlinGenerator extends Generator<KotlinOptions> {
   }
 
   void _writeWrapError(Indent indent) {
+    indent.addln('');
     indent.write('private fun wrapError(exception: Throwable): List<Any> ');
     indent.scoped('{', '}', () {
       indent.write('return ');
@@ -638,6 +621,13 @@ class KotlinGenerator extends Generator<KotlinOptions> {
       });
     });
   }
+
+  @override
+  void postWriteFile(KotlinOptions generatorOptions, Root root, StringSink sink,
+      Indent indent) {
+    _writeWrapResult(indent);
+    _writeWrapError(indent);
+  }
 }
 
 HostDatatype _getHostDatatype(Root root, NamedType field) {
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 15c5b51250a..9e862cd0f33 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -49,50 +49,10 @@ class SwiftOptions {
 }
 
 /// Class that manages all Swift code generation.
-class SwiftGenerator extends Generator<SwiftOptions> {
+class SwiftGenerator extends StructuredGenerator<SwiftOptions> {
   /// Instantiates a Swift Generator.
   SwiftGenerator();
 
-  /// Generates Swift files with specified [SwiftOptions]
-  @override
-  void generate(SwiftOptions generatorOptions, Root root, StringSink sink) {
-    final Indent indent = Indent(sink);
-    writeFilePrologue(generatorOptions, root, sink, indent);
-    writeFileImports(generatorOptions, root, sink, indent);
-    indent.writeln('$_docCommentPrefix Generated class from Pigeon.');
-    for (final Enum anEnum in root.enums) {
-      indent.writeln('');
-      writeEnum(generatorOptions, root, sink, indent, anEnum);
-    }
-    for (final Class klass in root.classes) {
-      indent.addln('');
-      writeDataClass(generatorOptions, root, sink, indent, klass);
-    }
-
-    if (root.apis.any((Api api) =>
-        api.location == ApiLocation.host &&
-        api.methods.any((Method it) => it.isAsynchronous))) {
-      indent.addln('');
-    }
-
-    for (final Api api in root.apis) {
-      if (getCodecClasses(api, root).isNotEmpty) {
-        _writeCodec(indent, api, root);
-        indent.addln('');
-      }
-      if (api.location == ApiLocation.host) {
-        writeHostApi(generatorOptions, root, sink, indent, api);
-      } else if (api.location == ApiLocation.flutter) {
-        writeFlutterApi(generatorOptions, root, sink, indent, api);
-      }
-    }
-
-    indent.addln('');
-    _writeWrapResult(indent);
-    indent.addln('');
-    _writeWrapError(indent);
-  }
-
   @override
   void writeFilePrologue(SwiftOptions generatorOptions, Root root,
       StringSink sink, Indent indent) {
@@ -123,6 +83,7 @@ import FlutterMacOS
   @override
   void writeEnum(SwiftOptions generatorOptions, Root root, StringSink sink,
       Indent indent, Enum anEnum) {
+    indent.writeln('');
     addDocumentationComments(
         indent, anEnum.documentationComments, _docCommentSpec);
 
@@ -147,6 +108,7 @@ import FlutterMacOS
     const List<String> generatedComments = <String>[
       ' Generated class from Pigeon that represents data sent in messages.'
     ];
+    indent.addln('');
     addDocumentationComments(
         indent, klass.documentationComments, _docCommentSpec,
         generatorComments: generatedComments);
@@ -278,6 +240,20 @@ import FlutterMacOS
     indent.addln(defaultNil);
   }
 
+  @override
+  void preApis(
+    SwiftOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+  ) {
+    if (root.apis.any((Api api) =>
+        api.location == ApiLocation.host &&
+        api.methods.any((Method it) => it.isAsynchronous))) {
+      indent.addln('');
+    }
+  }
+
   /// Writes the code for a flutter [Api], [api].
   /// Example:
   /// class Foo {
@@ -294,6 +270,10 @@ import FlutterMacOS
     Api api,
   ) {
     assert(api.location == ApiLocation.flutter);
+    final bool isCustomCodec = getCodecClasses(api, root).isNotEmpty;
+    if (isCustomCodec) {
+      _writeCodec(indent, api, root);
+    }
     const List<String> generatedComments = <String>[
       ' Generated class from Pigeon that represents Flutter messages that can be called from Swift.'
     ];
@@ -389,6 +369,11 @@ import FlutterMacOS
 
     final String apiName = api.name;
 
+    final bool isCustomCodec = getCodecClasses(api, root).isNotEmpty;
+    if (isCustomCodec) {
+      _writeCodec(indent, api, root);
+    }
+
     const List<String> generatedComments = <String>[
       ' Generated protocol from Pigeon that represents a handler of messages from Flutter.'
     ];
@@ -587,9 +572,11 @@ import FlutterMacOS
       indent.writeln(
           'static let shared = $codecName(readerWriter: $readerWriterName())');
     });
+    indent.addln('');
   }
 
   void _writeWrapResult(Indent indent) {
+    indent.addln('');
     indent.write('private func wrapResult(_ result: Any?) -> [Any?] ');
     indent.scoped('{', '}', () {
       indent.writeln('return [result]');
@@ -597,6 +584,7 @@ import FlutterMacOS
   }
 
   void _writeWrapError(Indent indent) {
+    indent.addln('');
     indent.write('private func wrapError(_ error: FlutterError) -> [Any?] ');
     indent.scoped('{', '}', () {
       indent.write('return ');
@@ -607,6 +595,13 @@ import FlutterMacOS
       });
     });
   }
+
+  @override
+  void postWriteFile(SwiftOptions generatorOptions, Root root, StringSink sink,
+      Indent indent) {
+    _writeWrapResult(indent);
+    _writeWrapError(indent);
+  }
 }
 
 HostDatatype _getHostDatatype(Root root, NamedType field) {
diff --git a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
index 15d31704b6d..903a87d4e70 100644
--- a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
+++ b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
@@ -15,8 +15,6 @@ import io.flutter.plugin.common.StandardMessageCodec
 import java.io.ByteArrayOutputStream
 import java.nio.ByteBuffer
 
-/** Generated class from Pigeon. */
-
 enum class AnEnum(val raw: Int) {
   ONE(0),
   TWO(1),
diff --git a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
index ecd65d85009..2b4138e4b2b 100644
--- a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
@@ -15,7 +15,6 @@ import FlutterMacOS
 #endif
 
 
-/// Generated class from Pigeon.
 
 enum AnEnum: Int {
   case one = 0
diff --git a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
index ecd65d85009..2b4138e4b2b 100644
--- a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
@@ -15,7 +15,6 @@ import FlutterMacOS
 #endif
 
 
-/// Generated class from Pigeon.
 
 enum AnEnum: Int {
   case one = 0

From 0da8ba8d6a74a5d20a6d3af1261bf761508fe36a Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 10 Jan 2023 23:28:01 -0800
Subject: [PATCH 72/87] objc

---
 packages/pigeon/lib/objc_generator.dart       | 1005 ++++++++---------
 .../ios/Classes/CoreTests.gen.h               |    1 +
 .../ios/Classes/CoreTests.gen.m               |    3 +
 3 files changed, 465 insertions(+), 544 deletions(-)

diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index e09e3dbe2e8..5c330de9be8 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -64,206 +64,41 @@ class ObjcOptions {
   }
 }
 
-/// Class that manages all Objc header code generation.
+/// Class that manages all Objc code generation.
 class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
   /// Instantiates a Objc Generator.
   ObjcGenerator();
 
-  /// Generates Objc header files with specified [ObjcOptions]
+  /// Generates Objc files of type specified in [ObjcOptions]
   @override
   void generate(OutputFileOptions<ObjcOptions> generatorOptions, Root root,
       StringSink sink) {
-    final Indent indent = Indent(sink);
-
-    writeFilePrologue(generatorOptions, root, sink, indent);
-    writeFileImports(generatorOptions, root, sink, indent);
     if (generatorOptions.fileType == FileType.header) {
-      indent.writeln('NS_ASSUME_NONNULL_BEGIN');
-
-      for (final Enum anEnum in root.enums) {
-        indent.writeln('');
-        writeEnum(generatorOptions, root, sink, indent, anEnum);
-      }
-      indent.writeln('');
-      for (final Class klass in root.classes) {
-        indent.writeln(
-            '@class ${_className(generatorOptions.languageOptions.prefix, klass.name)};');
-      }
-      indent.addln('');
+      ObjcHeaderGenerator()
+          .generate(generatorOptions.languageOptions, root, sink);
     } else if (generatorOptions.fileType == FileType.source) {
-      _writeObjcSourceHelperFunctions(indent);
-      indent.addln('');
-
-      for (final Class klass in root.classes) {
-        _writeObjcSourceDataClassExtension(
-            generatorOptions.languageOptions, indent, klass);
-      }
-      indent.writeln('');
-    }
-
-    for (final Class klass in root.classes) {
-      writeDataClass(generatorOptions, root, sink, indent, klass);
-    }
-
-    indent.writeln('');
-
-    for (final Api api in root.apis) {
-      if (generatorOptions.fileType == FileType.source) {
-        final String codecName =
-            _getCodecName(generatorOptions.languageOptions.prefix, api.name);
-        if (getCodecClasses(api, root).isNotEmpty) {
-          _writeCodec(
-              indent, codecName, generatorOptions.languageOptions, api, root);
-          indent.addln('');
-        }
-        _writeCodecGetter(
-            indent, codecName, generatorOptions.languageOptions, api, root);
-        indent.addln('');
-      }
-      if (api.location == ApiLocation.host) {
-        writeHostApi(generatorOptions, root, sink, indent, api);
-      } else if (api.location == ApiLocation.flutter) {
-        writeFlutterApi(generatorOptions, root, sink, indent, api);
-      }
-    }
-    if (generatorOptions.fileType == FileType.header) {
-      indent.writeln('NS_ASSUME_NONNULL_END');
-    }
-  }
-
-  @override
-  void writeFilePrologue(OutputFileOptions<ObjcOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent) {
-    if (generatorOptions.fileType == FileType.header) {
-      _writeObjcHeaderPrologue(
-          generatorOptions.languageOptions, root, sink, indent);
-    } else {
-      _writeObjcSourcePrologue(
-          generatorOptions.languageOptions, root, sink, indent);
-    }
-  }
-
-  @override
-  void writeFileImports(OutputFileOptions<ObjcOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent) {
-    if (generatorOptions.fileType == FileType.header) {
-      _writeObjcHeaderImports(
-          generatorOptions.languageOptions, root, sink, indent);
-    } else {
-      _writeObjcSourceImports(
-          generatorOptions.languageOptions, root, sink, indent);
-    }
-  }
-
-  @override
-  void writeEnum(OutputFileOptions<ObjcOptions> generatorOptions, Root root,
-      StringSink sink, Indent indent, Enum anEnum) {
-    if (generatorOptions.fileType == FileType.header) {
-      _writeObjcHeaderEnum(
-          generatorOptions.languageOptions, root, sink, indent, anEnum);
-    }
-  }
-
-  @override
-  void writeDataClass(OutputFileOptions<ObjcOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent, Class klass) {
-    if (generatorOptions.fileType == FileType.header) {
-      _writeObjcHeaderDataClass(
-          generatorOptions.languageOptions, root, sink, indent, klass);
-    } else {
-      _writeObjcSourceDataClassImplementation(
-          generatorOptions, root, sink, indent, klass);
-      indent.writeln('');
-    }
-  }
-
-  @override
-  void writeClassEncode(
-    OutputFileOptions<ObjcOptions> generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Class klass,
-    Set<String> customClassNames,
-    Set<String> customEnumNames,
-  ) {
-    if (generatorOptions.fileType == FileType.source) {
-      final String className =
-          _className(generatorOptions.languageOptions.prefix, klass.name);
-
-      _writeObjcSourceClassEncode(generatorOptions.languageOptions, root, sink,
-          indent, klass, customClassNames, customEnumNames, className);
-    }
-  }
-
-  @override
-  void writeClassDecode(
-    OutputFileOptions<ObjcOptions> generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Class klass,
-    Set<String> customClassNames,
-    Set<String> customEnumNames,
-  ) {
-    if (generatorOptions.fileType == FileType.source) {
-      final String className =
-          _className(generatorOptions.languageOptions.prefix, klass.name);
-
-      _writeObjcSourceClassDecode(generatorOptions.languageOptions, root, sink,
-          indent, klass, customClassNames, customEnumNames, className);
-    }
-  }
-
-  @override
-  void writeFlutterApi(
-    OutputFileOptions<ObjcOptions> generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Api api,
-  ) {
-    if (generatorOptions.fileType == FileType.header) {
-      _writeFlutterApiDeclaration(
-          indent, api, generatorOptions.languageOptions, root);
-    } else {
-      _writeFlutterApiSource(
-          indent, generatorOptions.languageOptions, api, root);
+      ObjcSourceGenerator()
+          .generate(generatorOptions.languageOptions, root, sink);
     }
   }
+}
 
+/// Generates Objc .h file.
+class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
   @override
-  void writeHostApi(
-    OutputFileOptions<ObjcOptions> generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Api api,
-  ) {
-    if (generatorOptions.fileType == FileType.header) {
-      _writeHostApiDeclaration(
-          indent, api, generatorOptions.languageOptions, root);
-    } else {
-      _writeHostApiSource(indent, generatorOptions.languageOptions, api, root);
-    }
-  }
-
-  // Header File Methods.
-
-  /// Writes Objc header file header to sink.
-  void _writeObjcHeaderPrologue(
-      ObjcOptions languageOptions, Root root, StringSink sink, Indent indent) {
-    if (languageOptions.copyrightHeader != null) {
-      addLines(indent, languageOptions.copyrightHeader!, linePrefix: '// ');
+  void writeFilePrologue(
+      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    if (generatorOptions.copyrightHeader != null) {
+      addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
     }
     indent.writeln('// $generatedCodeWarning');
     indent.writeln('// $seeAlsoWarning');
     indent.addln('');
   }
 
-  /// Writes Objc header file imports to sink.
-  void _writeObjcHeaderImports(
-      ObjcOptions languageOptions, Root root, StringSink sink, Indent indent) {
+  @override
+  void writeFileImports(
+      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     indent.writeln('#import <Foundation/Foundation.h>');
     indent.addln('');
 
@@ -272,12 +107,14 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
     indent.writeln('@class FlutterError;');
     indent.writeln('@class FlutterStandardTypedData;');
     indent.addln('');
+    indent.writeln('NS_ASSUME_NONNULL_BEGIN');
   }
 
-  /// Writes single Objc header enum.
-  void _writeObjcHeaderEnum(ObjcOptions languageOptions, Root root,
-      StringSink sink, Indent indent, Enum anEnum) {
-    final String enumName = _className(languageOptions.prefix, anEnum.name);
+  @override
+  void writeEnum(ObjcOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Enum anEnum) {
+    final String enumName = _className(generatorOptions.prefix, anEnum.name);
+    indent.writeln('');
     addDocumentationComments(
         indent, anEnum.documentationComments, _docCommentSpec);
 
@@ -293,14 +130,20 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
     });
   }
 
-  /// Writes the class declaration for a data class.
-  ///
-  /// Example:
-  /// @interface Foo : NSObject
-  /// @property (nonatomic, copy) NSString *bar;
-  /// @end
-  void _writeObjcHeaderDataClass(ObjcOptions generatorOptions, Root root,
-      StringSink sink, Indent indent, Class klass) {
+  @override
+  void preDataClasses(
+      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    indent.writeln('');
+    for (final Class klass in root.classes) {
+      indent.writeln(
+          '@class ${_className(generatorOptions.prefix, klass.name)};');
+    }
+    indent.writeln('');
+  }
+
+  @override
+  void writeDataClass(ObjcOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Class klass) {
     final List<Class> classes = root.classes;
     final List<Enum> enums = root.enums;
     final String? prefix = generatorOptions.prefix;
@@ -348,29 +191,89 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
     indent.writeln('');
   }
 
-  /// Writes the declaration for an host [Api].
-  ///
-  /// Example:
-  /// @protocol Foo
-  /// - (NSInteger)add:(NSInteger)x to:(NSInteger)y error:(NSError**)error;
-  /// @end
-  ///
-  /// extern void FooSetup(id<FlutterBinaryMessenger> binaryMessenger, NSObject<Foo> *_Nullable api);
-  void _writeHostApiDeclaration(
-      Indent indent, Api api, ObjcOptions options, Root root) {
+  @override
+  void writeClassEncode(
+    ObjcOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {}
+
+  @override
+  void writeClassDecode(
+    ObjcOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {}
+
+  @override
+  void writeFlutterApi(
+    ObjcOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
     indent.writeln(
-        '$_docCommentPrefix The codec used by ${_className(options.prefix, api.name)}.');
+        '$_docCommentPrefix The codec used by ${_className(generatorOptions.prefix, api.name)}.');
     indent.writeln(
-        'NSObject<FlutterMessageCodec> *${_getCodecGetterName(options.prefix, api.name)}(void);');
+        'NSObject<FlutterMessageCodec> *${_getCodecGetterName(generatorOptions.prefix, api.name)}(void);');
     indent.addln('');
-    final String apiName = _className(options.prefix, api.name);
+    final String apiName = _className(generatorOptions.prefix, api.name);
+    addDocumentationComments(
+        indent, api.documentationComments, _docCommentSpec);
+
+    indent.writeln('@interface $apiName : NSObject');
+    indent.writeln(
+        '- (instancetype)initWithBinaryMessenger:(id<FlutterBinaryMessenger>)binaryMessenger;');
+    for (final Method func in api.methods) {
+      final _ObjcPtr returnType =
+          _objcTypeForDartType(generatorOptions.prefix, func.returnType);
+      final String callbackType = _callbackForType(func.returnType, returnType);
+      addDocumentationComments(
+          indent, func.documentationComments, _docCommentSpec);
+
+      indent.writeln('${_makeObjcSignature(
+        func: func,
+        options: generatorOptions,
+        returnType: 'void',
+        lastArgName: 'completion',
+        lastArgType: callbackType,
+        isEnum: (TypeDeclaration t) => isEnum(root, t),
+      )};');
+    }
+    indent.writeln('@end');
+    indent.writeln('');
+  }
+
+  @override
+  void writeHostApi(
+    ObjcOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    indent.writeln(
+        '$_docCommentPrefix The codec used by ${_className(generatorOptions.prefix, api.name)}.');
+    indent.writeln(
+        'NSObject<FlutterMessageCodec> *${_getCodecGetterName(generatorOptions.prefix, api.name)}(void);');
+    indent.addln('');
+    final String apiName = _className(generatorOptions.prefix, api.name);
     addDocumentationComments(
         indent, api.documentationComments, _docCommentSpec);
 
     indent.writeln('@protocol $apiName');
     for (final Method func in api.methods) {
       final _ObjcPtr returnTypeName =
-          _objcTypeForDartType(options.prefix, func.returnType);
+          _objcTypeForDartType(generatorOptions.prefix, func.returnType);
 
       String? lastArgName;
       String? lastArgType;
@@ -404,7 +307,7 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
 
       final String signature = _makeObjcSignature(
         func: func,
-        options: options,
+        options: generatorOptions,
         returnType: returnType,
         lastArgName: lastArgName,
         lastArgType: lastArgType,
@@ -419,71 +322,330 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
     indent.writeln('');
   }
 
-  /// Writes the declaration for an flutter [Api].
-  ///
-  /// Example:
-  ///
-  /// @interface Foo : NSObject
-  /// - (instancetype)initWithBinaryMessenger:(id<FlutterBinaryMessenger>)binaryMessenger;
-  /// - (void)add:(NSInteger)x to:(NSInteger)y completion:(void(^)(NSError *, NSInteger result)completion;
-  /// @end
-  void _writeFlutterApiDeclaration(
-      Indent indent, Api api, ObjcOptions options, Root root) {
-    indent.writeln(
-        '$_docCommentPrefix The codec used by ${_className(options.prefix, api.name)}.');
-    indent.writeln(
-        'NSObject<FlutterMessageCodec> *${_getCodecGetterName(options.prefix, api.name)}(void);');
+  @override
+  void postWriteFile(
+      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    indent.writeln('NS_ASSUME_NONNULL_END');
+  }
+}
+
+/// Generates Objc .m file.
+class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
+  @override
+  void writeFilePrologue(
+      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    if (generatorOptions.copyrightHeader != null) {
+      addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
+    }
+    indent.writeln('// $generatedCodeWarning');
+    indent.writeln('// $seeAlsoWarning');
     indent.addln('');
-    final String apiName = _className(options.prefix, api.name);
-    addDocumentationComments(
-        indent, api.documentationComments, _docCommentSpec);
+  }
+
+  @override
+  void writeFileImports(
+      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    indent.writeln('#import "${generatorOptions.headerIncludePath}"');
+    indent.writeln('#import <Flutter/Flutter.h>');
+    indent.addln('');
+
+    indent.writeln('#if !__has_feature(objc_arc)');
+    indent.writeln('#error File requires ARC to be enabled.');
+    indent.writeln('#endif');
+    indent.addln('');
+  }
+
+  @override
+  void writeEnum(ObjcOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Enum anEnum) {
+    // Intentionally left blank.
+  }
+
+  @override
+  void preDataClasses(
+      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    _writeObjcSourceHelperFunctions(indent);
+    indent.addln('');
+
+    for (final Class klass in root.classes) {
+      _writeObjcSourceDataClassExtension(generatorOptions, indent, klass);
+    }
+    indent.writeln('');
+  }
+
+  @override
+  void writeDataClass(ObjcOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Class klass) {
+    final Set<String> customClassNames =
+        root.classes.map((Class x) => x.name).toSet();
+    final Set<String> customEnumNames =
+        root.enums.map((Enum x) => x.name).toSet();
+    final String className = _className(generatorOptions.prefix, klass.name);
+
+    indent.writeln('@implementation $className');
+    _writeObjcSourceClassInitializer(generatorOptions, root, sink, indent,
+        klass, customClassNames, customEnumNames, className);
+    writeClassDecode(generatorOptions, root, sink, indent, klass,
+        customClassNames, customEnumNames);
+    writeClassEncode(generatorOptions, root, sink, indent, klass,
+        customClassNames, customEnumNames);
+    indent.writeln('@end');
+    indent.writeln('');
+  }
+
+  @override
+  void writeClassEncode(
+    ObjcOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    indent.write('- (NSArray *)toList ');
+    indent.scoped('{', '}', () {
+      indent.write('return');
+      indent.scoped(' @[', '];', () {
+        for (final NamedType field in klass.fields) {
+          indent.writeln(
+              '${_arrayValue(customClassNames, customEnumNames, field)},');
+        }
+      });
+    });
+  }
+
+  @override
+  void writeClassDecode(
+    ObjcOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    final String className = _className(generatorOptions.prefix, klass.name);
+    indent.write('+ ($className *)fromList:(NSArray *)list ');
+    indent.scoped('{', '}', () {
+      const String resultName = 'pigeonResult';
+      indent.writeln('$className *$resultName = [[$className alloc] init];');
+      enumerate(getFieldsInSerializationOrder(klass),
+          (int index, final NamedType field) {
+        if (customEnumNames.contains(field.type.baseName)) {
+          indent.writeln(
+              '$resultName.${field.name} = [${_listGetter(customClassNames, 'list', field, index, generatorOptions.prefix)} integerValue];');
+        } else {
+          indent.writeln(
+              '$resultName.${field.name} = ${_listGetter(customClassNames, 'list', field, index, generatorOptions.prefix)};');
+          if (!field.type.isNullable) {
+            indent.writeln('NSAssert($resultName.${field.name} != nil, @"");');
+          }
+        }
+      });
+      indent.writeln('return $resultName;');
+    });
 
-    indent.writeln('@interface $apiName : NSObject');
     indent.writeln(
-        '- (instancetype)initWithBinaryMessenger:(id<FlutterBinaryMessenger>)binaryMessenger;');
-    for (final Method func in api.methods) {
-      final _ObjcPtr returnType =
-          _objcTypeForDartType(options.prefix, func.returnType);
-      final String callbackType = _callbackForType(func.returnType, returnType);
-      addDocumentationComments(
-          indent, func.documentationComments, _docCommentSpec);
+        '+ (nullable $className *)nullableFromList:(NSArray *)list { return (list) ? [$className fromList:list] : nil; }');
+  }
 
-      indent.writeln('${_makeObjcSignature(
-        func: func,
-        options: options,
-        returnType: 'void',
-        lastArgName: 'completion',
-        lastArgType: callbackType,
-        isEnum: (TypeDeclaration t) => isEnum(root, t),
-      )};');
+  _writeCodecAndGetter(ObjcOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Api api) {
+    final String codecName = _getCodecName(generatorOptions.prefix, api.name);
+    if (getCodecClasses(api, root).isNotEmpty) {
+      _writeCodec(indent, codecName, generatorOptions, api, root);
+      indent.addln('');
+    }
+    _writeCodecGetter(indent, codecName, generatorOptions, api, root);
+    indent.addln('');
+  }
+
+  @override
+  void writeFlutterApi(
+    ObjcOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    assert(api.location == ApiLocation.flutter);
+    final String apiName = _className(generatorOptions.prefix, api.name);
+
+    _writeCodecAndGetter(generatorOptions, root, sink, indent, api);
+
+    _writeExtension(indent, apiName);
+    indent.addln('');
+    indent.writeln('@implementation $apiName');
+    indent.addln('');
+    _writeInitializer(indent);
+    for (final Method func in api.methods) {
+      _writeMethod(generatorOptions, root, indent, api, func);
     }
     indent.writeln('@end');
+    indent.writeln('');
+  }
+
+  @override
+  void writeHostApi(
+    ObjcOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    assert(api.location == ApiLocation.host);
+    final String apiName = _className(generatorOptions.prefix, api.name);
+
+    _writeCodecAndGetter(generatorOptions, root, sink, indent, api);
+
+    const String channelName = 'channel';
+    indent.write(
+        'void ${apiName}Setup(id<FlutterBinaryMessenger> binaryMessenger, NSObject<$apiName> *api) ');
+    indent.scoped('{', '}', () {
+      for (final Method func in api.methods) {
+        indent.write('');
+        addDocumentationComments(
+            indent, func.documentationComments, _docCommentSpec);
+
+        indent.scoped('{', '}', () {
+          String? taskQueue;
+          if (func.taskQueueType != TaskQueueType.serial) {
+            taskQueue = 'taskQueue';
+            indent.writeln(
+                'NSObject<FlutterTaskQueue> *$taskQueue = [binaryMessenger makeBackgroundTaskQueue];');
+          }
+          _writeChannelAllocation(
+              generatorOptions, indent, api, func, channelName, taskQueue);
+          indent.write('if (api) ');
+          indent.scoped('{', '}', () {
+            _writeChannelApiBinding(
+                generatorOptions, root, indent, apiName, func, channelName);
+          });
+          indent.write('else ');
+          indent.scoped('{', '}', () {
+            indent.writeln('[$channelName setMessageHandler:nil];');
+          });
+        });
+      }
+    });
+  }
+
+  void _writeChannelApiBinding(ObjcOptions generatorOptions, Root root,
+      Indent indent, String apiName, Method func, String channel) {
+    void unpackArgs(String variable, Iterable<String> argNames) {
+      indent.writeln('NSArray *args = $variable;');
+      map3(wholeNumbers.take(func.arguments.length), argNames, func.arguments,
+          (int count, String argName, NamedType arg) {
+        if (isEnum(root, arg.type)) {
+          return '${_className(generatorOptions.prefix, arg.type.baseName)} $argName = [GetNullableObjectAtIndex(args, $count) integerValue];';
+        } else {
+          final _ObjcPtr argType =
+              _objcTypeForDartType(generatorOptions.prefix, arg.type);
+          return '${argType.ptr}$argName = GetNullableObjectAtIndex(args, $count);';
+        }
+      }).forEach(indent.writeln);
+    }
+
+    void writeAsyncBindings(Iterable<String> selectorComponents,
+        String callSignature, _ObjcPtr returnType) {
+      if (func.returnType.isVoid) {
+        const String callback = 'callback(wrapResult(nil, error));';
+        if (func.arguments.isEmpty) {
+          indent.writeScoped(
+              '[api ${selectorComponents.first}:^(FlutterError *_Nullable error) {',
+              '}];', () {
+            indent.writeln(callback);
+          });
+        } else {
+          indent.writeScoped(
+              '[api $callSignature ${selectorComponents.last}:^(FlutterError *_Nullable error) {',
+              '}];', () {
+            indent.writeln(callback);
+          });
+        }
+      } else {
+        const String callback = 'callback(wrapResult(output, error));';
+        if (func.arguments.isEmpty) {
+          indent.writeScoped(
+              '[api ${selectorComponents.first}:^(${returnType.ptr}_Nullable output, FlutterError *_Nullable error) {',
+              '}];', () {
+            indent.writeln(callback);
+          });
+        } else {
+          indent.writeScoped(
+              '[api $callSignature ${selectorComponents.last}:^(${returnType.ptr}_Nullable output, FlutterError *_Nullable error) {',
+              '}];', () {
+            indent.writeln(callback);
+          });
+        }
+      }
+    }
+
+    void writeSyncBindings(String call, _ObjcPtr returnType) {
+      indent.writeln('FlutterError *error;');
+      if (func.returnType.isVoid) {
+        indent.writeln('$call;');
+        indent.writeln('callback(wrapResult(nil, error));');
+      } else {
+        indent.writeln('${returnType.ptr}output = $call;');
+        indent.writeln('callback(wrapResult(output, error));');
+      }
+    }
+
+    // TODO(gaaclarke): Incorporate this into _getSelectorComponents.
+    final String lastSelectorComponent =
+        func.isAsynchronous ? 'completion' : 'error';
+    final String selector = _getSelector(func, lastSelectorComponent);
+    indent.writeln(
+        'NSCAssert([api respondsToSelector:@selector($selector)], @"$apiName api (%@) doesn\'t respond to @selector($selector)", api);');
+    indent.write(
+        '[$channel setMessageHandler:^(id _Nullable message, FlutterReply callback) ');
+    indent.scoped('{', '}];', () {
+      final _ObjcPtr returnType =
+          _objcTypeForDartType(generatorOptions.prefix, func.returnType);
+      final Iterable<String> selectorComponents =
+          _getSelectorComponents(func, lastSelectorComponent);
+      final Iterable<String> argNames =
+          indexMap(func.arguments, _getSafeArgName);
+      final String callSignature =
+          map2(selectorComponents.take(argNames.length), argNames,
+              (String selectorComponent, String argName) {
+        return '$selectorComponent:$argName';
+      }).join(' ');
+      if (func.arguments.isNotEmpty) {
+        unpackArgs('message', argNames);
+      }
+      if (func.isAsynchronous) {
+        writeAsyncBindings(selectorComponents, callSignature, returnType);
+      } else {
+        final String syncCall = func.arguments.isEmpty
+            ? '[api ${selectorComponents.first}:&error]'
+            : '[api $callSignature error:&error]';
+        writeSyncBindings(syncCall, returnType);
+      }
+    });
   }
 
-  // Source File Methods.
+  void _writeChannelAllocation(ObjcOptions generatorOptions, Indent indent,
+      Api api, Method func, String varName, String? taskQueue) {
+    indent.writeln('FlutterBasicMessageChannel *$varName =');
+    indent.inc();
+    indent.writeln('[[FlutterBasicMessageChannel alloc]');
+    indent.inc();
+    indent.writeln('initWithName:@"${makeChannelName(api, func)}"');
+    indent.writeln('binaryMessenger:binaryMessenger');
+    indent.write('codec:');
+    indent.add('${_getCodecGetterName(generatorOptions.prefix, api.name)}()');
 
-  /// Writes Objc Source file header to sink.
-  void _writeObjcSourcePrologue(
-      ObjcOptions languageOptions, Root root, StringSink sink, Indent indent) {
-    if (languageOptions.copyrightHeader != null) {
-      addLines(indent, languageOptions.copyrightHeader!, linePrefix: '// ');
+    if (taskQueue != null) {
+      indent.addln('');
+      indent.addln('taskQueue:$taskQueue];');
+    } else {
+      indent.addln('];');
     }
-    indent.writeln('// $generatedCodeWarning');
-    indent.writeln('// $seeAlsoWarning');
-    indent.addln('');
-  }
-
-  /// Writes Objc source file imports to sink.
-  void _writeObjcSourceImports(
-      ObjcOptions languageOptions, Root root, StringSink sink, Indent indent) {
-    indent.writeln('#import "${languageOptions.headerIncludePath}"');
-    indent.writeln('#import <Flutter/Flutter.h>');
-    indent.addln('');
-
-    indent.writeln('#if !__has_feature(objc_arc)');
-    indent.writeln('#error File requires ARC to be enabled.');
-    indent.writeln('#endif');
-    indent.addln('');
+    indent.dec();
+    indent.dec();
   }
 
   void _writeObjcSourceHelperFunctions(Indent indent) {
@@ -515,30 +677,11 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
         .writeln('+ (nullable $className *)nullableFromList:(NSArray *)list;');
     indent.writeln('- (NSArray *)toList;');
     indent.writeln('@end');
+    indent.writeln('');
   }
 
-  void _writeObjcSourceDataClassImplementation(
-      OutputFileOptions<ObjcOptions> generatorOptions,
-      Root root,
-      StringSink sink,
-      Indent indent,
-      Class klass) {
-    final Set<String> customClassNames =
-        root.classes.map((Class x) => x.name).toSet();
-    final Set<String> customEnumNames =
-        root.enums.map((Enum x) => x.name).toSet();
-    final String className =
-        _className(generatorOptions.languageOptions.prefix, klass.name);
-
-    indent.writeln('@implementation $className');
-    _writeObjcSourceClassInitializer(generatorOptions.languageOptions, root,
-        sink, indent, klass, customClassNames, customEnumNames, className);
-    writeClassDecode(generatorOptions, root, sink, indent, klass,
-        customClassNames, customEnumNames);
-    writeClassEncode(generatorOptions, root, sink, indent, klass,
-        customClassNames, customEnumNames);
-    indent.writeln('@end');
-  }
+  void _writeObjcSourceDataClassImplementation(ObjcOptions generatorOptions,
+      Root root, StringSink sink, Indent indent, Class klass) {}
 
   void _writeObjcSourceClassInitializer(
     ObjcOptions languageOptions,
@@ -562,95 +705,6 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
     });
   }
 
-  void _writeObjcSourceClassDecode(
-    ObjcOptions languageOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Class klass,
-    Set<String> customClassNames,
-    Set<String> customEnumNames,
-    String className,
-  ) {
-    indent.write('+ ($className *)fromList:(NSArray *)list ');
-    indent.scoped('{', '}', () {
-      const String resultName = 'pigeonResult';
-      indent.writeln('$className *$resultName = [[$className alloc] init];');
-      enumerate(getFieldsInSerializationOrder(klass),
-          (int index, final NamedType field) {
-        if (customEnumNames.contains(field.type.baseName)) {
-          indent.writeln(
-              '$resultName.${field.name} = [${_listGetter(customClassNames, 'list', field, index, languageOptions.prefix)} integerValue];');
-        } else {
-          indent.writeln(
-              '$resultName.${field.name} = ${_listGetter(customClassNames, 'list', field, index, languageOptions.prefix)};');
-          if (!field.type.isNullable) {
-            indent.writeln('NSAssert($resultName.${field.name} != nil, @"");');
-          }
-        }
-      });
-      indent.writeln('return $resultName;');
-    });
-
-    indent.writeln(
-        '+ (nullable $className *)nullableFromList:(NSArray *)list { return (list) ? [$className fromList:list] : nil; }');
-  }
-
-  void _writeObjcSourceClassEncode(
-    ObjcOptions languageOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Class klass,
-    Set<String> customClassNames,
-    Set<String> customEnumNames,
-    String className,
-  ) {
-    indent.write('- (NSArray *)toList ');
-    indent.scoped('{', '}', () {
-      indent.write('return');
-      indent.scoped(' @[', '];', () {
-        for (final NamedType field in klass.fields) {
-          indent.writeln(
-              '${_arrayValue(customClassNames, customEnumNames, field)},');
-        }
-      });
-    });
-  }
-
-  /// Writes the method declaration for the initializer.
-  ///
-  /// Example '+ (instancetype)makeWithFoo:(NSString *)foo'
-  void _writeObjcSourceClassInitializerDeclaration(Indent indent, Class klass,
-      List<Class> classes, List<Enum> enums, String? prefix) {
-    final List<String> customEnumNames = enums.map((Enum x) => x.name).toList();
-    indent.write('+ (instancetype)makeWith');
-    bool isFirst = true;
-    indent.nest(2, () {
-      for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-        final String label = isFirst ? _capitalize(field.name) : field.name;
-        final void Function(String) printer = isFirst
-            ? indent.add
-            : (String x) {
-                indent.addln('');
-                indent.write(x);
-              };
-        isFirst = false;
-        final HostDatatype hostDatatype = getFieldHostDatatype(
-            field,
-            classes,
-            enums,
-            (TypeDeclaration x) => _objcTypePtrForPrimitiveDartType(prefix, x),
-            customResolver: customEnumNames.contains(field.type.baseName)
-                ? (String x) => _className(prefix, x)
-                : (String x) => '${_className(prefix, x)} *');
-        final String nullable =
-            _isNullable(hostDatatype, field.type) ? 'nullable ' : '';
-        printer('$label:($nullable${hostDatatype.datatype})${field.name}');
-      }
-    });
-  }
-
   /// Writes the codec that will be used for encoding messages for the [api].
   ///
   /// Example:
@@ -751,6 +805,39 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
   }
 }
 
+/// Writes the method declaration for the initializer.
+///
+/// Example '+ (instancetype)makeWithFoo:(NSString *)foo'
+void _writeObjcSourceClassInitializerDeclaration(Indent indent, Class klass,
+    List<Class> classes, List<Enum> enums, String? prefix) {
+  final List<String> customEnumNames = enums.map((Enum x) => x.name).toList();
+  indent.write('+ (instancetype)makeWith');
+  bool isFirst = true;
+  indent.nest(2, () {
+    for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+      final String label = isFirst ? _capitalize(field.name) : field.name;
+      final void Function(String) printer = isFirst
+          ? indent.add
+          : (String x) {
+              indent.addln('');
+              indent.write(x);
+            };
+      isFirst = false;
+      final HostDatatype hostDatatype = getFieldHostDatatype(
+          field,
+          classes,
+          enums,
+          (TypeDeclaration x) => _objcTypePtrForPrimitiveDartType(prefix, x),
+          customResolver: customEnumNames.contains(field.type.baseName)
+              ? (String x) => _className(prefix, x)
+              : (String x) => '${_className(prefix, x)} *');
+      final String nullable =
+          _isNullable(hostDatatype, field.type) ? 'nullable ' : '';
+      printer('$label:($nullable${hostDatatype.datatype})${field.name}');
+    }
+  });
+}
+
 /// Calculates the ObjC class name, possibly prefixed.
 String _className(String? prefix, String className) {
   if (prefix != null) {
@@ -971,176 +1058,6 @@ String _getSelector(Method func, String lastSelectorComponent) =>
 String _getSafeArgName(int count, NamedType arg) =>
     arg.name.isEmpty ? 'arg$count' : 'arg_${arg.name}';
 
-/// Writes the definition code for a host [Api].
-/// See also: [_writeHostApiDeclaration]
-void _writeHostApiSource(
-    Indent indent, ObjcOptions options, Api api, Root root) {
-  assert(api.location == ApiLocation.host);
-  final String apiName = _className(options.prefix, api.name);
-
-  void writeChannelAllocation(Method func, String varName, String? taskQueue) {
-    indent.writeln('FlutterBasicMessageChannel *$varName =');
-    indent.inc();
-    indent.writeln('[[FlutterBasicMessageChannel alloc]');
-    indent.inc();
-    indent.writeln('initWithName:@"${makeChannelName(api, func)}"');
-    indent.writeln('binaryMessenger:binaryMessenger');
-    indent.write('codec:');
-    indent.add('${_getCodecGetterName(options.prefix, api.name)}()');
-
-    if (taskQueue != null) {
-      indent.addln('');
-      indent.addln('taskQueue:$taskQueue];');
-    } else {
-      indent.addln('];');
-    }
-    indent.dec();
-    indent.dec();
-  }
-
-  void writeChannelApiBinding(Method func, String channel) {
-    void unpackArgs(String variable, Iterable<String> argNames) {
-      indent.writeln('NSArray *args = $variable;');
-      map3(wholeNumbers.take(func.arguments.length), argNames, func.arguments,
-          (int count, String argName, NamedType arg) {
-        if (isEnum(root, arg.type)) {
-          return '${_className(options.prefix, arg.type.baseName)} $argName = [GetNullableObjectAtIndex(args, $count) integerValue];';
-        } else {
-          final _ObjcPtr argType =
-              _objcTypeForDartType(options.prefix, arg.type);
-          return '${argType.ptr}$argName = GetNullableObjectAtIndex(args, $count);';
-        }
-      }).forEach(indent.writeln);
-    }
-
-    void writeAsyncBindings(Iterable<String> selectorComponents,
-        String callSignature, _ObjcPtr returnType) {
-      if (func.returnType.isVoid) {
-        const String callback = 'callback(wrapResult(nil, error));';
-        if (func.arguments.isEmpty) {
-          indent.writeScoped(
-              '[api ${selectorComponents.first}:^(FlutterError *_Nullable error) {',
-              '}];', () {
-            indent.writeln(callback);
-          });
-        } else {
-          indent.writeScoped(
-              '[api $callSignature ${selectorComponents.last}:^(FlutterError *_Nullable error) {',
-              '}];', () {
-            indent.writeln(callback);
-          });
-        }
-      } else {
-        const String callback = 'callback(wrapResult(output, error));';
-        if (func.arguments.isEmpty) {
-          indent.writeScoped(
-              '[api ${selectorComponents.first}:^(${returnType.ptr}_Nullable output, FlutterError *_Nullable error) {',
-              '}];', () {
-            indent.writeln(callback);
-          });
-        } else {
-          indent.writeScoped(
-              '[api $callSignature ${selectorComponents.last}:^(${returnType.ptr}_Nullable output, FlutterError *_Nullable error) {',
-              '}];', () {
-            indent.writeln(callback);
-          });
-        }
-      }
-    }
-
-    void writeSyncBindings(String call, _ObjcPtr returnType) {
-      indent.writeln('FlutterError *error;');
-      if (func.returnType.isVoid) {
-        indent.writeln('$call;');
-        indent.writeln('callback(wrapResult(nil, error));');
-      } else {
-        indent.writeln('${returnType.ptr}output = $call;');
-        indent.writeln('callback(wrapResult(output, error));');
-      }
-    }
-
-    // TODO(gaaclarke): Incorporate this into _getSelectorComponents.
-    final String lastSelectorComponent =
-        func.isAsynchronous ? 'completion' : 'error';
-    final String selector = _getSelector(func, lastSelectorComponent);
-    indent.writeln(
-        'NSCAssert([api respondsToSelector:@selector($selector)], @"$apiName api (%@) doesn\'t respond to @selector($selector)", api);');
-    indent.write(
-        '[$channel setMessageHandler:^(id _Nullable message, FlutterReply callback) ');
-    indent.scoped('{', '}];', () {
-      final _ObjcPtr returnType =
-          _objcTypeForDartType(options.prefix, func.returnType);
-      final Iterable<String> selectorComponents =
-          _getSelectorComponents(func, lastSelectorComponent);
-      final Iterable<String> argNames =
-          indexMap(func.arguments, _getSafeArgName);
-      final String callSignature =
-          map2(selectorComponents.take(argNames.length), argNames,
-              (String selectorComponent, String argName) {
-        return '$selectorComponent:$argName';
-      }).join(' ');
-      if (func.arguments.isNotEmpty) {
-        unpackArgs('message', argNames);
-      }
-      if (func.isAsynchronous) {
-        writeAsyncBindings(selectorComponents, callSignature, returnType);
-      } else {
-        final String syncCall = func.arguments.isEmpty
-            ? '[api ${selectorComponents.first}:&error]'
-            : '[api $callSignature error:&error]';
-        writeSyncBindings(syncCall, returnType);
-      }
-    });
-  }
-
-  const String channelName = 'channel';
-  indent.write(
-      'void ${apiName}Setup(id<FlutterBinaryMessenger> binaryMessenger, NSObject<$apiName> *api) ');
-  indent.scoped('{', '}', () {
-    for (final Method func in api.methods) {
-      indent.write('');
-      addDocumentationComments(
-          indent, func.documentationComments, _docCommentSpec);
-
-      indent.scoped('{', '}', () {
-        String? taskQueue;
-        if (func.taskQueueType != TaskQueueType.serial) {
-          taskQueue = 'taskQueue';
-          indent.writeln(
-              'NSObject<FlutterTaskQueue> *$taskQueue = [binaryMessenger makeBackgroundTaskQueue];');
-        }
-        writeChannelAllocation(func, channelName, taskQueue);
-        indent.write('if (api) ');
-        indent.scoped('{', '}', () {
-          writeChannelApiBinding(func, channelName);
-        });
-        indent.write('else ');
-        indent.scoped('{', '}', () {
-          indent.writeln('[$channelName setMessageHandler:nil];');
-        });
-      });
-    }
-  });
-}
-
-/// Writes the definition code for a flutter [Api].
-/// See also: [_writeFlutterApiDeclaration]
-void _writeFlutterApiSource(
-    Indent indent, ObjcOptions languageOptions, Api api, Root root) {
-  assert(api.location == ApiLocation.flutter);
-  final String apiName = _className(languageOptions.prefix, api.name);
-
-  _writeExtension(indent, apiName);
-  indent.addln('');
-  indent.writeln('@implementation $apiName');
-  indent.addln('');
-  _writeInitializer(indent);
-  for (final Method func in api.methods) {
-    _writeMethod(languageOptions, root, indent, api, func);
-  }
-  indent.writeln('@end');
-}
-
 void _writeExtension(Indent indent, String apiName) {
   indent.writeln('@interface $apiName ()');
   indent.writeln(
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
index 74c3c2e68f4..e0ac4f05d54 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h
@@ -209,6 +209,7 @@ NSObject<FlutterMessageCodec> *FlutterIntegrationCoreApiGetCodec(void);
 - (void)echoString:(NSString *)aString
         completion:(void (^)(NSString *_Nullable, NSError *_Nullable))completion;
 @end
+
 /// The codec used by HostTrivialApi.
 NSObject<FlutterMessageCodec> *HostTrivialApiGetCodec(void);
 
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
index c52ea0822e1..1b0720b5276 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m
@@ -34,11 +34,13 @@ + (AllTypes *)fromList:(NSArray *)list;
 + (nullable AllTypes *)nullableFromList:(NSArray *)list;
 - (NSArray *)toList;
 @end
+
 @interface AllNullableTypes ()
 + (AllNullableTypes *)fromList:(NSArray *)list;
 + (nullable AllNullableTypes *)nullableFromList:(NSArray *)list;
 - (NSArray *)toList;
 @end
+
 @interface AllNullableTypesWrapper ()
 + (AllNullableTypesWrapper *)fromList:(NSArray *)list;
 + (nullable AllNullableTypesWrapper *)nullableFromList:(NSArray *)list;
@@ -895,6 +897,7 @@ - (void)echoString:(NSString *)arg_aString
                  }];
 }
 @end
+
 NSObject<FlutterMessageCodec> *HostTrivialApiGetCodec() {
   static FlutterStandardMessageCodec *sSharedObject = nil;
   sSharedObject = [FlutterStandardMessageCodec sharedInstance];

From a7356c58cb861e9ac925df734690633bc664672d Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Tue, 10 Jan 2023 23:57:34 -0800
Subject: [PATCH 73/87] Cpp

---
 packages/pigeon/lib/cpp_generator.dart  | 996 +++++++++++-------------
 packages/pigeon/lib/objc_generator.dart |   2 +-
 2 files changed, 469 insertions(+), 529 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 313c993ed64..1a119691948 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -75,203 +75,40 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
   /// Instantiates a Cpp Generator.
   CppGenerator();
 
-  /// Generates Cpp header files with specified [CppOptions]
+  /// Generates C++ file of type specified in [generatorOptions]
   @override
   void generate(OutputFileOptions<CppOptions> generatorOptions, Root root,
       StringSink sink) {
     assert(generatorOptions.fileType == FileType.header ||
         generatorOptions.fileType == FileType.source);
-
-    final Indent indent = Indent(sink);
-    writeFilePrologue(generatorOptions, root, sink, indent);
-    writeFileImports(generatorOptions, root, sink, indent);
-
-    for (final Enum anEnum in root.enums) {
-      writeEnum(generatorOptions, root, sink, indent, anEnum);
-    }
-
-    indent.addln('');
-    if (generatorOptions.fileType == FileType.header) {
-      _writeErrorOr(indent, friends: root.apis.map((Api api) => api.name));
-    }
-    for (final Class klass in root.classes) {
-      writeDataClass(generatorOptions, root, sink, indent, klass);
-    }
-
-    for (final Api api in root.apis) {
-      if (getCodecClasses(api, root).isNotEmpty) {
-        _writeCodec(generatorOptions, root, sink, indent, api);
-        indent.addln('');
-      }
-      if (api.location == ApiLocation.host) {
-        writeHostApi(generatorOptions, root, sink, indent, api);
-      } else if (api.location == ApiLocation.flutter) {
-        writeFlutterApi(generatorOptions, root, sink, indent, api);
-      }
-    }
-
-    if (generatorOptions.fileType == FileType.header) {
-      if (generatorOptions.languageOptions.namespace != null) {
-        indent.writeln(
-            '}  // namespace ${generatorOptions.languageOptions.namespace}');
-      }
-      final String guardName = _getGuardName(
-          generatorOptions.languageOptions.headerIncludePath,
-          generatorOptions.languageOptions.namespace);
-      indent.writeln('#endif  // $guardName');
-    } else {
-      if (generatorOptions.languageOptions.namespace != null) {
-        indent.writeln(
-            '}  // namespace ${generatorOptions.languageOptions.namespace}');
-      }
-    }
-  }
-
-  @override
-  void writeFilePrologue(OutputFileOptions<CppOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent) {
-    final FileType fileType = generatorOptions.fileType;
-    if (fileType == FileType.header) {
-      _writeCppHeaderPrologue(generatorOptions, root, sink, indent);
-    } else {
-      _writeCppSourcePrologue(generatorOptions, root, sink, indent);
-    }
-  }
-
-  @override
-  void writeFileImports(OutputFileOptions<CppOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent) {
-    final FileType fileType = generatorOptions.fileType;
-    if (fileType == FileType.header) {
-      _writeCppHeaderImports(generatorOptions, root, sink, indent);
-    } else {
-      _writeCppSourceImports(generatorOptions, root, sink, indent);
-    }
-  }
-
-  @override
-  void writeEnum(OutputFileOptions<CppOptions> generatorOptions, Root root,
-      StringSink sink, Indent indent, Enum anEnum) {
-    final FileType fileType = generatorOptions.fileType;
-    if (fileType == FileType.header) {
-      _writeCppHeaderEnum(generatorOptions, root, sink, indent, anEnum);
-    }
-  }
-
-  @override
-  void writeDataClass(OutputFileOptions<CppOptions> generatorOptions, Root root,
-      StringSink sink, Indent indent, Class klass) {
-    if (generatorOptions.fileType == FileType.header) {
-      // When generating for a Pigeon unit test, add a test fixture friend class to
-      // allow unit testing private methods, since testing serialization via public
-      // methods is essentially an end-to-end test.
-      String? testFixtureClass;
-      if (generatorOptions.languageOptions.namespace?.endsWith('_pigeontest') ??
-          false) {
-        testFixtureClass =
-            '${_pascalCaseFromSnakeCase(generatorOptions.languageOptions.namespace!.replaceAll('_pigeontest', ''))}Test';
-      }
-      _writeCppHeaderDataClass(generatorOptions, root, sink, indent, klass,
-          testFriend: testFixtureClass);
-    } else {
-      _writeCppSourceDataClass(generatorOptions, root, sink, indent, klass);
-    }
-  }
-
-  @override
-  void writeClassEncode(
-    OutputFileOptions<CppOptions> generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Class klass,
-    Set<String> customClassNames,
-    Set<String> customEnumNames,
-  ) {
-    assert(generatorOptions.fileType == FileType.source);
-    _writeCppSourceClassEncode(generatorOptions.languageOptions, root, sink,
-        indent, klass, customClassNames, customEnumNames);
-  }
-
-  @override
-  void writeClassDecode(
-    OutputFileOptions<CppOptions> generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Class klass,
-    Set<String> customClassNames,
-    Set<String> customEnumNames,
-  ) {
-    assert(generatorOptions.fileType == FileType.source);
-    _writeCppSourceClassDecode(generatorOptions, root, sink, indent, klass,
-        customClassNames, customEnumNames);
-  }
-
-  @override
-  void writeFlutterApi(
-    OutputFileOptions<CppOptions> generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Api api,
-  ) {
     if (generatorOptions.fileType == FileType.header) {
-      _writeFlutterApiHeader(indent, api, root);
-    } else {
-      _writeFlutterApiSource(indent, api, root);
+      CppHeaderGenerator()
+          .generate(generatorOptions.languageOptions, root, sink);
+    } else if (generatorOptions.fileType == FileType.source) {
+      CppSourceGenerator()
+          .generate(generatorOptions.languageOptions, root, sink);
     }
   }
+}
 
+/// Writes C++ header (.h) file to sink.
+class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
   @override
-  void writeHostApi(
-    OutputFileOptions<CppOptions> generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Api api,
-  ) {
-    if (generatorOptions.fileType == FileType.header) {
-      _writeHostApiHeader(indent, api, root);
-    } else {
-      _writeHostApiSource(indent, api, root);
-    }
-  }
-
-  void _writeCodec(
-    OutputFileOptions<CppOptions> generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Api api,
-  ) {
-    if (generatorOptions.fileType == FileType.header) {
-      _writeCodecHeader(indent, api, root);
-    } else {
-      _writeCodecSource(indent, api, root);
-    }
-  }
-
-  // Header methods.
-
-  /// Writes Cpp header file header to sink.
-  void _writeCppHeaderPrologue(OutputFileOptions<CppOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent) {
-    if (generatorOptions.languageOptions.copyrightHeader != null) {
-      addLines(indent, generatorOptions.languageOptions.copyrightHeader!,
-          linePrefix: '// ');
+  void writeFilePrologue(
+      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    if (generatorOptions.copyrightHeader != null) {
+      addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
     }
     indent.writeln('$_commentPrefix $generatedCodeWarning');
     indent.writeln('$_commentPrefix $seeAlsoWarning');
     indent.addln('');
   }
 
-  /// Writes Cpp header file imports to sink.
-  void _writeCppHeaderImports(OutputFileOptions<CppOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent) {
+  @override
+  void writeFileImports(
+      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     final String guardName = _getGuardName(
-        generatorOptions.languageOptions.headerIncludePath,
-        generatorOptions.languageOptions.namespace);
+        generatorOptions.headerIncludePath, generatorOptions.namespace);
     indent.writeln('#ifndef $guardName');
     indent.writeln('#define $guardName');
 
@@ -288,24 +125,22 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
       'optional',
     ]);
     indent.addln('');
-    if (generatorOptions.languageOptions.namespace != null) {
-      indent
-          .writeln('namespace ${generatorOptions.languageOptions.namespace} {');
+    if (generatorOptions.namespace != null) {
+      indent.writeln('namespace ${generatorOptions.namespace} {');
     }
     indent.addln('');
-    if (generatorOptions.languageOptions.namespace?.endsWith('_pigeontest') ??
-        false) {
+    if (generatorOptions.namespace?.endsWith('_pigeontest') ?? false) {
       final String testFixtureClass =
-          '${_pascalCaseFromSnakeCase(generatorOptions.languageOptions.namespace!.replaceAll('_pigeontest', ''))}Test';
+          '${_pascalCaseFromSnakeCase(generatorOptions.namespace!.replaceAll('_pigeontest', ''))}Test';
       indent.writeln('class $testFixtureClass;');
     }
     indent.addln('');
     indent.writeln('$_commentPrefix Generated class from Pigeon.');
   }
 
-  /// Writes Cpp header enum to sink.
-  void _writeCppHeaderEnum(OutputFileOptions<CppOptions> options, Root root,
-      StringSink sink, Indent indent, Enum anEnum) {
+  @override
+  void writeEnum(CppOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Enum anEnum) {
     indent.writeln('');
     addDocumentationComments(
         indent, anEnum.documentationComments, _docCommentSpec);
@@ -320,13 +155,23 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
     });
   }
 
-  /// Writes the declaration for the custom class [klass].
-  ///
-  /// See [_writeCppSourceDataClass] for the corresponding declaration.
-  /// This is intended to be added to the header.
-  void _writeCppHeaderDataClass(OutputFileOptions<CppOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent, Class klass,
-      {String? testFriend}) {
+  @override
+  void preDataClasses(
+      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    _writeErrorOr(indent, friends: root.apis.map((Api api) => api.name));
+  }
+
+  @override
+  void writeDataClass(CppOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Class klass) {
+    // When generating for a Pigeon unit test, add a test fixture friend class to
+    // allow unit testing private methods, since testing serialization via public
+    // methods is essentially an end-to-end test.
+    String? testFixtureClass;
+    if (generatorOptions.namespace?.endsWith('_pigeontest') ?? false) {
+      testFixtureClass =
+          '${_pascalCaseFromSnakeCase(generatorOptions.namespace!.replaceAll('_pigeontest', ''))}Test';
+    }
     indent.addln('');
 
     const List<String> generatedMessages = <String>[
@@ -381,8 +226,8 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
           indent.writeln('friend class ${api.name};');
           indent.writeln('friend class ${_getCodecSerializerName(api)};');
         }
-        if (testFriend != null) {
-          indent.writeln('friend class $testFriend;');
+        if (testFixtureClass != null) {
+          indent.writeln('friend class $testFixtureClass;');
         }
 
         for (final NamedType field in getFieldsInSerializationOrder(klass)) {
@@ -399,84 +244,97 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
     indent.writeln('');
   }
 
-  void _writeCodecHeader(Indent indent, Api api, Root root) {
-    assert(getCodecClasses(api, root).isNotEmpty);
-    final String codeSerializerName = _getCodecSerializerName(api);
-    indent
-        .write('class $codeSerializerName : public $_defaultCodecSerializer ');
+  @override
+  void writeClassEncode(
+    CppOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    // Intentionally left blank.
+  }
+
+  @override
+  void writeClassDecode(
+    CppOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Class klass,
+    Set<String> customClassNames,
+    Set<String> customEnumNames,
+  ) {
+    // Intentionally left blank.
+  }
+
+  @override
+  void writeFlutterApi(
+    CppOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    assert(api.location == ApiLocation.flutter);
+    if (getCodecClasses(api, root).isNotEmpty) {
+      _writeCodec(generatorOptions, root, sink, indent, api);
+    }
+    const List<String> generatedMessages = <String>[
+      ' Generated class from Pigeon that represents Flutter messages that can be called from C++.'
+    ];
+    addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
+        generatorComments: generatedMessages);
+    indent.write('class ${api.name} ');
     indent.scoped('{', '};', () {
+      indent.scoped(' private:', '', () {
+        indent.writeln('flutter::BinaryMessenger* binary_messenger_;');
+      });
       indent.scoped(' public:', '', () {
+        indent
+            .write('${api.name}(flutter::BinaryMessenger* binary_messenger);');
         indent.writeln('');
-        indent.format('''
-inline static $codeSerializerName& GetInstance() {
-\tstatic $codeSerializerName sInstance;
-\treturn sInstance;
-}
-''');
-        indent.writeln('$codeSerializerName();');
-      });
-      indent.writeScoped(' public:', '', () {
-        indent.writeln(
-            'void WriteValue(const flutter::EncodableValue& value, flutter::ByteStreamWriter* stream) const override;');
-      });
-      indent.writeScoped(' protected:', '', () {
-        indent.writeln(
-            'flutter::EncodableValue ReadValueOfType(uint8_t type, flutter::ByteStreamReader* stream) const override;');
+        indent
+            .writeln('static const flutter::StandardMessageCodec& GetCodec();');
+        for (final Method func in api.methods) {
+          final String returnType = func.returnType.isVoid
+              ? 'void'
+              : _nullSafeCppTypeForDartType(func.returnType);
+          final String callback = 'std::function<void($returnType)>&& callback';
+          addDocumentationComments(
+              indent, func.documentationComments, _docCommentSpec);
+          if (func.arguments.isEmpty) {
+            indent.writeln('void ${func.name}($callback);');
+          } else {
+            final Iterable<String> argTypes = func.arguments
+                .map((NamedType e) => _nullSafeCppTypeForDartType(e.type));
+            final Iterable<String> argNames =
+                indexMap(func.arguments, _getSafeArgumentName);
+            final String argsSignature =
+                map2(argTypes, argNames, (String x, String y) => '$x $y')
+                    .join(', ');
+            indent.writeln('void ${func.name}($argsSignature, $callback);');
+          }
+        }
       });
     }, nestCount: 0);
+    indent.writeln('');
   }
 
-  void _writeErrorOr(Indent indent,
-      {Iterable<String> friends = const <String>[]}) {
-    final String friendLines = friends
-        .map((String className) => '\tfriend class $className;')
-        .join('\n');
-    indent.format('''
-class FlutterError {
- public:
-\texplicit FlutterError(const std::string& code)
-\t\t: code_(code) {}
-\texplicit FlutterError(const std::string& code, const std::string& message)
-\t\t: code_(code), message_(message) {}
-\texplicit FlutterError(const std::string& code, const std::string& message, const flutter::EncodableValue& details)
-\t\t: code_(code), message_(message), details_(details) {}
-
-\tconst std::string& code() const { return code_; }
-\tconst std::string& message() const { return message_; }
-\tconst flutter::EncodableValue& details() const { return details_; }
-
- private:
-\tstd::string code_;
-\tstd::string message_;
-\tflutter::EncodableValue details_;
-};
-
-template<class T> class ErrorOr {
- public:
-\tErrorOr(const T& rhs) { new(&v_) T(rhs); }
-\tErrorOr(const T&& rhs) { v_ = std::move(rhs); }
-\tErrorOr(const FlutterError& rhs) {
-\t\tnew(&v_) FlutterError(rhs);
-\t}
-\tErrorOr(const FlutterError&& rhs) { v_ = std::move(rhs); }
-
-\tbool has_error() const { return std::holds_alternative<FlutterError>(v_); }
-\tconst T& value() const { return std::get<T>(v_); };
-\tconst FlutterError& error() const { return std::get<FlutterError>(v_); };
-
- private:
-$friendLines
-\tErrorOr() = default;
-\tT TakeValue() && { return std::get<T>(std::move(v_)); }
-
-\tstd::variant<T, FlutterError> v_;
-};
-''');
-  }
-
-  void _writeHostApiHeader(Indent indent, Api api, Root root) {
+  @override
+  void writeHostApi(
+    CppOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
     assert(api.location == ApiLocation.host);
-
+    if (getCodecClasses(api, root).isNotEmpty) {
+      _writeCodec(generatorOptions, root, sink, indent, api);
+    }
     const List<String> generatedMessages = <String>[
       ' Generated interface from Pigeon that represents a handler of messages from Flutter.'
     ];
@@ -547,58 +405,107 @@ $friendLines
     }, nestCount: 0);
   }
 
-  void _writeFlutterApiHeader(Indent indent, Api api, Root root) {
-    assert(api.location == ApiLocation.flutter);
-
-    const List<String> generatedMessages = <String>[
-      ' Generated class from Pigeon that represents Flutter messages that can be called from C++.'
-    ];
-    addDocumentationComments(indent, api.documentationComments, _docCommentSpec,
-        generatorComments: generatedMessages);
-    indent.write('class ${api.name} ');
+  void _writeCodec(CppOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Api api) {
+    assert(getCodecClasses(api, root).isNotEmpty);
+    final String codeSerializerName = _getCodecSerializerName(api);
+    indent
+        .write('class $codeSerializerName : public $_defaultCodecSerializer ');
     indent.scoped('{', '};', () {
-      indent.scoped(' private:', '', () {
-        indent.writeln('flutter::BinaryMessenger* binary_messenger_;');
-      });
       indent.scoped(' public:', '', () {
-        indent
-            .write('${api.name}(flutter::BinaryMessenger* binary_messenger);');
         indent.writeln('');
-        indent
-            .writeln('static const flutter::StandardMessageCodec& GetCodec();');
-        for (final Method func in api.methods) {
-          final String returnType = func.returnType.isVoid
-              ? 'void'
-              : _nullSafeCppTypeForDartType(func.returnType);
-          final String callback = 'std::function<void($returnType)>&& callback';
-          addDocumentationComments(
-              indent, func.documentationComments, _docCommentSpec);
-          if (func.arguments.isEmpty) {
-            indent.writeln('void ${func.name}($callback);');
-          } else {
-            final Iterable<String> argTypes = func.arguments
-                .map((NamedType e) => _nullSafeCppTypeForDartType(e.type));
-            final Iterable<String> argNames =
-                indexMap(func.arguments, _getSafeArgumentName);
-            final String argsSignature =
-                map2(argTypes, argNames, (String x, String y) => '$x $y')
-                    .join(', ');
-            indent.writeln('void ${func.name}($argsSignature, $callback);');
-          }
-        }
+        indent.format('''
+inline static $codeSerializerName& GetInstance() {
+\tstatic $codeSerializerName sInstance;
+\treturn sInstance;
+}
+''');
+        indent.writeln('$codeSerializerName();');
+      });
+      indent.writeScoped(' public:', '', () {
+        indent.writeln(
+            'void WriteValue(const flutter::EncodableValue& value, flutter::ByteStreamWriter* stream) const override;');
+      });
+      indent.writeScoped(' protected:', '', () {
+        indent.writeln(
+            'flutter::EncodableValue ReadValueOfType(uint8_t type, flutter::ByteStreamReader* stream) const override;');
       });
     }, nestCount: 0);
-    indent.writeln('');
+    indent.addln('');
   }
 
-  // Source methods.
+  @override
+  void postWriteFile(
+    CppOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+  ) {
+    if (generatorOptions.namespace != null) {
+      indent.writeln('}  // namespace ${generatorOptions.namespace}');
+    }
+    final String guardName = _getGuardName(
+        generatorOptions.headerIncludePath, generatorOptions.namespace);
+    indent.writeln('#endif  // $guardName');
+  }
 
-  /// Writes Cpp source file header to sink.
-  void _writeCppSourcePrologue(OutputFileOptions<CppOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent) {
-    if (generatorOptions.languageOptions.copyrightHeader != null) {
-      addLines(indent, generatorOptions.languageOptions.copyrightHeader!,
-          linePrefix: '// ');
+  void _writeErrorOr(Indent indent,
+      {Iterable<String> friends = const <String>[]}) {
+    final String friendLines = friends
+        .map((String className) => '\tfriend class $className;')
+        .join('\n');
+    indent.format('''
+
+class FlutterError {
+ public:
+\texplicit FlutterError(const std::string& code)
+\t\t: code_(code) {}
+\texplicit FlutterError(const std::string& code, const std::string& message)
+\t\t: code_(code), message_(message) {}
+\texplicit FlutterError(const std::string& code, const std::string& message, const flutter::EncodableValue& details)
+\t\t: code_(code), message_(message), details_(details) {}
+
+\tconst std::string& code() const { return code_; }
+\tconst std::string& message() const { return message_; }
+\tconst flutter::EncodableValue& details() const { return details_; }
+
+ private:
+\tstd::string code_;
+\tstd::string message_;
+\tflutter::EncodableValue details_;
+};
+
+template<class T> class ErrorOr {
+ public:
+\tErrorOr(const T& rhs) { new(&v_) T(rhs); }
+\tErrorOr(const T&& rhs) { v_ = std::move(rhs); }
+\tErrorOr(const FlutterError& rhs) {
+\t\tnew(&v_) FlutterError(rhs);
+\t}
+\tErrorOr(const FlutterError&& rhs) { v_ = std::move(rhs); }
+
+\tbool has_error() const { return std::holds_alternative<FlutterError>(v_); }
+\tconst T& value() const { return std::get<T>(v_); };
+\tconst FlutterError& error() const { return std::get<FlutterError>(v_); };
+
+ private:
+$friendLines
+\tErrorOr() = default;
+\tT TakeValue() && { return std::get<T>(std::move(v_)); }
+
+\tstd::variant<T, FlutterError> v_;
+};
+''');
+  }
+}
+
+/// Writes C++ source (.cpp) file to sink.
+class CppSourceGenerator extends StructuredGenerator<CppOptions> {
+  @override
+  void writeFilePrologue(
+      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    if (generatorOptions.copyrightHeader != null) {
+      addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
     }
     indent.writeln('$_commentPrefix $generatedCodeWarning');
     indent.writeln('$_commentPrefix $seeAlsoWarning');
@@ -607,11 +514,10 @@ $friendLines
     indent.addln('');
   }
 
-  /// Writes Cpp source file imports to sink.
-  void _writeCppSourceImports(OutputFileOptions<CppOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent) {
-    indent.writeln(
-        '#include "${generatorOptions.languageOptions.headerIncludePath}"');
+  @override
+  void writeFileImports(
+      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    indent.writeln('#include "${generatorOptions.headerIncludePath}"');
     indent.addln('');
     _writeSystemHeaderIncludeBlock(indent, <String>[
       'flutter/basic_message_channel.h',
@@ -627,13 +533,50 @@ $friendLines
     ]);
     indent.addln('');
 
-    if (generatorOptions.languageOptions.namespace != null) {
-      indent
-          .writeln('namespace ${generatorOptions.languageOptions.namespace} {');
+    if (generatorOptions.namespace != null) {
+      indent.writeln('namespace ${generatorOptions.namespace} {');
     }
   }
 
-  void _writeCppSourceClassEncode(
+  @override
+  void writeEnum(CppOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Enum anEnum) {
+    // Intentionally left empty.
+  }
+
+  @override
+  void writeDataClass(CppOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Class klass) {
+    final Set<String> customClassNames =
+        root.classes.map((Class x) => x.name).toSet();
+    final Set<String> customEnumNames =
+        root.enums.map((Enum x) => x.name).toSet();
+
+    indent.addln('');
+    indent.writeln('$_commentPrefix ${klass.name}');
+    indent.addln('');
+
+    // Getters and setters.
+    for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+      _writeCppSourceClassField(
+          generatorOptions, root, sink, indent, klass, field);
+    }
+
+    // Serialization.
+    writeClassEncode(generatorOptions, root, sink, indent, klass,
+        customClassNames, customEnumNames);
+
+    // Default constructor.
+    indent.writeln('${klass.name}::${klass.name}() {}');
+    indent.addln('');
+
+    // Deserialization.
+    writeClassDecode(generatorOptions, root, sink, indent, klass,
+        customClassNames, customEnumNames);
+  }
+
+  @override
+  void writeClassEncode(
     CppOptions generatorOptions,
     Root root,
     StringSink sink,
@@ -685,8 +628,9 @@ $friendLines
     indent.addln('');
   }
 
-  void _writeCppSourceClassDecode(
-    OutputFileOptions<CppOptions> generatorOptions,
+  @override
+  void writeClassDecode(
+    CppOptions generatorOptions,
     Root root,
     StringSink sink,
     Indent indent,
@@ -743,124 +687,122 @@ else if (const int64_t* ${pointerFieldName}_64 = std::get_if<int64_t>(&$encodabl
     indent.addln('');
   }
 
-  void _writeCppSourceClassField(OutputFileOptions<CppOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent, Class klass, NamedType field) {
-    final HostDatatype hostDatatype = getFieldHostDatatype(field, root.classes,
-        root.enums, (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
-    final String instanceVariableName = _makeInstanceVariableName(field);
-    final String qualifiedGetterName =
-        '${klass.name}::${_makeGetterName(field)}';
-    final String qualifiedSetterName =
-        '${klass.name}::${_makeSetterName(field)}';
-    final String returnExpression = hostDatatype.isNullable
-        ? '$instanceVariableName ? &(*$instanceVariableName) : nullptr'
-        : instanceVariableName;
-
-    // Generates the string for a setter treating the type as [type], to allow
-    // generating multiple setter variants.
-    String makeSetter(HostDatatype type) {
-      const String setterArgumentName = 'value_arg';
-      final String valueExpression = type.isNullable
-          ? '$setterArgumentName ? ${_valueType(type)}(*$setterArgumentName) : std::nullopt'
-          : setterArgumentName;
-      return 'void $qualifiedSetterName(${_unownedArgumentType(type)} $setterArgumentName) '
-          '{ $instanceVariableName = $valueExpression; }';
+  @override
+  void writeFlutterApi(
+    CppOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    assert(api.location == ApiLocation.flutter);
+    if (getCodecClasses(api, root).isNotEmpty) {
+      _writeCodec(generatorOptions, root, sink, indent, api);
     }
-
     indent.writeln(
-        '${_getterReturnType(hostDatatype)} $qualifiedGetterName() const '
-        '{ return $returnExpression; }');
-    indent.writeln(makeSetter(hostDatatype));
-    if (hostDatatype.isNullable) {
-      // Write the non-nullable variant; see _writeCppHeaderDataClass.
-      final HostDatatype nonNullType = _nonNullableType(hostDatatype);
-      indent.writeln(makeSetter(nonNullType));
-    }
-
-    indent.addln('');
-  }
-
-  /// Writes the implementation for the custom class [klass].
-  ///
-  /// See [_writeCppHeaderDataClass] for the corresponding declaration.
-  /// This is intended to be added to the implementation file.
-  void _writeCppSourceDataClass(OutputFileOptions<CppOptions> generatorOptions,
-      Root root, StringSink sink, Indent indent, Class klass) {
-    final Set<String> customClassNames =
-        root.classes.map((Class x) => x.name).toSet();
-    final Set<String> customEnumNames =
-        root.enums.map((Enum x) => x.name).toSet();
-
-    indent.addln('');
-    indent.writeln('$_commentPrefix ${klass.name}');
-    indent.addln('');
-
-    // Getters and setters.
-    for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-      _writeCppSourceClassField(
-          generatorOptions, root, sink, indent, klass, field);
-    }
-
-    // Serialization.
-    writeClassEncode(generatorOptions, root, sink, indent, klass,
-        customClassNames, customEnumNames);
-
-    // Default constructor.
-    indent.writeln('${klass.name}::${klass.name}() {}');
-    indent.addln('');
-
-    // Deserialization.
-    writeClassDecode(generatorOptions, root, sink, indent, klass,
-        customClassNames, customEnumNames);
-  }
-
-  void _writeCodecSource(Indent indent, Api api, Root root) {
-    assert(getCodecClasses(api, root).isNotEmpty);
-    final String codeSerializerName = _getCodecSerializerName(api);
-    indent.writeln('$codeSerializerName::$codeSerializerName() {}');
+        '$_commentPrefix Generated class from Pigeon that represents Flutter messages that can be called from C++.');
     indent.write(
-        'flutter::EncodableValue $codeSerializerName::ReadValueOfType(uint8_t type, flutter::ByteStreamReader* stream) const ');
+        '${api.name}::${api.name}(flutter::BinaryMessenger* binary_messenger) ');
     indent.scoped('{', '}', () {
-      indent.write('switch (type) ');
-      indent.scoped('{', '}', () {
-        for (final EnumeratedClass customClass in getCodecClasses(api, root)) {
-          indent.write('case ${customClass.enumeration}:');
-          indent.writeScoped('', '', () {
-            indent.writeln(
-                'return flutter::CustomEncodableValue(${customClass.name}(std::get<flutter::EncodableList>(ReadValue(stream))));');
-          });
-        }
-        indent.write('default:');
-        indent.writeScoped('', '', () {
-          indent.writeln(
-              'return $_defaultCodecSerializer::ReadValueOfType(type, stream);');
-        }, addTrailingNewline: false);
-      });
+      indent.writeln('this->binary_messenger_ = binary_messenger;');
     });
     indent.writeln('');
-    indent.write(
-        'void $codeSerializerName::WriteValue(const flutter::EncodableValue& value, flutter::ByteStreamWriter* stream) const ');
-    indent.writeScoped('{', '}', () {
-      indent.write(
-          'if (const flutter::CustomEncodableValue* custom_value = std::get_if<flutter::CustomEncodableValue>(&value)) ');
+    final String codeSerializerName = getCodecClasses(api, root).isNotEmpty
+        ? _getCodecSerializerName(api)
+        : _defaultCodecSerializer;
+    indent.format('''
+const flutter::StandardMessageCodec& ${api.name}::GetCodec() {
+\treturn flutter::StandardMessageCodec::GetInstance(&$codeSerializerName::GetInstance());
+}
+''');
+    for (final Method func in api.methods) {
+      final String channelName = makeChannelName(api, func);
+      final String returnType = func.returnType.isVoid
+          ? 'void'
+          : _nullSafeCppTypeForDartType(func.returnType);
+      String sendArgument;
+      final String callback = 'std::function<void($returnType)>&& callback';
+      if (func.arguments.isEmpty) {
+        indent.write('void ${api.name}::${func.name}($callback) ');
+        sendArgument = 'flutter::EncodableValue()';
+      } else {
+        final Iterable<String> argTypes = func.arguments
+            .map((NamedType e) => _nullSafeCppTypeForDartType(e.type));
+        final Iterable<String> argNames =
+            indexMap(func.arguments, _getSafeArgumentName);
+        sendArgument =
+            'flutter::EncodableList { ${argNames.map((String arg) => 'flutter::CustomEncodableValue($arg)').join(', ')} }';
+        final String argsSignature =
+            map2(argTypes, argNames, (String x, String y) => '$x $y')
+                .join(', ');
+        indent.write(
+            'void ${api.name}::${func.name}($argsSignature, $callback) ');
+      }
       indent.scoped('{', '}', () {
-        for (final EnumeratedClass customClass in getCodecClasses(api, root)) {
-          indent.write(
-              'if (custom_value->type() == typeid(${customClass.name})) ');
-          indent.scoped('{', '}', () {
-            indent.writeln('stream->WriteByte(${customClass.enumeration});');
+        const String channel = 'channel';
+        indent.writeln(
+            'auto channel = std::make_unique<flutter::BasicMessageChannel<flutter::EncodableValue>>(');
+        indent.inc();
+        indent.inc();
+        indent.writeln('binary_messenger_, "$channelName", &GetCodec());');
+        indent.dec();
+        indent.dec();
+        indent.write(
+            '$channel->Send($sendArgument, [callback](const uint8_t* reply, size_t reply_size) ');
+        indent.scoped('{', '});', () {
+          if (func.returnType.isVoid) {
+            indent.writeln('callback();');
+          } else {
             indent.writeln(
-                'WriteValue(flutter::EncodableValue(std::any_cast<${customClass.name}>(*custom_value).ToEncodableList()), stream);');
-            indent.writeln('return;');
-          });
-        }
+                'std::unique_ptr<flutter::EncodableValue> decoded_reply = GetCodec().DecodeMessage(reply, reply_size);');
+            indent.writeln(
+                'flutter::EncodableValue args = *(flutter::EncodableValue*)(decoded_reply.release());');
+            const String output = 'output';
+
+            final bool isBuiltin =
+                _baseCppTypeForBuiltinDartType(func.returnType) != null;
+            final String returnTypeName =
+                _baseCppTypeForDartType(func.returnType);
+            if (func.returnType.isNullable) {
+              indent.writeln('$returnType $output{};');
+            } else {
+              indent.writeln('$returnTypeName $output{};');
+            }
+            const String pointerVariable = '${_pointerPrefix}_$output';
+            if (func.returnType.baseName == 'int') {
+              indent.format('''
+if (const int32_t* $pointerVariable = std::get_if<int32_t>(&args))
+\t$output = *$pointerVariable;
+else if (const int64_t* ${pointerVariable}_64 = std::get_if<int64_t>(&args))
+\t$output = *${pointerVariable}_64;''');
+            } else if (!isBuiltin) {
+              indent.write(
+                  'if (const flutter::EncodableList* $pointerVariable = std::get_if<flutter::EncodableList>(&args)) ');
+              indent.scoped('{', '}', () {
+                indent.writeln('$output = $returnTypeName(*$pointerVariable);');
+              });
+            } else {
+              indent.write(
+                  'if (const $returnTypeName* $pointerVariable = std::get_if<$returnTypeName>(&args)) ');
+              indent.scoped('{', '}', () {
+                indent.writeln('$output = *$pointerVariable;');
+              });
+            }
+
+            indent.writeln('callback($output);');
+          }
+        });
       });
-      indent.writeln('$_defaultCodecSerializer::WriteValue(value, stream);');
-    });
+    }
   }
 
-  void _writeHostApiSource(Indent indent, Api api, Root root) {
+  @override
+  void writeHostApi(CppOptions generatorOptions, Root root, StringSink sink,
+      Indent indent, Api api) {
     assert(api.location == ApiLocation.host);
+    if (getCodecClasses(api, root).isNotEmpty) {
+      _writeCodec(generatorOptions, root, sink, indent, api);
+    }
 
     final String codeSerializerName = getCodecClasses(api, root).isNotEmpty
         ? _getCodecSerializerName(api)
@@ -1054,6 +996,103 @@ flutter::EncodableList ${api.name}::WrapError(const FlutterError& error) {
     indent.addln('');
   }
 
+  @override
+  void postWriteFile(
+      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    if (generatorOptions.namespace != null) {
+      indent.writeln('}  // namespace ${generatorOptions.namespace}');
+    }
+  }
+
+  void _writeCodec(
+    CppOptions generatorOptions,
+    Root root,
+    StringSink sink,
+    Indent indent,
+    Api api,
+  ) {
+    assert(getCodecClasses(api, root).isNotEmpty);
+    final String codeSerializerName = _getCodecSerializerName(api);
+    indent.writeln('$codeSerializerName::$codeSerializerName() {}');
+    indent.write(
+        'flutter::EncodableValue $codeSerializerName::ReadValueOfType(uint8_t type, flutter::ByteStreamReader* stream) const ');
+    indent.scoped('{', '}', () {
+      indent.write('switch (type) ');
+      indent.scoped('{', '}', () {
+        for (final EnumeratedClass customClass in getCodecClasses(api, root)) {
+          indent.write('case ${customClass.enumeration}:');
+          indent.writeScoped('', '', () {
+            indent.writeln(
+                'return flutter::CustomEncodableValue(${customClass.name}(std::get<flutter::EncodableList>(ReadValue(stream))));');
+          });
+        }
+        indent.write('default:');
+        indent.writeScoped('', '', () {
+          indent.writeln(
+              'return $_defaultCodecSerializer::ReadValueOfType(type, stream);');
+        }, addTrailingNewline: false);
+      });
+    });
+    indent.writeln('');
+    indent.write(
+        'void $codeSerializerName::WriteValue(const flutter::EncodableValue& value, flutter::ByteStreamWriter* stream) const ');
+    indent.writeScoped('{', '}', () {
+      indent.write(
+          'if (const flutter::CustomEncodableValue* custom_value = std::get_if<flutter::CustomEncodableValue>(&value)) ');
+      indent.scoped('{', '}', () {
+        for (final EnumeratedClass customClass in getCodecClasses(api, root)) {
+          indent.write(
+              'if (custom_value->type() == typeid(${customClass.name})) ');
+          indent.scoped('{', '}', () {
+            indent.writeln('stream->WriteByte(${customClass.enumeration});');
+            indent.writeln(
+                'WriteValue(flutter::EncodableValue(std::any_cast<${customClass.name}>(*custom_value).ToEncodableList()), stream);');
+            indent.writeln('return;');
+          });
+        }
+      });
+      indent.writeln('$_defaultCodecSerializer::WriteValue(value, stream);');
+    });
+    indent.writeln('');
+  }
+
+  void _writeCppSourceClassField(CppOptions generatorOptions, Root root,
+      StringSink sink, Indent indent, Class klass, NamedType field) {
+    final HostDatatype hostDatatype = getFieldHostDatatype(field, root.classes,
+        root.enums, (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
+    final String instanceVariableName = _makeInstanceVariableName(field);
+    final String qualifiedGetterName =
+        '${klass.name}::${_makeGetterName(field)}';
+    final String qualifiedSetterName =
+        '${klass.name}::${_makeSetterName(field)}';
+    final String returnExpression = hostDatatype.isNullable
+        ? '$instanceVariableName ? &(*$instanceVariableName) : nullptr'
+        : instanceVariableName;
+
+    // Generates the string for a setter treating the type as [type], to allow
+    // generating multiple setter variants.
+    String makeSetter(HostDatatype type) {
+      const String setterArgumentName = 'value_arg';
+      final String valueExpression = type.isNullable
+          ? '$setterArgumentName ? ${_valueType(type)}(*$setterArgumentName) : std::nullopt'
+          : setterArgumentName;
+      return 'void $qualifiedSetterName(${_unownedArgumentType(type)} $setterArgumentName) '
+          '{ $instanceVariableName = $valueExpression; }';
+    }
+
+    indent.writeln(
+        '${_getterReturnType(hostDatatype)} $qualifiedGetterName() const '
+        '{ return $returnExpression; }');
+    indent.writeln(makeSetter(hostDatatype));
+    if (hostDatatype.isNullable) {
+      // Write the non-nullable variant; see _writeCppHeaderDataClass.
+      final HostDatatype nonNullType = _nonNullableType(hostDatatype);
+      indent.writeln(makeSetter(nonNullType));
+    }
+
+    indent.addln('');
+  }
+
   String _wrapResponse(
       Indent indent, Root root, String reply, TypeDeclaration returnType) {
     String elseBody = '';
@@ -1097,105 +1136,6 @@ $prefix\t}${indent.newline}''';
         '$prefix}'
         '$prefix$reply';
   }
-
-  void _writeFlutterApiSource(Indent indent, Api api, Root root) {
-    assert(api.location == ApiLocation.flutter);
-    indent.writeln(
-        '$_commentPrefix Generated class from Pigeon that represents Flutter messages that can be called from C++.');
-    indent.write(
-        '${api.name}::${api.name}(flutter::BinaryMessenger* binary_messenger) ');
-    indent.scoped('{', '}', () {
-      indent.writeln('this->binary_messenger_ = binary_messenger;');
-    });
-    indent.writeln('');
-    final String codeSerializerName = getCodecClasses(api, root).isNotEmpty
-        ? _getCodecSerializerName(api)
-        : _defaultCodecSerializer;
-    indent.format('''
-const flutter::StandardMessageCodec& ${api.name}::GetCodec() {
-\treturn flutter::StandardMessageCodec::GetInstance(&$codeSerializerName::GetInstance());
-}
-''');
-    for (final Method func in api.methods) {
-      final String channelName = makeChannelName(api, func);
-      final String returnType = func.returnType.isVoid
-          ? 'void'
-          : _nullSafeCppTypeForDartType(func.returnType);
-      String sendArgument;
-      final String callback = 'std::function<void($returnType)>&& callback';
-      if (func.arguments.isEmpty) {
-        indent.write('void ${api.name}::${func.name}($callback) ');
-        sendArgument = 'flutter::EncodableValue()';
-      } else {
-        final Iterable<String> argTypes = func.arguments
-            .map((NamedType e) => _nullSafeCppTypeForDartType(e.type));
-        final Iterable<String> argNames =
-            indexMap(func.arguments, _getSafeArgumentName);
-        sendArgument =
-            'flutter::EncodableList { ${argNames.map((String arg) => 'flutter::CustomEncodableValue($arg)').join(', ')} }';
-        final String argsSignature =
-            map2(argTypes, argNames, (String x, String y) => '$x $y')
-                .join(', ');
-        indent.write(
-            'void ${api.name}::${func.name}($argsSignature, $callback) ');
-      }
-      indent.scoped('{', '}', () {
-        const String channel = 'channel';
-        indent.writeln(
-            'auto channel = std::make_unique<flutter::BasicMessageChannel<flutter::EncodableValue>>(');
-        indent.inc();
-        indent.inc();
-        indent.writeln('binary_messenger_, "$channelName", &GetCodec());');
-        indent.dec();
-        indent.dec();
-        indent.write(
-            '$channel->Send($sendArgument, [callback](const uint8_t* reply, size_t reply_size) ');
-        indent.scoped('{', '});', () {
-          if (func.returnType.isVoid) {
-            indent.writeln('callback();');
-          } else {
-            indent.writeln(
-                'std::unique_ptr<flutter::EncodableValue> decoded_reply = GetCodec().DecodeMessage(reply, reply_size);');
-            indent.writeln(
-                'flutter::EncodableValue args = *(flutter::EncodableValue*)(decoded_reply.release());');
-            const String output = 'output';
-
-            final bool isBuiltin =
-                _baseCppTypeForBuiltinDartType(func.returnType) != null;
-            final String returnTypeName =
-                _baseCppTypeForDartType(func.returnType);
-            if (func.returnType.isNullable) {
-              indent.writeln('$returnType $output{};');
-            } else {
-              indent.writeln('$returnTypeName $output{};');
-            }
-            const String pointerVariable = '${_pointerPrefix}_$output';
-            if (func.returnType.baseName == 'int') {
-              indent.format('''
-if (const int32_t* $pointerVariable = std::get_if<int32_t>(&args))
-\t$output = *$pointerVariable;
-else if (const int64_t* ${pointerVariable}_64 = std::get_if<int64_t>(&args))
-\t$output = *${pointerVariable}_64;''');
-            } else if (!isBuiltin) {
-              indent.write(
-                  'if (const flutter::EncodableList* $pointerVariable = std::get_if<flutter::EncodableList>(&args)) ');
-              indent.scoped('{', '}', () {
-                indent.writeln('$output = $returnTypeName(*$pointerVariable);');
-              });
-            } else {
-              indent.write(
-                  'if (const $returnTypeName* $pointerVariable = std::get_if<$returnTypeName>(&args)) ');
-              indent.scoped('{', '}', () {
-                indent.writeln('$output = *$pointerVariable;');
-              });
-            }
-
-            indent.writeln('callback($output);');
-          }
-        });
-      });
-    }
-  }
 }
 
 String _getCodecSerializerName(Api api) => '${api.name}CodecSerializer';
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 5c330de9be8..f3f174289e4 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -69,7 +69,7 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
   /// Instantiates a Objc Generator.
   ObjcGenerator();
 
-  /// Generates Objc files of type specified in [ObjcOptions]
+  /// Generates Objc file of type specified in [generatorOptions]
   @override
   void generate(OutputFileOptions<ObjcOptions> generatorOptions, Root root,
       StringSink sink) {

From 892ac554370b8976c4daf27f99eb175efecdbca6 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 11 Jan 2023 13:36:53 -0800
Subject: [PATCH 74/87] analyze

---
 packages/pigeon/lib/objc_generator.dart | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index f3f174289e4..711c1e73687 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -450,8 +450,8 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
         '+ (nullable $className *)nullableFromList:(NSArray *)list { return (list) ? [$className fromList:list] : nil; }');
   }
 
-  _writeCodecAndGetter(ObjcOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Api api) {
+  void _writeCodecAndGetter(ObjcOptions generatorOptions, Root root,
+      StringSink sink, Indent indent, Api api) {
     final String codecName = _getCodecName(generatorOptions.prefix, api.name);
     if (getCodecClasses(api, root).isNotEmpty) {
       _writeCodec(indent, codecName, generatorOptions, api, root);
@@ -680,9 +680,6 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
     indent.writeln('');
   }
 
-  void _writeObjcSourceDataClassImplementation(ObjcOptions generatorOptions,
-      Root root, StringSink sink, Indent indent, Class klass) {}
-
   void _writeObjcSourceClassInitializer(
     ObjcOptions languageOptions,
     Root root,

From 1e6e5c2503190da1ded36fb78af5f4759ee3e06c Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 11 Jan 2023 13:53:39 -0800
Subject: [PATCH 75/87] vocab

---
 packages/pigeon/lib/cpp_generator.dart  | 4 ++--
 packages/pigeon/lib/objc_generator.dart | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 1a119691948..9a3e6bc90d3 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -254,7 +254,7 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
     Set<String> customClassNames,
     Set<String> customEnumNames,
   ) {
-    // Intentionally left blank.
+    // Intentionally left empty.
   }
 
   @override
@@ -267,7 +267,7 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
     Set<String> customClassNames,
     Set<String> customEnumNames,
   ) {
-    // Intentionally left blank.
+    // Intentionally left empty.
   }
 
   @override
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 711c1e73687..4bf159814bd 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -358,7 +358,7 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
   @override
   void writeEnum(ObjcOptions generatorOptions, Root root, StringSink sink,
       Indent indent, Enum anEnum) {
-    // Intentionally left blank.
+    // Intentionally left empty.
   }
 
   @override

From 98d78c35c629f53ee3b2ea9cdbe682e1950e068c Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Wed, 11 Jan 2023 14:58:58 -0800
Subject: [PATCH 76/87] vocab

---
 packages/pigeon/lib/cpp_generator.dart    | 4 ++--
 packages/pigeon/lib/generator.dart        | 4 ++--
 packages/pigeon/lib/java_generator.dart   | 4 ++--
 packages/pigeon/lib/kotlin_generator.dart | 4 ++--
 packages/pigeon/lib/objc_generator.dart   | 2 +-
 packages/pigeon/lib/swift_generator.dart  | 2 +-
 6 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 9a3e6bc90d3..acd3300ecd4 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -435,7 +435,7 @@ inline static $codeSerializerName& GetInstance() {
   }
 
   @override
-  void postWriteFile(
+  void finalWriteFile(
     CppOptions generatorOptions,
     Root root,
     StringSink sink,
@@ -997,7 +997,7 @@ flutter::EncodableList ${api.name}::WrapError(const FlutterError& error) {
   }
 
   @override
-  void postWriteFile(
+  void finalWriteFile(
       CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     if (generatorOptions.namespace != null) {
       indent.writeln('}  // namespace ${generatorOptions.namespace}');
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index e0a3d6e6f66..4e9f8a6fd4e 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -49,7 +49,7 @@ abstract class StructuredGenerator<T> extends Generator<T> {
         writeFlutterApi(generatorOptions, root, sink, indent, api);
       }
     }
-    postWriteFile(generatorOptions, root, sink, indent);
+    finalWriteFile(generatorOptions, root, sink, indent);
   }
 
   /// Pre-process or write before [writeFilePrologue].
@@ -169,7 +169,7 @@ abstract class StructuredGenerator<T> extends Generator<T> {
   /// Post-process for generate and/or writes after all other methods.
   ///
   /// This method is not a reqiured method, and does not need to be overriden if not needed.
-  void postWriteFile(
+  void finalWriteFile(
     T generatorOptions,
     Root root,
     StringSink sink,
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 844695eabe9..5f708e09e28 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -113,7 +113,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
         writeFlutterApi(generatorOptions, root, sink, indent, api);
       }
     }
-    postWriteFile(generatorOptions, root, sink, indent);
+    finalWriteFile(generatorOptions, root, sink, indent);
   }
 
   @override
@@ -762,7 +762,7 @@ Result<$returnType> $resultName = new Result<$returnType>() {
   }
 
   @override
-  void postWriteFile(
+  void finalWriteFile(
       JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     _writeWrapError(indent);
     indent.dec();
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 115f55be9f4..32ae1761700 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -623,8 +623,8 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   }
 
   @override
-  void postWriteFile(KotlinOptions generatorOptions, Root root, StringSink sink,
-      Indent indent) {
+  void finalWriteFile(KotlinOptions generatorOptions, Root root,
+      StringSink sink, Indent indent) {
     _writeWrapResult(indent);
     _writeWrapError(indent);
   }
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 4bf159814bd..bc1bae88795 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -323,7 +323,7 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
   }
 
   @override
-  void postWriteFile(
+  void finalWriteFile(
       ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     indent.writeln('NS_ASSUME_NONNULL_END');
   }
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 9e862cd0f33..0622c9659d2 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -597,7 +597,7 @@ import FlutterMacOS
   }
 
   @override
-  void postWriteFile(SwiftOptions generatorOptions, Root root, StringSink sink,
+  void finalWriteFile(SwiftOptions generatorOptions, Root root, StringSink sink,
       Indent indent) {
     _writeWrapResult(indent);
     _writeWrapError(indent);

From 555b240c284d0b547d1739d0b576f00fc180085d Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 12 Jan 2023 10:16:20 -0800
Subject: [PATCH 77/87] typo

---
 packages/pigeon/lib/generator.dart | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 4e9f8a6fd4e..2cf46a77d7e 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -54,7 +54,7 @@ abstract class StructuredGenerator<T> extends Generator<T> {
 
   /// Pre-process or write before [writeFilePrologue].
   ///
-  /// This method is not a reqiured method, and does not need to be overriden if not needed.
+  /// This method is not a reqiured method, and does not need to be overridden if not needed.
   void prePrologue(
     T generatorOptions,
     Root root,
@@ -80,7 +80,7 @@ abstract class StructuredGenerator<T> extends Generator<T> {
 
   /// Pre-process for enums or writes before any [writeEnum] calls.
   ///
-  /// This method is not a reqiured method, and does not need to be overriden if not needed.
+  /// This method is not a reqiured method, and does not need to be overridden if not needed.
   void preEnums(
     T generatorOptions,
     Root root,
@@ -99,7 +99,7 @@ abstract class StructuredGenerator<T> extends Generator<T> {
 
   /// Pre-process for data classes or writes before any [writeDataClass] calls.
   ///
-  /// This method is not a reqiured method, and does not need to be overriden if not needed.
+  /// This method is not a reqiured method, and does not need to be overridden if not needed.
   void preDataClasses(
     T generatorOptions,
     Root root,
@@ -140,7 +140,7 @@ abstract class StructuredGenerator<T> extends Generator<T> {
 
   /// Pre-process for apis and/or writes before any [writeFlutterApi] or [writeHostApi] calls.
   ///
-  /// This method is not a reqiured method, and does not need to be overriden if not needed.
+  /// This method is not a reqiured method, and does not need to be overridden if not needed.
   void preApis(
     T generatorOptions,
     Root root,
@@ -168,7 +168,7 @@ abstract class StructuredGenerator<T> extends Generator<T> {
 
   /// Post-process for generate and/or writes after all other methods.
   ///
-  /// This method is not a reqiured method, and does not need to be overriden if not needed.
+  /// This method is not a reqiured method, and does not need to be overridden if not needed.
   void finalWriteFile(
     T generatorOptions,
     Root root,

From d80046b49298747deb8b27ece5669ad950a4250a Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 12 Jan 2023 10:17:13 -0800
Subject: [PATCH 78/87] less comma

---
 packages/pigeon/lib/generator.dart | 81 ++++++------------------------
 1 file changed, 14 insertions(+), 67 deletions(-)

diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 2cf46a77d7e..2b6823431aa 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -10,11 +10,7 @@ import 'generator_tools.dart';
 /// This provides the structure that is common across generators for different languages.
 abstract class Generator<T> {
   /// Generates files for specified language with specified [generatorOptions]
-  void generate(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-  );
+  void generate(T generatorOptions, Root root, StringSink sink);
 }
 
 /// A Superclass that enforces code generation across platforms.
@@ -56,65 +52,35 @@ abstract class StructuredGenerator<T> extends Generator<T> {
   ///
   /// This method is not a reqiured method, and does not need to be overridden if not needed.
   void prePrologue(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-  ) {}
+      T generatorOptions, Root root, StringSink sink, Indent indent) {}
 
   /// Adds specified headers to file.
   void writeFilePrologue(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-  );
+      T generatorOptions, Root root, StringSink sink, Indent indent);
 
   /// Adds specified imports to file.
   void writeFileImports(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-  );
+      T generatorOptions, Root root, StringSink sink, Indent indent);
 
   /// Pre-process for enums or writes before any [writeEnum] calls.
   ///
   /// This method is not a reqiured method, and does not need to be overridden if not needed.
   void preEnums(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-  ) {}
+      T generatorOptions, Root root, StringSink sink, Indent indent) {}
 
   /// Writes a single Enum to file.
-  void writeEnum(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Enum anEnum,
-  );
+  void writeEnum(T generatorOptions, Root root, StringSink sink, Indent indent,
+      Enum anEnum);
 
   /// Pre-process for data classes or writes before any [writeDataClass] calls.
   ///
   /// This method is not a reqiured method, and does not need to be overridden if not needed.
   void preDataClasses(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-  ) {}
+      T generatorOptions, Root root, StringSink sink, Indent indent) {}
 
   /// Writes a single data class to file.
-  void writeDataClass(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Class klass,
-  );
+  void writeDataClass(T generatorOptions, Root root, StringSink sink,
+      Indent indent, Class klass);
 
   /// Writes a single class encode method to file.
   void writeClassEncode(
@@ -141,38 +107,19 @@ abstract class StructuredGenerator<T> extends Generator<T> {
   /// Pre-process for apis and/or writes before any [writeFlutterApi] or [writeHostApi] calls.
   ///
   /// This method is not a reqiured method, and does not need to be overridden if not needed.
-  void preApis(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-  ) {}
+  void preApis(T generatorOptions, Root root, StringSink sink, Indent indent) {}
 
   /// Writes a single Flutter Api to file.
   void writeFlutterApi(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Api api,
-  );
+      T generatorOptions, Root root, StringSink sink, Indent indent, Api api);
 
   /// Writes a single Host Api to file.
   void writeHostApi(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Api api,
-  );
+      T generatorOptions, Root root, StringSink sink, Indent indent, Api api);
 
   /// Post-process for generate and/or writes after all other methods.
   ///
   /// This method is not a reqiured method, and does not need to be overridden if not needed.
   void finalWriteFile(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-  ) {}
+      T generatorOptions, Root root, StringSink sink, Indent indent) {}
 }

From a70a0e7e2497e3816a9403ffbcb4f364846d592e Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 12 Jan 2023 12:15:56 -0800
Subject: [PATCH 79/87] wrap write methods

---
 packages/pigeon/lib/cpp_generator.dart    |  7 ++-
 packages/pigeon/lib/generator.dart        | 77 +++++++++++------------
 packages/pigeon/lib/java_generator.dart   | 34 ++--------
 packages/pigeon/lib/kotlin_generator.dart |  5 +-
 packages/pigeon/lib/objc_generator.dart   |  8 ++-
 packages/pigeon/lib/swift_generator.dart  |  7 ++-
 6 files changed, 56 insertions(+), 82 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index acd3300ecd4..b20ad8810e7 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -156,9 +156,10 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
   }
 
   @override
-  void preDataClasses(
+  void writeDataClasses(
       CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     _writeErrorOr(indent, friends: root.apis.map((Api api) => api.name));
+    super.writeDataClasses(generatorOptions, root, sink, indent);
   }
 
   @override
@@ -435,7 +436,7 @@ inline static $codeSerializerName& GetInstance() {
   }
 
   @override
-  void finalWriteFile(
+  void writeGeneralUtilities(
     CppOptions generatorOptions,
     Root root,
     StringSink sink,
@@ -997,7 +998,7 @@ flutter::EncodableList ${api.name}::WrapError(const FlutterError& error) {
   }
 
   @override
-  void finalWriteFile(
+  void writeGeneralUtilities(
       CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     if (generatorOptions.namespace != null) {
       indent.writeln('}  // namespace ${generatorOptions.namespace}');
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 2b6823431aa..ae100c96402 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -23,60 +23,46 @@ abstract class StructuredGenerator<T> extends Generator<T> {
   ) {
     final Indent indent = Indent(sink);
 
-    prePrologue(generatorOptions, root, sink, indent);
     writeFilePrologue(generatorOptions, root, sink, indent);
+
     writeFileImports(generatorOptions, root, sink, indent);
 
-    preEnums(generatorOptions, root, sink, indent);
-    for (final Enum anEnum in root.enums) {
-      writeEnum(generatorOptions, root, sink, indent, anEnum);
-    }
+    writeEnums(generatorOptions, root, sink, indent);
 
-    preDataClasses(generatorOptions, root, sink, indent);
-    for (final Class klass in root.classes) {
-      writeDataClass(generatorOptions, root, sink, indent, klass);
-    }
+    writeDataClasses(generatorOptions, root, sink, indent);
 
-    preApis(generatorOptions, root, sink, indent);
-    for (final Api api in root.apis) {
-      if (api.location == ApiLocation.host) {
-        writeHostApi(generatorOptions, root, sink, indent, api);
-      } else if (api.location == ApiLocation.flutter) {
-        writeFlutterApi(generatorOptions, root, sink, indent, api);
-      }
-    }
-    finalWriteFile(generatorOptions, root, sink, indent);
-  }
+    writeApis(generatorOptions, root, sink, indent);
 
-  /// Pre-process or write before [writeFilePrologue].
-  ///
-  /// This method is not a reqiured method, and does not need to be overridden if not needed.
-  void prePrologue(
-      T generatorOptions, Root root, StringSink sink, Indent indent) {}
+    writeGeneralUtilities(generatorOptions, root, sink, indent);
+  }
 
   /// Adds specified headers to file.
   void writeFilePrologue(
       T generatorOptions, Root root, StringSink sink, Indent indent);
 
-  /// Adds specified imports to file.
+  /// Writes specified imports to file.
   void writeFileImports(
       T generatorOptions, Root root, StringSink sink, Indent indent);
 
-  /// Pre-process for enums or writes before any [writeEnum] calls.
-  ///
-  /// This method is not a reqiured method, and does not need to be overridden if not needed.
-  void preEnums(
-      T generatorOptions, Root root, StringSink sink, Indent indent) {}
+  /// Writes all enums to file. Can be overridden to add extra code before/after enums.
+  void writeEnums(
+      T generatorOptions, Root root, StringSink sink, Indent indent) {
+    for (final Enum anEnum in root.enums) {
+      writeEnum(generatorOptions, root, sink, indent, anEnum);
+    }
+  }
 
   /// Writes a single Enum to file.
   void writeEnum(T generatorOptions, Root root, StringSink sink, Indent indent,
       Enum anEnum);
 
-  /// Pre-process for data classes or writes before any [writeDataClass] calls.
-  ///
-  /// This method is not a reqiured method, and does not need to be overridden if not needed.
-  void preDataClasses(
-      T generatorOptions, Root root, StringSink sink, Indent indent) {}
+  /// Writes all apis to file. Can be overridden to add extra code before/after apis.
+  void writeDataClasses(
+      T generatorOptions, Root root, StringSink sink, Indent indent) {
+    for (final Class klass in root.classes) {
+      writeDataClass(generatorOptions, root, sink, indent, klass);
+    }
+  }
 
   /// Writes a single data class to file.
   void writeDataClass(T generatorOptions, Root root, StringSink sink,
@@ -104,10 +90,17 @@ abstract class StructuredGenerator<T> extends Generator<T> {
     Set<String> customEnumNames,
   );
 
-  /// Pre-process for apis and/or writes before any [writeFlutterApi] or [writeHostApi] calls.
-  ///
-  /// This method is not a reqiured method, and does not need to be overridden if not needed.
-  void preApis(T generatorOptions, Root root, StringSink sink, Indent indent) {}
+  /// Writes all data classes to file. Can be overridden to add extra code before/after classes.
+  void writeApis(
+      T generatorOptions, Root root, StringSink sink, Indent indent) {
+    for (final Api api in root.apis) {
+      if (api.location == ApiLocation.host) {
+        writeHostApi(generatorOptions, root, sink, indent, api);
+      } else if (api.location == ApiLocation.flutter) {
+        writeFlutterApi(generatorOptions, root, sink, indent, api);
+      }
+    }
+  }
 
   /// Writes a single Flutter Api to file.
   void writeFlutterApi(
@@ -117,9 +110,9 @@ abstract class StructuredGenerator<T> extends Generator<T> {
   void writeHostApi(
       T generatorOptions, Root root, StringSink sink, Indent indent, Api api);
 
-  /// Post-process for generate and/or writes after all other methods.
+  /// Writes any necessary helper utilities to file if needed.
   ///
-  /// This method is not a reqiured method, and does not need to be overridden if not needed.
-  void finalWriteFile(
+  /// This method is not reqiured, and does not need to be overridden.
+  void writeGeneralUtilities(
       T generatorOptions, Root root, StringSink sink, Indent indent) {}
 }
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 5f708e09e28..cfd53057ef8 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -90,32 +90,6 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   /// Instantiates a Java Generator.
   JavaGenerator();
 
-  /// Generates the ".java" file for the AST represented by [root] to [sink] with the
-  /// provided [generatorOptions].
-  @override
-  void generate(JavaOptions generatorOptions, Root root, StringSink sink) {
-    final Indent indent = Indent(sink);
-
-    writeFilePrologue(generatorOptions, root, sink, indent);
-    writeFileImports(generatorOptions, root, sink, indent);
-    preEnums(generatorOptions, root, sink, indent);
-    for (final Enum anEnum in root.enums) {
-      writeEnum(generatorOptions, root, sink, indent, anEnum);
-    }
-    for (final Class klass in root.classes) {
-      writeDataClass(generatorOptions, root, sink, indent, klass);
-    }
-    preApis(generatorOptions, root, sink, indent);
-    for (final Api api in root.apis) {
-      if (api.location == ApiLocation.host) {
-        writeHostApi(generatorOptions, root, sink, indent, api);
-      } else if (api.location == ApiLocation.flutter) {
-        writeFlutterApi(generatorOptions, root, sink, indent, api);
-      }
-    }
-    finalWriteFile(generatorOptions, root, sink, indent);
-  }
-
   @override
   void writeFilePrologue(
       JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
@@ -152,7 +126,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   }
 
   @override
-  void preEnums(
+  void writeEnums(
       JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     indent.writeln(
         '$_docCommentPrefix Generated class from Pigeon.$_docCommentSuffix');
@@ -163,6 +137,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
     }
     indent.writeln('public class ${generatorOptions.className!} {');
     indent.inc();
+    super.writeEnums(generatorOptions, root, sink, indent);
   }
 
   @override
@@ -479,7 +454,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   }
 
   @override
-  void preApis(
+  void writeApis(
       JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     if (root.apis.any((Api api) =>
         api.location == ApiLocation.host &&
@@ -487,6 +462,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
       indent.addln('');
       _writeResultInterface(indent);
     }
+    super.writeApis(generatorOptions, root, sink, indent);
   }
 
   /// Write the java code that represents a host [Api], [api].
@@ -762,7 +738,7 @@ Result<$returnType> $resultName = new Result<$returnType>() {
   }
 
   @override
-  void finalWriteFile(
+  void writeGeneralUtilities(
       JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     _writeWrapError(indent);
     indent.dec();
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 32ae1761700..d48a62c6b82 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -285,7 +285,7 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   }
 
   @override
-  void preApis(
+  void writeApis(
     KotlinOptions generatorOptions,
     Root root,
     StringSink sink,
@@ -296,6 +296,7 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
         api.methods.any((Method it) => it.isAsynchronous))) {
       indent.addln('');
     }
+    super.writeApis(generatorOptions, root, sink, indent);
   }
 
   /// Writes the code for a flutter [Api], [api].
@@ -623,7 +624,7 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   }
 
   @override
-  void finalWriteFile(KotlinOptions generatorOptions, Root root,
+  void writeGeneralUtilities(KotlinOptions generatorOptions, Root root,
       StringSink sink, Indent indent) {
     _writeWrapResult(indent);
     _writeWrapError(indent);
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index bc1bae88795..e7f21d81e8b 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -131,7 +131,7 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
   }
 
   @override
-  void preDataClasses(
+  void writeDataClasses(
       ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     indent.writeln('');
     for (final Class klass in root.classes) {
@@ -139,6 +139,7 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
           '@class ${_className(generatorOptions.prefix, klass.name)};');
     }
     indent.writeln('');
+    super.writeDataClasses(generatorOptions, root, sink, indent);
   }
 
   @override
@@ -323,7 +324,7 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
   }
 
   @override
-  void finalWriteFile(
+  void writeGeneralUtilities(
       ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     indent.writeln('NS_ASSUME_NONNULL_END');
   }
@@ -362,7 +363,7 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
   }
 
   @override
-  void preDataClasses(
+  void writeDataClasses(
       ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     _writeObjcSourceHelperFunctions(indent);
     indent.addln('');
@@ -371,6 +372,7 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
       _writeObjcSourceDataClassExtension(generatorOptions, indent, klass);
     }
     indent.writeln('');
+    super.writeDataClasses(generatorOptions, root, sink, indent);
   }
 
   @override
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 0622c9659d2..fb5f49754a6 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -241,7 +241,7 @@ import FlutterMacOS
   }
 
   @override
-  void preApis(
+  void writeApis(
     SwiftOptions generatorOptions,
     Root root,
     StringSink sink,
@@ -252,6 +252,7 @@ import FlutterMacOS
         api.methods.any((Method it) => it.isAsynchronous))) {
       indent.addln('');
     }
+    super.writeApis(generatorOptions, root, sink, indent);
   }
 
   /// Writes the code for a flutter [Api], [api].
@@ -597,8 +598,8 @@ import FlutterMacOS
   }
 
   @override
-  void finalWriteFile(SwiftOptions generatorOptions, Root root, StringSink sink,
-      Indent indent) {
+  void writeGeneralUtilities(SwiftOptions generatorOptions, Root root,
+      StringSink sink, Indent indent) {
     _writeWrapResult(indent);
     _writeWrapError(indent);
   }

From 585c9d832c5dc846c2828e17556050fa3f1d566c Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 12 Jan 2023 12:21:35 -0800
Subject: [PATCH 80/87] move code from writeGeneralUtilities

---
 packages/pigeon/lib/cpp_generator.dart  | 44 ++++++++++++-------------
 packages/pigeon/lib/java_generator.dart |  2 ++
 packages/pigeon/lib/objc_generator.dart | 13 ++++----
 3 files changed, 30 insertions(+), 29 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index b20ad8810e7..d5cae464da0 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -271,6 +271,18 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
     // Intentionally left empty.
   }
 
+  @override
+  void writeApis(
+      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    super.writeApis(generatorOptions, root, sink, indent);
+    if (generatorOptions.namespace != null) {
+      indent.writeln('}  // namespace ${generatorOptions.namespace}');
+    }
+    final String guardName = _getGuardName(
+        generatorOptions.headerIncludePath, generatorOptions.namespace);
+    indent.writeln('#endif  // $guardName');
+  }
+
   @override
   void writeFlutterApi(
     CppOptions generatorOptions,
@@ -435,21 +447,6 @@ inline static $codeSerializerName& GetInstance() {
     indent.addln('');
   }
 
-  @override
-  void writeGeneralUtilities(
-    CppOptions generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-  ) {
-    if (generatorOptions.namespace != null) {
-      indent.writeln('}  // namespace ${generatorOptions.namespace}');
-    }
-    final String guardName = _getGuardName(
-        generatorOptions.headerIncludePath, generatorOptions.namespace);
-    indent.writeln('#endif  // $guardName');
-  }
-
   void _writeErrorOr(Indent indent,
       {Iterable<String> friends = const <String>[]}) {
     final String friendLines = friends
@@ -688,6 +685,15 @@ else if (const int64_t* ${pointerFieldName}_64 = std::get_if<int64_t>(&$encodabl
     indent.addln('');
   }
 
+  @override
+  void writeApis(
+      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    super.writeApis(generatorOptions, root, sink, indent);
+    if (generatorOptions.namespace != null) {
+      indent.writeln('}  // namespace ${generatorOptions.namespace}');
+    }
+  }
+
   @override
   void writeFlutterApi(
     CppOptions generatorOptions,
@@ -997,14 +1003,6 @@ flutter::EncodableList ${api.name}::WrapError(const FlutterError& error) {
     indent.addln('');
   }
 
-  @override
-  void writeGeneralUtilities(
-      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
-    if (generatorOptions.namespace != null) {
-      indent.writeln('}  // namespace ${generatorOptions.namespace}');
-    }
-  }
-
   void _writeCodec(
     CppOptions generatorOptions,
     Root root,
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index cfd53057ef8..7b8916db0ea 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -741,6 +741,8 @@ Result<$returnType> $resultName = new Result<$returnType>() {
   void writeGeneralUtilities(
       JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     _writeWrapError(indent);
+
+    // These lines close the main class.
     indent.dec();
     indent.addln('}');
   }
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index e7f21d81e8b..a3374dc6013 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -214,6 +214,13 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
     Set<String> customEnumNames,
   ) {}
 
+  @override
+  void writeApis(
+      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    super.writeApis(generatorOptions, root, sink, indent);
+    indent.writeln('NS_ASSUME_NONNULL_END');
+  }
+
   @override
   void writeFlutterApi(
     ObjcOptions generatorOptions,
@@ -322,12 +329,6 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
         'extern void ${apiName}Setup(id<FlutterBinaryMessenger> binaryMessenger, NSObject<$apiName> *_Nullable api);');
     indent.writeln('');
   }
-
-  @override
-  void writeGeneralUtilities(
-      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
-    indent.writeln('NS_ASSUME_NONNULL_END');
-  }
 }
 
 /// Generates Objc .m file.

From ab2fef1a298dc5d13a7d6d834b5c0e64f51a5a2a Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 12 Jan 2023 12:28:59 -0800
Subject: [PATCH 81/87] update changelog

---
 packages/pigeon/CHANGELOG.md             | 20 ++------------------
 packages/pigeon/lib/generator_tools.dart |  2 +-
 packages/pigeon/pubspec.yaml             |  2 +-
 3 files changed, 4 insertions(+), 20 deletions(-)

diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index bda54aef371..dd900fc77dd 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,22 +1,6 @@
-## 5.0.5
+## 6.0.0
 
-* Adds writeApi method to Generator classes.
-
-## 5.0.4
-
-* Adds writeEnum method to Generator classes.
-
-## 5.0.3
-
-* Adds writeEnum method to Generator classes.
-
-## 5.0.2
-
-* Adds writeImports method to Generator classes.
-
-## 5.0.1
-
-* Adds writeHeaders method to Generator classes and updates tests to use new Generators.
+* Creates StructuredGenerator class and implements it on all platforms.
 
 ## 5.0.0
 
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 07eac70ad9b..3dc1df4d513 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -9,7 +9,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon. This must match the version in pubspec.yaml.
-const String pigeonVersion = '5.0.5';
+const String pigeonVersion = '6.0.0';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index e4feca00cb9..caa82a391df 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 5.0.5 # This must match the version in lib/generator_tools.dart
+version: 6.0.0 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

From f324943c6bdd9235da7e7346e41aabf8f55316d0 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 12 Jan 2023 16:34:15 -0800
Subject: [PATCH 82/87] adds open and close namespace and fixes nits

---
 packages/pigeon/lib/cpp_generator.dart        |  63 +++-----
 packages/pigeon/lib/dart_generator.dart       |   2 +-
 packages/pigeon/lib/generator.dart            |  38 ++++-
 packages/pigeon/lib/java_generator.dart       |  10 +-
 packages/pigeon/lib/kotlin_generator.dart     |   2 +-
 packages/pigeon/lib/objc_generator.dart       |  14 +-
 packages/pigeon/lib/pigeon_lib.dart           |  14 +-
 packages/pigeon/lib/swift_generator.dart      |   2 +-
 .../CoreTests.java                            |  19 ++-
 .../com/example/test_plugin/CoreTests.gen.kt  |  24 +--
 .../ios/Classes/CoreTests.gen.swift           |  24 +--
 .../macos/Classes/CoreTests.gen.swift         |  24 +--
 packages/pigeon/test/cpp_generator_test.dart  |  56 +++----
 packages/pigeon/test/dart_generator_test.dart |  82 +++++-----
 packages/pigeon/test/java_generator_test.dart |  78 ++++-----
 .../pigeon/test/kotlin_generator_test.dart    |  66 ++++----
 packages/pigeon/test/objc_generator_test.dart | 148 +++++++++---------
 .../pigeon/test/swift_generator_test.dart     |  66 ++++----
 18 files changed, 372 insertions(+), 360 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 470ffc40a3c..402ed286a31 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -72,8 +72,8 @@ class CppOptions {
 
 /// Class that manages all Cpp code generation.
 class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
-  /// Instantiates a Cpp Generator.
-  CppGenerator();
+  /// Constructor.
+  const CppGenerator();
 
   /// Generates C++ file of type specified in [generatorOptions]
   @override
@@ -82,10 +82,10 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
     assert(generatorOptions.fileType == FileType.header ||
         generatorOptions.fileType == FileType.source);
     if (generatorOptions.fileType == FileType.header) {
-      CppHeaderGenerator()
+      const CppHeaderGenerator()
           .generate(generatorOptions.languageOptions, root, sink);
     } else if (generatorOptions.fileType == FileType.source) {
-      CppSourceGenerator()
+      const CppSourceGenerator()
           .generate(generatorOptions.languageOptions, root, sink);
     }
   }
@@ -93,6 +93,9 @@ class CppGenerator extends Generator<OutputFileOptions<CppOptions>> {
 
 /// Writes C++ header (.h) file to sink.
 class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
+  /// Constructor.
+  const CppHeaderGenerator();
+
   @override
   void writeFilePrologue(
       CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
@@ -245,32 +248,6 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
     indent.writeln('');
   }
 
-  @override
-  void writeClassEncode(
-    CppOptions generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Class klass,
-    Set<String> customClassNames,
-    Set<String> customEnumNames,
-  ) {
-    // Intentionally left empty.
-  }
-
-  @override
-  void writeClassDecode(
-    CppOptions generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Class klass,
-    Set<String> customClassNames,
-    Set<String> customEnumNames,
-  ) {
-    // Intentionally left empty.
-  }
-
   @override
   void writeApis(
       CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
@@ -499,6 +476,9 @@ $friendLines
 
 /// Writes C++ source (.cpp) file to sink.
 class CppSourceGenerator extends StructuredGenerator<CppOptions> {
+  /// Constructor.
+  const CppSourceGenerator();
+
   @override
   void writeFilePrologue(
       CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
@@ -530,7 +510,11 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
       'optional',
     ]);
     indent.addln('');
+  }
 
+  @override
+  void writeOpenNamespace(
+      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     if (generatorOptions.namespace != null) {
       indent.writeln('namespace ${generatorOptions.namespace} {');
     }
@@ -539,7 +523,7 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
   @override
   void writeEnum(CppOptions generatorOptions, Root root, StringSink sink,
       Indent indent, Enum anEnum) {
-    // Intentionally left empty.
+    // Intentionally left empty as there are no enums in this file.
   }
 
   @override
@@ -685,15 +669,6 @@ else if (const int64_t* ${pointerFieldName}_64 = std::get_if<int64_t>(&$encodabl
     indent.addln('');
   }
 
-  @override
-  void writeApis(
-      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
-    super.writeApis(generatorOptions, root, sink, indent);
-    if (generatorOptions.namespace != null) {
-      indent.writeln('}  // namespace ${generatorOptions.namespace}');
-    }
-  }
-
   @override
   void writeFlutterApi(
     CppOptions generatorOptions,
@@ -1138,6 +1113,14 @@ ${prefix}flutter::EncodableList wrapped;
 $nonErrorPath
 ${prefix}reply(flutter::EncodableValue(std::move(wrapped)));''';
   }
+
+  @override
+  void writeCloseNamespace(
+      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+    if (generatorOptions.namespace != null) {
+      indent.writeln('}  // namespace ${generatorOptions.namespace}');
+    }
+  }
 }
 
 String _getCodecSerializerName(Api api) => '${api.name}CodecSerializer';
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index ba40f3f0f7e..80fa954c00a 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -73,7 +73,7 @@ class DartOptions {
 /// Class that manages all Dart code generation.
 class DartGenerator extends StructuredGenerator<DartOptions> {
   /// Instantiates a Dart Generator.
-  DartGenerator();
+  const DartGenerator();
 
   @override
   void writeFilePrologue(
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index ae100c96402..05e1a2db8ea 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -5,16 +5,22 @@
 import 'ast.dart';
 import 'generator_tools.dart';
 
-/// A superclass of generator classes.
+/// An abstract base class of generators.
 ///
 /// This provides the structure that is common across generators for different languages.
 abstract class Generator<T> {
+  /// Constructor.
+  const Generator();
+
   /// Generates files for specified language with specified [generatorOptions]
   void generate(T generatorOptions, Root root, StringSink sink);
 }
 
-/// A Superclass that enforces code generation across platforms.
+/// An abstract base class that enforces code generation across platforms.
 abstract class StructuredGenerator<T> extends Generator<T> {
+  /// Constructor.
+  const StructuredGenerator();
+
   @override
   void generate(
     T generatorOptions,
@@ -27,13 +33,17 @@ abstract class StructuredGenerator<T> extends Generator<T> {
 
     writeFileImports(generatorOptions, root, sink, indent);
 
+    writeOpenNamespace(generatorOptions, root, sink, indent);
+
+    writeGeneralUtilities(generatorOptions, root, sink, indent);
+
     writeEnums(generatorOptions, root, sink, indent);
 
     writeDataClasses(generatorOptions, root, sink, indent);
 
     writeApis(generatorOptions, root, sink, indent);
 
-    writeGeneralUtilities(generatorOptions, root, sink, indent);
+    writeCloseNamespace(generatorOptions, root, sink, indent);
   }
 
   /// Adds specified headers to file.
@@ -44,6 +54,18 @@ abstract class StructuredGenerator<T> extends Generator<T> {
   void writeFileImports(
       T generatorOptions, Root root, StringSink sink, Indent indent);
 
+  /// Writes necessary code that opens file namespace if needed.
+  ///
+  /// This method is not required, and does not need to be overridden.
+  void writeOpenNamespace(
+      T generatorOptions, Root root, StringSink sink, Indent indent) {}
+
+  /// Writes any necessary helper utilities to file if needed.
+  ///
+  /// This method is not required, and does not need to be overridden.
+  void writeGeneralUtilities(
+      T generatorOptions, Root root, StringSink sink, Indent indent) {}
+
   /// Writes all enums to file. Can be overridden to add extra code before/after enums.
   void writeEnums(
       T generatorOptions, Root root, StringSink sink, Indent indent) {
@@ -77,7 +99,7 @@ abstract class StructuredGenerator<T> extends Generator<T> {
     Class klass,
     Set<String> customClassNames,
     Set<String> customEnumNames,
-  );
+  ) {}
 
   /// Writes a single class decode method to file.
   void writeClassDecode(
@@ -88,7 +110,7 @@ abstract class StructuredGenerator<T> extends Generator<T> {
     Class klass,
     Set<String> customClassNames,
     Set<String> customEnumNames,
-  );
+  ) {}
 
   /// Writes all data classes to file. Can be overridden to add extra code before/after classes.
   void writeApis(
@@ -110,9 +132,9 @@ abstract class StructuredGenerator<T> extends Generator<T> {
   void writeHostApi(
       T generatorOptions, Root root, StringSink sink, Indent indent, Api api);
 
-  /// Writes any necessary helper utilities to file if needed.
+  /// Writes necessary code that closes file namespace if needed.
   ///
-  /// This method is not reqiured, and does not need to be overridden.
-  void writeGeneralUtilities(
+  /// This method is not required, and does not need to be overridden.
+  void writeCloseNamespace(
       T generatorOptions, Root root, StringSink sink, Indent indent) {}
 }
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 7b8916db0ea..830eefb1636 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -88,7 +88,7 @@ class JavaOptions {
 /// Class that manages all Java code generation.
 class JavaGenerator extends StructuredGenerator<JavaOptions> {
   /// Instantiates a Java Generator.
-  JavaGenerator();
+  const JavaGenerator();
 
   @override
   void writeFilePrologue(
@@ -126,7 +126,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   }
 
   @override
-  void writeEnums(
+  void writeOpenNamespace(
       JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     indent.writeln(
         '$_docCommentPrefix Generated class from Pigeon.$_docCommentSuffix');
@@ -137,7 +137,6 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
     }
     indent.writeln('public class ${generatorOptions.className!} {');
     indent.inc();
-    super.writeEnums(generatorOptions, root, sink, indent);
   }
 
   @override
@@ -741,8 +740,11 @@ Result<$returnType> $resultName = new Result<$returnType>() {
   void writeGeneralUtilities(
       JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     _writeWrapError(indent);
+  }
 
-    // These lines close the main class.
+  @override
+  void writeCloseNamespace(
+      JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
     indent.dec();
     indent.addln('}');
   }
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index d48a62c6b82..34564607ceb 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -68,7 +68,7 @@ class KotlinOptions {
 /// Class that manages all Kotlin code generation.
 class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   /// Instantiates a Kotlin Generator.
-  KotlinGenerator();
+  const KotlinGenerator();
 
   @override
   void writeFilePrologue(KotlinOptions generatorOptions, Root root,
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index a3374dc6013..cbd54a5fb20 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -67,17 +67,17 @@ class ObjcOptions {
 /// Class that manages all Objc code generation.
 class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
   /// Instantiates a Objc Generator.
-  ObjcGenerator();
+  const ObjcGenerator();
 
   /// Generates Objc file of type specified in [generatorOptions]
   @override
   void generate(OutputFileOptions<ObjcOptions> generatorOptions, Root root,
       StringSink sink) {
     if (generatorOptions.fileType == FileType.header) {
-      ObjcHeaderGenerator()
+      const ObjcHeaderGenerator()
           .generate(generatorOptions.languageOptions, root, sink);
     } else if (generatorOptions.fileType == FileType.source) {
-      ObjcSourceGenerator()
+      const ObjcSourceGenerator()
           .generate(generatorOptions.languageOptions, root, sink);
     }
   }
@@ -85,6 +85,9 @@ class ObjcGenerator extends Generator<OutputFileOptions<ObjcOptions>> {
 
 /// Generates Objc .h file.
 class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
+  /// Constructor.
+  const ObjcHeaderGenerator();
+
   @override
   void writeFilePrologue(
       ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
@@ -333,6 +336,9 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
 
 /// Generates Objc .m file.
 class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
+  /// Constructor.
+  const ObjcSourceGenerator();
+
   @override
   void writeFilePrologue(
       ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
@@ -360,7 +366,7 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
   @override
   void writeEnum(ObjcOptions generatorOptions, Root root, StringSink sink,
       Indent indent, Enum anEnum) {
-    // Intentionally left empty.
+    // Intentionally left empty as there are no enums in this file.
   }
 
   @override
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 40f3fee3048..04c0b95ab6f 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -426,7 +426,7 @@ class DartGeneratorAdapter implements GeneratorAdapter {
       StringSink sink, PigeonOptions options, Root root, FileType fileType) {
     final DartOptions dartOptionsWithHeader = _dartOptionsWithCopyrightHeader(
         options.dartOptions, options.copyrightHeader);
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(dartOptionsWithHeader, root, sink);
   }
 
@@ -455,7 +455,7 @@ class DartTestGeneratorAdapter implements GeneratorAdapter {
       dartOutPath: options.dartOut,
       testOutPath: options.dartTestOut,
     );
-    final DartGenerator testGenerator = DartGenerator();
+    const DartGenerator testGenerator = DartGenerator();
     testGenerator.generateTest(dartOptionsWithHeader, root, sink);
   }
 
@@ -493,7 +493,7 @@ class ObjcGeneratorAdapter implements GeneratorAdapter {
     final OutputFileOptions<ObjcOptions> outputFileOptions =
         OutputFileOptions<ObjcOptions>(
             fileType: fileType, languageOptions: objcOptionsWithHeader);
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     generator.generate(outputFileOptions, root, sink);
   }
 
@@ -528,7 +528,7 @@ class JavaGeneratorAdapter implements GeneratorAdapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
   }
 
@@ -556,7 +556,7 @@ class SwiftGeneratorAdapter implements GeneratorAdapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
   }
 
@@ -589,7 +589,7 @@ class CppGeneratorAdapter implements GeneratorAdapter {
     final OutputFileOptions<CppOptions> outputFileOptions =
         OutputFileOptions<CppOptions>(
             fileType: fileType, languageOptions: cppOptionsWithHeader);
-    final CppGenerator generator = CppGenerator();
+    const CppGenerator generator = CppGenerator();
     generator.generate(outputFileOptions, root, sink);
   }
 
@@ -623,7 +623,7 @@ class KotlinGeneratorAdapter implements GeneratorAdapter {
         copyrightHeader: options.copyrightHeader != null
             ? _lineReader(options.copyrightHeader!)
             : null));
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
   }
 
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index fb5f49754a6..1347a3cc770 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -51,7 +51,7 @@ class SwiftOptions {
 /// Class that manages all Swift code generation.
 class SwiftGenerator extends StructuredGenerator<SwiftOptions> {
   /// Instantiates a Swift Generator.
-  SwiftGenerator();
+  const SwiftGenerator();
 
   @override
   void writeFilePrologue(SwiftOptions generatorOptions, Root root,
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
index bce812b6749..d97d0cc5df9 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java
@@ -24,6 +24,15 @@
 /** Generated class from Pigeon. */
 @SuppressWarnings({"unused", "unchecked", "CodeBlock2Expr", "RedundantSuppression"})
 public class CoreTests {
+  @NonNull
+  private static ArrayList<Object> wrapError(@NonNull Throwable exception) {
+    ArrayList<Object> errorList = new ArrayList<>(3);
+    errorList.add(exception.toString());
+    errorList.add(exception.getClass().getSimpleName());
+    errorList.add(
+        "Cause: " + exception.getCause() + ", Stacktrace: " + Log.getStackTraceString(exception));
+    return errorList;
+  }
 
   public enum AnEnum {
     ONE(0),
@@ -1647,14 +1656,4 @@ static void setup(BinaryMessenger binaryMessenger, HostTrivialApi api) {
       }
     }
   }
-
-  @NonNull
-  private static ArrayList<Object> wrapError(@NonNull Throwable exception) {
-    ArrayList<Object> errorList = new ArrayList<>(3);
-    errorList.add(exception.toString());
-    errorList.add(exception.getClass().getSimpleName());
-    errorList.add(
-        "Cause: " + exception.getCause() + ", Stacktrace: " + Log.getStackTraceString(exception));
-    return errorList;
-  }
 }
diff --git a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
index 46ac1490507..c2c039086f5 100644
--- a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
+++ b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/CoreTests.gen.kt
@@ -15,6 +15,18 @@ import io.flutter.plugin.common.StandardMessageCodec
 import java.io.ByteArrayOutputStream
 import java.nio.ByteBuffer
 
+private fun wrapResult(result: Any?): List<Any?> {
+  return listOf(result)
+}
+
+private fun wrapError(exception: Throwable): List<Any> {
+  return listOf<Any>(
+    exception.javaClass.simpleName,
+    exception.toString(),
+    "Cause: " + exception.cause + ", Stacktrace: " + Log.getStackTraceString(exception)
+  )
+}
+
 enum class AnEnum(val raw: Int) {
   ONE(0),
   TWO(1),
@@ -808,15 +820,3 @@ interface HostTrivialApi {
     }
   }
 }
-
-private fun wrapResult(result: Any?): List<Any?> {
-  return listOf(result)
-}
-
-private fun wrapError(exception: Throwable): List<Any> {
-  return listOf<Any>(
-    exception.javaClass.simpleName,
-    exception.toString(),
-    "Cause: " + exception.cause + ", Stacktrace: " + Log.getStackTraceString(exception)
-  )
-}
diff --git a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
index b957c87a03b..407ee693538 100644
--- a/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift
@@ -16,6 +16,18 @@ import FlutterMacOS
 
 
 
+private func wrapResult(_ result: Any?) -> [Any?] {
+  return [result]
+}
+
+private func wrapError(_ error: FlutterError) -> [Any?] {
+  return [
+    error.code,
+    error.message,
+    error.details
+  ]
+}
+
 enum AnEnum: Int {
   case one = 0
   case two = 1
@@ -665,15 +677,3 @@ class HostTrivialApiSetup {
     }
   }
 }
-
-private func wrapResult(_ result: Any?) -> [Any?] {
-  return [result]
-}
-
-private func wrapError(_ error: FlutterError) -> [Any?] {
-  return [
-    error.code,
-    error.message,
-    error.details
-  ]
-}
diff --git a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
index b957c87a03b..407ee693538 100644
--- a/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
+++ b/packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift
@@ -16,6 +16,18 @@ import FlutterMacOS
 
 
 
+private func wrapResult(_ result: Any?) -> [Any?] {
+  return [result]
+}
+
+private func wrapError(_ error: FlutterError) -> [Any?] {
+  return [
+    error.code,
+    error.message,
+    error.details
+  ]
+}
+
 enum AnEnum: Int {
   case one = 0
   case two = 1
@@ -665,15 +677,3 @@ class HostTrivialApiSetup {
     }
   }
 }
-
-private func wrapResult(_ result: Any?) -> [Any?] {
-  return [result]
-}
-
-private func wrapError(_ error: FlutterError) -> [Any?] {
-  return [
-    error.code,
-    error.message,
-    error.details
-  ]
-}
diff --git a/packages/pigeon/test/cpp_generator_test.dart b/packages/pigeon/test/cpp_generator_test.dart
index 16854a0f509..97dc1298600 100644
--- a/packages/pigeon/test/cpp_generator_test.dart
+++ b/packages/pigeon/test/cpp_generator_test.dart
@@ -46,7 +46,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -60,7 +60,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.source,
@@ -114,7 +114,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -135,7 +135,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.source,
@@ -169,7 +169,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -219,7 +219,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -279,7 +279,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -292,7 +292,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.source,
@@ -324,7 +324,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -345,7 +345,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.source,
@@ -387,7 +387,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -400,7 +400,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.source,
@@ -467,7 +467,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -505,7 +505,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.source,
@@ -610,7 +610,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -641,7 +641,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.source,
@@ -745,7 +745,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -856,7 +856,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -944,7 +944,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -964,7 +964,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.source,
@@ -1087,7 +1087,7 @@ void main() {
     ], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.header,
@@ -1107,7 +1107,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final CppGenerator generator = CppGenerator();
+      const CppGenerator generator = CppGenerator();
       final OutputFileOptions<CppOptions> generatorOptions =
           OutputFileOptions<CppOptions>(
         fileType: FileType.source,
@@ -1173,7 +1173,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    final CppGenerator generator = CppGenerator();
+    const CppGenerator generator = CppGenerator();
     final OutputFileOptions<CppOptions> generatorOptions =
         OutputFileOptions<CppOptions>(
       fileType: FileType.source,
@@ -1291,7 +1291,7 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    final CppGenerator generator = CppGenerator();
+    const CppGenerator generator = CppGenerator();
     final OutputFileOptions<CppOptions> generatorOptions =
         OutputFileOptions<CppOptions>(
       fileType: FileType.header,
@@ -1332,7 +1332,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final CppGenerator generator = CppGenerator();
+    const CppGenerator generator = CppGenerator();
     final OutputFileOptions<CppOptions> generatorOptions =
         OutputFileOptions<CppOptions>(
       fileType: FileType.header,
@@ -1380,7 +1380,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final CppGenerator generator = CppGenerator();
+    const CppGenerator generator = CppGenerator();
     final OutputFileOptions<CppOptions> generatorOptions =
         OutputFileOptions<CppOptions>(
       fileType: FileType.header,
@@ -1455,7 +1455,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final CppGenerator generator = CppGenerator();
+    const CppGenerator generator = CppGenerator();
     final OutputFileOptions<CppOptions> generatorOptions =
         OutputFileOptions<CppOptions>(
       fileType: FileType.source,
@@ -1515,7 +1515,7 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final CppGenerator generator = CppGenerator();
+    const CppGenerator generator = CppGenerator();
     final OutputFileOptions<CppOptions> generatorOptions =
         OutputFileOptions<CppOptions>(
       fileType: FileType.source,
diff --git a/packages/pigeon/test/dart_generator_test.dart b/packages/pigeon/test/dart_generator_test.dart
index 15ce9e09ac4..d99dde7a71b 100644
--- a/packages/pigeon/test/dart_generator_test.dart
+++ b/packages/pigeon/test/dart_generator_test.dart
@@ -29,7 +29,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
@@ -50,7 +50,7 @@ void main() {
       enums: <Enum>[anEnum],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foobar'));
@@ -94,7 +94,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
@@ -121,7 +121,7 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
@@ -149,7 +149,7 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
@@ -187,7 +187,7 @@ void main() {
       )
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
@@ -230,7 +230,7 @@ void main() {
       )
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
@@ -283,7 +283,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('abstract class Api'));
@@ -318,7 +318,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<void> doSomething'));
@@ -352,7 +352,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     // The next line verifies that we're not setting a variable to the value of "doSomething", but
@@ -383,7 +383,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('output.*=.*doSomething[(][)]'));
@@ -426,7 +426,7 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum1?.index,'));
@@ -454,7 +454,7 @@ void main() {
       ])
     ]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foo {'));
@@ -498,7 +498,7 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('enum1.index,'));
@@ -526,7 +526,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('channel.send[(]null[)]'));
@@ -585,7 +585,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer mainCodeSink = StringBuffer();
     final StringBuffer testCodeSink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, mainCodeSink);
     final String mainCode = mainCodeSink.toString();
     expect(mainCode, isNot(contains(r"import 'fo\'o.dart';")));
@@ -595,7 +595,7 @@ void main() {
     expect(mainCode, isNot(contains("'${Keys.result}': output")));
     expect(mainCode, isNot(contains('return <Object>[];')));
 
-    final DartGenerator testGenerator = DartGenerator();
+    const DartGenerator testGenerator = DartGenerator();
     testGenerator.generateTest(
       DartOptions(
         sourceOutPath: "fo'o.dart",
@@ -650,7 +650,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('abstract class Api'));
@@ -695,7 +695,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('=.s*doSomething')));
@@ -740,7 +740,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
@@ -769,7 +769,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, matches('channel.send[(]null[)]'));
@@ -783,7 +783,7 @@ void main() {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
 
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(
       DartOptions(copyrightHeader: makeIterable('hello world')),
       root,
@@ -813,7 +813,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
@@ -841,7 +841,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
@@ -871,7 +871,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(List<int?> arg'));
@@ -900,7 +900,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(List<int?> arg'));
@@ -925,7 +925,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<List<int?>> doit('));
@@ -961,7 +961,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('List<int?> doit('));
@@ -989,7 +989,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit()'));
@@ -1015,7 +1015,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<List<int?>?> doit()'));
@@ -1041,7 +1041,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit()'));
@@ -1065,7 +1065,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('int? doit();'));
@@ -1090,7 +1090,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<int?> doit();'));
@@ -1114,7 +1114,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(
@@ -1144,7 +1144,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('Future<void> doit(int? arg_foo) async {'));
@@ -1171,7 +1171,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('void doit(int? foo);'));
@@ -1189,7 +1189,7 @@ name: foobar
       final Root root =
           Root(classes: <Class>[], apis: <Api>[], enums: <Enum>[]);
       final StringBuffer sink = StringBuffer();
-      final DartGenerator testGenerator = DartGenerator();
+      const DartGenerator testGenerator = DartGenerator();
       testGenerator.generateTest(
         DartOptions(
           sourceOutPath: path.join(foo.path, 'bar.dart'),
@@ -1279,7 +1279,7 @@ name: foobar
       ],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
@@ -1315,7 +1315,7 @@ name: foobar
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains('extends StandardMessageCodec')));
@@ -1359,7 +1359,7 @@ name: foobar
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final DartGenerator generator = DartGenerator();
+    const DartGenerator generator = DartGenerator();
     generator.generate(DartOptions(), root, sink);
     final String code = sink.toString();
     expect(code, contains('extends StandardMessageCodec'));
@@ -1399,7 +1399,7 @@ name: foobar
     );
     final StringBuffer sink = StringBuffer();
 
-    final DartGenerator testGenerator = DartGenerator();
+    const DartGenerator testGenerator = DartGenerator();
     testGenerator.generateTest(
       DartOptions(
         sourceOutPath: 'code.dart',
diff --git a/packages/pigeon/test/java_generator_test.dart b/packages/pigeon/test/java_generator_test.dart
index f2a25288754..40ec00545e7 100644
--- a/packages/pigeon/test/java_generator_test.dart
+++ b/packages/pigeon/test/java_generator_test.dart
@@ -27,7 +27,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public class Messages'));
@@ -56,7 +56,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public enum Foobar'));
@@ -88,7 +88,7 @@ void main() {
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions =
         JavaOptions(className: 'Messages', package: 'com.google.foobar');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('package com.google.foobar;'));
@@ -132,7 +132,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public interface Api'));
@@ -204,7 +204,7 @@ void main() {
 
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('private @Nullable Boolean aBool;'));
@@ -254,7 +254,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Api'));
@@ -289,7 +289,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('=.*doSomething')));
@@ -324,7 +324,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('Reply<Void>'));
@@ -353,7 +353,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('Output doSomething()'));
@@ -382,7 +382,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doSomething(Reply<Output>'));
@@ -402,7 +402,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Foobar'));
@@ -422,7 +422,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Foobar'));
@@ -459,7 +459,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public class Messages'));
@@ -511,7 +511,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public interface Api'));
@@ -563,7 +563,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Api'));
@@ -597,7 +597,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public enum Enum1'));
@@ -637,7 +637,7 @@ void main() {
     ]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public enum Foo'));
@@ -658,7 +658,7 @@ void main() {
       className: 'Messages',
       copyrightHeader: makeIterable('hello world'),
     );
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
@@ -685,7 +685,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
@@ -714,7 +714,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Foobar'));
@@ -745,7 +745,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(@NonNull List<Long> arg'));
@@ -775,7 +775,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(@NonNull List<Long> arg'));
@@ -801,7 +801,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('List<Long> doit('));
@@ -828,7 +828,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(Reply<List<Long>> callback)'));
@@ -852,7 +852,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doit(Reply<Long> callback)'));
@@ -883,7 +883,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Messages'));
@@ -915,7 +915,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Api');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('Object xArg = args.get(0)'));
@@ -942,7 +942,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Messages'));
@@ -975,7 +975,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(
@@ -1002,7 +1002,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@Nullable Long doit();'));
@@ -1027,7 +1027,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     // Java doesn't accept nullability annotations in type arguments.
@@ -1056,7 +1056,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('  void doit(@Nullable Long foo);'));
@@ -1084,7 +1084,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(
@@ -1116,7 +1116,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(
@@ -1142,7 +1142,7 @@ void main() {
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions =
         JavaOptions(className: 'Messages', useGeneratedAnnotation: true);
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('@javax.annotation.Generated("dev.flutter.pigeon")'));
@@ -1160,7 +1160,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code,
@@ -1243,7 +1243,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
@@ -1284,7 +1284,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' extends StandardMessageCodec')));
@@ -1329,7 +1329,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const JavaOptions javaOptions = JavaOptions(className: 'Messages');
-    final JavaGenerator generator = JavaGenerator();
+    const JavaGenerator generator = JavaGenerator();
     generator.generate(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains(' extends StandardMessageCodec'));
diff --git a/packages/pigeon/test/kotlin_generator_test.dart b/packages/pigeon/test/kotlin_generator_test.dart
index 96056c1b1b1..aa4ec3efb37 100644
--- a/packages/pigeon/test/kotlin_generator_test.dart
+++ b/packages/pigeon/test/kotlin_generator_test.dart
@@ -27,7 +27,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar ('));
@@ -51,7 +51,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum class Foobar(val raw: Int) {'));
@@ -80,7 +80,7 @@ void main() {
     ]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum class Foo(val raw: Int) {'));
@@ -127,7 +127,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('interface Api'));
@@ -217,7 +217,7 @@ void main() {
     final StringBuffer sink = StringBuffer();
 
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('val aBool: Boolean? = null'));
@@ -270,7 +270,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code,
@@ -308,7 +308,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('.*doSomething(.*) ->')));
@@ -345,7 +345,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('callback: () -> Unit'));
@@ -375,7 +375,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doSomething(): Output'));
@@ -407,7 +407,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doSomething(callback: (Output) -> Unit)'));
@@ -428,7 +428,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
@@ -449,7 +449,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
@@ -488,7 +488,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Outer'));
@@ -542,7 +542,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('interface Api'));
@@ -591,7 +591,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
@@ -625,7 +625,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum class Enum1(val raw: Int)'));
@@ -643,7 +643,7 @@ void main() {
     final KotlinOptions kotlinOptions = KotlinOptions(
       copyrightHeader: makeIterable('hello world'),
     );
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
@@ -671,7 +671,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
@@ -701,7 +701,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('data class Foobar'));
@@ -733,7 +733,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(arg: List<Long?>'));
@@ -764,7 +764,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(argArg: List<Long?>'));
@@ -790,7 +790,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(): List<Long?>'));
@@ -818,7 +818,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(callback: (List<Long?>) -> Unit'));
@@ -847,7 +847,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun add(x: Long, y: Long): Long'));
@@ -885,7 +885,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('val channel = BasicMessageChannel'));
@@ -914,7 +914,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(): Long?'));
@@ -939,7 +939,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(callback: (Long?) -> Unit'));
@@ -967,7 +967,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(
@@ -998,7 +998,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('fun doit(fooArg: Long?, callback: () -> Unit'));
@@ -1034,7 +1034,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('val input: String\n'));
@@ -1116,7 +1116,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
@@ -1157,7 +1157,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(' : StandardMessageCodec() ')));
@@ -1202,7 +1202,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const KotlinOptions kotlinOptions = KotlinOptions();
-    final KotlinGenerator generator = KotlinGenerator();
+    const KotlinGenerator generator = KotlinGenerator();
     generator.generate(kotlinOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains(' : StandardMessageCodec() '));
diff --git a/packages/pigeon/test/objc_generator_test.dart b/packages/pigeon/test/objc_generator_test.dart
index c6b45fd4d43..64f92c857eb 100644
--- a/packages/pigeon/test/objc_generator_test.dart
+++ b/packages/pigeon/test/objc_generator_test.dart
@@ -18,7 +18,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -39,7 +39,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -62,7 +62,7 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -86,7 +86,7 @@ void main() {
       )
     ]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -128,7 +128,7 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -167,7 +167,7 @@ void main() {
     const ObjcOptions options =
         ObjcOptions(headerIncludePath: 'foo.h', prefix: 'AC');
     {
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -179,7 +179,7 @@ void main() {
       expect(code, contains(':(ACFoo)foo error:'));
     }
     {
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -248,7 +248,7 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -286,7 +286,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -331,7 +331,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -384,7 +384,7 @@ void main() {
     ], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -418,7 +418,7 @@ void main() {
     ], enums: <Enum>[]);
 
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -445,7 +445,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -471,7 +471,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -496,7 +496,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -516,7 +516,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -556,7 +556,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -598,7 +598,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -640,7 +640,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -685,7 +685,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -720,7 +720,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -755,7 +755,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -792,7 +792,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -827,7 +827,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -857,7 +857,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -886,7 +886,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -915,7 +915,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -947,7 +947,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -972,7 +972,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -993,7 +993,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -1020,7 +1020,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -1055,7 +1055,7 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -1095,7 +1095,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -1140,7 +1140,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -1173,7 +1173,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -1199,7 +1199,7 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -1244,7 +1244,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -1288,7 +1288,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -1314,7 +1314,7 @@ void main() {
       ])
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -1347,7 +1347,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -1369,7 +1369,7 @@ void main() {
   test('source copyright', () {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -1386,7 +1386,7 @@ void main() {
   test('header copyright', () {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -1420,7 +1420,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -1456,7 +1456,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -1469,7 +1469,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -1509,7 +1509,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -1522,7 +1522,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -1565,7 +1565,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -1598,7 +1598,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -1612,7 +1612,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -1645,7 +1645,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -1659,7 +1659,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -1694,7 +1694,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -1710,7 +1710,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -1751,7 +1751,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -1767,7 +1767,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -1806,7 +1806,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -1822,7 +1822,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -1872,7 +1872,7 @@ void main() {
     final Root divideRoot = getDivideRoot(ApiLocation.host);
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -1885,7 +1885,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -1902,7 +1902,7 @@ void main() {
     final Root divideRoot = getDivideRoot(ApiLocation.flutter);
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -1915,7 +1915,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -1937,7 +1937,7 @@ void main() {
       ]),
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -1966,7 +1966,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -1997,7 +1997,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -2025,7 +2025,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -2058,7 +2058,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -2070,7 +2070,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -2105,7 +2105,7 @@ void main() {
     );
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.header,
@@ -2117,7 +2117,7 @@ void main() {
     }
     {
       final StringBuffer sink = StringBuffer();
-      final ObjcGenerator generator = ObjcGenerator();
+      const ObjcGenerator generator = ObjcGenerator();
       final OutputFileOptions<ObjcOptions> generatorOptions =
           OutputFileOptions<ObjcOptions>(
         fileType: FileType.source,
@@ -2147,7 +2147,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -2237,7 +2237,7 @@ void main() {
       ],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.header,
@@ -2278,7 +2278,7 @@ void main() {
       enums: <Enum>[],
     );
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
@@ -2326,7 +2326,7 @@ void main() {
       ])
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final ObjcGenerator generator = ObjcGenerator();
+    const ObjcGenerator generator = ObjcGenerator();
     final OutputFileOptions<ObjcOptions> generatorOptions =
         OutputFileOptions<ObjcOptions>(
       fileType: FileType.source,
diff --git a/packages/pigeon/test/swift_generator_test.dart b/packages/pigeon/test/swift_generator_test.dart
index 305ca203fe7..dfd2dfbb487 100644
--- a/packages/pigeon/test/swift_generator_test.dart
+++ b/packages/pigeon/test/swift_generator_test.dart
@@ -26,7 +26,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
@@ -50,7 +50,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foobar: Int'));
@@ -79,7 +79,7 @@ void main() {
     ]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foo: Int'));
@@ -123,7 +123,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('protocol Api'));
@@ -187,7 +187,7 @@ void main() {
 
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('var aBool: Bool? = nil'));
@@ -237,7 +237,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
@@ -273,7 +273,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('.*doSomething(.*) ->')));
@@ -308,7 +308,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('completion: @escaping () -> Void'));
@@ -337,7 +337,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doSomething() -> Output'));
@@ -367,7 +367,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code,
@@ -388,7 +388,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
@@ -408,7 +408,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
@@ -445,7 +445,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Outer'));
@@ -494,7 +494,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('protocol Api'));
@@ -540,7 +540,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('class Api'));
@@ -573,7 +573,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Enum1: Int'));
@@ -591,7 +591,7 @@ void main() {
     final SwiftOptions swiftOptions = SwiftOptions(
       copyrightHeader: makeIterable('hello world'),
     );
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
@@ -618,7 +618,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
@@ -647,7 +647,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
@@ -678,7 +678,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit(arg: [Int32?]'));
@@ -708,7 +708,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit(arg argArg: [Int32?]'));
@@ -734,7 +734,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit() -> [Int32?]'));
@@ -762,7 +762,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(
@@ -792,7 +792,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func add(x: Int32, y: Int32) -> Int32'));
@@ -824,7 +824,7 @@ void main() {
     ], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('let channel = FlutterBasicMessageChannel'));
@@ -855,7 +855,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit() -> Int32?'));
@@ -880,7 +880,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('func doit(completion: @escaping (Int32?) -> Void'));
@@ -908,7 +908,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('let fooArg = args[0] as? Int32'));
@@ -936,7 +936,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(
@@ -973,7 +973,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('var input: String\n'));
@@ -1055,7 +1055,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     for (final String comment in comments) {
@@ -1092,7 +1092,7 @@ void main() {
     );
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(contains(': FlutterStandardReader ')));
@@ -1136,7 +1136,7 @@ void main() {
     ], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
     const SwiftOptions swiftOptions = SwiftOptions();
-    final SwiftGenerator generator = SwiftGenerator();
+    const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains(': FlutterStandardReader '));

From 32bb197f981e99959b383924dff7299134b8c21d Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 12 Jan 2023 16:42:38 -0800
Subject: [PATCH 83/87] makes writeEnum optional

---
 packages/pigeon/lib/cpp_generator.dart  | 6 ------
 packages/pigeon/lib/generator.dart      | 4 ++--
 packages/pigeon/lib/objc_generator.dart | 6 ------
 3 files changed, 2 insertions(+), 14 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 402ed286a31..b5def44593e 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -520,12 +520,6 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
     }
   }
 
-  @override
-  void writeEnum(CppOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Enum anEnum) {
-    // Intentionally left empty as there are no enums in this file.
-  }
-
   @override
   void writeDataClass(CppOptions generatorOptions, Root root, StringSink sink,
       Indent indent, Class klass) {
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 05e1a2db8ea..13bd4ff92a9 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -74,9 +74,9 @@ abstract class StructuredGenerator<T> extends Generator<T> {
     }
   }
 
-  /// Writes a single Enum to file.
+  /// Writes a single Enum to file. This is needed in most generators.
   void writeEnum(T generatorOptions, Root root, StringSink sink, Indent indent,
-      Enum anEnum);
+      Enum anEnum) {}
 
   /// Writes all apis to file. Can be overridden to add extra code before/after apis.
   void writeDataClasses(
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index cbd54a5fb20..4197f23741d 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -363,12 +363,6 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
     indent.addln('');
   }
 
-  @override
-  void writeEnum(ObjcOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Enum anEnum) {
-    // Intentionally left empty as there are no enums in this file.
-  }
-
   @override
   void writeDataClasses(
       ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {

From c9f2a57c8200f6540cdf9ea93858c1b054af03ae Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Thu, 12 Jan 2023 22:35:31 -0800
Subject: [PATCH 84/87] remove unneeded sink

---
 packages/pigeon/lib/cpp_generator.dart        |  71 ++++------
 packages/pigeon/lib/dart_generator.dart       |  40 +++---
 packages/pigeon/lib/generator.dart            | 129 ++++++++----------
 packages/pigeon/lib/java_generator.dart       |  58 ++++----
 packages/pigeon/lib/kotlin_generator.dart     |  35 ++---
 packages/pigeon/lib/objc_generator.dart       |  65 ++++-----
 packages/pigeon/lib/swift_generator.dart      |  38 +++---
 .../windows/pigeon/core_tests.gen.h           |   4 +-
 8 files changed, 188 insertions(+), 252 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index b5def44593e..b7cc211ed5f 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -98,7 +98,7 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
 
   @override
   void writeFilePrologue(
-      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      CppOptions generatorOptions, Root root, Indent indent) {
     if (generatorOptions.copyrightHeader != null) {
       addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
     }
@@ -108,8 +108,7 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
   }
 
   @override
-  void writeFileImports(
-      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+  void writeFileImports(CppOptions generatorOptions, Root root, Indent indent) {
     final String guardName = _getGuardName(
         generatorOptions.headerIncludePath, generatorOptions.namespace);
     indent.writeln('#ifndef $guardName');
@@ -142,8 +141,8 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
   }
 
   @override
-  void writeEnum(CppOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Enum anEnum) {
+  void writeEnum(
+      CppOptions generatorOptions, Root root, Indent indent, Enum anEnum) {
     indent.writeln('');
     addDocumentationComments(
         indent, anEnum.documentationComments, _docCommentSpec);
@@ -159,15 +158,14 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
   }
 
   @override
-  void writeDataClasses(
-      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+  void writeGeneralUtilities(
+      CppOptions generatorOptions, Root root, Indent indent) {
     _writeErrorOr(indent, friends: root.apis.map((Api api) => api.name));
-    super.writeDataClasses(generatorOptions, root, sink, indent);
   }
 
   @override
-  void writeDataClass(CppOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Class klass) {
+  void writeDataClass(
+      CppOptions generatorOptions, Root root, Indent indent, Class klass) {
     // When generating for a Pigeon unit test, add a test fixture friend class to
     // allow unit testing private methods, since testing serialization via public
     // methods is essentially an end-to-end test.
@@ -249,9 +247,8 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
   }
 
   @override
-  void writeApis(
-      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
-    super.writeApis(generatorOptions, root, sink, indent);
+  void writeApis(CppOptions generatorOptions, Root root, Indent indent) {
+    super.writeApis(generatorOptions, root, indent);
     if (generatorOptions.namespace != null) {
       indent.writeln('}  // namespace ${generatorOptions.namespace}');
     }
@@ -264,13 +261,12 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
   void writeFlutterApi(
     CppOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
     assert(api.location == ApiLocation.flutter);
     if (getCodecClasses(api, root).isNotEmpty) {
-      _writeCodec(generatorOptions, root, sink, indent, api);
+      _writeCodec(generatorOptions, root, indent, api);
     }
     const List<String> generatedMessages = <String>[
       ' Generated class from Pigeon that represents Flutter messages that can be called from C++.'
@@ -317,13 +313,12 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
   void writeHostApi(
     CppOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
     assert(api.location == ApiLocation.host);
     if (getCodecClasses(api, root).isNotEmpty) {
-      _writeCodec(generatorOptions, root, sink, indent, api);
+      _writeCodec(generatorOptions, root, indent, api);
     }
     const List<String> generatedMessages = <String>[
       ' Generated interface from Pigeon that represents a handler of messages from Flutter.'
@@ -395,8 +390,8 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
     }, nestCount: 0);
   }
 
-  void _writeCodec(CppOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Api api) {
+  void _writeCodec(
+      CppOptions generatorOptions, Root root, Indent indent, Api api) {
     assert(getCodecClasses(api, root).isNotEmpty);
     final String codeSerializerName = _getCodecSerializerName(api);
     indent
@@ -481,7 +476,7 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
 
   @override
   void writeFilePrologue(
-      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      CppOptions generatorOptions, Root root, Indent indent) {
     if (generatorOptions.copyrightHeader != null) {
       addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
     }
@@ -493,8 +488,7 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
   }
 
   @override
-  void writeFileImports(
-      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+  void writeFileImports(CppOptions generatorOptions, Root root, Indent indent) {
     indent.writeln('#include "${generatorOptions.headerIncludePath}"');
     indent.addln('');
     _writeSystemHeaderIncludeBlock(indent, <String>[
@@ -514,15 +508,15 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
 
   @override
   void writeOpenNamespace(
-      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      CppOptions generatorOptions, Root root, Indent indent) {
     if (generatorOptions.namespace != null) {
       indent.writeln('namespace ${generatorOptions.namespace} {');
     }
   }
 
   @override
-  void writeDataClass(CppOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Class klass) {
+  void writeDataClass(
+      CppOptions generatorOptions, Root root, Indent indent, Class klass) {
     final Set<String> customClassNames =
         root.classes.map((Class x) => x.name).toSet();
     final Set<String> customEnumNames =
@@ -534,28 +528,26 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
 
     // Getters and setters.
     for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-      _writeCppSourceClassField(
-          generatorOptions, root, sink, indent, klass, field);
+      _writeCppSourceClassField(generatorOptions, root, indent, klass, field);
     }
 
     // Serialization.
-    writeClassEncode(generatorOptions, root, sink, indent, klass,
-        customClassNames, customEnumNames);
+    writeClassEncode(generatorOptions, root, indent, klass, customClassNames,
+        customEnumNames);
 
     // Default constructor.
     indent.writeln('${klass.name}::${klass.name}() {}');
     indent.addln('');
 
     // Deserialization.
-    writeClassDecode(generatorOptions, root, sink, indent, klass,
-        customClassNames, customEnumNames);
+    writeClassDecode(generatorOptions, root, indent, klass, customClassNames,
+        customEnumNames);
   }
 
   @override
   void writeClassEncode(
     CppOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -608,7 +600,6 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
   void writeClassDecode(
     CppOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -667,13 +658,12 @@ else if (const int64_t* ${pointerFieldName}_64 = std::get_if<int64_t>(&$encodabl
   void writeFlutterApi(
     CppOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
     assert(api.location == ApiLocation.flutter);
     if (getCodecClasses(api, root).isNotEmpty) {
-      _writeCodec(generatorOptions, root, sink, indent, api);
+      _writeCodec(generatorOptions, root, indent, api);
     }
     indent.writeln(
         '$_commentPrefix Generated class from Pigeon that represents Flutter messages that can be called from C++.');
@@ -773,11 +763,11 @@ else if (const int64_t* ${pointerVariable}_64 = std::get_if<int64_t>(&args))
   }
 
   @override
-  void writeHostApi(CppOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Api api) {
+  void writeHostApi(
+      CppOptions generatorOptions, Root root, Indent indent, Api api) {
     assert(api.location == ApiLocation.host);
     if (getCodecClasses(api, root).isNotEmpty) {
-      _writeCodec(generatorOptions, root, sink, indent, api);
+      _writeCodec(generatorOptions, root, indent, api);
     }
 
     final String codeSerializerName = getCodecClasses(api, root).isNotEmpty
@@ -973,7 +963,6 @@ flutter::EncodableValue ${api.name}::WrapError(const FlutterError& error) {
   void _writeCodec(
     CppOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
@@ -1023,7 +1012,7 @@ flutter::EncodableValue ${api.name}::WrapError(const FlutterError& error) {
   }
 
   void _writeCppSourceClassField(CppOptions generatorOptions, Root root,
-      StringSink sink, Indent indent, Class klass, NamedType field) {
+      Indent indent, Class klass, NamedType field) {
     final HostDatatype hostDatatype = getFieldHostDatatype(field, root.classes,
         root.enums, (TypeDeclaration x) => _baseCppTypeForBuiltinDartType(x));
     final String instanceVariableName = _makeInstanceVariableName(field);
@@ -1110,7 +1099,7 @@ ${prefix}reply(flutter::EncodableValue(std::move(wrapped)));''';
 
   @override
   void writeCloseNamespace(
-      CppOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      CppOptions generatorOptions, Root root, Indent indent) {
     if (generatorOptions.namespace != null) {
       indent.writeln('}  // namespace ${generatorOptions.namespace}');
     }
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 80fa954c00a..0961f006ce4 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -77,7 +77,7 @@ class DartGenerator extends StructuredGenerator<DartOptions> {
 
   @override
   void writeFilePrologue(
-      DartOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      DartOptions generatorOptions, Root root, Indent indent) {
     if (generatorOptions.copyrightHeader != null) {
       addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
     }
@@ -91,7 +91,7 @@ class DartGenerator extends StructuredGenerator<DartOptions> {
 
   @override
   void writeFileImports(
-      DartOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      DartOptions generatorOptions, Root root, Indent indent) {
     indent.writeln("import 'dart:async';");
     indent.writeln(
       "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
@@ -103,8 +103,8 @@ class DartGenerator extends StructuredGenerator<DartOptions> {
   }
 
   @override
-  void writeEnum(DartOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Enum anEnum) {
+  void writeEnum(
+      DartOptions generatorOptions, Root root, Indent indent, Enum anEnum) {
     indent.writeln('');
     addDocumentationComments(
         indent, anEnum.documentationComments, _docCommentSpec);
@@ -119,8 +119,8 @@ class DartGenerator extends StructuredGenerator<DartOptions> {
   }
 
   @override
-  void writeDataClass(DartOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Class klass) {
+  void writeDataClass(
+      DartOptions generatorOptions, Root root, Indent indent, Class klass) {
     final Set<String> customClassNames =
         root.classes.map((Class x) => x.name).toSet();
     final Set<String> customEnumNames =
@@ -142,11 +142,11 @@ class DartGenerator extends StructuredGenerator<DartOptions> {
         indent.writeln('$datatype ${field.name};');
         indent.writeln('');
       }
-      writeClassEncode(generatorOptions, root, sink, indent, klass,
-          customClassNames, customEnumNames);
+      writeClassEncode(generatorOptions, root, indent, klass, customClassNames,
+          customEnumNames);
       indent.writeln('');
-      writeClassDecode(generatorOptions, root, sink, indent, klass,
-          customClassNames, customEnumNames);
+      writeClassDecode(generatorOptions, root, indent, klass, customClassNames,
+          customEnumNames);
     });
   }
 
@@ -164,7 +164,6 @@ class DartGenerator extends StructuredGenerator<DartOptions> {
   void writeClassEncode(
     DartOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -198,7 +197,6 @@ class DartGenerator extends StructuredGenerator<DartOptions> {
   void writeClassDecode(
     DartOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -281,7 +279,6 @@ $resultAt != null
   void writeFlutterApi(
     DartOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api, {
     String Function(Method)? channelNameFunc,
@@ -441,8 +438,8 @@ $resultAt != null
   /// If the message was a failure, the list will contain 3 items:
   /// a code, a message, and details in that order.
   @override
-  void writeHostApi(DartOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Api api) {
+  void writeHostApi(
+      DartOptions generatorOptions, Root root, Indent indent, Api api) {
     assert(api.location == ApiLocation.host);
     String codecName = _standardMessageCodec;
     if (getCodecClasses(api, root).isNotEmpty) {
@@ -559,8 +556,8 @@ if (replyList == null) {
     final Indent indent = Indent(sink);
     final String sourceOutPath = generatorOptions.sourceOutPath ?? '';
     final String testOutPath = generatorOptions.testOutPath ?? '';
-    _writeTestPrologue(generatorOptions, root, sink, indent);
-    _writeTestImports(generatorOptions, root, sink, indent);
+    _writeTestPrologue(generatorOptions, root, indent);
+    _writeTestImports(generatorOptions, root, indent);
     final String relativeDartPath =
         path.Context(style: path.Style.posix).relative(
       _posixify(sourceOutPath),
@@ -592,7 +589,6 @@ if (replyList == null) {
         writeFlutterApi(
           generatorOptions,
           root,
-          sink,
           indent,
           mockApi,
           channelNameFunc: (Method func) => makeChannelName(api, func),
@@ -603,8 +599,7 @@ if (replyList == null) {
   }
 
   /// Writes file header to sink.
-  void _writeTestPrologue(
-      DartOptions opt, Root root, StringSink sink, Indent indent) {
+  void _writeTestPrologue(DartOptions opt, Root root, Indent indent) {
     if (opt.copyrightHeader != null) {
       addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
     }
@@ -617,8 +612,7 @@ if (replyList == null) {
   }
 
   /// Writes file imports to sink.
-  void _writeTestImports(
-      DartOptions opt, Root root, StringSink sink, Indent indent) {
+  void _writeTestImports(DartOptions opt, Root root, Indent indent) {
     indent.writeln("import 'dart:async';");
     indent.writeln(
       "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
@@ -764,7 +758,7 @@ String _addGenericTypesNullable(TypeDeclaration type) {
 
 /// Generates Dart source code for the given AST represented by [root],
 /// outputting the code to [sink].
-void generateDart(DartOptions opt, Root root, StringSink sink, Indent indent) {}
+void generateDart(DartOptions opt, Root root, Indent indent) {}
 
 /// Crawls up the path of [dartFilePath] until it finds a pubspec.yaml in a
 /// parent directory and returns its path.
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 13bd4ff92a9..b7c0bf2de3c 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -1,6 +1,6 @@
 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
+// found in the LICENSE [indent].
 
 import 'ast.dart';
 import 'generator_tools.dart';
@@ -29,112 +29,93 @@ abstract class StructuredGenerator<T> extends Generator<T> {
   ) {
     final Indent indent = Indent(sink);
 
-    writeFilePrologue(generatorOptions, root, sink, indent);
+    writeFilePrologue(generatorOptions, root, indent);
 
-    writeFileImports(generatorOptions, root, sink, indent);
+    writeFileImports(generatorOptions, root, indent);
 
-    writeOpenNamespace(generatorOptions, root, sink, indent);
+    writeOpenNamespace(generatorOptions, root, indent);
 
-    writeGeneralUtilities(generatorOptions, root, sink, indent);
+    writeGeneralUtilities(generatorOptions, root, indent);
 
-    writeEnums(generatorOptions, root, sink, indent);
+    writeEnums(generatorOptions, root, indent);
 
-    writeDataClasses(generatorOptions, root, sink, indent);
+    writeDataClasses(generatorOptions, root, indent);
 
-    writeApis(generatorOptions, root, sink, indent);
+    writeApis(generatorOptions, root, indent);
 
-    writeCloseNamespace(generatorOptions, root, sink, indent);
+    writeCloseNamespace(generatorOptions, root, indent);
   }
 
-  /// Adds specified headers to file.
-  void writeFilePrologue(
-      T generatorOptions, Root root, StringSink sink, Indent indent);
+  /// Adds specified headers to [indent].
+  void writeFilePrologue(T generatorOptions, Root root, Indent indent);
 
-  /// Writes specified imports to file.
-  void writeFileImports(
-      T generatorOptions, Root root, StringSink sink, Indent indent);
+  /// Writes specified imports to [indent].
+  void writeFileImports(T generatorOptions, Root root, Indent indent);
 
-  /// Writes necessary code that opens file namespace if needed.
+  /// Writes code to [indent] that opens file namespace if needed.
   ///
   /// This method is not required, and does not need to be overridden.
-  void writeOpenNamespace(
-      T generatorOptions, Root root, StringSink sink, Indent indent) {}
+  void writeOpenNamespace(T generatorOptions, Root root, Indent indent) {}
 
-  /// Writes any necessary helper utilities to file if needed.
+  /// Writes code to [indent] that closes file namespace if needed.
   ///
   /// This method is not required, and does not need to be overridden.
-  void writeGeneralUtilities(
-      T generatorOptions, Root root, StringSink sink, Indent indent) {}
+  void writeCloseNamespace(T generatorOptions, Root root, Indent indent) {}
 
-  /// Writes all enums to file. Can be overridden to add extra code before/after enums.
-  void writeEnums(
-      T generatorOptions, Root root, StringSink sink, Indent indent) {
+  /// Writes any necessary helper utilities to [indent] if needed.
+  ///
+  /// This method is not required, and does not need to be overridden.
+  void writeGeneralUtilities(T generatorOptions, Root root, Indent indent) {}
+
+  /// Writes all enums to [indent].
+  ///
+  /// Can be overridden to add extra code before/after enums.
+  void writeEnums(T generatorOptions, Root root, Indent indent) {
     for (final Enum anEnum in root.enums) {
-      writeEnum(generatorOptions, root, sink, indent, anEnum);
+      writeEnum(generatorOptions, root, indent, anEnum);
     }
   }
 
-  /// Writes a single Enum to file. This is needed in most generators.
-  void writeEnum(T generatorOptions, Root root, StringSink sink, Indent indent,
-      Enum anEnum) {}
+  /// Writes a single Enum to [indent]. This is needed in most generators.
+  void writeEnum(T generatorOptions, Root root, Indent indent, Enum anEnum) {}
 
-  /// Writes all apis to file. Can be overridden to add extra code before/after apis.
-  void writeDataClasses(
-      T generatorOptions, Root root, StringSink sink, Indent indent) {
+  /// Writes all data classes to [indent].
+  ///
+  /// Can be overridden to add extra code before/after apis.
+  void writeDataClasses(T generatorOptions, Root root, Indent indent) {
     for (final Class klass in root.classes) {
-      writeDataClass(generatorOptions, root, sink, indent, klass);
+      writeDataClass(generatorOptions, root, indent, klass);
     }
   }
 
-  /// Writes a single data class to file.
-  void writeDataClass(T generatorOptions, Root root, StringSink sink,
-      Indent indent, Class klass);
+  /// Writes a single data class to [indent].
+  void writeDataClass(
+      T generatorOptions, Root root, Indent indent, Class klass);
 
-  /// Writes a single class encode method to file.
-  void writeClassEncode(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Class klass,
-    Set<String> customClassNames,
-    Set<String> customEnumNames,
-  ) {}
-
-  /// Writes a single class decode method to file.
-  void writeClassDecode(
-    T generatorOptions,
-    Root root,
-    StringSink sink,
-    Indent indent,
-    Class klass,
-    Set<String> customClassNames,
-    Set<String> customEnumNames,
-  ) {}
-
-  /// Writes all data classes to file. Can be overridden to add extra code before/after classes.
-  void writeApis(
-      T generatorOptions, Root root, StringSink sink, Indent indent) {
+  /// Writes a single class encode method to [indent].
+  void writeClassEncode(T generatorOptions, Root root, Indent indent,
+      Class klass, Set<String> customClassNames, Set<String> customEnumNames) {}
+
+  /// Writes a single class decode method to [indent].
+  void writeClassDecode(T generatorOptions, Root root, Indent indent,
+      Class klass, Set<String> customClassNames, Set<String> customEnumNames) {}
+
+  /// Writes all apis to [indent].
+  ///
+  /// Can be overridden to add extra code before/after classes.
+  void writeApis(T generatorOptions, Root root, Indent indent) {
     for (final Api api in root.apis) {
       if (api.location == ApiLocation.host) {
-        writeHostApi(generatorOptions, root, sink, indent, api);
+        writeHostApi(generatorOptions, root, indent, api);
       } else if (api.location == ApiLocation.flutter) {
-        writeFlutterApi(generatorOptions, root, sink, indent, api);
+        writeFlutterApi(generatorOptions, root, indent, api);
       }
     }
   }
 
-  /// Writes a single Flutter Api to file.
-  void writeFlutterApi(
-      T generatorOptions, Root root, StringSink sink, Indent indent, Api api);
-
-  /// Writes a single Host Api to file.
-  void writeHostApi(
-      T generatorOptions, Root root, StringSink sink, Indent indent, Api api);
+  /// Writes a single Flutter Api to [indent].
+  void writeFlutterApi(T generatorOptions, Root root, Indent indent, Api api);
 
-  /// Writes necessary code that closes file namespace if needed.
-  ///
-  /// This method is not required, and does not need to be overridden.
-  void writeCloseNamespace(
-      T generatorOptions, Root root, StringSink sink, Indent indent) {}
+  /// Writes a single Host Api to [indent].
+  void writeHostApi(T generatorOptions, Root root, Indent indent, Api api);
 }
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 830eefb1636..e6e7f8c921b 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -92,7 +92,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
 
   @override
   void writeFilePrologue(
-      JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      JavaOptions generatorOptions, Root root, Indent indent) {
     if (generatorOptions.copyrightHeader != null) {
       addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
     }
@@ -103,7 +103,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
 
   @override
   void writeFileImports(
-      JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      JavaOptions generatorOptions, Root root, Indent indent) {
     if (generatorOptions.package != null) {
       indent.writeln('package ${generatorOptions.package};');
     }
@@ -127,7 +127,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
 
   @override
   void writeOpenNamespace(
-      JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      JavaOptions generatorOptions, Root root, Indent indent) {
     indent.writeln(
         '$_docCommentPrefix Generated class from Pigeon.$_docCommentSuffix');
     indent.writeln(
@@ -140,8 +140,8 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   }
 
   @override
-  void writeEnum(JavaOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Enum anEnum) {
+  void writeEnum(
+      JavaOptions generatorOptions, Root root, Indent indent, Enum anEnum) {
     String camelToSnake(String camelCase) {
       final RegExp regex = RegExp('([a-z])([A-Z]+)');
       return camelCase
@@ -171,8 +171,8 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   }
 
   @override
-  void writeDataClass(JavaOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Class klass) {
+  void writeDataClass(
+      JavaOptions generatorOptions, Root root, Indent indent, Class klass) {
     final Set<String> customClassNames =
         root.classes.map((Class x) => x.name).toSet();
     final Set<String> customEnumNames =
@@ -189,7 +189,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
     indent.write('public static class ${klass.name} ');
     indent.scoped('{', '}', () {
       for (final NamedType field in getFieldsInSerializationOrder(klass)) {
-        _writeClassField(generatorOptions, root, sink, indent, field);
+        _writeClassField(generatorOptions, root, indent, field);
         indent.addln('');
       }
 
@@ -201,16 +201,16 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
         indent.writeln('private ${klass.name}() {}');
       }
 
-      _writeClassBuilder(generatorOptions, root, sink, indent, klass);
-      writeClassEncode(generatorOptions, root, sink, indent, klass,
-          customClassNames, customEnumNames);
-      writeClassDecode(generatorOptions, root, sink, indent, klass,
-          customClassNames, customEnumNames);
+      _writeClassBuilder(generatorOptions, root, indent, klass);
+      writeClassEncode(generatorOptions, root, indent, klass, customClassNames,
+          customEnumNames);
+      writeClassDecode(generatorOptions, root, indent, klass, customClassNames,
+          customEnumNames);
     });
   }
 
-  void _writeClassField(JavaOptions generatorOptions, Root root,
-      StringSink sink, Indent indent, NamedType field) {
+  void _writeClassField(
+      JavaOptions generatorOptions, Root root, Indent indent, NamedType field) {
     final HostDatatype hostDatatype = getFieldHostDatatype(field, root.classes,
         root.enums, (TypeDeclaration x) => _javaTypeForBuiltinDartType(x));
     final String nullability = field.type.isNullable ? '@Nullable' : '@NonNull';
@@ -237,7 +237,6 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   void _writeClassBuilder(
     JavaOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
   ) {
@@ -276,7 +275,6 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   void writeClassEncode(
     JavaOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -313,7 +311,6 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   void writeClassDecode(
     JavaOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -354,7 +351,6 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   void writeFlutterApi(
     JavaOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
@@ -453,15 +449,14 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   }
 
   @override
-  void writeApis(
-      JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+  void writeApis(JavaOptions generatorOptions, Root root, Indent indent) {
     if (root.apis.any((Api api) =>
         api.location == ApiLocation.host &&
         api.methods.any((Method it) => it.isAsynchronous))) {
       indent.addln('');
       _writeResultInterface(indent);
     }
-    super.writeApis(generatorOptions, root, sink, indent);
+    super.writeApis(generatorOptions, root, indent);
   }
 
   /// Write the java code that represents a host [Api], [api].
@@ -471,8 +466,8 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   ///   static void setup(BinaryMessenger binaryMessenger, Foo api) {...}
   /// }
   @override
-  void writeHostApi(JavaOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Api api) {
+  void writeHostApi(
+      JavaOptions generatorOptions, Root root, Indent indent, Api api) {
     assert(api.location == ApiLocation.host);
     if (getCodecClasses(api, root).isNotEmpty) {
       _writeCodec(indent, api, root);
@@ -486,8 +481,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
     indent.write('public interface ${api.name} ');
     indent.scoped('{', '}', () {
       for (final Method method in api.methods) {
-        _writeInterfaceMethod(
-            generatorOptions, root, sink, indent, api, method);
+        _writeInterfaceMethod(generatorOptions, root, indent, api, method);
       }
       indent.addln('');
       final String codecName = _getCodecName(api);
@@ -508,7 +502,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
           'static void setup(BinaryMessenger binaryMessenger, ${api.name} api) ');
       indent.scoped('{', '}', () {
         for (final Method method in api.methods) {
-          _writeMethodSetup(generatorOptions, root, sink, indent, api, method);
+          _writeMethodSetup(generatorOptions, root, indent, api, method);
         }
       });
     });
@@ -518,7 +512,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   /// Example:
   ///   int add(int x, int y);
   void _writeInterfaceMethod(JavaOptions generatorOptions, Root root,
-      StringSink sink, Indent indent, Api api, final Method method) {
+      Indent indent, Api api, final Method method) {
     final String returnType = method.isAsynchronous
         ? 'void'
         : _nullsafeJavaTypeForDartType(method.returnType);
@@ -548,8 +542,8 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
   /// Write a static setup function in the interface.
   /// Example:
   ///   static void setup(BinaryMessenger binaryMessenger, Foo api) {...}
-  void _writeMethodSetup(JavaOptions generatorOptions, Root root,
-      StringSink sink, Indent indent, Api api, final Method method) {
+  void _writeMethodSetup(JavaOptions generatorOptions, Root root, Indent indent,
+      Api api, final Method method) {
     final String channelName = makeChannelName(api, method);
     indent.write('');
     indent.scoped('{', '}', () {
@@ -738,13 +732,13 @@ Result<$returnType> $resultName = new Result<$returnType>() {
 
   @override
   void writeGeneralUtilities(
-      JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      JavaOptions generatorOptions, Root root, Indent indent) {
     _writeWrapError(indent);
   }
 
   @override
   void writeCloseNamespace(
-      JavaOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      JavaOptions generatorOptions, Root root, Indent indent) {
     indent.dec();
     indent.addln('}');
   }
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 34564607ceb..76b270ba67e 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -71,8 +71,8 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   const KotlinGenerator();
 
   @override
-  void writeFilePrologue(KotlinOptions generatorOptions, Root root,
-      StringSink sink, Indent indent) {
+  void writeFilePrologue(
+      KotlinOptions generatorOptions, Root root, Indent indent) {
     if (generatorOptions.copyrightHeader != null) {
       addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
     }
@@ -81,8 +81,8 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   }
 
   @override
-  void writeFileImports(KotlinOptions generatorOptions, Root root,
-      StringSink sink, Indent indent) {
+  void writeFileImports(
+      KotlinOptions generatorOptions, Root root, Indent indent) {
     indent.addln('');
     if (generatorOptions.package != null) {
       indent.writeln('package ${generatorOptions.package}');
@@ -98,8 +98,8 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   }
 
   @override
-  void writeEnum(KotlinOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Enum anEnum) {
+  void writeEnum(
+      KotlinOptions generatorOptions, Root root, Indent indent, Enum anEnum) {
     indent.writeln('');
     addDocumentationComments(
         indent, anEnum.documentationComments, _docCommentSpec);
@@ -128,8 +128,8 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   }
 
   @override
-  void writeDataClass(KotlinOptions generatorOptions, Root root,
-      StringSink sink, Indent indent, Class klass) {
+  void writeDataClass(
+      KotlinOptions generatorOptions, Root root, Indent indent, Class klass) {
     final Set<String> customClassNames =
         root.classes.map((Class x) => x.name).toSet();
     final Set<String> customEnumNames =
@@ -156,10 +156,10 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
     });
 
     indent.scoped(') {', '}', () {
-      writeClassDecode(generatorOptions, root, sink, indent, klass,
-          customClassNames, customEnumNames);
-      writeClassEncode(generatorOptions, root, sink, indent, klass,
-          customClassNames, customEnumNames);
+      writeClassDecode(generatorOptions, root, indent, klass, customClassNames,
+          customEnumNames);
+      writeClassEncode(generatorOptions, root, indent, klass, customClassNames,
+          customEnumNames);
     });
   }
 
@@ -167,7 +167,6 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   void writeClassEncode(
     KotlinOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -200,7 +199,6 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   void writeClassDecode(
     KotlinOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -288,7 +286,6 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   void writeApis(
     KotlinOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
   ) {
     if (root.apis.any((Api api) =>
@@ -296,7 +293,7 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
         api.methods.any((Method it) => it.isAsynchronous))) {
       indent.addln('');
     }
-    super.writeApis(generatorOptions, root, sink, indent);
+    super.writeApis(generatorOptions, root, indent);
   }
 
   /// Writes the code for a flutter [Api], [api].
@@ -308,7 +305,6 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   void writeFlutterApi(
     KotlinOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
@@ -404,7 +400,6 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   void writeHostApi(
     KotlinOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
@@ -624,8 +619,8 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
   }
 
   @override
-  void writeGeneralUtilities(KotlinOptions generatorOptions, Root root,
-      StringSink sink, Indent indent) {
+  void writeGeneralUtilities(
+      KotlinOptions generatorOptions, Root root, Indent indent) {
     _writeWrapResult(indent);
     _writeWrapError(indent);
   }
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 4197f23741d..2b165c91d1d 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -90,7 +90,7 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
 
   @override
   void writeFilePrologue(
-      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      ObjcOptions generatorOptions, Root root, Indent indent) {
     if (generatorOptions.copyrightHeader != null) {
       addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
     }
@@ -101,7 +101,7 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
 
   @override
   void writeFileImports(
-      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      ObjcOptions generatorOptions, Root root, Indent indent) {
     indent.writeln('#import <Foundation/Foundation.h>');
     indent.addln('');
 
@@ -114,8 +114,8 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
   }
 
   @override
-  void writeEnum(ObjcOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Enum anEnum) {
+  void writeEnum(
+      ObjcOptions generatorOptions, Root root, Indent indent, Enum anEnum) {
     final String enumName = _className(generatorOptions.prefix, anEnum.name);
     indent.writeln('');
     addDocumentationComments(
@@ -135,19 +135,19 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
 
   @override
   void writeDataClasses(
-      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      ObjcOptions generatorOptions, Root root, Indent indent) {
     indent.writeln('');
     for (final Class klass in root.classes) {
       indent.writeln(
           '@class ${_className(generatorOptions.prefix, klass.name)};');
     }
     indent.writeln('');
-    super.writeDataClasses(generatorOptions, root, sink, indent);
+    super.writeDataClasses(generatorOptions, root, indent);
   }
 
   @override
-  void writeDataClass(ObjcOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Class klass) {
+  void writeDataClass(
+      ObjcOptions generatorOptions, Root root, Indent indent, Class klass) {
     final List<Class> classes = root.classes;
     final List<Enum> enums = root.enums;
     final String? prefix = generatorOptions.prefix;
@@ -199,7 +199,6 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
   void writeClassEncode(
     ObjcOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -210,7 +209,6 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
   void writeClassDecode(
     ObjcOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -218,9 +216,8 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
   ) {}
 
   @override
-  void writeApis(
-      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
-    super.writeApis(generatorOptions, root, sink, indent);
+  void writeApis(ObjcOptions generatorOptions, Root root, Indent indent) {
+    super.writeApis(generatorOptions, root, indent);
     indent.writeln('NS_ASSUME_NONNULL_END');
   }
 
@@ -228,7 +225,6 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
   void writeFlutterApi(
     ObjcOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
@@ -268,7 +264,6 @@ class ObjcHeaderGenerator extends StructuredGenerator<ObjcOptions> {
   void writeHostApi(
     ObjcOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
@@ -341,7 +336,7 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
 
   @override
   void writeFilePrologue(
-      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      ObjcOptions generatorOptions, Root root, Indent indent) {
     if (generatorOptions.copyrightHeader != null) {
       addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
     }
@@ -352,7 +347,7 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
 
   @override
   void writeFileImports(
-      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      ObjcOptions generatorOptions, Root root, Indent indent) {
     indent.writeln('#import "${generatorOptions.headerIncludePath}"');
     indent.writeln('#import <Flutter/Flutter.h>');
     indent.addln('');
@@ -365,7 +360,7 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
 
   @override
   void writeDataClasses(
-      ObjcOptions generatorOptions, Root root, StringSink sink, Indent indent) {
+      ObjcOptions generatorOptions, Root root, Indent indent) {
     _writeObjcSourceHelperFunctions(indent);
     indent.addln('');
 
@@ -373,12 +368,12 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
       _writeObjcSourceDataClassExtension(generatorOptions, indent, klass);
     }
     indent.writeln('');
-    super.writeDataClasses(generatorOptions, root, sink, indent);
+    super.writeDataClasses(generatorOptions, root, indent);
   }
 
   @override
-  void writeDataClass(ObjcOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Class klass) {
+  void writeDataClass(
+      ObjcOptions generatorOptions, Root root, Indent indent, Class klass) {
     final Set<String> customClassNames =
         root.classes.map((Class x) => x.name).toSet();
     final Set<String> customEnumNames =
@@ -386,12 +381,12 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
     final String className = _className(generatorOptions.prefix, klass.name);
 
     indent.writeln('@implementation $className');
-    _writeObjcSourceClassInitializer(generatorOptions, root, sink, indent,
-        klass, customClassNames, customEnumNames, className);
-    writeClassDecode(generatorOptions, root, sink, indent, klass,
-        customClassNames, customEnumNames);
-    writeClassEncode(generatorOptions, root, sink, indent, klass,
-        customClassNames, customEnumNames);
+    _writeObjcSourceClassInitializer(generatorOptions, root, indent, klass,
+        customClassNames, customEnumNames, className);
+    writeClassDecode(generatorOptions, root, indent, klass, customClassNames,
+        customEnumNames);
+    writeClassEncode(generatorOptions, root, indent, klass, customClassNames,
+        customEnumNames);
     indent.writeln('@end');
     indent.writeln('');
   }
@@ -400,7 +395,6 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
   void writeClassEncode(
     ObjcOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -422,7 +416,6 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
   void writeClassDecode(
     ObjcOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -453,8 +446,8 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
         '+ (nullable $className *)nullableFromList:(NSArray *)list { return (list) ? [$className fromList:list] : nil; }');
   }
 
-  void _writeCodecAndGetter(ObjcOptions generatorOptions, Root root,
-      StringSink sink, Indent indent, Api api) {
+  void _writeCodecAndGetter(
+      ObjcOptions generatorOptions, Root root, Indent indent, Api api) {
     final String codecName = _getCodecName(generatorOptions.prefix, api.name);
     if (getCodecClasses(api, root).isNotEmpty) {
       _writeCodec(indent, codecName, generatorOptions, api, root);
@@ -468,14 +461,13 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
   void writeFlutterApi(
     ObjcOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
     assert(api.location == ApiLocation.flutter);
     final String apiName = _className(generatorOptions.prefix, api.name);
 
-    _writeCodecAndGetter(generatorOptions, root, sink, indent, api);
+    _writeCodecAndGetter(generatorOptions, root, indent, api);
 
     _writeExtension(indent, apiName);
     indent.addln('');
@@ -493,14 +485,13 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
   void writeHostApi(
     ObjcOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
     assert(api.location == ApiLocation.host);
     final String apiName = _className(generatorOptions.prefix, api.name);
 
-    _writeCodecAndGetter(generatorOptions, root, sink, indent, api);
+    _writeCodecAndGetter(generatorOptions, root, indent, api);
 
     const String channelName = 'channel';
     indent.write(
@@ -686,7 +677,6 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
   void _writeObjcSourceClassInitializer(
     ObjcOptions languageOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -1024,8 +1014,7 @@ String _makeObjcSignature({
 
 /// Generates the ".h" file for the AST represented by [root] to [sink] with the
 /// provided [options].
-void generateObjcHeader(
-    ObjcOptions options, Root root, StringSink sink, Indent indent) {}
+void generateObjcHeader(ObjcOptions options, Root root, Indent indent) {}
 
 String _listGetter(Set<String> customClassNames, String list, NamedType field,
     int index, String? prefix) {
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 1347a3cc770..879d51b5f23 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -54,8 +54,8 @@ class SwiftGenerator extends StructuredGenerator<SwiftOptions> {
   const SwiftGenerator();
 
   @override
-  void writeFilePrologue(SwiftOptions generatorOptions, Root root,
-      StringSink sink, Indent indent) {
+  void writeFilePrologue(
+      SwiftOptions generatorOptions, Root root, Indent indent) {
     if (generatorOptions.copyrightHeader != null) {
       addLines(indent, generatorOptions.copyrightHeader!, linePrefix: '// ');
     }
@@ -65,8 +65,8 @@ class SwiftGenerator extends StructuredGenerator<SwiftOptions> {
   }
 
   @override
-  void writeFileImports(SwiftOptions generatorOptions, Root root,
-      StringSink sink, Indent indent) {
+  void writeFileImports(
+      SwiftOptions generatorOptions, Root root, Indent indent) {
     indent.writeln('import Foundation');
     indent.format('''
 #if os(iOS)
@@ -81,8 +81,8 @@ import FlutterMacOS
   }
 
   @override
-  void writeEnum(SwiftOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Enum anEnum) {
+  void writeEnum(
+      SwiftOptions generatorOptions, Root root, Indent indent, Enum anEnum) {
     indent.writeln('');
     addDocumentationComments(
         indent, anEnum.documentationComments, _docCommentSpec);
@@ -98,8 +98,8 @@ import FlutterMacOS
   }
 
   @override
-  void writeDataClass(SwiftOptions generatorOptions, Root root, StringSink sink,
-      Indent indent, Class klass) {
+  void writeDataClass(
+      SwiftOptions generatorOptions, Root root, Indent indent, Class klass) {
     final Set<String> customClassNames =
         root.classes.map((Class x) => x.name).toSet();
     final Set<String> customEnumNames =
@@ -120,10 +120,10 @@ import FlutterMacOS
       });
 
       indent.writeln('');
-      writeClassDecode(generatorOptions, root, sink, indent, klass,
-          customClassNames, customEnumNames);
-      writeClassEncode(generatorOptions, root, sink, indent, klass,
-          customClassNames, customEnumNames);
+      writeClassDecode(generatorOptions, root, indent, klass, customClassNames,
+          customEnumNames);
+      writeClassEncode(generatorOptions, root, indent, klass, customClassNames,
+          customEnumNames);
     });
   }
 
@@ -131,7 +131,6 @@ import FlutterMacOS
   void writeClassEncode(
     SwiftOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -166,7 +165,6 @@ import FlutterMacOS
   void writeClassDecode(
     SwiftOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Class klass,
     Set<String> customClassNames,
@@ -244,7 +242,6 @@ import FlutterMacOS
   void writeApis(
     SwiftOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
   ) {
     if (root.apis.any((Api api) =>
@@ -252,7 +249,7 @@ import FlutterMacOS
         api.methods.any((Method it) => it.isAsynchronous))) {
       indent.addln('');
     }
-    super.writeApis(generatorOptions, root, sink, indent);
+    super.writeApis(generatorOptions, root, indent);
   }
 
   /// Writes the code for a flutter [Api], [api].
@@ -266,7 +263,6 @@ import FlutterMacOS
   void writeFlutterApi(
     SwiftOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
@@ -362,7 +358,6 @@ import FlutterMacOS
   void writeHostApi(
     SwiftOptions generatorOptions,
     Root root,
-    StringSink sink,
     Indent indent,
     Api api,
   ) {
@@ -598,8 +593,8 @@ import FlutterMacOS
   }
 
   @override
-  void writeGeneralUtilities(SwiftOptions generatorOptions, Root root,
-      StringSink sink, Indent indent) {
+  void writeGeneralUtilities(
+      SwiftOptions generatorOptions, Root root, Indent indent) {
     _writeWrapResult(indent);
     _writeWrapError(indent);
   }
@@ -702,5 +697,4 @@ String _nullsafeSwiftTypeForDartType(TypeDeclaration type) {
 
 /// Generates the ".swift" file for the AST represented by [root] to [sink] with the
 /// provided [options].
-void generateSwift(
-    SwiftOptions options, Root root, StringSink sink, Indent indent) {}
+void generateSwift(SwiftOptions options, Root root, Indent indent) {}
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
index d57104b14aa..8dbd2dcb495 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
@@ -22,8 +22,6 @@ class CoreTestsTest;
 
 // Generated class from Pigeon.
 
-enum class AnEnum { one = 0, two = 1, three = 2 };
-
 class FlutterError {
  public:
   explicit FlutterError(const std::string& code) : code_(code) {}
@@ -65,6 +63,8 @@ class ErrorOr {
   std::variant<T, FlutterError> v_;
 };
 
+enum class AnEnum { one = 0, two = 1, three = 2 };
+
 // Generated class from Pigeon that represents data sent in messages.
 class AllTypes {
  public:

From e45c622a3f49a5d8d4dccd85811b20da2f3723d5 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 13 Jan 2023 08:26:53 -0800
Subject: [PATCH 85/87] remove unneeded namespace from guardname

---
 packages/pigeon/lib/cpp_generator.dart                | 11 +++--------
 .../test_plugin/windows/pigeon/core_tests.gen.h       |  6 +++---
 2 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index b7cc211ed5f..c00f8ef78c8 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -109,8 +109,7 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
 
   @override
   void writeFileImports(CppOptions generatorOptions, Root root, Indent indent) {
-    final String guardName = _getGuardName(
-        generatorOptions.headerIncludePath, generatorOptions.namespace);
+    final String guardName = _getGuardName(generatorOptions.headerIncludePath);
     indent.writeln('#ifndef $guardName');
     indent.writeln('#define $guardName');
 
@@ -252,8 +251,7 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
     if (generatorOptions.namespace != null) {
       indent.writeln('}  // namespace ${generatorOptions.namespace}');
     }
-    final String guardName = _getGuardName(
-        generatorOptions.headerIncludePath, generatorOptions.namespace);
+    final String guardName = _getGuardName(generatorOptions.headerIncludePath);
     indent.writeln('#endif  // $guardName');
   }
 
@@ -1275,14 +1273,11 @@ String _nullSafeCppTypeForDartType(TypeDeclaration type,
   }
 }
 
-String _getGuardName(String? headerFileName, String? namespace) {
+String _getGuardName(String? headerFileName) {
   String guardName = 'PIGEON_';
   if (headerFileName != null) {
     guardName += '${headerFileName.replaceAll('.', '_').toUpperCase()}_';
   }
-  if (namespace != null) {
-    guardName += '${namespace.toUpperCase()}_';
-  }
   return '${guardName}H_';
 }
 
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
index 8dbd2dcb495..c752a5a1f3d 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
+++ b/packages/pigeon/platform_tests/test_plugin/windows/pigeon/core_tests.gen.h
@@ -5,8 +5,8 @@
 // Autogenerated from Pigeon (v6.0.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
-#ifndef PIGEON_CORE_TESTS_GEN_H_CORE_TESTS_PIGEONTEST_H_
-#define PIGEON_CORE_TESTS_GEN_H_CORE_TESTS_PIGEONTEST_H_
+#ifndef PIGEON_CORE_TESTS_GEN_H_H_
+#define PIGEON_CORE_TESTS_GEN_H_H_
 #include <flutter/basic_message_channel.h>
 #include <flutter/binary_messenger.h>
 #include <flutter/encodable_value.h>
@@ -413,4 +413,4 @@ class HostTrivialApi {
   HostTrivialApi() = default;
 };
 }  // namespace core_tests_pigeontest
-#endif  // PIGEON_CORE_TESTS_GEN_H_CORE_TESTS_PIGEONTEST_H_
+#endif  // PIGEON_CORE_TESTS_GEN_H_H_

From 7dc64d31c3956d2526e6ca61bfce63474774f112 Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 13 Jan 2023 08:30:56 -0800
Subject: [PATCH 86/87] [indent]

---
 packages/pigeon/lib/generator.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index b7c0bf2de3c..c730f92a714 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -1,6 +1,6 @@
 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE [indent].
+// found in the LICENSE file.
 
 import 'ast.dart';
 import 'generator_tools.dart';

From 263e832e69c7788c697115f064bdd337e4017d1c Mon Sep 17 00:00:00 2001
From: tarrinneal <tarrinneal@gmail.com>
Date: Fri, 13 Jan 2023 10:25:51 -0800
Subject: [PATCH 87/87] clean up

---
 packages/pigeon/lib/cpp_generator.dart   | 20 ++++++++++----------
 packages/pigeon/lib/dart_generator.dart  |  4 ----
 packages/pigeon/lib/swift_generator.dart |  4 ----
 3 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index c00f8ef78c8..105f6bd0f0e 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -245,16 +245,6 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
     indent.writeln('');
   }
 
-  @override
-  void writeApis(CppOptions generatorOptions, Root root, Indent indent) {
-    super.writeApis(generatorOptions, root, indent);
-    if (generatorOptions.namespace != null) {
-      indent.writeln('}  // namespace ${generatorOptions.namespace}');
-    }
-    final String guardName = _getGuardName(generatorOptions.headerIncludePath);
-    indent.writeln('#endif  // $guardName');
-  }
-
   @override
   void writeFlutterApi(
     CppOptions generatorOptions,
@@ -465,6 +455,16 @@ $friendLines
 };
 ''');
   }
+
+  @override
+  void writeCloseNamespace(
+      CppOptions generatorOptions, Root root, Indent indent) {
+    if (generatorOptions.namespace != null) {
+      indent.writeln('}  // namespace ${generatorOptions.namespace}');
+    }
+    final String guardName = _getGuardName(generatorOptions.headerIncludePath);
+    indent.writeln('#endif  // $guardName');
+  }
 }
 
 /// Writes C++ source (.cpp) file to sink.
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 0961f006ce4..3b62affc3b1 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -756,10 +756,6 @@ String _addGenericTypesNullable(TypeDeclaration type) {
   return type.isNullable ? '$genericdType?' : genericdType;
 }
 
-/// Generates Dart source code for the given AST represented by [root],
-/// outputting the code to [sink].
-void generateDart(DartOptions opt, Root root, Indent indent) {}
-
 /// Crawls up the path of [dartFilePath] until it finds a pubspec.yaml in a
 /// parent directory and returns its path.
 String? _findPubspecPath(String dartFilePath) {
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index 879d51b5f23..46e14005ca4 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -694,7 +694,3 @@ String _nullsafeSwiftTypeForDartType(TypeDeclaration type) {
   final String nullSafe = type.isNullable ? '?' : '';
   return '${_swiftTypeForDartType(type)}$nullSafe';
 }
-
-/// Generates the ".swift" file for the AST represented by [root] to [sink] with the
-/// provided [options].
-void generateSwift(SwiftOptions options, Root root, Indent indent) {}