[gen-l10n] Fix forwarding of output-dir in l10n.yaml file (#71128)

packages/flutter_tools/lib/src/build_system/targets/localizations.dart

@@ -43,7 +43,7 @@ void generateLocalizations({
 
   precacheLanguageAndRegionTags();
 
-  final String inputPathString = options?.arbDirectory?.toFilePath() ?? globals.fs.path.join('lib', 'l10n');
+  final String inputPathString = options?.arbDirectory?.path ?? globals.fs.path.join('lib', 'l10n');
   final String templateArbFileName = options?.templateArbFile?.toFilePath() ?? 'app_en.arb';
   final String outputFileString = options?.outputLocalizationsFile?.toFilePath() ?? 'app_localizations.dart';
 
@@ -55,6 +55,7 @@ void generateLocalizations({
         inputPathString: inputPathString,
         templateArbFileName: templateArbFileName,
         outputFileString: outputFileString,
+        outputPathString: options?.outputDirectory?.path,
         classNameString: options.outputClass ?? 'AppLocalizations',
         preferredSupportedLocale: options.preferredSupportedLocales,
         headerString: options.header,
@@ -155,6 +156,7 @@ class LocalizationOptions {
     this.untranslatedMessagesFile,
     this.header,
     this.outputClass,
+    this.outputDirectory,
     this.preferredSupportedLocales,
     this.headerFile,
     this.deferredLoading,
@@ -164,7 +166,7 @@ class LocalizationOptions {
 
   /// The `--arb-dir` argument.
   ///
-  /// The directory where all localization files should reside.
+  /// The directory where all input localization files should reside.
   final Uri arbDirectory;
 
   /// The `--template-arb-file` argument.
@@ -190,6 +192,11 @@ class LocalizationOptions {
   /// The `--output-class` argument.
   final String outputClass;
 
+  /// The `--output-dir` argument.
+  ///
+  /// The directory where all output localization files should be generated.
+  final Uri outputDirectory;
+
   /// The `--preferred-supported-locales` argument.
   final List<String> preferredSupportedLocales;
 
@@ -244,6 +251,7 @@ LocalizationOptions parseLocalizationsOptions({
     untranslatedMessagesFile: _tryReadUri(yamlMap, 'untranslated-messages-file', logger),
     header: _tryReadString(yamlMap, 'header', logger),
     outputClass: _tryReadString(yamlMap, 'output-class', logger),
+    outputDirectory: _tryReadUri(yamlMap, 'output-dir', logger),
     preferredSupportedLocales: _tryReadStringList(yamlMap, 'preferred-supported-locales', logger),
     headerFile: _tryReadUri(yamlMap, 'header-file', logger),
     deferredLoading: _tryReadBool(yamlMap, 'use-deferred-loading', logger),

packages/flutter_tools/test/general.shard/build_system/targets/localizations_test.dart

@@ -35,6 +35,7 @@ void main() {
       deferredLoading: true,
       outputClass: 'Foo',
       outputLocalizationsFile: Uri.file('bar'),
+      outputDirectory: Uri.directory(fileSystem.path.join('lib', 'l10n')),
       preferredSupportedLocales: <String>['en_US'],
       templateArbFile: Uri.file('example.arb'),
       untranslatedMessagesFile: Uri.file('untranslated'),
@@ -50,11 +51,10 @@ void main() {
       projectDir: fileSystem.currentDirectory,
       dependenciesDir: fileSystem.currentDirectory,
     );
-
     verify(
       mockLocalizationsGenerator.initialize(
         inputPathString: 'arb',
-        outputPathString: null,
+        outputPathString: fileSystem.path.join('lib', 'l10n/'),
         templateArbFileName: 'example.arb',
         outputFileString: 'bar',
         classNameString: 'Foo',