diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index 6a901e11287..6c26d0287fd 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 16.0.4
+
+* [swift] Improve style of Swift output.
+
 ## 16.0.3
 
 * [kotlin] Separates message call code generation into separate methods.
diff --git a/packages/pigeon/example/app/ios/Runner/Messages.g.swift b/packages/pigeon/example/app/ios/Runner/Messages.g.swift
index ad6a337a6db..100fa3b7753 100644
--- a/packages/pigeon/example/app/ios/Runner/Messages.g.swift
+++ b/packages/pigeon/example/app/ios/Runner/Messages.g.swift
@@ -5,12 +5,13 @@
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
+
 #if os(iOS)
-import Flutter
+  import Flutter
 #elseif os(macOS)
-import FlutterMacOS
+  import FlutterMacOS
 #else
-#error("Unsupported platform.")
+  #error("Unsupported platform.")
 #endif
 
 private func wrapResult(_ result: Any?) -> [Any?] {
@@ -22,13 +23,13 @@ private func wrapError(_ error: Any) -> [Any?] {
     return [
       flutterError.code,
       flutterError.message,
-      flutterError.details
+      flutterError.details,
     ]
   }
   return [
     "\(error)",
     "\(type(of: error))",
-    "Stacktrace: \(Thread.callStackSymbols)"
+    "Stacktrace: \(Thread.callStackSymbols)",
   ]
 }
 
@@ -83,10 +84,10 @@ struct MessageData {
 private class ExampleHostApiCodecReader: FlutterStandardReader {
   override func readValue(ofType type: UInt8) -> Any? {
     switch type {
-      case 128:
-        return MessageData.fromList(self.readValue() as! [Any?])
-      default:
-        return super.readValue(ofType: type)
+    case 128:
+      return MessageData.fromList(self.readValue() as! [Any?])
+    default:
+      return super.readValue(ofType: type)
     }
   }
 }
@@ -165,10 +166,10 @@ class ExampleHostApiSetup {
         let messageArg = args[0] as! MessageData
         api.sendMessage(message: messageArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -183,7 +184,7 @@ protocol MessageFlutterApiProtocol {
 }
 class MessageFlutterApi: MessageFlutterApiProtocol {
   private let binaryMessenger: FlutterBinaryMessenger
-  init(binaryMessenger: FlutterBinaryMessenger){
+  init(binaryMessenger: FlutterBinaryMessenger) {
     self.binaryMessenger = binaryMessenger
   }
   func flutterMethod(aString aStringArg: String?, completion: @escaping (Result<String, FlutterError>) -> Void) {
@@ -191,15 +192,15 @@ class MessageFlutterApi: MessageFlutterApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger)
     channel.sendMessage([aStringArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! String
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 31a4d0e778b..a399c62f1be 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -13,7 +13,7 @@ import 'ast.dart';
 /// The current version of pigeon.
 ///
 /// This must match the version in pubspec.yaml.
-const String pigeonVersion = '16.0.3';
+const String pigeonVersion = '16.0.4';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
@@ -309,7 +309,7 @@ bool isVoid(TypeMirror type) {
 void addLines(Indent indent, Iterable<String> lines, {String? linePrefix}) {
   final String prefix = linePrefix ?? '';
   for (final String line in lines) {
-    indent.writeln('$prefix$line');
+    indent.writeln(line.isNotEmpty ? '$prefix$line' : prefix.trimRight());
   }
 }
 
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index ae869426e62..91319402c4f 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -76,13 +76,14 @@ class SwiftGenerator extends StructuredGenerator<SwiftOptions> {
     required String dartPackageName,
   }) {
     indent.writeln('import Foundation');
+    indent.newln();
     indent.format('''
 #if os(iOS)
-import Flutter
+  import Flutter
 #elseif os(macOS)
-import FlutterMacOS
+  import FlutterMacOS
 #else
-#error("Unsupported platform.")
+  #error("Unsupported platform.")
 #endif''');
   }
 
@@ -160,6 +161,9 @@ import FlutterMacOS
     indent.addScoped('{', '}', () {
       indent.write('return ');
       indent.addScoped('[', ']', () {
+        // Follow swift-format style, which is to use a trailing comma unless
+        // there is only one element.
+        final String separator = classDefinition.fields.length > 1 ? ',' : '';
         for (final NamedType field
             in getFieldsInSerializationOrder(classDefinition)) {
           String toWriteValue = '';
@@ -173,7 +177,7 @@ import FlutterMacOS
             toWriteValue = field.name;
           }
 
-          indent.writeln('$toWriteValue,');
+          indent.writeln('$toWriteValue$separator');
         }
       });
     });
@@ -294,7 +298,7 @@ import FlutterMacOS
     indent.write('class ${api.name}: ${api.name}Protocol ');
     indent.addScoped('{', '}', () {
       indent.writeln('private let binaryMessenger: FlutterBinaryMessenger');
-      indent.write('init(binaryMessenger: FlutterBinaryMessenger)');
+      indent.write('init(binaryMessenger: FlutterBinaryMessenger) ');
       indent.addScoped('{', '}', () {
         indent.writeln('self.binaryMessenger = binaryMessenger');
       });
@@ -330,20 +334,20 @@ import FlutterMacOS
             indent.writeScoped(
                 'guard let listResponse = response as? [Any?] else {', '}', () {
               indent.writeln(
-                  'completion(.failure(createConnectionError(withChannelName:channelName)))');
+                  'completion(.failure(createConnectionError(withChannelName: channelName)))');
               indent.writeln('return');
             });
-            indent.writeScoped('if (listResponse.count > 1) {', '} ', () {
+            indent.writeScoped('if listResponse.count > 1 {', '} ', () {
               indent.writeln('let code: String = listResponse[0] as! String');
               indent.writeln(
                   'let message: String? = nilOrValue(listResponse[1])');
               indent.writeln(
                   'let details: String? = nilOrValue(listResponse[2])');
               indent.writeln(
-                  'completion(.failure(FlutterError(code: code, message: message, details: details)));');
+                  'completion(.failure(FlutterError(code: code, message: message, details: details)))');
             }, addTrailingNewline: false);
             if (!func.returnType.isNullable && !func.returnType.isVoid) {
-              indent.addScoped('else if (listResponse[0] == nil) {', '} ', () {
+              indent.addScoped('else if listResponse[0] == nil {', '} ', () {
                 indent.writeln(
                     'completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))');
               }, addTrailingNewline: false);
@@ -495,8 +499,14 @@ import FlutterMacOS
                 });
               }
               final String tryStatement = method.isAsynchronous ? '' : 'try ';
+              // Empty parens are not required when calling a method whose only
+              // argument is a trailing closure.
+              final String argumentString =
+                  methodArgument.isEmpty && method.isAsynchronous
+                      ? ''
+                      : '(${methodArgument.join(', ')})';
               final String call =
-                  '${tryStatement}api.${components.name}(${methodArgument.join(', ')})';
+                  '${tryStatement}api.${components.name}$argumentString';
               if (method.isAsynchronous) {
                 final String resultName =
                     method.returnType.isVoid ? 'nil' : 'res';
@@ -506,7 +516,7 @@ import FlutterMacOS
 
                 indent.addScoped('{ result in', '}', () {
                   indent.write('switch result ');
-                  indent.addScoped('{', '}', () {
+                  indent.addScoped('{', '}', nestCount: 0, () {
                     final String nullsafe =
                         method.returnType.isNullable ? '?' : '';
                     final String enumTag =
@@ -573,7 +583,7 @@ import FlutterMacOS
         indent.write('override func readValue(ofType type: UInt8) -> Any? ');
         indent.addScoped('{', '}', () {
           indent.write('switch type ');
-          indent.addScoped('{', '}', () {
+          indent.addScoped('{', '}', nestCount: 0, () {
             for (final EnumeratedClass customClass
                 in getCodecClasses(api, root)) {
               indent.writeln('case ${customClass.enumeration}:');
@@ -764,14 +774,14 @@ import FlutterMacOS
         indent.addScoped('[', ']', () {
           indent.writeln('flutterError.code,');
           indent.writeln('flutterError.message,');
-          indent.writeln('flutterError.details');
+          indent.writeln('flutterError.details,');
         });
       });
       indent.write('return ');
       indent.addScoped('[', ']', () {
         indent.writeln(r'"\(error)",');
         indent.writeln(r'"\(type(of: error))",');
-        indent.writeln(r'"Stacktrace: \(Thread.callStackSymbols)"');
+        indent.writeln(r'"Stacktrace: \(Thread.callStackSymbols)",');
       });
     });
   }
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 773b6e5c12e..4dd101c0ccc 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
@@ -1,17 +1,18 @@
 // 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.
-// 
+//
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
+
 #if os(iOS)
-import Flutter
+  import Flutter
 #elseif os(macOS)
-import FlutterMacOS
+  import FlutterMacOS
 #else
-#error("Unsupported platform.")
+  #error("Unsupported platform.")
 #endif
 
 private func wrapResult(_ result: Any?) -> [Any?] {
@@ -23,13 +24,13 @@ private func wrapError(_ error: Any) -> [Any?] {
     return [
       flutterError.code,
       flutterError.message,
-      flutterError.details
+      flutterError.details,
     ]
   }
   return [
     "\(error)",
     "\(type(of: error))",
-    "Stacktrace: \(Thread.callStackSymbols)"
+    "Stacktrace: \(Thread.callStackSymbols)",
   ]
 }
 
@@ -250,7 +251,7 @@ struct TestMessage {
   }
   func toList() -> [Any?] {
     return [
-      testList,
+      testList
     ]
   }
 }
@@ -258,16 +259,16 @@ struct TestMessage {
 private class HostIntegrationCoreApiCodecReader: FlutterStandardReader {
   override func readValue(ofType type: UInt8) -> Any? {
     switch type {
-      case 128:
-        return AllClassesWrapper.fromList(self.readValue() as! [Any?])
-      case 129:
-        return AllNullableTypes.fromList(self.readValue() as! [Any?])
-      case 130:
-        return AllTypes.fromList(self.readValue() as! [Any?])
-      case 131:
-        return TestMessage.fromList(self.readValue() as! [Any?])
-      default:
-        return super.readValue(ofType: type)
+    case 128:
+      return AllClassesWrapper.fromList(self.readValue() as! [Any?])
+    case 129:
+      return AllNullableTypes.fromList(self.readValue() as! [Any?])
+    case 130:
+      return AllTypes.fromList(self.readValue() as! [Any?])
+    case 131:
+      return TestMessage.fromList(self.readValue() as! [Any?])
+    default:
+      return super.readValue(ofType: type)
     }
   }
 }
@@ -987,12 +988,12 @@ class HostIntegrationCoreApiSetup {
     let noopAsyncChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.noopAsync", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       noopAsyncChannel.setMessageHandler { _, reply in
-        api.noopAsync() { result in
+        api.noopAsync { result in
           switch result {
-            case .success:
-              reply(wrapResult(nil))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success:
+            reply(wrapResult(nil))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1007,10 +1008,10 @@ class HostIntegrationCoreApiSetup {
         let anIntArg = args[0] is Int64 ? args[0] as! Int64 : Int64(args[0] as! Int32)
         api.echoAsync(anIntArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1025,10 +1026,10 @@ class HostIntegrationCoreApiSetup {
         let aDoubleArg = args[0] as! Double
         api.echoAsync(aDoubleArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1043,10 +1044,10 @@ class HostIntegrationCoreApiSetup {
         let aBoolArg = args[0] as! Bool
         api.echoAsync(aBoolArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1061,10 +1062,10 @@ class HostIntegrationCoreApiSetup {
         let aStringArg = args[0] as! String
         api.echoAsync(aStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1079,10 +1080,10 @@ class HostIntegrationCoreApiSetup {
         let aUint8ListArg = args[0] as! FlutterStandardTypedData
         api.echoAsync(aUint8ListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1097,10 +1098,10 @@ class HostIntegrationCoreApiSetup {
         let anObjectArg = args[0]!
         api.echoAsync(anObjectArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1115,10 +1116,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg = args[0] as! [Any?]
         api.echoAsync(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1133,10 +1134,10 @@ class HostIntegrationCoreApiSetup {
         let aMapArg = args[0] as! [String?: Any?]
         api.echoAsync(aMapArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1151,10 +1152,10 @@ class HostIntegrationCoreApiSetup {
         let anEnumArg = AnEnum(rawValue: args[0] as! Int)!
         api.echoAsync(anEnumArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res.rawValue))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res.rawValue))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1165,12 +1166,12 @@ class HostIntegrationCoreApiSetup {
     let throwAsyncErrorChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.throwAsyncError", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       throwAsyncErrorChannel.setMessageHandler { _, reply in
-        api.throwAsyncError() { result in
+        api.throwAsyncError { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1181,12 +1182,12 @@ class HostIntegrationCoreApiSetup {
     let throwAsyncErrorFromVoidChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.throwAsyncErrorFromVoid", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       throwAsyncErrorFromVoidChannel.setMessageHandler { _, reply in
-        api.throwAsyncErrorFromVoid() { result in
+        api.throwAsyncErrorFromVoid { result in
           switch result {
-            case .success:
-              reply(wrapResult(nil))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success:
+            reply(wrapResult(nil))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1197,12 +1198,12 @@ class HostIntegrationCoreApiSetup {
     let throwAsyncFlutterErrorChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.throwAsyncFlutterError", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       throwAsyncFlutterErrorChannel.setMessageHandler { _, reply in
-        api.throwAsyncFlutterError() { result in
+        api.throwAsyncFlutterError { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1217,10 +1218,10 @@ class HostIntegrationCoreApiSetup {
         let everythingArg = args[0] as! AllTypes
         api.echoAsync(everythingArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1235,10 +1236,10 @@ class HostIntegrationCoreApiSetup {
         let everythingArg: AllNullableTypes? = nilOrValue(args[0])
         api.echoAsync(everythingArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1253,10 +1254,10 @@ class HostIntegrationCoreApiSetup {
         let anIntArg: Int64? = isNullish(args[0]) ? nil : (args[0] is Int64? ? args[0] as! Int64? : Int64(args[0] as! Int32))
         api.echoAsyncNullable(anIntArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1271,10 +1272,10 @@ class HostIntegrationCoreApiSetup {
         let aDoubleArg: Double? = nilOrValue(args[0])
         api.echoAsyncNullable(aDoubleArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1289,10 +1290,10 @@ class HostIntegrationCoreApiSetup {
         let aBoolArg: Bool? = nilOrValue(args[0])
         api.echoAsyncNullable(aBoolArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1307,10 +1308,10 @@ class HostIntegrationCoreApiSetup {
         let aStringArg: String? = nilOrValue(args[0])
         api.echoAsyncNullable(aStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1325,10 +1326,10 @@ class HostIntegrationCoreApiSetup {
         let aUint8ListArg: FlutterStandardTypedData? = nilOrValue(args[0])
         api.echoAsyncNullable(aUint8ListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1343,10 +1344,10 @@ class HostIntegrationCoreApiSetup {
         let anObjectArg: Any? = args[0]
         api.echoAsyncNullable(anObjectArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1361,10 +1362,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg: [Any?]? = nilOrValue(args[0])
         api.echoAsyncNullable(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1379,10 +1380,10 @@ class HostIntegrationCoreApiSetup {
         let aMapArg: [String?: Any?]? = nilOrValue(args[0])
         api.echoAsyncNullable(aMapArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1397,10 +1398,10 @@ class HostIntegrationCoreApiSetup {
         let anEnumArg: AnEnum? = isNullish(args[0]) ? nil : AnEnum(rawValue: args[0] as! Int)!
         api.echoAsyncNullable(anEnumArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res?.rawValue))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res?.rawValue))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1410,12 +1411,12 @@ class HostIntegrationCoreApiSetup {
     let callFlutterNoopChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.callFlutterNoop", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       callFlutterNoopChannel.setMessageHandler { _, reply in
-        api.callFlutterNoop() { result in
+        api.callFlutterNoop { result in
           switch result {
-            case .success:
-              reply(wrapResult(nil))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success:
+            reply(wrapResult(nil))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1425,12 +1426,12 @@ class HostIntegrationCoreApiSetup {
     let callFlutterThrowErrorChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.callFlutterThrowError", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       callFlutterThrowErrorChannel.setMessageHandler { _, reply in
-        api.callFlutterThrowError() { result in
+        api.callFlutterThrowError { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1440,12 +1441,12 @@ class HostIntegrationCoreApiSetup {
     let callFlutterThrowErrorFromVoidChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.callFlutterThrowErrorFromVoid", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       callFlutterThrowErrorFromVoidChannel.setMessageHandler { _, reply in
-        api.callFlutterThrowErrorFromVoid() { result in
+        api.callFlutterThrowErrorFromVoid { result in
           switch result {
-            case .success:
-              reply(wrapResult(nil))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success:
+            reply(wrapResult(nil))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1459,10 +1460,10 @@ class HostIntegrationCoreApiSetup {
         let everythingArg = args[0] as! AllTypes
         api.callFlutterEcho(everythingArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1476,10 +1477,10 @@ class HostIntegrationCoreApiSetup {
         let everythingArg: AllNullableTypes? = nilOrValue(args[0])
         api.callFlutterEcho(everythingArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1495,10 +1496,10 @@ class HostIntegrationCoreApiSetup {
         let aNullableStringArg: String? = nilOrValue(args[2])
         api.callFlutterSendMultipleNullableTypes(aBool: aNullableBoolArg, anInt: aNullableIntArg, aString: aNullableStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1512,10 +1513,10 @@ class HostIntegrationCoreApiSetup {
         let aBoolArg = args[0] as! Bool
         api.callFlutterEcho(aBoolArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1529,10 +1530,10 @@ class HostIntegrationCoreApiSetup {
         let anIntArg = args[0] is Int64 ? args[0] as! Int64 : Int64(args[0] as! Int32)
         api.callFlutterEcho(anIntArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1546,10 +1547,10 @@ class HostIntegrationCoreApiSetup {
         let aDoubleArg = args[0] as! Double
         api.callFlutterEcho(aDoubleArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1563,10 +1564,10 @@ class HostIntegrationCoreApiSetup {
         let aStringArg = args[0] as! String
         api.callFlutterEcho(aStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1580,10 +1581,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg = args[0] as! FlutterStandardTypedData
         api.callFlutterEcho(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1597,10 +1598,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg = args[0] as! [Any?]
         api.callFlutterEcho(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1614,10 +1615,10 @@ class HostIntegrationCoreApiSetup {
         let aMapArg = args[0] as! [String?: Any?]
         api.callFlutterEcho(aMapArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1631,10 +1632,10 @@ class HostIntegrationCoreApiSetup {
         let anEnumArg = AnEnum(rawValue: args[0] as! Int)!
         api.callFlutterEcho(anEnumArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res.rawValue))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res.rawValue))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1648,10 +1649,10 @@ class HostIntegrationCoreApiSetup {
         let aBoolArg: Bool? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aBoolArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1665,10 +1666,10 @@ class HostIntegrationCoreApiSetup {
         let anIntArg: Int64? = isNullish(args[0]) ? nil : (args[0] is Int64? ? args[0] as! Int64? : Int64(args[0] as! Int32))
         api.callFlutterEchoNullable(anIntArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1682,10 +1683,10 @@ class HostIntegrationCoreApiSetup {
         let aDoubleArg: Double? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aDoubleArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1699,10 +1700,10 @@ class HostIntegrationCoreApiSetup {
         let aStringArg: String? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1716,10 +1717,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg: FlutterStandardTypedData? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1733,10 +1734,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg: [Any?]? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1750,10 +1751,10 @@ class HostIntegrationCoreApiSetup {
         let aMapArg: [String?: Any?]? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aMapArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1767,10 +1768,10 @@ class HostIntegrationCoreApiSetup {
         let anEnumArg: AnEnum? = isNullish(args[0]) ? nil : AnEnum(rawValue: args[0] as! Int)!
         api.callFlutterNullableEcho(anEnumArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res?.rawValue))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res?.rawValue))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1782,16 +1783,16 @@ class HostIntegrationCoreApiSetup {
 private class FlutterIntegrationCoreApiCodecReader: FlutterStandardReader {
   override func readValue(ofType type: UInt8) -> Any? {
     switch type {
-      case 128:
-        return AllClassesWrapper.fromList(self.readValue() as! [Any?])
-      case 129:
-        return AllNullableTypes.fromList(self.readValue() as! [Any?])
-      case 130:
-        return AllTypes.fromList(self.readValue() as! [Any?])
-      case 131:
-        return TestMessage.fromList(self.readValue() as! [Any?])
-      default:
-        return super.readValue(ofType: type)
+    case 128:
+      return AllClassesWrapper.fromList(self.readValue() as! [Any?])
+    case 129:
+      return AllNullableTypes.fromList(self.readValue() as! [Any?])
+    case 130:
+      return AllTypes.fromList(self.readValue() as! [Any?])
+    case 131:
+      return TestMessage.fromList(self.readValue() as! [Any?])
+    default:
+      return super.readValue(ofType: type)
     }
   }
 }
@@ -1890,7 +1891,7 @@ protocol FlutterIntegrationCoreApiProtocol {
 }
 class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
   private let binaryMessenger: FlutterBinaryMessenger
-  init(binaryMessenger: FlutterBinaryMessenger){
+  init(binaryMessenger: FlutterBinaryMessenger) {
     self.binaryMessenger = binaryMessenger
   }
   var codec: FlutterStandardMessageCodec {
@@ -1903,14 +1904,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage(nil) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         completion(.success(Void()))
       }
@@ -1922,14 +1923,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage(nil) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: Any? = listResponse[0]
         completion(.success(result))
@@ -1942,14 +1943,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage(nil) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         completion(.success(Void()))
       }
@@ -1961,15 +1962,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([everythingArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! AllTypes
@@ -1983,14 +1984,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([everythingArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: AllNullableTypes? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2005,15 +2006,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aNullableBoolArg, aNullableIntArg, aNullableStringArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! AllNullableTypes
@@ -2027,15 +2028,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aBoolArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! Bool
@@ -2049,15 +2050,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([anIntArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] is Int64 ? listResponse[0] as! Int64 : Int64(listResponse[0] as! Int32)
@@ -2071,15 +2072,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aDoubleArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! Double
@@ -2093,15 +2094,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aStringArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! String
@@ -2115,15 +2116,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aListArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! FlutterStandardTypedData
@@ -2137,15 +2138,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aListArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! [Any?]
@@ -2159,15 +2160,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aMapArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! [String?: Any?]
@@ -2181,15 +2182,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([anEnumArg.rawValue] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = AnEnum(rawValue: listResponse[0] as! Int)!
@@ -2203,14 +2204,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aBoolArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: Bool? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2223,14 +2224,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([anIntArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: Int64? = isNullish(listResponse[0]) ? nil : (listResponse[0] is Int64? ? listResponse[0] as! Int64? : Int64(listResponse[0] as! Int32))
         completion(.success(result))
@@ -2243,14 +2244,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aDoubleArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: Double? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2263,14 +2264,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aStringArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: String? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2283,14 +2284,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aListArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: FlutterStandardTypedData? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2303,14 +2304,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aListArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: [Any?]? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2323,14 +2324,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aMapArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: [String?: Any?]? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2343,14 +2344,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([anEnumArg?.rawValue] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: AnEnum? = isNullish(listResponse[0]) ? nil : AnEnum(rawValue: listResponse[0] as! Int)!
         completion(.success(result))
@@ -2364,14 +2365,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage(nil) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         completion(.success(Void()))
       }
@@ -2383,15 +2384,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aStringArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! String
@@ -2447,10 +2448,10 @@ class HostSmallApiSetup {
         let aStringArg = args[0] as! String
         api.echo(aString: aStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -2460,12 +2461,12 @@ class HostSmallApiSetup {
     let voidVoidChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostSmallApi.voidVoid", binaryMessenger: binaryMessenger)
     if let api = api {
       voidVoidChannel.setMessageHandler { _, reply in
-        api.voidVoid() { result in
+        api.voidVoid { result in
           switch result {
-            case .success:
-              reply(wrapResult(nil))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success:
+            reply(wrapResult(nil))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -2477,10 +2478,10 @@ class HostSmallApiSetup {
 private class FlutterSmallApiCodecReader: FlutterStandardReader {
   override func readValue(ofType type: UInt8) -> Any? {
     switch type {
-      case 128:
-        return TestMessage.fromList(self.readValue() as! [Any?])
-      default:
-        return super.readValue(ofType: type)
+    case 128:
+      return TestMessage.fromList(self.readValue() as! [Any?])
+    default:
+      return super.readValue(ofType: type)
     }
   }
 }
@@ -2519,7 +2520,7 @@ protocol FlutterSmallApiProtocol {
 }
 class FlutterSmallApi: FlutterSmallApiProtocol {
   private let binaryMessenger: FlutterBinaryMessenger
-  init(binaryMessenger: FlutterBinaryMessenger){
+  init(binaryMessenger: FlutterBinaryMessenger) {
     self.binaryMessenger = binaryMessenger
   }
   var codec: FlutterStandardMessageCodec {
@@ -2530,15 +2531,15 @@ class FlutterSmallApi: FlutterSmallApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([msgArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! TestMessage
@@ -2551,15 +2552,15 @@ class FlutterSmallApi: FlutterSmallApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aStringArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! String
diff --git a/packages/pigeon/platform_tests/test_plugin/ios/Classes/TestPlugin.swift b/packages/pigeon/platform_tests/test_plugin/ios/Classes/TestPlugin.swift
index 8b4daf5a08e..0d04c9544ca 100644
--- a/packages/pigeon/platform_tests/test_plugin/ios/Classes/TestPlugin.swift
+++ b/packages/pigeon/platform_tests/test_plugin/ios/Classes/TestPlugin.swift
@@ -7,10 +7,8 @@ import UIKit
 
 extension FlutterError: Error {}
 
-/**
- * This plugin handles the native side of the integration tests in
- * example/integration_test/.
- */
+/// This plugin handles the native side of the integration tests in
+/// example/integration_test/.
 public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   var flutterAPI: FlutterIntegrationCoreApi
 
@@ -90,15 +88,18 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   }
 
   func extractNestedNullableString(from wrapper: AllClassesWrapper) -> String? {
-    return wrapper.allNullableTypes.aNullableString;
+    return wrapper.allNullableTypes.aNullableString
   }
 
   func createNestedObject(with nullableString: String?) -> AllClassesWrapper {
     return AllClassesWrapper(allNullableTypes: AllNullableTypes(aNullableString: nullableString))
   }
 
-  func sendMultipleNullableTypes(aBool aNullableBool: Bool?, anInt aNullableInt: Int64?, aString aNullableString: String?) -> AllNullableTypes {
-    let someThings = AllNullableTypes(aNullableBool: aNullableBool, aNullableInt: aNullableInt, aNullableString: aNullableString)
+  func sendMultipleNullableTypes(
+    aBool aNullableBool: Bool?, anInt aNullableInt: Int64?, aString aNullableString: String?
+  ) -> AllNullableTypes {
+    let someThings = AllNullableTypes(
+      aNullableBool: aNullableBool, aNullableInt: aNullableInt, aNullableString: aNullableString)
     return someThings
   }
 
@@ -178,7 +179,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(everything))
   }
 
-  func echoAsync(_ everything: AllNullableTypes?, completion: @escaping (Result<AllNullableTypes?, Error>) -> Void) {
+  func echoAsync(
+    _ everything: AllNullableTypes?,
+    completion: @escaping (Result<AllNullableTypes?, Error>) -> Void
+  ) {
     completion(.success(everything))
   }
 
@@ -198,7 +202,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(aString))
   }
 
-  func echoAsync(_ aUint8List: FlutterStandardTypedData, completion: @escaping (Result<FlutterStandardTypedData, Error>) -> Void) {
+  func echoAsync(
+    _ aUint8List: FlutterStandardTypedData,
+    completion: @escaping (Result<FlutterStandardTypedData, Error>) -> Void
+  ) {
     completion(.success(aUint8List))
   }
 
@@ -210,7 +217,9 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(aList))
   }
 
-  func echoAsync(_ aMap: [String?: Any?], completion: @escaping (Result<[String?: Any?], Error>) -> Void) {
+  func echoAsync(
+    _ aMap: [String?: Any?], completion: @escaping (Result<[String?: Any?], Error>) -> Void
+  ) {
     completion(.success(aMap))
   }
 
@@ -222,7 +231,8 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(anInt))
   }
 
-  func echoAsyncNullable(_ aDouble: Double?, completion: @escaping (Result<Double?, Error>) -> Void) {
+  func echoAsyncNullable(_ aDouble: Double?, completion: @escaping (Result<Double?, Error>) -> Void)
+  {
     completion(.success(aDouble))
   }
 
@@ -230,11 +240,15 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(aBool))
   }
 
-  func echoAsyncNullable(_ aString: String?, completion: @escaping (Result<String?, Error>) -> Void) {
+  func echoAsyncNullable(_ aString: String?, completion: @escaping (Result<String?, Error>) -> Void)
+  {
     completion(.success(aString))
   }
 
-  func echoAsyncNullable(_ aUint8List: FlutterStandardTypedData?, completion: @escaping (Result<FlutterStandardTypedData?, Error>) -> Void) {
+  func echoAsyncNullable(
+    _ aUint8List: FlutterStandardTypedData?,
+    completion: @escaping (Result<FlutterStandardTypedData?, Error>) -> Void
+  ) {
     completion(.success(aUint8List))
   }
 
@@ -246,66 +260,74 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(aList))
   }
 
-  func echoAsyncNullable(_ aMap: [String?: Any?]?, completion: @escaping (Result<[String?: Any?]?, Error>) -> Void) {
+  func echoAsyncNullable(
+    _ aMap: [String?: Any?]?, completion: @escaping (Result<[String?: Any?]?, Error>) -> Void
+  ) {
     completion(.success(aMap))
   }
 
-  func echoAsyncNullable(_ anEnum: AnEnum?, completion: @escaping (Result<AnEnum?, Error>) -> Void) {
+  func echoAsyncNullable(_ anEnum: AnEnum?, completion: @escaping (Result<AnEnum?, Error>) -> Void)
+  {
     completion(.success(anEnum))
   }
 
   func callFlutterNoop(completion: @escaping (Result<Void, Error>) -> Void) {
-    flutterAPI.noop() { response in
+    flutterAPI.noop { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
   func callFlutterThrowError(completion: @escaping (Result<Any?, Error>) -> Void) {
-    flutterAPI.throwError() { response in
+    flutterAPI.throwError { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
   func callFlutterThrowErrorFromVoid(completion: @escaping (Result<Void, Error>) -> Void) {
-    flutterAPI.throwErrorFromVoid() { response in
+    flutterAPI.throwErrorFromVoid { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEcho(_ everything: AllTypes, completion: @escaping (Result<AllTypes, Error>) -> Void) {
+  func callFlutterEcho(
+    _ everything: AllTypes, completion: @escaping (Result<AllTypes, Error>) -> Void
+  ) {
     flutterAPI.echo(everything) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
-      } 
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
+      }
     }
   }
 
-  func callFlutterEcho(_ everything: AllNullableTypes?, completion: @escaping (Result<AllNullableTypes?, Error>) -> Void) {
+  func callFlutterEcho(
+    _ everything: AllNullableTypes?,
+    completion: @escaping (Result<AllNullableTypes?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(everything) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
-      } 
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
+      }
     }
   }
 
@@ -321,10 +343,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
       aString: aNullableString
     ) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -332,10 +354,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ aBool: Bool, completion: @escaping (Result<Bool, Error>) -> Void) {
     flutterAPI.echo(aBool) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -343,10 +365,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ anInt: Int64, completion: @escaping (Result<Int64, Error>) -> Void) {
     flutterAPI.echo(anInt) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -354,10 +376,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ aDouble: Double, completion: @escaping (Result<Double, Error>) -> Void) {
     flutterAPI.echo(aDouble) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -365,21 +387,24 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ aString: String, completion: @escaping (Result<String, Error>) -> Void) {
     flutterAPI.echo(aString) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEcho(_ aList: FlutterStandardTypedData, completion: @escaping (Result<FlutterStandardTypedData, Error>) -> Void) {
+  func callFlutterEcho(
+    _ aList: FlutterStandardTypedData,
+    completion: @escaping (Result<FlutterStandardTypedData, Error>) -> Void
+  ) {
     flutterAPI.echo(aList) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -387,21 +412,23 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ aList: [Any?], completion: @escaping (Result<[Any?], Error>) -> Void) {
     flutterAPI.echo(aList) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEcho(_ aMap: [String? : Any?], completion: @escaping (Result<[String? : Any?], Error>) -> Void) {
+  func callFlutterEcho(
+    _ aMap: [String?: Any?], completion: @escaping (Result<[String?: Any?], Error>) -> Void
+  ) {
     flutterAPI.echo(aMap) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -409,99 +436,115 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ anEnum: AnEnum, completion: @escaping (Result<AnEnum, Error>) -> Void) {
     flutterAPI.echo(anEnum) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ aBool: Bool?, completion: @escaping (Result<Bool?, Error>) -> Void) {
+  func callFlutterEchoNullable(_ aBool: Bool?, completion: @escaping (Result<Bool?, Error>) -> Void)
+  {
     flutterAPI.echoNullable(aBool) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ anInt: Int64?, completion: @escaping (Result<Int64?, Error>) -> Void) {
+  func callFlutterEchoNullable(
+    _ anInt: Int64?, completion: @escaping (Result<Int64?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(anInt) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ aDouble: Double?, completion: @escaping (Result<Double?, Error>) -> Void) {
+  func callFlutterEchoNullable(
+    _ aDouble: Double?, completion: @escaping (Result<Double?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(aDouble) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ aString: String?, completion: @escaping (Result<String?, Error>) -> Void) {
+  func callFlutterEchoNullable(
+    _ aString: String?, completion: @escaping (Result<String?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(aString) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
-  
-  func callFlutterEchoNullable(_ aList: FlutterStandardTypedData?, completion: @escaping (Result<FlutterStandardTypedData?, Error>) -> Void) {
+
+  func callFlutterEchoNullable(
+    _ aList: FlutterStandardTypedData?,
+    completion: @escaping (Result<FlutterStandardTypedData?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(aList) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ aList: [Any?]?, completion: @escaping (Result<[Any?]?, Error>) -> Void) {
+  func callFlutterEchoNullable(
+    _ aList: [Any?]?, completion: @escaping (Result<[Any?]?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(aList) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ aMap: [String? : Any?]?, completion: @escaping (Result<[String? : Any?]?, Error>) -> Void) {
+  func callFlutterEchoNullable(
+    _ aMap: [String?: Any?]?, completion: @escaping (Result<[String?: Any?]?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(aMap) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterNullableEcho(_ anEnum: AnEnum?, completion: @escaping (Result<AnEnum?, Error>) -> Void) {
+  func callFlutterNullableEcho(
+    _ anEnum: AnEnum?, completion: @escaping (Result<AnEnum?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(anEnum) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
-    }    
+    }
   }
 }
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 773b6e5c12e..4dd101c0ccc 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
@@ -1,17 +1,18 @@
 // 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.
-// 
+//
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 import Foundation
+
 #if os(iOS)
-import Flutter
+  import Flutter
 #elseif os(macOS)
-import FlutterMacOS
+  import FlutterMacOS
 #else
-#error("Unsupported platform.")
+  #error("Unsupported platform.")
 #endif
 
 private func wrapResult(_ result: Any?) -> [Any?] {
@@ -23,13 +24,13 @@ private func wrapError(_ error: Any) -> [Any?] {
     return [
       flutterError.code,
       flutterError.message,
-      flutterError.details
+      flutterError.details,
     ]
   }
   return [
     "\(error)",
     "\(type(of: error))",
-    "Stacktrace: \(Thread.callStackSymbols)"
+    "Stacktrace: \(Thread.callStackSymbols)",
   ]
 }
 
@@ -250,7 +251,7 @@ struct TestMessage {
   }
   func toList() -> [Any?] {
     return [
-      testList,
+      testList
     ]
   }
 }
@@ -258,16 +259,16 @@ struct TestMessage {
 private class HostIntegrationCoreApiCodecReader: FlutterStandardReader {
   override func readValue(ofType type: UInt8) -> Any? {
     switch type {
-      case 128:
-        return AllClassesWrapper.fromList(self.readValue() as! [Any?])
-      case 129:
-        return AllNullableTypes.fromList(self.readValue() as! [Any?])
-      case 130:
-        return AllTypes.fromList(self.readValue() as! [Any?])
-      case 131:
-        return TestMessage.fromList(self.readValue() as! [Any?])
-      default:
-        return super.readValue(ofType: type)
+    case 128:
+      return AllClassesWrapper.fromList(self.readValue() as! [Any?])
+    case 129:
+      return AllNullableTypes.fromList(self.readValue() as! [Any?])
+    case 130:
+      return AllTypes.fromList(self.readValue() as! [Any?])
+    case 131:
+      return TestMessage.fromList(self.readValue() as! [Any?])
+    default:
+      return super.readValue(ofType: type)
     }
   }
 }
@@ -987,12 +988,12 @@ class HostIntegrationCoreApiSetup {
     let noopAsyncChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.noopAsync", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       noopAsyncChannel.setMessageHandler { _, reply in
-        api.noopAsync() { result in
+        api.noopAsync { result in
           switch result {
-            case .success:
-              reply(wrapResult(nil))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success:
+            reply(wrapResult(nil))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1007,10 +1008,10 @@ class HostIntegrationCoreApiSetup {
         let anIntArg = args[0] is Int64 ? args[0] as! Int64 : Int64(args[0] as! Int32)
         api.echoAsync(anIntArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1025,10 +1026,10 @@ class HostIntegrationCoreApiSetup {
         let aDoubleArg = args[0] as! Double
         api.echoAsync(aDoubleArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1043,10 +1044,10 @@ class HostIntegrationCoreApiSetup {
         let aBoolArg = args[0] as! Bool
         api.echoAsync(aBoolArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1061,10 +1062,10 @@ class HostIntegrationCoreApiSetup {
         let aStringArg = args[0] as! String
         api.echoAsync(aStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1079,10 +1080,10 @@ class HostIntegrationCoreApiSetup {
         let aUint8ListArg = args[0] as! FlutterStandardTypedData
         api.echoAsync(aUint8ListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1097,10 +1098,10 @@ class HostIntegrationCoreApiSetup {
         let anObjectArg = args[0]!
         api.echoAsync(anObjectArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1115,10 +1116,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg = args[0] as! [Any?]
         api.echoAsync(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1133,10 +1134,10 @@ class HostIntegrationCoreApiSetup {
         let aMapArg = args[0] as! [String?: Any?]
         api.echoAsync(aMapArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1151,10 +1152,10 @@ class HostIntegrationCoreApiSetup {
         let anEnumArg = AnEnum(rawValue: args[0] as! Int)!
         api.echoAsync(anEnumArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res.rawValue))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res.rawValue))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1165,12 +1166,12 @@ class HostIntegrationCoreApiSetup {
     let throwAsyncErrorChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.throwAsyncError", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       throwAsyncErrorChannel.setMessageHandler { _, reply in
-        api.throwAsyncError() { result in
+        api.throwAsyncError { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1181,12 +1182,12 @@ class HostIntegrationCoreApiSetup {
     let throwAsyncErrorFromVoidChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.throwAsyncErrorFromVoid", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       throwAsyncErrorFromVoidChannel.setMessageHandler { _, reply in
-        api.throwAsyncErrorFromVoid() { result in
+        api.throwAsyncErrorFromVoid { result in
           switch result {
-            case .success:
-              reply(wrapResult(nil))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success:
+            reply(wrapResult(nil))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1197,12 +1198,12 @@ class HostIntegrationCoreApiSetup {
     let throwAsyncFlutterErrorChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.throwAsyncFlutterError", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       throwAsyncFlutterErrorChannel.setMessageHandler { _, reply in
-        api.throwAsyncFlutterError() { result in
+        api.throwAsyncFlutterError { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1217,10 +1218,10 @@ class HostIntegrationCoreApiSetup {
         let everythingArg = args[0] as! AllTypes
         api.echoAsync(everythingArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1235,10 +1236,10 @@ class HostIntegrationCoreApiSetup {
         let everythingArg: AllNullableTypes? = nilOrValue(args[0])
         api.echoAsync(everythingArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1253,10 +1254,10 @@ class HostIntegrationCoreApiSetup {
         let anIntArg: Int64? = isNullish(args[0]) ? nil : (args[0] is Int64? ? args[0] as! Int64? : Int64(args[0] as! Int32))
         api.echoAsyncNullable(anIntArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1271,10 +1272,10 @@ class HostIntegrationCoreApiSetup {
         let aDoubleArg: Double? = nilOrValue(args[0])
         api.echoAsyncNullable(aDoubleArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1289,10 +1290,10 @@ class HostIntegrationCoreApiSetup {
         let aBoolArg: Bool? = nilOrValue(args[0])
         api.echoAsyncNullable(aBoolArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1307,10 +1308,10 @@ class HostIntegrationCoreApiSetup {
         let aStringArg: String? = nilOrValue(args[0])
         api.echoAsyncNullable(aStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1325,10 +1326,10 @@ class HostIntegrationCoreApiSetup {
         let aUint8ListArg: FlutterStandardTypedData? = nilOrValue(args[0])
         api.echoAsyncNullable(aUint8ListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1343,10 +1344,10 @@ class HostIntegrationCoreApiSetup {
         let anObjectArg: Any? = args[0]
         api.echoAsyncNullable(anObjectArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1361,10 +1362,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg: [Any?]? = nilOrValue(args[0])
         api.echoAsyncNullable(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1379,10 +1380,10 @@ class HostIntegrationCoreApiSetup {
         let aMapArg: [String?: Any?]? = nilOrValue(args[0])
         api.echoAsyncNullable(aMapArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1397,10 +1398,10 @@ class HostIntegrationCoreApiSetup {
         let anEnumArg: AnEnum? = isNullish(args[0]) ? nil : AnEnum(rawValue: args[0] as! Int)!
         api.echoAsyncNullable(anEnumArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res?.rawValue))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res?.rawValue))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1410,12 +1411,12 @@ class HostIntegrationCoreApiSetup {
     let callFlutterNoopChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.callFlutterNoop", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       callFlutterNoopChannel.setMessageHandler { _, reply in
-        api.callFlutterNoop() { result in
+        api.callFlutterNoop { result in
           switch result {
-            case .success:
-              reply(wrapResult(nil))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success:
+            reply(wrapResult(nil))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1425,12 +1426,12 @@ class HostIntegrationCoreApiSetup {
     let callFlutterThrowErrorChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.callFlutterThrowError", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       callFlutterThrowErrorChannel.setMessageHandler { _, reply in
-        api.callFlutterThrowError() { result in
+        api.callFlutterThrowError { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1440,12 +1441,12 @@ class HostIntegrationCoreApiSetup {
     let callFlutterThrowErrorFromVoidChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostIntegrationCoreApi.callFlutterThrowErrorFromVoid", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       callFlutterThrowErrorFromVoidChannel.setMessageHandler { _, reply in
-        api.callFlutterThrowErrorFromVoid() { result in
+        api.callFlutterThrowErrorFromVoid { result in
           switch result {
-            case .success:
-              reply(wrapResult(nil))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success:
+            reply(wrapResult(nil))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1459,10 +1460,10 @@ class HostIntegrationCoreApiSetup {
         let everythingArg = args[0] as! AllTypes
         api.callFlutterEcho(everythingArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1476,10 +1477,10 @@ class HostIntegrationCoreApiSetup {
         let everythingArg: AllNullableTypes? = nilOrValue(args[0])
         api.callFlutterEcho(everythingArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1495,10 +1496,10 @@ class HostIntegrationCoreApiSetup {
         let aNullableStringArg: String? = nilOrValue(args[2])
         api.callFlutterSendMultipleNullableTypes(aBool: aNullableBoolArg, anInt: aNullableIntArg, aString: aNullableStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1512,10 +1513,10 @@ class HostIntegrationCoreApiSetup {
         let aBoolArg = args[0] as! Bool
         api.callFlutterEcho(aBoolArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1529,10 +1530,10 @@ class HostIntegrationCoreApiSetup {
         let anIntArg = args[0] is Int64 ? args[0] as! Int64 : Int64(args[0] as! Int32)
         api.callFlutterEcho(anIntArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1546,10 +1547,10 @@ class HostIntegrationCoreApiSetup {
         let aDoubleArg = args[0] as! Double
         api.callFlutterEcho(aDoubleArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1563,10 +1564,10 @@ class HostIntegrationCoreApiSetup {
         let aStringArg = args[0] as! String
         api.callFlutterEcho(aStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1580,10 +1581,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg = args[0] as! FlutterStandardTypedData
         api.callFlutterEcho(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1597,10 +1598,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg = args[0] as! [Any?]
         api.callFlutterEcho(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1614,10 +1615,10 @@ class HostIntegrationCoreApiSetup {
         let aMapArg = args[0] as! [String?: Any?]
         api.callFlutterEcho(aMapArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1631,10 +1632,10 @@ class HostIntegrationCoreApiSetup {
         let anEnumArg = AnEnum(rawValue: args[0] as! Int)!
         api.callFlutterEcho(anEnumArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res.rawValue))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res.rawValue))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1648,10 +1649,10 @@ class HostIntegrationCoreApiSetup {
         let aBoolArg: Bool? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aBoolArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1665,10 +1666,10 @@ class HostIntegrationCoreApiSetup {
         let anIntArg: Int64? = isNullish(args[0]) ? nil : (args[0] is Int64? ? args[0] as! Int64? : Int64(args[0] as! Int32))
         api.callFlutterEchoNullable(anIntArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1682,10 +1683,10 @@ class HostIntegrationCoreApiSetup {
         let aDoubleArg: Double? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aDoubleArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1699,10 +1700,10 @@ class HostIntegrationCoreApiSetup {
         let aStringArg: String? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1716,10 +1717,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg: FlutterStandardTypedData? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1733,10 +1734,10 @@ class HostIntegrationCoreApiSetup {
         let aListArg: [Any?]? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aListArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1750,10 +1751,10 @@ class HostIntegrationCoreApiSetup {
         let aMapArg: [String?: Any?]? = nilOrValue(args[0])
         api.callFlutterEchoNullable(aMapArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1767,10 +1768,10 @@ class HostIntegrationCoreApiSetup {
         let anEnumArg: AnEnum? = isNullish(args[0]) ? nil : AnEnum(rawValue: args[0] as! Int)!
         api.callFlutterNullableEcho(anEnumArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res?.rawValue))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res?.rawValue))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -1782,16 +1783,16 @@ class HostIntegrationCoreApiSetup {
 private class FlutterIntegrationCoreApiCodecReader: FlutterStandardReader {
   override func readValue(ofType type: UInt8) -> Any? {
     switch type {
-      case 128:
-        return AllClassesWrapper.fromList(self.readValue() as! [Any?])
-      case 129:
-        return AllNullableTypes.fromList(self.readValue() as! [Any?])
-      case 130:
-        return AllTypes.fromList(self.readValue() as! [Any?])
-      case 131:
-        return TestMessage.fromList(self.readValue() as! [Any?])
-      default:
-        return super.readValue(ofType: type)
+    case 128:
+      return AllClassesWrapper.fromList(self.readValue() as! [Any?])
+    case 129:
+      return AllNullableTypes.fromList(self.readValue() as! [Any?])
+    case 130:
+      return AllTypes.fromList(self.readValue() as! [Any?])
+    case 131:
+      return TestMessage.fromList(self.readValue() as! [Any?])
+    default:
+      return super.readValue(ofType: type)
     }
   }
 }
@@ -1890,7 +1891,7 @@ protocol FlutterIntegrationCoreApiProtocol {
 }
 class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
   private let binaryMessenger: FlutterBinaryMessenger
-  init(binaryMessenger: FlutterBinaryMessenger){
+  init(binaryMessenger: FlutterBinaryMessenger) {
     self.binaryMessenger = binaryMessenger
   }
   var codec: FlutterStandardMessageCodec {
@@ -1903,14 +1904,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage(nil) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         completion(.success(Void()))
       }
@@ -1922,14 +1923,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage(nil) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: Any? = listResponse[0]
         completion(.success(result))
@@ -1942,14 +1943,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage(nil) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         completion(.success(Void()))
       }
@@ -1961,15 +1962,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([everythingArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! AllTypes
@@ -1983,14 +1984,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([everythingArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: AllNullableTypes? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2005,15 +2006,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aNullableBoolArg, aNullableIntArg, aNullableStringArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! AllNullableTypes
@@ -2027,15 +2028,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aBoolArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! Bool
@@ -2049,15 +2050,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([anIntArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] is Int64 ? listResponse[0] as! Int64 : Int64(listResponse[0] as! Int32)
@@ -2071,15 +2072,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aDoubleArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! Double
@@ -2093,15 +2094,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aStringArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! String
@@ -2115,15 +2116,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aListArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! FlutterStandardTypedData
@@ -2137,15 +2138,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aListArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! [Any?]
@@ -2159,15 +2160,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aMapArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! [String?: Any?]
@@ -2181,15 +2182,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([anEnumArg.rawValue] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = AnEnum(rawValue: listResponse[0] as! Int)!
@@ -2203,14 +2204,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aBoolArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: Bool? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2223,14 +2224,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([anIntArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: Int64? = isNullish(listResponse[0]) ? nil : (listResponse[0] is Int64? ? listResponse[0] as! Int64? : Int64(listResponse[0] as! Int32))
         completion(.success(result))
@@ -2243,14 +2244,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aDoubleArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: Double? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2263,14 +2264,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aStringArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: String? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2283,14 +2284,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aListArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: FlutterStandardTypedData? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2303,14 +2304,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aListArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: [Any?]? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2323,14 +2324,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aMapArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: [String?: Any?]? = nilOrValue(listResponse[0])
         completion(.success(result))
@@ -2343,14 +2344,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([anEnumArg?.rawValue] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         let result: AnEnum? = isNullish(listResponse[0]) ? nil : AnEnum(rawValue: listResponse[0] as! Int)!
         completion(.success(result))
@@ -2364,14 +2365,14 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage(nil) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
       } else {
         completion(.success(Void()))
       }
@@ -2383,15 +2384,15 @@ class FlutterIntegrationCoreApi: FlutterIntegrationCoreApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aStringArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! String
@@ -2447,10 +2448,10 @@ class HostSmallApiSetup {
         let aStringArg = args[0] as! String
         api.echo(aString: aStringArg) { result in
           switch result {
-            case .success(let res):
-              reply(wrapResult(res))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success(let res):
+            reply(wrapResult(res))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -2460,12 +2461,12 @@ class HostSmallApiSetup {
     let voidVoidChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.pigeon_integration_tests.HostSmallApi.voidVoid", binaryMessenger: binaryMessenger)
     if let api = api {
       voidVoidChannel.setMessageHandler { _, reply in
-        api.voidVoid() { result in
+        api.voidVoid { result in
           switch result {
-            case .success:
-              reply(wrapResult(nil))
-            case .failure(let error):
-              reply(wrapError(error))
+          case .success:
+            reply(wrapResult(nil))
+          case .failure(let error):
+            reply(wrapError(error))
           }
         }
       }
@@ -2477,10 +2478,10 @@ class HostSmallApiSetup {
 private class FlutterSmallApiCodecReader: FlutterStandardReader {
   override func readValue(ofType type: UInt8) -> Any? {
     switch type {
-      case 128:
-        return TestMessage.fromList(self.readValue() as! [Any?])
-      default:
-        return super.readValue(ofType: type)
+    case 128:
+      return TestMessage.fromList(self.readValue() as! [Any?])
+    default:
+      return super.readValue(ofType: type)
     }
   }
 }
@@ -2519,7 +2520,7 @@ protocol FlutterSmallApiProtocol {
 }
 class FlutterSmallApi: FlutterSmallApiProtocol {
   private let binaryMessenger: FlutterBinaryMessenger
-  init(binaryMessenger: FlutterBinaryMessenger){
+  init(binaryMessenger: FlutterBinaryMessenger) {
     self.binaryMessenger = binaryMessenger
   }
   var codec: FlutterStandardMessageCodec {
@@ -2530,15 +2531,15 @@ class FlutterSmallApi: FlutterSmallApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([msgArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! TestMessage
@@ -2551,15 +2552,15 @@ class FlutterSmallApi: FlutterSmallApiProtocol {
     let channel = FlutterBasicMessageChannel(name: channelName, binaryMessenger: binaryMessenger, codec: codec)
     channel.sendMessage([aStringArg] as [Any?]) { response in
       guard let listResponse = response as? [Any?] else {
-        completion(.failure(createConnectionError(withChannelName:channelName)))
+        completion(.failure(createConnectionError(withChannelName: channelName)))
         return
       }
-      if (listResponse.count > 1) {
+      if listResponse.count > 1 {
         let code: String = listResponse[0] as! String
         let message: String? = nilOrValue(listResponse[1])
         let details: String? = nilOrValue(listResponse[2])
-        completion(.failure(FlutterError(code: code, message: message, details: details)));
-      } else if (listResponse[0] == nil) {
+        completion(.failure(FlutterError(code: code, message: message, details: details)))
+      } else if listResponse[0] == nil {
         completion(.failure(FlutterError(code: "null-error", message: "Flutter api returned null value for non-null return value.", details: "")))
       } else {
         let result = listResponse[0] as! String
diff --git a/packages/pigeon/platform_tests/test_plugin/macos/Classes/TestPlugin.swift b/packages/pigeon/platform_tests/test_plugin/macos/Classes/TestPlugin.swift
index c82f94b1c0b..5da16290c7a 100644
--- a/packages/pigeon/platform_tests/test_plugin/macos/Classes/TestPlugin.swift
+++ b/packages/pigeon/platform_tests/test_plugin/macos/Classes/TestPlugin.swift
@@ -7,10 +7,8 @@ import FlutterMacOS
 
 extension FlutterError: Error {}
 
-/**
- * This plugin handles the native side of the integration tests in
- * example/integration_test/.
- */
+/// This plugin handles the native side of the integration tests in
+/// example/integration_test/.
 public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   var flutterAPI: FlutterIntegrationCoreApi
 
@@ -102,15 +100,18 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   }
 
   func extractNestedNullableString(from wrapper: AllClassesWrapper) -> String? {
-    return wrapper.allNullableTypes.aNullableString;
+    return wrapper.allNullableTypes.aNullableString
   }
 
   func createNestedObject(with nullableString: String?) -> AllClassesWrapper {
     return AllClassesWrapper(allNullableTypes: AllNullableTypes(aNullableString: nullableString))
   }
 
-  func sendMultipleNullableTypes(aBool aNullableBool: Bool?, anInt aNullableInt: Int64?, aString aNullableString: String?) -> AllNullableTypes {
-    let someThings = AllNullableTypes(aNullableBool: aNullableBool, aNullableInt: aNullableInt, aNullableString: aNullableString)
+  func sendMultipleNullableTypes(
+    aBool aNullableBool: Bool?, anInt aNullableInt: Int64?, aString aNullableString: String?
+  ) -> AllNullableTypes {
+    let someThings = AllNullableTypes(
+      aNullableBool: aNullableBool, aNullableInt: aNullableInt, aNullableString: aNullableString)
     return someThings
   }
 
@@ -178,7 +179,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(everything))
   }
 
-  func echoAsync(_ everything: AllNullableTypes?, completion: @escaping (Result<AllNullableTypes?, Error>) -> Void) {
+  func echoAsync(
+    _ everything: AllNullableTypes?,
+    completion: @escaping (Result<AllNullableTypes?, Error>) -> Void
+  ) {
     completion(.success(everything))
   }
 
@@ -198,7 +202,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(aString))
   }
 
-  func echoAsync(_ aUint8List: FlutterStandardTypedData, completion: @escaping (Result<FlutterStandardTypedData, Error>) -> Void) {
+  func echoAsync(
+    _ aUint8List: FlutterStandardTypedData,
+    completion: @escaping (Result<FlutterStandardTypedData, Error>) -> Void
+  ) {
     completion(.success(aUint8List))
   }
 
@@ -210,7 +217,9 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(aList))
   }
 
-  func echoAsync(_ aMap: [String?: Any?], completion: @escaping (Result<[String?: Any?], Error>) -> Void) {
+  func echoAsync(
+    _ aMap: [String?: Any?], completion: @escaping (Result<[String?: Any?], Error>) -> Void
+  ) {
     completion(.success(aMap))
   }
 
@@ -222,7 +231,8 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(anInt))
   }
 
-  func echoAsyncNullable(_ aDouble: Double?, completion: @escaping (Result<Double?, Error>) -> Void) {
+  func echoAsyncNullable(_ aDouble: Double?, completion: @escaping (Result<Double?, Error>) -> Void)
+  {
     completion(.success(aDouble))
   }
 
@@ -230,11 +240,15 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(aBool))
   }
 
-  func echoAsyncNullable(_ aString: String?, completion: @escaping (Result<String?, Error>) -> Void) {
+  func echoAsyncNullable(_ aString: String?, completion: @escaping (Result<String?, Error>) -> Void)
+  {
     completion(.success(aString))
   }
 
-  func echoAsyncNullable(_ aUint8List: FlutterStandardTypedData?, completion: @escaping (Result<FlutterStandardTypedData?, Error>) -> Void) {
+  func echoAsyncNullable(
+    _ aUint8List: FlutterStandardTypedData?,
+    completion: @escaping (Result<FlutterStandardTypedData?, Error>) -> Void
+  ) {
     completion(.success(aUint8List))
   }
 
@@ -246,66 +260,74 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
     completion(.success(aList))
   }
 
-  func echoAsyncNullable(_ aMap: [String?: Any?]?, completion: @escaping (Result<[String?: Any?]?, Error>) -> Void) {
+  func echoAsyncNullable(
+    _ aMap: [String?: Any?]?, completion: @escaping (Result<[String?: Any?]?, Error>) -> Void
+  ) {
     completion(.success(aMap))
   }
 
-  func echoAsyncNullable(_ anEnum: AnEnum?, completion: @escaping (Result<AnEnum?, Error>) -> Void) {
+  func echoAsyncNullable(_ anEnum: AnEnum?, completion: @escaping (Result<AnEnum?, Error>) -> Void)
+  {
     completion(.success(anEnum))
   }
 
   func callFlutterNoop(completion: @escaping (Result<Void, Error>) -> Void) {
-    flutterAPI.noop() { response in
+    flutterAPI.noop { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
   func callFlutterThrowError(completion: @escaping (Result<Any?, Error>) -> Void) {
-    flutterAPI.throwError() { response in
+    flutterAPI.throwError { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
   func callFlutterThrowErrorFromVoid(completion: @escaping (Result<Void, Error>) -> Void) {
-    flutterAPI.throwErrorFromVoid() { response in
+    flutterAPI.throwErrorFromVoid { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEcho(_ everything: AllTypes, completion: @escaping (Result<AllTypes, Error>) -> Void) {
+  func callFlutterEcho(
+    _ everything: AllTypes, completion: @escaping (Result<AllTypes, Error>) -> Void
+  ) {
     flutterAPI.echo(everything) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
-      } 
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
+      }
     }
   }
 
-  func callFlutterEcho(_ everything: AllNullableTypes?, completion: @escaping (Result<AllNullableTypes?, Error>) -> Void) {
+  func callFlutterEcho(
+    _ everything: AllNullableTypes?,
+    completion: @escaping (Result<AllNullableTypes?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(everything) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
-      } 
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
+      }
     }
   }
 
@@ -321,10 +343,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
       aString: aNullableString
     ) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -332,10 +354,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ aBool: Bool, completion: @escaping (Result<Bool, Error>) -> Void) {
     flutterAPI.echo(aBool) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -343,10 +365,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ anInt: Int64, completion: @escaping (Result<Int64, Error>) -> Void) {
     flutterAPI.echo(anInt) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -354,10 +376,10 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ aDouble: Double, completion: @escaping (Result<Double, Error>) -> Void) {
     flutterAPI.echo(aDouble) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -365,21 +387,24 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ aString: String, completion: @escaping (Result<String, Error>) -> Void) {
     flutterAPI.echo(aString) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEcho(_ aList: FlutterStandardTypedData, completion: @escaping (Result<FlutterStandardTypedData, Error>) -> Void) {
+  func callFlutterEcho(
+    _ aList: FlutterStandardTypedData,
+    completion: @escaping (Result<FlutterStandardTypedData, Error>) -> Void
+  ) {
     flutterAPI.echo(aList) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -387,21 +412,23 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ aList: [Any?], completion: @escaping (Result<[Any?], Error>) -> Void) {
     flutterAPI.echo(aList) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEcho(_ aMap: [String? : Any?], completion: @escaping (Result<[String? : Any?], Error>) -> Void) {
+  func callFlutterEcho(
+    _ aMap: [String?: Any?], completion: @escaping (Result<[String?: Any?], Error>) -> Void
+  ) {
     flutterAPI.echo(aMap) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
@@ -409,99 +436,115 @@ public class TestPlugin: NSObject, FlutterPlugin, HostIntegrationCoreApi {
   func callFlutterEcho(_ anEnum: AnEnum, completion: @escaping (Result<AnEnum, Error>) -> Void) {
     flutterAPI.echo(anEnum) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ aBool: Bool?, completion: @escaping (Result<Bool?, Error>) -> Void) {
+  func callFlutterEchoNullable(_ aBool: Bool?, completion: @escaping (Result<Bool?, Error>) -> Void)
+  {
     flutterAPI.echoNullable(aBool) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ anInt: Int64?, completion: @escaping (Result<Int64?, Error>) -> Void) {
+  func callFlutterEchoNullable(
+    _ anInt: Int64?, completion: @escaping (Result<Int64?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(anInt) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ aDouble: Double?, completion: @escaping (Result<Double?, Error>) -> Void) {
+  func callFlutterEchoNullable(
+    _ aDouble: Double?, completion: @escaping (Result<Double?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(aDouble) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ aString: String?, completion: @escaping (Result<String?, Error>) -> Void) {
+  func callFlutterEchoNullable(
+    _ aString: String?, completion: @escaping (Result<String?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(aString) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
-  
-  func callFlutterEchoNullable(_ aList: FlutterStandardTypedData?, completion: @escaping (Result<FlutterStandardTypedData?, Error>) -> Void) {
+
+  func callFlutterEchoNullable(
+    _ aList: FlutterStandardTypedData?,
+    completion: @escaping (Result<FlutterStandardTypedData?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(aList) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ aList: [Any?]?, completion: @escaping (Result<[Any?]?, Error>) -> Void) {
+  func callFlutterEchoNullable(
+    _ aList: [Any?]?, completion: @escaping (Result<[Any?]?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(aList) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterEchoNullable(_ aMap: [String? : Any?]?, completion: @escaping (Result<[String? : Any?]?, Error>) -> Void) {
+  func callFlutterEchoNullable(
+    _ aMap: [String?: Any?]?, completion: @escaping (Result<[String?: Any?]?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(aMap) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
     }
   }
 
-  func callFlutterNullableEcho(_ anEnum: AnEnum?, completion: @escaping (Result<AnEnum?, Error>) -> Void) {
+  func callFlutterNullableEcho(
+    _ anEnum: AnEnum?, completion: @escaping (Result<AnEnum?, Error>) -> Void
+  ) {
     flutterAPI.echoNullable(anEnum) { response in
       switch response {
-        case .success(let res):
-          completion(.success(res))
-        case .failure(let error):
-          completion(.failure(error))
+      case .success(let res):
+        completion(.success(res))
+      case .failure(let error):
+        completion(.failure(error))
       }
-    }    
+    }
   }
 }
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index c6029d4ed30..6ac3bb29449 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%3A%22p%3A+pigeon%22
-version: 16.0.3 # This must match the version in lib/generator_tools.dart
+version: 16.0.4 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=3.0.0 <4.0.0"
diff --git a/packages/pigeon/test/swift_generator_test.dart b/packages/pigeon/test/swift_generator_test.dart
index 4c07b784eb7..b39909be32b 100644
--- a/packages/pigeon/test/swift_generator_test.dart
+++ b/packages/pigeon/test/swift_generator_test.dart
@@ -52,6 +52,7 @@ void main() {
     expect(code, contains('var field1: Int64? = nil'));
     expect(code, contains('static func fromList(_ list: [Any?]) -> Foobar?'));
     expect(code, contains('func toList() -> [Any?]'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('gen one enum', () {
@@ -80,6 +81,7 @@ void main() {
     expect(code, contains('enum Foobar: Int'));
     expect(code, contains('  case one = 0'));
     expect(code, contains('  case two = 1'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('primitive enum host', () {
@@ -116,6 +118,7 @@ void main() {
     final String code = sink.toString();
     expect(code, contains('enum Foo: Int'));
     expect(code, contains('let fooArg = Foo(rawValue: args[0] as! Int)!'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('gen one host api', () {
@@ -170,6 +173,7 @@ void main() {
     expect(code, contains('protocol Api'));
     expect(code, matches('func doSomething.*Input.*Output'));
     expect(code, contains('doSomethingChannel.setMessageHandler'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('all the simple datatypes header', () {
@@ -298,6 +302,8 @@ void main() {
     expect(code, contains('class Api'));
     expect(code, contains('init(binaryMessenger: FlutterBinaryMessenger)'));
     expect(code, matches('func doSomething.*Input.*Output'));
+    expect(code, isNot(contains('if (')));
+    expect(code, isNot(matches(RegExp(r';$', multiLine: true))));
   });
 
   test('gen host void api', () {
@@ -339,6 +345,7 @@ void main() {
     final String code = sink.toString();
     expect(code, isNot(matches('.*doSomething(.*) ->')));
     expect(code, matches('doSomething(.*)'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('gen flutter void return api', () {
@@ -381,6 +388,7 @@ void main() {
     expect(code,
         contains('completion: @escaping (Result<Void, FlutterError>) -> Void'));
     expect(code, contains('completion(.success(Void()))'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('gen host void argument api', () {
@@ -419,6 +427,7 @@ void main() {
     expect(code, contains('func doSomething() throws -> Output'));
     expect(code, contains('let result = try api.doSomething()'));
     expect(code, contains('reply(wrapResult(result))'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('gen flutter void argument api', () {
@@ -459,6 +468,7 @@ void main() {
         contains(
             'func doSomething(completion: @escaping (Result<Output, FlutterError>) -> Void)'));
     expect(code, contains('channel.sendMessage(nil'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('gen list', () {
@@ -484,6 +494,7 @@ void main() {
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: [Any?]? = nil'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('gen map', () {
@@ -509,6 +520,7 @@ void main() {
     final String code = sink.toString();
     expect(code, contains('struct Foobar'));
     expect(code, contains('var field1: [AnyHashable: Any?]? = nil'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('gen nested', () {
@@ -556,6 +568,9 @@ void main() {
     expect(code, contains('static func fromList(_ list: [Any?]) -> Outer?'));
     expect(code, contains('nested = Nested.fromList(nestedList)'));
     expect(code, contains('func toList() -> [Any?]'));
+    expect(code, isNot(contains('if (')));
+    // Single-element list serializations should not have a trailing comma.
+    expect(code, matches(RegExp(r'return \[\s*data\s*]')));
   });
 
   test('gen one async Host Api', () {
@@ -611,6 +626,7 @@ void main() {
     expect(code, contains('protocol Api'));
     expect(code, contains('api.doSomething(arg: argArg) { result in'));
     expect(code, contains('reply(wrapResult(res))'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('gen one async Flutter Api', () {
@@ -665,6 +681,7 @@ void main() {
     final String code = sink.toString();
     expect(code, contains('class Api'));
     expect(code, matches('func doSomething.*Input.*completion.*Output.*Void'));
+    expect(code, isNot(contains('if (')));
   });
 
   test('gen one enum class', () {
@@ -705,17 +722,14 @@ void main() {
     expect(code, contains('enum Enum1: Int'));
     expect(code, contains('case one = 0'));
     expect(code, contains('case two = 1'));
+    expect(code, isNot(contains('if (')));
   });
 
-  Iterable<String> makeIterable(String string) sync* {
-    yield string;
-  }
-
   test('header', () {
     final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
     final StringBuffer sink = StringBuffer();
-    final SwiftOptions swiftOptions = SwiftOptions(
-      copyrightHeader: makeIterable('hello world'),
+    const SwiftOptions swiftOptions = SwiftOptions(
+      copyrightHeader: <String>['hello world', ''],
     );
     const SwiftGenerator generator = SwiftGenerator();
     generator.generate(
@@ -726,6 +740,8 @@ void main() {
     );
     final String code = sink.toString();
     expect(code, startsWith('// hello world'));
+    // There should be no trailing whitespace on generated comments.
+    expect(code, isNot(matches(RegExp(r'^//.* $', multiLine: true))));
   });
 
   test('generics - list', () {
@@ -1522,7 +1538,7 @@ void main() {
     expect(
         code,
         contains(
-            'completion(.failure(createConnectionError(withChannelName:channelName)))'));
+            'completion(.failure(createConnectionError(withChannelName: channelName)))'));
     expect(
         code,
         contains(