Revert "Add a warning/additional handlers for parsingsynthetic-package." (#158078)

Reverts flutter/flutter#157934 to unblock https://github.com/flutter/flutter/pull/158076 and then flutter roll.

Reason: b/377107864

packages/flutter_tools/lib/src/commands/generate_localizations.dart

@@ -147,8 +147,6 @@ class GenerateLocalizationsCommand extends FlutterCommand {
             'generated as a synthetic package or at a specified directory in '
             'the Flutter project.\n'
             '\n'
-            'DEPRECATED: https://flutter.dev/to/flutter-gen-deprecation.\n'
-            '\n'
             'This flag is set to true by default.\n'
             '\n'
             'When synthetic-package is set to false, it will generate the '

packages/flutter_tools/lib/src/dart/generate_synthetic_packages.dart

@@ -15,10 +15,10 @@ Future<void> generateLocalizationsSyntheticPackage({
   required BuildSystem buildSystem,
   required BuildTargets buildTargets,
 }) async {
+
   final FileSystem fileSystem = environment.fileSystem;
   final File l10nYamlFile = fileSystem.file(
-    fileSystem.path.join(environment.projectDir.path, 'l10n.yaml'),
+    fileSystem.path.join(environment.projectDir.path, 'l10n.yaml'));
-  );
 
   // If pubspec.yaml has generate:true and if l10n.yaml exists in the
   // root project directory, check to see if a synthetic package should
@@ -30,7 +30,7 @@ Future<void> generateLocalizationsSyntheticPackage({
   final YamlNode yamlNode = loadYamlNode(l10nYamlFile.readAsStringSync());
   if (yamlNode.value != null && yamlNode is! YamlMap) {
     throwToolExit(
-      'Expected ${l10nYamlFile.path} to contain a map, instead was $yamlNode',
+      'Expected ${l10nYamlFile.path} to contain a map, instead was $yamlNode'
     );
   }
 
@@ -41,7 +41,8 @@ Future<void> generateLocalizationsSyntheticPackage({
     final Object? value = yamlMap['synthetic-package'];
     if (value is! bool && value != null) {
       throwToolExit(
-        'Expected "synthetic-package" to have a bool value, instead was "$value"',
+        'Expected "synthetic-package" to have a bool value, '
+        'instead was "$value"'
       );
     }
 
@@ -51,30 +52,8 @@ Future<void> generateLocalizationsSyntheticPackage({
     if (isSyntheticL10nPackage == false) {
       return;
     }
-  } else if (!environment.useImplicitPubspecResolution) {
-    // --no-implicit-pubspec-resolution was passed, and synthetic-packages: true was not.
-    return;
   }
 
-  if (!environment.useImplicitPubspecResolution) {
-    throwToolExit(
-      'Cannot generate a synthetic package when --no-implicit-pubspec-resolution is passed.\n'
-      '\n'
-      'Synthetic package output (package:flutter_gen) is deprecated: '
-      'https://flutter.dev/to/flutter-gen-deprecation. If you are seeing this '
-      'message either you have provided --no-implicit-pubspec-resolution, or '
-      'it is the default value (see flutter --verbose --help).',
-    );
-  }
-
-  // Log a warning: synthetic-package: true (or implicit true) is deprecated.
-  environment.logger.printWarning(
-    'Synthetic package output (package:flutter_gen) is deprecated: '
-    'https://flutter.dev/to/flutter-gen-deprecation. In a future release, '
-    'synthetic-package will default to `false` and will later be removed '
-    'entirely.',
-  );
-
   final BuildResult result = await buildSystem.build(
     buildTargets.generateLocalizationsTarget,
     environment,

packages/flutter_tools/test/general.shard/dart/generate_synthetic_packages_test.dart

@@ -267,185 +267,4 @@ void main() {
       throwsToolExit(message: 'to have a bool value, instead was "nonBoolValue"'),
     );
   });
-
-  testWithoutContext('synthetic-package: true (implicit) logs a deprecation warning', () async {
-    // Project directory setup for gen_l10n logic.
-    final MemoryFileSystem fileSystem = MemoryFileSystem.test();
-
-    // Add generate:true to pubspec.yaml.
-    final File pubspecFile = fileSystem.file('pubspec.yaml')..createSync();
-    final String content = pubspecFile.readAsStringSync().replaceFirst(
-      '\nflutter:\n',
-      '\nflutter:\n  generate: true\n',
-    );
-    pubspecFile.writeAsStringSync(content);
-
-    // Create a blank l10n.yaml file.
-    fileSystem.file('l10n.yaml').writeAsStringSync('');
-
-    final BufferLogger mockBufferLogger = BufferLogger.test();
-    final Environment environment = Environment.test(
-      fileSystem.currentDirectory,
-      fileSystem: fileSystem,
-      logger: mockBufferLogger,
-      artifacts: Artifacts.test(),
-      processManager: FakeProcessManager.any(),
-    );
-    final TestBuildSystem buildSystem = TestBuildSystem.all(BuildResult(success: true));
-
-    await generateLocalizationsSyntheticPackage(
-      environment: environment,
-      buildSystem: buildSystem,
-      buildTargets: const BuildTargetsImpl(),
-    );
-
-    expect(
-      mockBufferLogger.warningText,
-      contains('https://flutter.dev/to/flutter-gen-deprecation'),
-    );
-  });
-
-  testWithoutContext('synthetic-package: true (explicit) logs a deprecation warning', () async {
-    // Project directory setup for gen_l10n logic.
-    final MemoryFileSystem fileSystem = MemoryFileSystem.test();
-
-    // Add generate:true to pubspec.yaml.
-    final File pubspecFile = fileSystem.file('pubspec.yaml')..createSync();
-    final String content = pubspecFile.readAsStringSync().replaceFirst(
-      '\nflutter:\n',
-      '\nflutter:\n  generate: true\n',
-    );
-    pubspecFile.writeAsStringSync(content);
-    fileSystem.file('l10n.yaml').writeAsStringSync('synthetic-package: true');
-
-    final BufferLogger mockBufferLogger = BufferLogger.test();
-    final Environment environment = Environment.test(
-      fileSystem.currentDirectory,
-      fileSystem: fileSystem,
-      logger: mockBufferLogger,
-      artifacts: Artifacts.test(),
-      processManager: FakeProcessManager.any(),
-    );
-    final TestBuildSystem buildSystem = TestBuildSystem.all(BuildResult(success: true));
-
-    await generateLocalizationsSyntheticPackage(
-      environment: environment,
-      buildSystem: buildSystem,
-      buildTargets: const BuildTargetsImpl(),
-    );
-
-    expect(
-      mockBufferLogger.warningText,
-      contains('https://flutter.dev/to/flutter-gen-deprecation'),
-    );
-  });
-
-  testWithoutContext('synthetic-package: false has no deprecation warning', () async {
-    // Project directory setup for gen_l10n logic
-    final MemoryFileSystem fileSystem = MemoryFileSystem.test();
-
-    // Add generate:true to pubspec.yaml.
-    final File pubspecFile = fileSystem.file('pubspec.yaml')..createSync();
-    final String content = pubspecFile.readAsStringSync().replaceFirst(
-      '\nflutter:\n',
-      '\nflutter:\n  generate: true\n',
-    );
-    pubspecFile.writeAsStringSync(content);
-    fileSystem.file('l10n.yaml').writeAsStringSync('synthetic-package: false');
-
-    final BufferLogger mockBufferLogger = BufferLogger.test();
-    final Environment environment = Environment.test(
-      fileSystem.currentDirectory,
-      fileSystem: fileSystem,
-      logger: mockBufferLogger,
-      artifacts: Artifacts.test(),
-      processManager: FakeProcessManager.any(),
-    );
-    final TestBuildSystem buildSystem = TestBuildSystem.all(BuildResult(success: true));
-
-    await generateLocalizationsSyntheticPackage(
-      environment: environment,
-      buildSystem: buildSystem,
-      buildTargets: const BuildTargetsImpl(),
-    );
-
-    expect(
-      mockBufferLogger.warningText,
-      isNot(contains('https://flutter.dev/to/flutter-gen-deprecation')),
-    );
-  });
-
-  testWithoutContext('synthetic-package: true with --no-implicit-pubspec-resolution is an error', () async {
-    // Project directory setup for gen_l10n logic
-    final MemoryFileSystem fileSystem = MemoryFileSystem.test();
-
-    // Add generate:true to pubspec.yaml.
-    final File pubspecFile = fileSystem.file('pubspec.yaml')..createSync();
-    final String content = pubspecFile.readAsStringSync().replaceFirst(
-      '\nflutter:\n',
-      '\nflutter:\n  generate: true\n',
-    );
-    pubspecFile.writeAsStringSync(content);
-
-    // Create an l10n.yaml file
-    fileSystem.file('l10n.yaml').writeAsStringSync('synthetic-package: true');
-
-    final BufferLogger mockBufferLogger = BufferLogger.test();
-    final Environment environment = Environment.test(
-      fileSystem.currentDirectory,
-      fileSystem: fileSystem,
-      logger: mockBufferLogger,
-      artifacts: Artifacts.test(),
-      processManager: FakeProcessManager.any(),
-      useImplicitPubspecResolution: false,
-    );
-    // Will throw if build is called.
-    final TestBuildSystem buildSystem = TestBuildSystem.all(null);
-
-    await expectLater(
-      () => generateLocalizationsSyntheticPackage(
-        environment: environment,
-        buildSystem: buildSystem,
-        buildTargets: const NoOpBuildTargets(),
-      ),
-      throwsToolExit(message: 'Cannot generate a synthetic package when --no-implicit-pubspec-resolution is passed'),
-    );
-  });
-
-  testWithoutContext('synthetic-package defaults to false if --no-implicit-pubspec-resolution is passed', () async {
-    // Project directory setup for gen_l10n logic
-    final MemoryFileSystem fileSystem = MemoryFileSystem.test();
-
-    // Add generate:true to pubspec.yaml.
-    final File pubspecFile = fileSystem.file('pubspec.yaml')..createSync();
-    final String content = pubspecFile.readAsStringSync().replaceFirst(
-      '\nflutter:\n',
-      '\nflutter:\n  generate: true\n',
-    );
-    pubspecFile.writeAsStringSync(content);
-
-    // Create an l10n.yaml file
-    fileSystem.file('l10n.yaml').writeAsStringSync('');
-
-    final BufferLogger mockBufferLogger = BufferLogger.test();
-    final Environment environment = Environment.test(
-      fileSystem.currentDirectory,
-      fileSystem: fileSystem,
-      logger: mockBufferLogger,
-      artifacts: Artifacts.test(),
-      processManager: FakeProcessManager.any(),
-      useImplicitPubspecResolution: false,
-    );
-    // Will throw if build is called.
-    final TestBuildSystem buildSystem = TestBuildSystem.all(null);
-
-    await expectLater(
-      () => generateLocalizationsSyntheticPackage(
-        environment: environment,
-        buildSystem: buildSystem,
-        buildTargets: const NoOpBuildTargets(),
-      ),
-      returnsNormally,
-    );
-  });
 }