From de72c525880d567931ab309a9489594481c98012 Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Thu, 6 Aug 2026 16:34:44 -0700
Subject: [PATCH 01/16] Barebones command copied from the test command.

---
 script/tool/lib/src/main.dart            |   2 +
 script/tool/lib/src/test_dart_fixes.dart | 205 +++++++++++++++++++++++
 2 files changed, 207 insertions(+)
 create mode 100644 script/tool/lib/src/test_dart_fixes.dart

diff --git a/script/tool/lib/src/main.dart b/script/tool/lib/src/main.dart
index 89c7bf9525b0..55b3e9d5e204 100644
--- a/script/tool/lib/src/main.dart
+++ b/script/tool/lib/src/main.dart
@@ -30,6 +30,7 @@ import 'podspec_check_command.dart';
 import 'publish_check_command.dart';
 import 'publish_command.dart';
 import 'remove_dev_dependencies_command.dart';
+import 'test_dart_fixes.dart';
 import 'update_dependency_command.dart';
 import 'update_excerpts_command.dart';
 import 'update_min_sdk_command.dart';
@@ -75,6 +76,7 @@ void main(List<String> args) {
         ..addCommand(PublishCheckCommand(packagesDir))
         ..addCommand(PublishCommand(packagesDir))
         ..addCommand(RemoveDevDependenciesCommand(packagesDir))
+        ..addCommand(TestDartFixes(packagesDir))
         ..addCommand(UpdateDependencyCommand(packagesDir))
         ..addCommand(UpdateExcerptsCommand(packagesDir))
         ..addCommand(UpdateMinSdkCommand(packagesDir))
diff --git a/script/tool/lib/src/test_dart_fixes.dart b/script/tool/lib/src/test_dart_fixes.dart
new file mode 100644
index 000000000000..e1a5144e0fe2
--- /dev/null
+++ b/script/tool/lib/src/test_dart_fixes.dart
@@ -0,0 +1,205 @@
+// Copyright 2013 The Flutter Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:file/file.dart';
+
+import 'common/core.dart';
+import 'common/file_filters.dart';
+import 'common/output_utils.dart';
+import 'common/package_looping_command.dart';
+import 'common/plugin_utils.dart';
+import 'common/pub_utils.dart';
+import 'common/repository_package.dart';
+
+// TODO(justinmc): Possibly not relevant.
+const int _exitUnknownTestPlatform = 3;
+
+// TODO(justinmc): Possibly not relevant.
+enum _TestPlatform {
+  // Must run in the command-line VM.
+  vm,
+  // Must run in a browser.
+  browser,
+}
+
+/// A command to run dart fix tests for packages that have a test_fixes
+/// directory.
+class TestDartFixes extends PackageLoopingCommand {
+  /// Creates an instance of the test dart fixes command.
+  TestDartFixes(super.packagesDir, {super.processRunner, super.platform, super.gitDir}) {
+    // TODO(justinmc): Possibly not relevant.
+    argParser.addOption(
+      _platformFlag,
+      help:
+          'Runs tests on the given platform instead of the default platform '
+          '("vm" in most cases, "chrome" for web plugin implementations).',
+    );
+  }
+
+  static const String _platformFlag = 'platform';
+
+  @override
+  final String name = 'test-dart-fixes';
+
+  @override
+  List<String> get aliases => <String>[];
+
+  @override
+  final String description =
+      'Runs the Dart fix tests for all packages.\n\n'
+      'This command requires "flutter" to be in your path.';
+
+  @override
+  PackageLoopingType get packageLoopingType => PackageLoopingType.includeAllSubpackages;
+
+  // TODO(justinmc): Revisit.
+  @override
+  bool shouldIgnoreFile(String path) {
+    return isRepoLevelNonCodeImpactingFile(path) ||
+        isNativeCodeFile(path) ||
+        isPackageSupportFile(path);
+  }
+
+  @override
+  Future<PackageResult> runForPackage(RepositoryPackage package) async {
+    // TODO(justinmc): Should check for test_fix directory.
+    if (!package.testDirectory.existsSync()) {
+      return PackageResult.skip('No test/ directory.');
+    }
+
+    return PackageResult.skip('Not yet implemented.');
+    // TODO(justinmc): See packages/go_router/tool/run_tests.dart.
+    String? platform = getNullableStringArg(_platformFlag);
+
+    // Skip running plugin tests for non-web-supporting plugins (or non-web
+    // federated plugin implementations) on web, since there's no reason to
+    // expect them to work.
+    final bool webPlatform = platform != null && platform != 'vm';
+    final explicitVMPlatform = platform == 'vm';
+    final bool isWebOnlyPluginImplementation =
+        pluginSupportsPlatform(platformWeb, package, requiredMode: PlatformSupport.inline) &&
+        package.directory.basename.endsWith('_web');
+    if (webPlatform) {
+      if (isFlutterPlugin(package) && !pluginSupportsPlatform(platformWeb, package)) {
+        return PackageResult.skip("Non-web plugin tests don't need web testing.");
+      }
+      if (_testOnTarget(package) == _TestPlatform.vm) {
+        // This explict skip is necessary because trying to run tests in a mode
+        // that the package has opted out of returns a non-zero exit code.
+        return PackageResult.skip('Package has opted out of non-vm testing.');
+      }
+    } else if (explicitVMPlatform) {
+      if (isWebOnlyPluginImplementation) {
+        return PackageResult.skip("Web plugin tests don't need vm testing.");
+      }
+      final _TestPlatform? target = _testOnTarget(package);
+      if (target != null && _testOnTarget(package) != _TestPlatform.vm) {
+        // This explict skip is necessary because trying to run tests in a mode
+        // that the package has opted out of returns a non-zero exit code.
+        return PackageResult.skip('Package has opted out of vm testing.');
+      }
+    } else if (platform == null && isWebOnlyPluginImplementation) {
+      // If no explicit mode is requested, run web plugin implementations in
+      // Chrome since their tests are not expected to work in vm mode. This
+      // allows easily running all unit tests locally, without having to run
+      // both modes.
+      platform = 'chrome';
+    }
+
+    // Whether to run web tests compiled to wasm.
+    final bool wasm = platform != 'vm' && getBoolArg(kWebWasmFlag);
+
+    bool passed;
+    if (package.requiresFlutter()) {
+      passed = await _runFlutterTests(package, platform: platform, wasm: wasm);
+    } else {
+      passed = await _runDartTests(package, platform: platform, wasm: wasm);
+    }
+    return passed ? PackageResult.success() : PackageResult.fail();
+  }
+
+  /// Runs the Dart tests for a Flutter package, returning true on success.
+  Future<bool> _runFlutterTests(
+    RepositoryPackage package, {
+    String? platform,
+    bool wasm = false,
+  }) async {
+    final String experiment = getStringArg(kEnableExperiment);
+
+    final int exitCode = await processRunner.runAndStream(flutterCommand, <String>[
+      'test',
+      '--color',
+      if (experiment.isNotEmpty) '--enable-experiment=$experiment',
+      // Flutter defaults to VM mode (under a different name) and explicitly
+      // setting it is deprecated, so pass nothing in that case.
+      if (platform != null && platform != 'vm') '--platform=$platform',
+      if (wasm) '--wasm',
+    ], workingDir: package.directory);
+    return exitCode == 0;
+  }
+
+  /// Runs the Dart tests for a non-Flutter package, returning true on success.
+  Future<bool> _runDartTests(
+    RepositoryPackage package, {
+    String? platform,
+    bool wasm = false,
+  }) async {
+    // Unlike `flutter test`, `dart run test` does not automatically get
+    // packages
+    if (!await runPubGet(package, processRunner, super.platform)) {
+      printError('Unable to fetch dependencies.');
+      return false;
+    }
+
+    final String experiment = getStringArg(kEnableExperiment);
+
+    final int exitCode = await processRunner.runAndStream('dart', <String>[
+      'run',
+      if (experiment.isNotEmpty) '--enable-experiment=$experiment',
+      'test',
+      if (platform != null) '--platform=$platform',
+      if (wasm) '--compiler=dart2wasm',
+    ], workingDir: package.directory);
+
+    return exitCode == 0;
+  }
+
+  /// Returns the required test environment, or null if none is specified.
+  ///
+  /// Throws if the target is not recognized.
+  _TestPlatform? _testOnTarget(RepositoryPackage package) {
+    final File testConfig = package.directory.childFile('dart_test.yaml');
+    if (!testConfig.existsSync()) {
+      return null;
+    }
+    final testOnRegex = RegExp(r'^test_on:\s*([a-z].*[a-z])\s*$');
+    for (final String line in testConfig.readAsLinesSync()) {
+      final RegExpMatch? match = testOnRegex.firstMatch(line);
+      if (match != null) {
+        final String targetFilter = match.group(1)!;
+        // test_on lines can be very complex, but in pratice the packages in
+        // this repo currently only need the ability to require vm or not, so a
+        // simple one-target directive is all that's supported currently.
+        // Making it deliberately strict avoids the possibility of accidentally
+        // skipping vm coverage due to a complex expression that's not handled
+        // correctly.
+        switch (targetFilter) {
+          case 'vm':
+            return _TestPlatform.vm;
+          case 'browser':
+            return _TestPlatform.browser;
+          default:
+            printError(
+              'Unknown "test_on" value: "$targetFilter"\n'
+              "If this value needs to be supported for this package's tests, "
+              'please update the repository tooling to support more test_on '
+              'modes.',
+            );
+            throw ToolExit(_exitUnknownTestPlatform);
+        }
+      }
+    }
+    return null;
+  }
+}

From dfa7553ac7f78a6278bf12e8a1e09617c9ce44cb Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Fri, 7 Aug 2026 12:34:24 -0700
Subject: [PATCH 02/16] Works for running dart fix tests on go_router,
 cupertino, and material.

Adapted from go_router's run_tests script.
---
 .../lib/src/common/repository_package.dart    |   3 +
 script/tool/lib/src/test_dart_fixes.dart      | 246 +++++++-----------
 script/tool/pubspec.yaml                      |   1 +
 3 files changed, 99 insertions(+), 151 deletions(-)

diff --git a/script/tool/lib/src/common/repository_package.dart b/script/tool/lib/src/common/repository_package.dart
index 92f775917c1f..861058af0e18 100644
--- a/script/tool/lib/src/common/repository_package.dart
+++ b/script/tool/lib/src/common/repository_package.dart
@@ -74,6 +74,9 @@ class RepositoryPackage {
   /// The test directory containing the package's Dart tests.
   Directory get testDirectory => directory.childDirectory('test');
 
+  /// The test directory containing the tests for the package's dart fixes.
+  Directory get dartFixTestDirectory => directory.childDirectory('test_fixes');
+
   /// The path to the script that is run by the `custom-test` command.
   File get customTestScript => directory.childDirectory('tool').childFile('run_tests.dart');
 
diff --git a/script/tool/lib/src/test_dart_fixes.dart b/script/tool/lib/src/test_dart_fixes.dart
index e1a5144e0fe2..44cc04ed8bf1 100644
--- a/script/tool/lib/src/test_dart_fixes.dart
+++ b/script/tool/lib/src/test_dart_fixes.dart
@@ -2,42 +2,23 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:async';
+import 'dart:io';
+
 import 'package:file/file.dart';
+import 'package:file/local.dart';
+import 'package:io/io.dart' as io;
+import 'package:path/path.dart' as p;
 
-import 'common/core.dart';
 import 'common/file_filters.dart';
-import 'common/output_utils.dart';
 import 'common/package_looping_command.dart';
-import 'common/plugin_utils.dart';
-import 'common/pub_utils.dart';
 import 'common/repository_package.dart';
 
-// TODO(justinmc): Possibly not relevant.
-const int _exitUnknownTestPlatform = 3;
-
-// TODO(justinmc): Possibly not relevant.
-enum _TestPlatform {
-  // Must run in the command-line VM.
-  vm,
-  // Must run in a browser.
-  browser,
-}
-
 /// A command to run dart fix tests for packages that have a test_fixes
 /// directory.
 class TestDartFixes extends PackageLoopingCommand {
   /// Creates an instance of the test dart fixes command.
-  TestDartFixes(super.packagesDir, {super.processRunner, super.platform, super.gitDir}) {
-    // TODO(justinmc): Possibly not relevant.
-    argParser.addOption(
-      _platformFlag,
-      help:
-          'Runs tests on the given platform instead of the default platform '
-          '("vm" in most cases, "chrome" for web plugin implementations).',
-    );
-  }
-
-  static const String _platformFlag = 'platform';
+  TestDartFixes(super.packagesDir, {super.processRunner, super.platform, super.gitDir});
 
   @override
   final String name = 'test-dart-fixes';
@@ -53,7 +34,6 @@ class TestDartFixes extends PackageLoopingCommand {
   @override
   PackageLoopingType get packageLoopingType => PackageLoopingType.includeAllSubpackages;
 
-  // TODO(justinmc): Revisit.
   @override
   bool shouldIgnoreFile(String path) {
     return isRepoLevelNonCodeImpactingFile(path) ||
@@ -63,143 +43,107 @@ class TestDartFixes extends PackageLoopingCommand {
 
   @override
   Future<PackageResult> runForPackage(RepositoryPackage package) async {
-    // TODO(justinmc): Should check for test_fix directory.
-    if (!package.testDirectory.existsSync()) {
-      return PackageResult.skip('No test/ directory.');
+    // Only run for packages that have a fix_tests directory.
+    if (!package.dartFixTestDirectory.existsSync()) {
+      return PackageResult.skip('No ${package.dartFixTestDirectory} directory.');
     }
 
-    return PackageResult.skip('Not yet implemented.');
-    // TODO(justinmc): See packages/go_router/tool/run_tests.dart.
-    String? platform = getNullableStringArg(_platformFlag);
-
-    // Skip running plugin tests for non-web-supporting plugins (or non-web
-    // federated plugin implementations) on web, since there's no reason to
-    // expect them to work.
-    final bool webPlatform = platform != null && platform != 'vm';
-    final explicitVMPlatform = platform == 'vm';
-    final bool isWebOnlyPluginImplementation =
-        pluginSupportsPlatform(platformWeb, package, requiredMode: PlatformSupport.inline) &&
-        package.directory.basename.endsWith('_web');
-    if (webPlatform) {
-      if (isFlutterPlugin(package) && !pluginSupportsPlatform(platformWeb, package)) {
-        return PackageResult.skip("Non-web plugin tests don't need web testing.");
-      }
-      if (_testOnTarget(package) == _TestPlatform.vm) {
-        // This explict skip is necessary because trying to run tests in a mode
-        // that the package has opted out of returns a non-zero exit code.
-        return PackageResult.skip('Package has opted out of non-vm testing.');
-      }
-    } else if (explicitVMPlatform) {
-      if (isWebOnlyPluginImplementation) {
-        return PackageResult.skip("Web plugin tests don't need vm testing.");
-      }
-      final _TestPlatform? target = _testOnTarget(package);
-      if (target != null && _testOnTarget(package) != _TestPlatform.vm) {
-        // This explict skip is necessary because trying to run tests in a mode
-        // that the package has opted out of returns a non-zero exit code.
-        return PackageResult.skip('Package has opted out of vm testing.');
+    // Create a temporary directory to run the tests in.
+    const fileSystem = LocalFileSystem();
+    final Directory testTempDir = await fileSystem.systemTempDirectory.createTemp();
+
+    late final PackageResult result;
+    try {
+      final int statusCode = await _runDartFixTests(package, testTempDir);
+      if (statusCode != 0) {
+        throw Exception('Status code $statusCode');
       }
-    } else if (platform == null && isWebOnlyPluginImplementation) {
-      // If no explicit mode is requested, run web plugin implementations in
-      // Chrome since their tests are not expected to work in vm mode. This
-      // allows easily running all unit tests locally, without having to run
-      // both modes.
-      platform = 'chrome';
+      result = PackageResult.success();
+    } catch (error) {
+      result = PackageResult.fail(['Dart fix tests failed: $error}']);
     }
+    if (testTempDir.existsSync()) {
+      await testTempDir.delete(recursive: true);
+    }
+    return result;
+  }
 
-    // Whether to run web tests compiled to wasm.
-    final bool wasm = platform != 'vm' && getBoolArg(kWebWasmFlag);
-
-    bool passed;
-    if (package.requiresFlutter()) {
-      passed = await _runFlutterTests(package, platform: platform, wasm: wasm);
-    } else {
-      passed = await _runDartTests(package, platform: platform, wasm: wasm);
+  /// Run the dart fix tests for the package in the given temporary directory.
+  ///
+  /// Resolves with the status code of the command.
+  Future<int> _runDartFixTests(RepositoryPackage package, Directory testTempDir) async {
+    // Copy the test_fixes folder to the temporary testTempDir.
+    //
+    // This also creates the proper pubspec.yaml in the temp directory.
+    await _prepareTemplate(package: package, testTempDir: testTempDir);
+
+    // Run dart pub get in the temp directory to set it up.
+    final int pubGetStatusCode = await _runProcess('dart', <String>[
+      'pub',
+      'get',
+    ], workingDirectory: testTempDir.path);
+
+    if (pubGetStatusCode != 0) {
+      await testTempDir.delete(recursive: true);
+      return pubGetStatusCode;
     }
-    return passed ? PackageResult.success() : PackageResult.fail();
+
+    // Run dart fix --compare-to-golden in the temp directory.
+    final int dartFixStatusCode = await _runProcess('dart', <String>[
+      'fix',
+      '--compare-to-golden',
+    ], workingDirectory: testTempDir.path);
+
+    await testTempDir.delete(recursive: true);
+    return dartFixStatusCode;
   }
 
-  /// Runs the Dart tests for a Flutter package, returning true on success.
-  Future<bool> _runFlutterTests(
-    RepositoryPackage package, {
-    String? platform,
-    bool wasm = false,
+  Future<void> _prepareTemplate({
+    required RepositoryPackage package,
+    required Directory testTempDir,
   }) async {
-    final String experiment = getStringArg(kEnableExperiment);
-
-    final int exitCode = await processRunner.runAndStream(flutterCommand, <String>[
-      'test',
-      '--color',
-      if (experiment.isNotEmpty) '--enable-experiment=$experiment',
-      // Flutter defaults to VM mode (under a different name) and explicitly
-      // setting it is deprecated, so pass nothing in that case.
-      if (platform != null && platform != 'vm') '--platform=$platform',
-      if (wasm) '--wasm',
-    ], workingDir: package.directory);
-    return exitCode == 0;
+    // Copy from src `test_fixes/` to the temp directory.
+    await io.copyPath(package.dartFixTestDirectory.path, testTempDir.path);
+
+    // The pubspec.yaml file to create.
+    const fileSystem = LocalFileSystem();
+    final File targetPubspecFile = fileSystem.file(p.join(testTempDir.path, 'pubspec.yaml'));
+
+    final targetYaml =
+        '''
+  name: test_fixes
+  publish_to: "none"
+  version: 1.0.0
+
+  environment:
+    sdk: ">=2.18.0 <4.0.0"
+    flutter: ">=3.3.0"
+
+  dependencies:
+    flutter:
+      sdk: flutter
+    ${package.directory.basename}:
+      path: ${package.directory.path}
+  ''';
+
+    await targetPubspecFile.writeAsString(targetYaml);
   }
 
-  /// Runs the Dart tests for a non-Flutter package, returning true on success.
-  Future<bool> _runDartTests(
-    RepositoryPackage package, {
-    String? platform,
-    bool wasm = false,
+  Future<int> _runProcess(
+    String command,
+    List<String> arguments, {
+    String? workingDirectory,
   }) async {
-    // Unlike `flutter test`, `dart run test` does not automatically get
-    // packages
-    if (!await runPubGet(package, processRunner, super.platform)) {
-      printError('Unable to fetch dependencies.');
-      return false;
-    }
-
-    final String experiment = getStringArg(kEnableExperiment);
-
-    final int exitCode = await processRunner.runAndStream('dart', <String>[
-      'run',
-      if (experiment.isNotEmpty) '--enable-experiment=$experiment',
-      'test',
-      if (platform != null) '--platform=$platform',
-      if (wasm) '--compiler=dart2wasm',
-    ], workingDir: package.directory);
-
-    return exitCode == 0;
+    final Process process = await _streamOutput(
+      Process.start(command, arguments, workingDirectory: workingDirectory),
+    );
+    return process.exitCode;
   }
 
-  /// Returns the required test environment, or null if none is specified.
-  ///
-  /// Throws if the target is not recognized.
-  _TestPlatform? _testOnTarget(RepositoryPackage package) {
-    final File testConfig = package.directory.childFile('dart_test.yaml');
-    if (!testConfig.existsSync()) {
-      return null;
-    }
-    final testOnRegex = RegExp(r'^test_on:\s*([a-z].*[a-z])\s*$');
-    for (final String line in testConfig.readAsLinesSync()) {
-      final RegExpMatch? match = testOnRegex.firstMatch(line);
-      if (match != null) {
-        final String targetFilter = match.group(1)!;
-        // test_on lines can be very complex, but in pratice the packages in
-        // this repo currently only need the ability to require vm or not, so a
-        // simple one-target directive is all that's supported currently.
-        // Making it deliberately strict avoids the possibility of accidentally
-        // skipping vm coverage due to a complex expression that's not handled
-        // correctly.
-        switch (targetFilter) {
-          case 'vm':
-            return _TestPlatform.vm;
-          case 'browser':
-            return _TestPlatform.browser;
-          default:
-            printError(
-              'Unknown "test_on" value: "$targetFilter"\n'
-              "If this value needs to be supported for this package's tests, "
-              'please update the repository tooling to support more test_on '
-              'modes.',
-            );
-            throw ToolExit(_exitUnknownTestPlatform);
-        }
-      }
-    }
-    return null;
+  Future<Process> _streamOutput(Future<Process> processFuture) async {
+    final Process process = await processFuture;
+    unawaited(stdout.addStream(process.stdout));
+    unawaited(stderr.addStream(process.stderr));
+    return process;
   }
 }
diff --git a/script/tool/pubspec.yaml b/script/tool/pubspec.yaml
index 957b1ebe343d..94286da51efa 100644
--- a/script/tool/pubspec.yaml
+++ b/script/tool/pubspec.yaml
@@ -13,6 +13,7 @@ dependencies:
   glob: ^2.1.3
   http: ^1.0.0
   http_multi_server: ^3.0.1
+  io: ^1.0.5
   meta: ^1.10.0
   path: ^1.8.3
   platform: ^3.0.2

From e280734a79b0e4b074cba2acb207185152ee6b17 Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Fri, 7 Aug 2026 12:37:21 -0700
Subject: [PATCH 03/16] This is covered by the global script now.

---
 packages/go_router/tool/run_tests.dart | 101 -------------------------
 1 file changed, 101 deletions(-)
 delete mode 100644 packages/go_router/tool/run_tests.dart

diff --git a/packages/go_router/tool/run_tests.dart b/packages/go_router/tool/run_tests.dart
deleted file mode 100644
index ca09bed0f7cd..000000000000
--- a/packages/go_router/tool/run_tests.dart
+++ /dev/null
@@ -1,101 +0,0 @@
-// Copyright 2013 The Flutter Authors
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Called from the custom-tests CI action.
-//
-// usage: dart run tool/run_tests.dart
-
-// ignore_for_file: avoid_print
-
-import 'dart:async';
-import 'dart:io';
-import 'package:io/io.dart' as io;
-import 'package:path/path.dart' as p;
-
-// This test runner simulates a consumption of go_router that checks if
-// the dart fixes are applied correctly.
-// This is done by copying the `test_fixes/` directory to a temp directory
-// that references `go_router`, and running `dart fix --compare-to-golden`
-// on the temp directory.
-Future<void> main(List<String> args) async {
-  final Directory goRouterPackageRoot = File.fromUri(Platform.script).parent.parent;
-
-  final Directory testTempDir = await Directory.systemTemp.createTemp();
-
-  // Cleans up the temp directory and exits with a given statusCode.
-  Future<Never> cleanUpAndExit(int statusCode) async {
-    await testTempDir.delete(recursive: true);
-    exit(statusCode);
-  }
-
-  // Copy the test_fixes folder to the temporary testFixesTargetDir.
-  //
-  // This also creates the proper pubspec.yaml in the temp directory.
-  await _prepareTemplate(packageRoot: goRouterPackageRoot, testTempDir: testTempDir);
-
-  // Run dart pub get in the temp directory to set it up.
-  final int pubGetStatusCode = await _runProcess('dart', <String>[
-    'pub',
-    'get',
-  ], workingDirectory: testTempDir.path);
-
-  if (pubGetStatusCode != 0) {
-    await cleanUpAndExit(pubGetStatusCode);
-  }
-
-  // Run dart fix --compare-to-golden in the temp directory.
-  final int dartFixStatusCode = await _runProcess('dart', <String>[
-    'fix',
-    '--compare-to-golden',
-  ], workingDirectory: testTempDir.path);
-
-  await cleanUpAndExit(dartFixStatusCode);
-}
-
-Future<void> _prepareTemplate({
-  required Directory packageRoot,
-  required Directory testTempDir,
-}) async {
-  // The src test_fixes directory.
-  final testFixesSrcDir = Directory(p.join(packageRoot.path, 'test_fixes'));
-
-  // Copy from src `test_fixes/` to the temp directory.
-  await io.copyPath(testFixesSrcDir.path, testTempDir.path);
-
-  // The pubspec.yaml file to create.
-  final targetPubspecFile = File(p.join(testTempDir.path, 'pubspec.yaml'));
-
-  final targetYaml =
-      '''
-name: test_fixes
-publish_to: "none"
-version: 1.0.0
-
-environment:
-  sdk: ">=2.18.0 <4.0.0"
-  flutter: ">=3.3.0"
-
-dependencies:
-  flutter:
-    sdk: flutter
-  go_router:
-    path: ${packageRoot.path}
-''';
-
-  await targetPubspecFile.writeAsString(targetYaml);
-}
-
-Future<Process> _streamOutput(Future<Process> processFuture) async {
-  final Process process = await processFuture;
-  unawaited(stdout.addStream(process.stdout));
-  unawaited(stderr.addStream(process.stderr));
-  return process;
-}
-
-Future<int> _runProcess(String command, List<String> arguments, {String? workingDirectory}) async {
-  final Process process = await _streamOutput(
-    Process.start(command, arguments, workingDirectory: workingDirectory),
-  );
-  return process.exitCode;
-}

From 20b78424605e5f5688ff8a330bc4f55d7d9f4d2a Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Fri, 7 Aug 2026 12:50:57 -0700
Subject: [PATCH 04/16] Code cleanup

---
 script/tool/lib/src/test_dart_fixes.dart | 103 +++++++++++------------
 1 file changed, 51 insertions(+), 52 deletions(-)

diff --git a/script/tool/lib/src/test_dart_fixes.dart b/script/tool/lib/src/test_dart_fixes.dart
index 44cc04ed8bf1..f8f8e7d0c091 100644
--- a/script/tool/lib/src/test_dart_fixes.dart
+++ b/script/tool/lib/src/test_dart_fixes.dart
@@ -48,13 +48,16 @@ class TestDartFixes extends PackageLoopingCommand {
       return PackageResult.skip('No ${package.dartFixTestDirectory} directory.');
     }
 
-    // Create a temporary directory to run the tests in.
-    const fileSystem = LocalFileSystem();
-    final Directory testTempDir = await fileSystem.systemTempDirectory.createTemp();
+    final Directory testDirectory;
+    try {
+      testDirectory = await _createTestDirectory(package);
+    } catch (error) {
+      return PackageResult.fail(['Failed to create temporary test directory: $error}']);
+    }
 
     late final PackageResult result;
     try {
-      final int statusCode = await _runDartFixTests(package, testTempDir);
+      final int statusCode = await _runDartFixTests(package, testDirectory);
       if (statusCode != 0) {
         throw Exception('Status code $statusCode');
       }
@@ -62,74 +65,70 @@ class TestDartFixes extends PackageLoopingCommand {
     } catch (error) {
       result = PackageResult.fail(['Dart fix tests failed: $error}']);
     }
-    if (testTempDir.existsSync()) {
-      await testTempDir.delete(recursive: true);
+    if (testDirectory.existsSync()) {
+      await testDirectory.delete(recursive: true);
     }
     return result;
   }
 
+  /// Create and prepare a temporary directory in which to run the dart fix
+  /// tests.
+  ///
+  /// It is the responsibility of the caller to delete this directory and its
+  /// contents when done.
+  static Future<Directory> _createTestDirectory(RepositoryPackage package) async {
+    const fileSystem = LocalFileSystem();
+    final Directory testTempDirectory = await fileSystem.systemTempDirectory.createTemp();
+
+    // Copy from `test_fixes/` to the temp directory.
+    await io.copyPath(package.dartFixTestDirectory.path, testTempDirectory.path);
+
+    // The pubspec.yaml file to create.
+    final File targetPubspecFile = fileSystem.file(p.join(testTempDirectory.path, 'pubspec.yaml'));
+
+    final targetYaml =
+        '''
+name: test_fixes
+publish_to: "none"
+version: 1.0.0
+
+environment:
+  sdk: ">=2.18.0 <4.0.0"
+  flutter: ">=3.3.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+  ${package.directory.basename}:
+    path: ${package.directory.path}
+''';
+
+    await targetPubspecFile.writeAsString(targetYaml);
+    return testTempDirectory;
+  }
+
   /// Run the dart fix tests for the package in the given temporary directory.
   ///
   /// Resolves with the status code of the command.
-  Future<int> _runDartFixTests(RepositoryPackage package, Directory testTempDir) async {
-    // Copy the test_fixes folder to the temporary testTempDir.
-    //
-    // This also creates the proper pubspec.yaml in the temp directory.
-    await _prepareTemplate(package: package, testTempDir: testTempDir);
-
+  static Future<int> _runDartFixTests(RepositoryPackage package, Directory testDirectory) async {
     // Run dart pub get in the temp directory to set it up.
     final int pubGetStatusCode = await _runProcess('dart', <String>[
       'pub',
       'get',
-    ], workingDirectory: testTempDir.path);
+    ], workingDirectory: testDirectory.path);
 
     if (pubGetStatusCode != 0) {
-      await testTempDir.delete(recursive: true);
       return pubGetStatusCode;
     }
 
     // Run dart fix --compare-to-golden in the temp directory.
-    final int dartFixStatusCode = await _runProcess('dart', <String>[
+    return _runProcess('dart', <String>[
       'fix',
       '--compare-to-golden',
-    ], workingDirectory: testTempDir.path);
-
-    await testTempDir.delete(recursive: true);
-    return dartFixStatusCode;
-  }
-
-  Future<void> _prepareTemplate({
-    required RepositoryPackage package,
-    required Directory testTempDir,
-  }) async {
-    // Copy from src `test_fixes/` to the temp directory.
-    await io.copyPath(package.dartFixTestDirectory.path, testTempDir.path);
-
-    // The pubspec.yaml file to create.
-    const fileSystem = LocalFileSystem();
-    final File targetPubspecFile = fileSystem.file(p.join(testTempDir.path, 'pubspec.yaml'));
-
-    final targetYaml =
-        '''
-  name: test_fixes
-  publish_to: "none"
-  version: 1.0.0
-
-  environment:
-    sdk: ">=2.18.0 <4.0.0"
-    flutter: ">=3.3.0"
-
-  dependencies:
-    flutter:
-      sdk: flutter
-    ${package.directory.basename}:
-      path: ${package.directory.path}
-  ''';
-
-    await targetPubspecFile.writeAsString(targetYaml);
+    ], workingDirectory: testDirectory.path);
   }
 
-  Future<int> _runProcess(
+  static Future<int> _runProcess(
     String command,
     List<String> arguments, {
     String? workingDirectory,
@@ -140,7 +139,7 @@ class TestDartFixes extends PackageLoopingCommand {
     return process.exitCode;
   }
 
-  Future<Process> _streamOutput(Future<Process> processFuture) async {
+  static Future<Process> _streamOutput(Future<Process> processFuture) async {
     final Process process = await processFuture;
     unawaited(stdout.addStream(process.stdout));
     unawaited(stderr.addStream(process.stderr));

From 52517d3f783c295c381062b4957e229373fad8f9 Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Fri, 7 Aug 2026 15:47:54 -0700
Subject: [PATCH 05/16] Gemini code review

---
 script/tool/lib/src/test_dart_fixes.dart | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/script/tool/lib/src/test_dart_fixes.dart b/script/tool/lib/src/test_dart_fixes.dart
index f8f8e7d0c091..4b1bd29633d1 100644
--- a/script/tool/lib/src/test_dart_fixes.dart
+++ b/script/tool/lib/src/test_dart_fixes.dart
@@ -6,7 +6,6 @@ import 'dart:async';
 import 'dart:io';
 
 import 'package:file/file.dart';
-import 'package:file/local.dart';
 import 'package:io/io.dart' as io;
 import 'package:path/path.dart' as p;
 
@@ -52,7 +51,7 @@ class TestDartFixes extends PackageLoopingCommand {
     try {
       testDirectory = await _createTestDirectory(package);
     } catch (error) {
-      return PackageResult.fail(['Failed to create temporary test directory: $error}']);
+      return PackageResult.fail(['Failed to create temporary test directory: $error']);
     }
 
     late final PackageResult result;
@@ -63,7 +62,7 @@ class TestDartFixes extends PackageLoopingCommand {
       }
       result = PackageResult.success();
     } catch (error) {
-      result = PackageResult.fail(['Dart fix tests failed: $error}']);
+      result = PackageResult.fail(['Dart fix tests failed: $error']);
     }
     if (testDirectory.existsSync()) {
       await testDirectory.delete(recursive: true);
@@ -77,7 +76,7 @@ class TestDartFixes extends PackageLoopingCommand {
   /// It is the responsibility of the caller to delete this directory and its
   /// contents when done.
   static Future<Directory> _createTestDirectory(RepositoryPackage package) async {
-    const fileSystem = LocalFileSystem();
+    final FileSystem fileSystem = package.directory.fileSystem;
     final Directory testTempDirectory = await fileSystem.systemTempDirectory.createTemp();
 
     // Copy from `test_fixes/` to the temp directory.
@@ -110,12 +109,12 @@ dependencies:
   /// Run the dart fix tests for the package in the given temporary directory.
   ///
   /// Resolves with the status code of the command.
-  static Future<int> _runDartFixTests(RepositoryPackage package, Directory testDirectory) async {
+  Future<int> _runDartFixTests(RepositoryPackage package, Directory testDirectory) async {
     // Run dart pub get in the temp directory to set it up.
     final int pubGetStatusCode = await _runProcess('dart', <String>[
       'pub',
       'get',
-    ], workingDirectory: testDirectory.path);
+    ], workingDirectory: testDirectory);
 
     if (pubGetStatusCode != 0) {
       return pubGetStatusCode;
@@ -125,16 +124,16 @@ dependencies:
     return _runProcess('dart', <String>[
       'fix',
       '--compare-to-golden',
-    ], workingDirectory: testDirectory.path);
+    ], workingDirectory: testDirectory);
   }
 
-  static Future<int> _runProcess(
+  Future<int> _runProcess(
     String command,
     List<String> arguments, {
-    String? workingDirectory,
+    Directory? workingDirectory,
   }) async {
     final Process process = await _streamOutput(
-      Process.start(command, arguments, workingDirectory: workingDirectory),
+      processRunner.start(command, arguments, workingDirectory: workingDirectory),
     );
     return process.exitCode;
   }

From 91670248605c901c5af1069d9a117d2ce7f6b70e Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Wed, 12 Aug 2026 13:59:22 -0700
Subject: [PATCH 06/16] flutter pub get, not dart

---
 script/tool/lib/src/test_dart_fixes.dart | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/script/tool/lib/src/test_dart_fixes.dart b/script/tool/lib/src/test_dart_fixes.dart
index 4b1bd29633d1..48ef62371193 100644
--- a/script/tool/lib/src/test_dart_fixes.dart
+++ b/script/tool/lib/src/test_dart_fixes.dart
@@ -110,8 +110,8 @@ dependencies:
   ///
   /// Resolves with the status code of the command.
   Future<int> _runDartFixTests(RepositoryPackage package, Directory testDirectory) async {
-    // Run dart pub get in the temp directory to set it up.
-    final int pubGetStatusCode = await _runProcess('dart', <String>[
+    // Run flutter pub get in the temp directory to set it up.
+    final int pubGetStatusCode = await _runProcess('flutter', <String>[
       'pub',
       'get',
     ], workingDirectory: testDirectory);

From f7232b73748b041d0fa935f510f549947013094f Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Wed, 12 Aug 2026 14:06:55 -0700
Subject: [PATCH 07/16] Add to CI unit tests, under the assumption that the
 ~40s running time is not too long

---
 .ci/targets/dart_unit_tests.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.ci/targets/dart_unit_tests.yaml b/.ci/targets/dart_unit_tests.yaml
index 6c5d6c4288d6..c2a1281d2f39 100644
--- a/.ci/targets/dart_unit_tests.yaml
+++ b/.ci/targets/dart_unit_tests.yaml
@@ -11,3 +11,6 @@ tasks:
   - name: Dart unit tests - pathified
     script: .ci/scripts/dart_unit_tests_pathified.sh
     args: ["--platform=vm"]
+  - name: Dart fix tests
+    script: script/tool/bin/flutter_plugin_tools.dart
+    args: ["test-dart-fixes"]

From de6d383360f2677a0f5853b8a2c97cb51ae9c6e8 Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Wed, 12 Aug 2026 14:20:11 -0700
Subject: [PATCH 08/16] Command in name

---
 script/tool/lib/src/main.dart                                 | 2 +-
 .../{test_dart_fixes.dart => test_dart_fixes_command.dart}    | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)
 rename script/tool/lib/src/{test_dart_fixes.dart => test_dart_fixes_command.dart} (96%)

diff --git a/script/tool/lib/src/main.dart b/script/tool/lib/src/main.dart
index 55b3e9d5e204..22018b18e342 100644
--- a/script/tool/lib/src/main.dart
+++ b/script/tool/lib/src/main.dart
@@ -76,7 +76,7 @@ void main(List<String> args) {
         ..addCommand(PublishCheckCommand(packagesDir))
         ..addCommand(PublishCommand(packagesDir))
         ..addCommand(RemoveDevDependenciesCommand(packagesDir))
-        ..addCommand(TestDartFixes(packagesDir))
+        ..addCommand(TestDartFixesCommand(packagesDir))
         ..addCommand(UpdateDependencyCommand(packagesDir))
         ..addCommand(UpdateExcerptsCommand(packagesDir))
         ..addCommand(UpdateMinSdkCommand(packagesDir))
diff --git a/script/tool/lib/src/test_dart_fixes.dart b/script/tool/lib/src/test_dart_fixes_command.dart
similarity index 96%
rename from script/tool/lib/src/test_dart_fixes.dart
rename to script/tool/lib/src/test_dart_fixes_command.dart
index 48ef62371193..5dc69c47e9de 100644
--- a/script/tool/lib/src/test_dart_fixes.dart
+++ b/script/tool/lib/src/test_dart_fixes_command.dart
@@ -15,9 +15,9 @@ import 'common/repository_package.dart';
 
 /// A command to run dart fix tests for packages that have a test_fixes
 /// directory.
-class TestDartFixes extends PackageLoopingCommand {
+class TestDartFixesCommand extends PackageLoopingCommand {
   /// Creates an instance of the test dart fixes command.
-  TestDartFixes(super.packagesDir, {super.processRunner, super.platform, super.gitDir});
+  TestDartFixesCommand(super.packagesDir, {super.processRunner, super.platform, super.gitDir});
 
   @override
   final String name = 'test-dart-fixes';

From 08a076fc728179e3dd194479db053c2d1bc886ef Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Wed, 12 Aug 2026 14:49:28 -0700
Subject: [PATCH 09/16] Copy in memory temp directory properly.

---
 script/tool/lib/src/test_dart_fixes_command.dart | 12 ++++++++++--
 script/tool/pubspec.yaml                         |  1 -
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/script/tool/lib/src/test_dart_fixes_command.dart b/script/tool/lib/src/test_dart_fixes_command.dart
index 5dc69c47e9de..46293cf1a82b 100644
--- a/script/tool/lib/src/test_dart_fixes_command.dart
+++ b/script/tool/lib/src/test_dart_fixes_command.dart
@@ -6,7 +6,6 @@ import 'dart:async';
 import 'dart:io';
 
 import 'package:file/file.dart';
-import 'package:io/io.dart' as io;
 import 'package:path/path.dart' as p;
 
 import 'common/file_filters.dart';
@@ -80,7 +79,16 @@ class TestDartFixesCommand extends PackageLoopingCommand {
     final Directory testTempDirectory = await fileSystem.systemTempDirectory.createTemp();
 
     // Copy from `test_fixes/` to the temp directory.
-    await io.copyPath(package.dartFixTestDirectory.path, testTempDirectory.path);
+    for (final FileSystemEntity entity in package.dartFixTestDirectory.listSync(recursive: true)) {
+      final String relativePath = p.relative(entity.path, from: package.dartFixTestDirectory.path);
+      final String destPath = p.join(testTempDirectory.path, relativePath);
+      if (entity is Directory) {
+        fileSystem.directory(destPath).createSync(recursive: true);
+      } else if (entity is File) {
+        fileSystem.file(destPath).parent.createSync(recursive: true);
+        entity.copySync(destPath);
+      }
+    }
 
     // The pubspec.yaml file to create.
     final File targetPubspecFile = fileSystem.file(p.join(testTempDirectory.path, 'pubspec.yaml'));
diff --git a/script/tool/pubspec.yaml b/script/tool/pubspec.yaml
index 94286da51efa..957b1ebe343d 100644
--- a/script/tool/pubspec.yaml
+++ b/script/tool/pubspec.yaml
@@ -13,7 +13,6 @@ dependencies:
   glob: ^2.1.3
   http: ^1.0.0
   http_multi_server: ^3.0.1
-  io: ^1.0.5
   meta: ^1.10.0
   path: ^1.8.3
   platform: ^3.0.2

From 9173808290701620fca0e0f00cfe5b293c3fd86c Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Wed, 12 Aug 2026 14:57:21 -0700
Subject: [PATCH 10/16] Variable name consistency

---
 script/tool/lib/src/test_dart_fixes_command.dart | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/script/tool/lib/src/test_dart_fixes_command.dart b/script/tool/lib/src/test_dart_fixes_command.dart
index 46293cf1a82b..b7c5d521ba11 100644
--- a/script/tool/lib/src/test_dart_fixes_command.dart
+++ b/script/tool/lib/src/test_dart_fixes_command.dart
@@ -76,12 +76,12 @@ class TestDartFixesCommand extends PackageLoopingCommand {
   /// contents when done.
   static Future<Directory> _createTestDirectory(RepositoryPackage package) async {
     final FileSystem fileSystem = package.directory.fileSystem;
-    final Directory testTempDirectory = await fileSystem.systemTempDirectory.createTemp();
+    final Directory testDirectory = await fileSystem.systemTempDirectory.createTemp();
 
     // Copy from `test_fixes/` to the temp directory.
     for (final FileSystemEntity entity in package.dartFixTestDirectory.listSync(recursive: true)) {
       final String relativePath = p.relative(entity.path, from: package.dartFixTestDirectory.path);
-      final String destPath = p.join(testTempDirectory.path, relativePath);
+      final String destPath = p.join(testDirectory.path, relativePath);
       if (entity is Directory) {
         fileSystem.directory(destPath).createSync(recursive: true);
       } else if (entity is File) {
@@ -91,7 +91,7 @@ class TestDartFixesCommand extends PackageLoopingCommand {
     }
 
     // The pubspec.yaml file to create.
-    final File targetPubspecFile = fileSystem.file(p.join(testTempDirectory.path, 'pubspec.yaml'));
+    final File targetPubspecFile = fileSystem.file(p.join(testDirectory.path, 'pubspec.yaml'));
 
     final targetYaml =
         '''
@@ -111,7 +111,7 @@ dependencies:
 ''';
 
     await targetPubspecFile.writeAsString(targetYaml);
-    return testTempDirectory;
+    return testDirectory;
   }
 
   /// Run the dart fix tests for the package in the given temporary directory.

From 1e588048572cda83c641485bbd7cad623c2551e9 Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Wed, 12 Aug 2026 15:47:42 -0700
Subject: [PATCH 11/16] Working tests

---
 .../tool/lib/src/test_dart_fixes_command.dart |   6 +
 .../test/test_dart_fixes_command_test.dart    | 160 ++++++++++++++++++
 2 files changed, 166 insertions(+)
 create mode 100644 script/tool/test/test_dart_fixes_command_test.dart

diff --git a/script/tool/lib/src/test_dart_fixes_command.dart b/script/tool/lib/src/test_dart_fixes_command.dart
index b7c5d521ba11..ef31234a1d26 100644
--- a/script/tool/lib/src/test_dart_fixes_command.dart
+++ b/script/tool/lib/src/test_dart_fixes_command.dart
@@ -6,6 +6,7 @@ import 'dart:async';
 import 'dart:io';
 
 import 'package:file/file.dart';
+import 'package:meta/meta.dart';
 import 'package:path/path.dart' as p;
 
 import 'common/file_filters.dart';
@@ -18,6 +19,10 @@ class TestDartFixesCommand extends PackageLoopingCommand {
   /// Creates an instance of the test dart fixes command.
   TestDartFixesCommand(super.packagesDir, {super.processRunner, super.platform, super.gitDir});
 
+  /// A map of the test directory used for each package passed to runForPackage.
+  @visibleForTesting
+  final testDirectories = <String, Directory>{};
+
   @override
   final String name = 'test-dart-fixes';
 
@@ -66,6 +71,7 @@ class TestDartFixesCommand extends PackageLoopingCommand {
     if (testDirectory.existsSync()) {
       await testDirectory.delete(recursive: true);
     }
+    testDirectories[package.displayName] = testDirectory;
     return result;
   }
 
diff --git a/script/tool/test/test_dart_fixes_command_test.dart b/script/tool/test/test_dart_fixes_command_test.dart
new file mode 100644
index 000000000000..7794a3a261e4
--- /dev/null
+++ b/script/tool/test/test_dart_fixes_command_test.dart
@@ -0,0 +1,160 @@
+// Copyright 2013 The Flutter Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:args/command_runner.dart';
+import 'package:file/file.dart';
+import 'package:flutter_plugin_tools/src/common/core.dart';
+import 'package:flutter_plugin_tools/src/test_dart_fixes_command.dart';
+import 'package:git/git.dart';
+import 'package:platform/platform.dart';
+import 'package:test/test.dart';
+
+import 'mocks.dart';
+import 'util.dart';
+
+void main() {
+  group('TestDartFixesCommand', () {
+    late Platform mockPlatform;
+    late Directory packagesDir;
+    late CommandRunner<void> runner;
+    late RecordingProcessRunner processRunner;
+    late TestDartFixesCommand command;
+
+    setUp(() {
+      mockPlatform = MockPlatform();
+      final GitDir gitDir;
+      (:packagesDir, :processRunner, gitProcessRunner: _, :gitDir) = configureBaseCommandMocks(
+        platform: mockPlatform,
+      );
+      command = TestDartFixesCommand(
+        packagesDir,
+        processRunner: processRunner,
+        platform: mockPlatform,
+        gitDir: gitDir,
+      );
+
+      runner = CommandRunner<void>('test_dart_fixes', 'Test for $TestDartFixesCommand');
+      runner.addCommand(command);
+    });
+
+    test('runs on each package with a test_fixes directory', () async {
+      final RepositoryPackage package1 = createFakePackage(
+        'package1',
+        packagesDir,
+        examples: <String>[],
+        extraFiles: <String>['test_fixes/empty.dart', 'test_fixes/empty.dart.expect'],
+      );
+      final RepositoryPackage package2 = createFakePackage(
+        'package2',
+        packagesDir,
+        examples: <String>[],
+        extraFiles: <String>['test_fixes/empty.dart', 'test_fixes/empty.dart.expect'],
+      );
+      createFakePackage('package3', packagesDir, examples: <String>[]);
+
+      final List<String> output = await runCapturingPrint(runner, <String>['test-dart-fixes']);
+
+      expect(
+        output,
+        containsAllInOrder(<Matcher>[
+          contains('Running for package1'),
+          contains('Running for package2'),
+          contains('Running for package3'),
+          contains("SKIPPING: No MemoryDirectory: '/packages/package3/test_fixes' directory."),
+        ]),
+      );
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall(getFlutterCommand(mockPlatform), const <String>[
+            'pub',
+            'get',
+          ], command.testDirectories[package1.displayName]!.path),
+          ProcessCall('dart', const <String>[
+            'fix',
+            '--compare-to-golden',
+          ], command.testDirectories[package1.displayName]!.path),
+          ProcessCall(getFlutterCommand(mockPlatform), const <String>[
+            'pub',
+            'get',
+          ], command.testDirectories[package2.displayName]!.path),
+          ProcessCall('dart', const <String>[
+            'fix',
+            '--compare-to-golden',
+          ], command.testDirectories[package2.displayName]!.path),
+        ]),
+      );
+    });
+
+    test('fails when dart fix test fails', () async {
+      final RepositoryPackage packageThatFails = createFakePackage(
+        'package1',
+        packagesDir,
+        examples: <String>[],
+        extraFiles: <String>['test_fixes/fix.dart', 'test_fixes/fix.dart.expect'],
+      );
+      packageThatFails.dartFixTestDirectory.childFile('fix.dart').writeAsStringSync('a');
+      packageThatFails.dartFixTestDirectory.childFile('fix.dart.expect').writeAsStringSync('b');
+
+      final RepositoryPackage packageThatSucceeds = createFakePackage(
+        'package2',
+        packagesDir,
+        examples: <String>[],
+        extraFiles: <String>['test_fixes/fix.dart', 'test_fixes/fix.dart.expect'],
+      );
+      packageThatSucceeds.dartFixTestDirectory.childFile('fix.dart').writeAsStringSync('c');
+      packageThatSucceeds.dartFixTestDirectory.childFile('fix.dart.expect').writeAsStringSync('c');
+
+      processRunner.mockProcessesForExecutable['dart'] = <FakeProcessInfo>[
+        FakeProcessInfo(_MockDartFixProcess(processRunner, packagesDir.fileSystem), const <String>[
+          'fix',
+          '--compare-to-golden',
+        ]),
+        FakeProcessInfo(_MockDartFixProcess(processRunner, packagesDir.fileSystem), const <String>[
+          'fix',
+          '--compare-to-golden',
+        ]),
+      ];
+
+      Error? commandError;
+      final List<String> output = await runCapturingPrint(
+        runner,
+        <String>['test-dart-fixes'],
+        errorHandler: (e) {
+          commandError = e;
+        },
+      );
+
+      expect(commandError, isA<ToolExit>());
+      expect(
+        output,
+        containsAllInOrder(<Matcher>[
+          contains('The following packages had errors:'),
+          contains('  package1'),
+          isNot(contains('package2')),
+        ]),
+      );
+    });
+  });
+}
+
+/// Fails when fix.dart does not equal fix.dart.expect.
+class _MockDartFixProcess extends MockProcess {
+  _MockDartFixProcess(this.processRunner, this.fileSystem);
+  final RecordingProcessRunner processRunner;
+  final FileSystem fileSystem;
+
+  @override
+  Future<int> get exitCode async {
+    final ProcessCall call = processRunner.recordedCalls.last;
+    final String? workingDir = call.workingDir;
+    final File fixDart = fileSystem.file(fileSystem.path.join(workingDir!, 'fix.dart'));
+    final File fixExpect = fileSystem.file(fileSystem.path.join(workingDir, 'fix.dart.expect'));
+    if (!fixDart.existsSync() || !fixExpect.existsSync()) {
+      return 1;
+    }
+    return fixDart.readAsStringSync() == fixExpect.readAsStringSync() ? 0 : 1;
+  }
+}

From e553f85a67f4ef2add6babc99578b5f3b7f6d017 Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Wed, 12 Aug 2026 16:02:19 -0700
Subject: [PATCH 12/16] Fixes from stuart's code review

---
 script/tool/lib/src/main.dart                 |  2 +-
 .../tool/lib/src/test_dart_fixes_command.dart | 44 ++++++-------------
 2 files changed, 14 insertions(+), 32 deletions(-)

diff --git a/script/tool/lib/src/main.dart b/script/tool/lib/src/main.dart
index 22018b18e342..48bc4bf4f6bb 100644
--- a/script/tool/lib/src/main.dart
+++ b/script/tool/lib/src/main.dart
@@ -30,7 +30,7 @@ import 'podspec_check_command.dart';
 import 'publish_check_command.dart';
 import 'publish_command.dart';
 import 'remove_dev_dependencies_command.dart';
-import 'test_dart_fixes.dart';
+import 'test_dart_fixes_command.dart';
 import 'update_dependency_command.dart';
 import 'update_excerpts_command.dart';
 import 'update_min_sdk_command.dart';
diff --git a/script/tool/lib/src/test_dart_fixes_command.dart b/script/tool/lib/src/test_dart_fixes_command.dart
index ef31234a1d26..914dafdfbe32 100644
--- a/script/tool/lib/src/test_dart_fixes_command.dart
+++ b/script/tool/lib/src/test_dart_fixes_command.dart
@@ -11,6 +11,7 @@ import 'package:path/path.dart' as p;
 
 import 'common/file_filters.dart';
 import 'common/package_looping_command.dart';
+import 'common/pub_utils.dart';
 import 'common/repository_package.dart';
 
 /// A command to run dart fix tests for packages that have a test_fixes
@@ -35,7 +36,7 @@ class TestDartFixesCommand extends PackageLoopingCommand {
       'This command requires "flutter" to be in your path.';
 
   @override
-  PackageLoopingType get packageLoopingType => PackageLoopingType.includeAllSubpackages;
+  PackageLoopingType get packageLoopingType => PackageLoopingType.topLevelOnly;
 
   @override
   bool shouldIgnoreFile(String path) {
@@ -58,11 +59,11 @@ class TestDartFixesCommand extends PackageLoopingCommand {
       return PackageResult.fail(['Failed to create temporary test directory: $error']);
     }
 
-    late final PackageResult result;
+    PackageResult result;
     try {
-      final int statusCode = await _runDartFixTests(package, testDirectory);
-      if (statusCode != 0) {
-        throw Exception('Status code $statusCode');
+      final bool success = await _runDartFixTests(testDirectory);
+      if (!success) {
+        throw Exception('Failed to run dart fix tests.');
       }
       result = PackageResult.success();
     } catch (error) {
@@ -123,39 +124,20 @@ dependencies:
   /// Run the dart fix tests for the package in the given temporary directory.
   ///
   /// Resolves with the status code of the command.
-  Future<int> _runDartFixTests(RepositoryPackage package, Directory testDirectory) async {
+  Future<bool> _runDartFixTests(Directory testDirectory) async {
     // Run flutter pub get in the temp directory to set it up.
-    final int pubGetStatusCode = await _runProcess('flutter', <String>[
-      'pub',
-      'get',
-    ], workingDirectory: testDirectory);
+    final bool success = await runPubGet(RepositoryPackage(testDirectory), processRunner, platform);
 
-    if (pubGetStatusCode != 0) {
-      return pubGetStatusCode;
+    if (!success) {
+      return success;
     }
 
     // Run dart fix --compare-to-golden in the temp directory.
-    return _runProcess('dart', <String>[
+    final int exitCode = await processRunner.runAndStream('dart', <String>[
       'fix',
       '--compare-to-golden',
-    ], workingDirectory: testDirectory);
-  }
-
-  Future<int> _runProcess(
-    String command,
-    List<String> arguments, {
-    Directory? workingDirectory,
-  }) async {
-    final Process process = await _streamOutput(
-      processRunner.start(command, arguments, workingDirectory: workingDirectory),
-    );
-    return process.exitCode;
-  }
+    ], workingDir: testDirectory);
 
-  static Future<Process> _streamOutput(Future<Process> processFuture) async {
-    final Process process = await processFuture;
-    unawaited(stdout.addStream(process.stdout));
-    unawaited(stderr.addStream(process.stderr));
-    return process;
+    return exitCode == 0;
   }
 }

From a9cbde22896854504c51986b209b35579bf65615 Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Wed, 12 Aug 2026 16:06:29 -0700
Subject: [PATCH 13/16] Unused import

---
 script/tool/lib/src/test_dart_fixes_command.dart | 1 -
 1 file changed, 1 deletion(-)

diff --git a/script/tool/lib/src/test_dart_fixes_command.dart b/script/tool/lib/src/test_dart_fixes_command.dart
index 914dafdfbe32..7c4f4061d9c8 100644
--- a/script/tool/lib/src/test_dart_fixes_command.dart
+++ b/script/tool/lib/src/test_dart_fixes_command.dart
@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:io';
 
 import 'package:file/file.dart';
 import 'package:meta/meta.dart';

From 94e7a119da99cbdbc87ca71674b79799f89ffaa9 Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Thu, 13 Aug 2026 09:27:14 -0700
Subject: [PATCH 14/16] Fix CI execution of dart fix tests

---
 .ci/targets/dart_unit_tests.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.ci/targets/dart_unit_tests.yaml b/.ci/targets/dart_unit_tests.yaml
index c2a1281d2f39..291c4e1c1102 100644
--- a/.ci/targets/dart_unit_tests.yaml
+++ b/.ci/targets/dart_unit_tests.yaml
@@ -12,5 +12,5 @@ tasks:
     script: .ci/scripts/dart_unit_tests_pathified.sh
     args: ["--platform=vm"]
   - name: Dart fix tests
-    script: script/tool/bin/flutter_plugin_tools.dart
+    script: .ci/scripts/tool_runner.sh
     args: ["test-dart-fixes"]

From aa09ca3a2a406a1ee339e59cf475ef66cd7f2ed5 Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Thu, 13 Aug 2026 09:34:44 -0700
Subject: [PATCH 15/16] Fix for Windows by using FileSystem not Path

---
 script/tool/lib/src/test_dart_fixes_command.dart | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/script/tool/lib/src/test_dart_fixes_command.dart b/script/tool/lib/src/test_dart_fixes_command.dart
index 7c4f4061d9c8..256cdaafb1e4 100644
--- a/script/tool/lib/src/test_dart_fixes_command.dart
+++ b/script/tool/lib/src/test_dart_fixes_command.dart
@@ -6,7 +6,6 @@ import 'dart:async';
 
 import 'package:file/file.dart';
 import 'package:meta/meta.dart';
-import 'package:path/path.dart' as p;
 
 import 'common/file_filters.dart';
 import 'common/package_looping_command.dart';
@@ -86,8 +85,8 @@ class TestDartFixesCommand extends PackageLoopingCommand {
 
     // Copy from `test_fixes/` to the temp directory.
     for (final FileSystemEntity entity in package.dartFixTestDirectory.listSync(recursive: true)) {
-      final String relativePath = p.relative(entity.path, from: package.dartFixTestDirectory.path);
-      final String destPath = p.join(testDirectory.path, relativePath);
+      final String relativePath = fileSystem.path.relative(entity.path, from: package.dartFixTestDirectory.path);
+      final String destPath = fileSystem.path.join(testDirectory.path, relativePath);
       if (entity is Directory) {
         fileSystem.directory(destPath).createSync(recursive: true);
       } else if (entity is File) {
@@ -97,7 +96,7 @@ class TestDartFixesCommand extends PackageLoopingCommand {
     }
 
     // The pubspec.yaml file to create.
-    final File targetPubspecFile = fileSystem.file(p.join(testDirectory.path, 'pubspec.yaml'));
+    final File targetPubspecFile = fileSystem.file(fileSystem.path.join(testDirectory.path, 'pubspec.yaml'));
 
     final targetYaml =
         '''

From 143f2b9f2301fc5222c230926ed41cd9961d4ade Mon Sep 17 00:00:00 2001
From: Justin McCandless <jmccandless@google.com>
Date: Thu, 13 Aug 2026 09:46:06 -0700
Subject: [PATCH 16/16] Formatting

---
 script/tool/lib/src/test_dart_fixes_command.dart | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/script/tool/lib/src/test_dart_fixes_command.dart b/script/tool/lib/src/test_dart_fixes_command.dart
index 256cdaafb1e4..53d2e771dd2c 100644
--- a/script/tool/lib/src/test_dart_fixes_command.dart
+++ b/script/tool/lib/src/test_dart_fixes_command.dart
@@ -85,7 +85,10 @@ class TestDartFixesCommand extends PackageLoopingCommand {
 
     // Copy from `test_fixes/` to the temp directory.
     for (final FileSystemEntity entity in package.dartFixTestDirectory.listSync(recursive: true)) {
-      final String relativePath = fileSystem.path.relative(entity.path, from: package.dartFixTestDirectory.path);
+      final String relativePath = fileSystem.path.relative(
+        entity.path,
+        from: package.dartFixTestDirectory.path,
+      );
       final String destPath = fileSystem.path.join(testDirectory.path, relativePath);
       if (entity is Directory) {
         fileSystem.directory(destPath).createSync(recursive: true);
@@ -96,7 +99,9 @@ class TestDartFixesCommand extends PackageLoopingCommand {
     }
 
     // The pubspec.yaml file to create.
-    final File targetPubspecFile = fileSystem.file(fileSystem.path.join(testDirectory.path, 'pubspec.yaml'));
+    final File targetPubspecFile = fileSystem.file(
+      fileSystem.path.join(testDirectory.path, 'pubspec.yaml'),
+    );
 
     final targetYaml =
         '''