gen_l10n.dart tool testing (#44856)

* Add tests to gen_l10n.dart tool

* Separate out LocalizationsGenerator class to improve testability of code

* Add testing dependencies to dev/tools

* Integrate dev/tools testing to flutter CI

* Restructure dev/tools folder for testing

* Fix license headers

dev/bots/test.dart

@@ -423,6 +423,7 @@ Future<void> _runFrameworkTests() async {
     await _pubRunTest(path.join(flutterRoot, 'dev', 'bots'), tableData: bigqueryApi?.tabledata);
     await _pubRunTest(path.join(flutterRoot, 'dev', 'devicelab'), tableData: bigqueryApi?.tabledata);
     await _pubRunTest(path.join(flutterRoot, 'dev', 'snippets'), tableData: bigqueryApi?.tabledata);
+    await _pubRunTest(path.join(flutterRoot, 'dev', 'tools'), tableData: bigqueryApi?.tabledata);
     await _runFlutterTest(path.join(flutterRoot, 'dev', 'integration_tests', 'android_semantics_testing'), tableData: bigqueryApi?.tabledata);
     await _runFlutterTest(path.join(flutterRoot, 'dev', 'manual_tests'), tableData: bigqueryApi?.tabledata);
     await _runFlutterTest(path.join(flutterRoot, 'dev', 'tools', 'vitool'), tableData: bigqueryApi?.tabledata);

dev/tools/localization/bin/gen_l10n.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+import 'dart:io';
+
+import 'package:args/args.dart' as argslib;
+import 'package:file/local.dart' as local;
+import 'package:path/path.dart' as path;
+
+import '../gen_l10n.dart';
+import '../localizations_utils.dart';
+
+Future<void> main(List<String> arguments) async {
+  final argslib.ArgParser parser = argslib.ArgParser();
+  parser.addFlag(
+    'help',
+    defaultsTo: false,
+    negatable: false,
+    help: 'Print this help message.',
+  );
+  parser.addOption(
+    'arb-dir',
+    defaultsTo: path.join('lib', 'l10n'),
+    help: 'The directory where all localization files should reside. For '
+      'example, the template and translated arb files should be located here. '
+      'Also, the generated output messages Dart files for each locale and the '
+      'generated localizations classes will be created here.',
+  );
+  parser.addOption(
+    'template-arb-file',
+    defaultsTo: 'app_en.arb',
+    help: 'The template arb file that will be used as the basis for '
+      'generating the Dart localization and messages files.',
+  );
+  parser.addOption(
+    'output-localization-file',
+    defaultsTo: 'app_localizations.dart',
+    help: 'The filename for the output localization and localizations '
+      'delegate classes.',
+  );
+  parser.addOption(
+    'output-class',
+    defaultsTo: 'AppLocalizations',
+    help: 'The Dart class name to use for the output localization and '
+      'localizations delegate classes.',
+  );
+
+  final argslib.ArgResults results = parser.parse(arguments);
+  if (results['help'] == true) {
+    print(parser.usage);
+    exit(0);
+  }
+
+  final String arbPathString = results['arb-dir'];
+  final String outputFileString = results['output-localization-file'];
+  final String templateArbFileName = results['template-arb-file'];
+  final String classNameString = results['output-class'];
+
+  const local.LocalFileSystem fs = local.LocalFileSystem();
+  final LocalizationsGenerator localizationsGenerator = LocalizationsGenerator(fs);
+  try {
+    localizationsGenerator
+      ..initialize(
+        l10nDirectoryPath: arbPathString,
+        templateArbFileName: templateArbFileName,
+        outputFileString: outputFileString,
+        classNameString: classNameString,
+      )
+      ..parseArbFiles()
+      ..generateClassMethods()
+      ..generateOutputFile();
+  } on FileSystemException catch (e) {
+    exitWithError(e.message);
+  } on FormatException catch (e) {
+    exitWithError(e.message);
+  } on L10nException catch (e) {
+    exitWithError(e.message);
+  }
+
+  final ProcessResult pubGetResult = await Process.run('flutter', <String>['pub', 'get']);
+  if (pubGetResult.exitCode != 0) {
+    stderr.write(pubGetResult.stderr);
+    exit(1);
+  }
+
+  final ProcessResult generateFromArbResult = await Process.run('flutter', <String>[
+    'pub',
+    'run',
+    'intl_translation:generate_from_arb',
+    '--output-dir=${localizationsGenerator.l10nDirectory.path}',
+    '--no-use-deferred-loading',
+    localizationsGenerator.outputFile.path,
+    ...localizationsGenerator.arbFilenames,
+  ]);
+  if (generateFromArbResult.exitCode != 0) {
+    stderr.write(generateFromArbResult.stderr);
+    exit(1);
+  }
+}

dev/tools/localization/gen_l10n.dart

@@ -2,11 +2,11 @@
 // 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:convert';
 import 'dart:io';
 
-import 'package:args/args.dart' as argslib;
+import 'package:file/file.dart' as file;
+import 'package:meta/meta.dart';
 import 'package:path/path.dart' as path;
 
 import 'localizations_utils.dart';
@@ -149,10 +149,6 @@ const String pluralMethodTemplate = '''
   }
 ''';
 
-int sortFilesByPath (FileSystemEntity a, FileSystemEntity b) {
-  return a.path.compareTo(b.path);
-}
-
 List<String> genMethodParameters(Map<String, dynamic> bundle, String key, String type) {
   final Map<String, dynamic> attributesMap = bundle['@$key'] as Map<String, dynamic>;
   if (attributesMap != null && attributesMap.containsKey('placeholders')) {
@@ -193,7 +189,7 @@ String genSimpleMethod(Map<String, dynamic> bundle, String key) {
 
   final Map<String, dynamic> attributesMap = bundle['@$key'] as Map<String, dynamic>;
   if (attributesMap == null)
-    exitWithError(
+    throw L10nException(
       'Resource attribute "@$key" was not found. Please ensure that each '
       'resource id has a corresponding resource attribute.'
     );
@@ -238,7 +234,7 @@ String genPluralMethod(Map<String, dynamic> bundle, String key) {
     ...genIntlMethodArgs(bundle, key),
   ];
 
-  for(String pluralKey in pluralIds.keys) {
+  for (String pluralKey in pluralIds.keys) {
     final RegExp expRE = RegExp('($pluralKey){([^}]+)}');
     final RegExpMatch match = expRE.firstMatch(message);
     if (match != null && match.groupCount == 2) {
@@ -289,6 +285,19 @@ bool _isValidClassName(String className) {
   return true;
 }
 
+bool _isNotReadable(FileStat fileStat) {
+  final String rawStatString = fileStat.modeString();
+  // Removes potential prepended permission bits, such as '(suid)' and '(guid)'.
+  final String statString = rawStatString.substring(rawStatString.length - 9);
+  return !(statString[0] == 'r' || statString[3] == 'r' || statString[6] == 'r');
+}
+bool _isNotWritable(FileStat fileStat) {
+  final String rawStatString = fileStat.modeString();
+  // Removes potential prepended permission bits, such as '(suid)' and '(guid)'.
+  final String statString = rawStatString.substring(rawStatString.length - 9);
+  return !(statString[1] == 'w' || statString[4] == 'w' || statString[7] == 'w');
+}
+
 bool _isValidGetterAndMethodName(String name) {
   // Dart getter and method name cannot contain non-alphanumeric symbols
   if (name.contains(RegExp(r'[^a-zA-Z\d]')))
@@ -302,184 +311,250 @@ bool _isValidGetterAndMethodName(String name) {
   return true;
 }
 
-bool _isDirectoryReadableAndWritable(String statString) {
-  if (statString[0] == '-' || statString[1] == '-')
-    return false;
-  return true;
-}
+/// The localizations generation class used to generate the localizations
+/// classes, as well as all pertinent Dart files required to internationalize a
+/// Flutter application.
+class LocalizationsGenerator {
+  /// Creates an instance of the localizations generator class.
+  ///
+  /// It takes in a [FileSystem] representation that the class will act upon.
+  LocalizationsGenerator(this._fs);
 
-String _importFilePath(String path, String fileName) {
-  final String replaceLib = path.replaceAll('lib/', '');
-  return '$replaceLib/$fileName';
-}
+  static RegExp arbFilenameLocaleRE = RegExp(r'^[^_]*_(\w+)\.arb$');
+  static RegExp arbFilenameRE = RegExp(r'(\w+)\.arb$');
+  static RegExp pluralValueRE = RegExp(r'^\s*\{[\w\s,]*,\s*plural\s*,');
 
-Future<void> main(List<String> arguments) async {
-  final argslib.ArgParser parser = argslib.ArgParser();
-  parser.addFlag(
-    'help',
-    defaultsTo: false,
-    negatable: false,
-    help: 'Print this help message.',
-  );
-  parser.addOption(
-    'arb-dir',
-    defaultsTo: path.join('lib', 'l10n'),
-    help: 'The directory where all localization files should reside. For '
-      'example, the template and translated arb files should be located here. '
-      'Also, the generated output messages Dart files for each locale and the '
-      'generated localizations classes will be created here.',
-  );
-  parser.addOption(
-    'template-arb-file',
-    defaultsTo: 'app_en.arb',
-    help: 'The template arb file that will be used as the basis for '
-      'generating the Dart localization and messages files.',
-  );
-  parser.addOption(
-    'output-localization-file',
-    defaultsTo: 'app_localizations.dart',
-    help: 'The filename for the output localization and localizations '
-      'delegate classes.',
-  );
-  parser.addOption(
-    'output-class',
-    defaultsTo: 'AppLocalizations',
-    help: 'The Dart class name to use for the output localization and '
-      'localizations delegate classes.',
-  );
+  final file.FileSystem _fs;
 
-  final argslib.ArgResults results = parser.parse(arguments);
-  if (results['help'] == true) {
-    print(parser.usage);
-    exit(0);
-  }
+  /// The reference to the project's l10n directory.
+  ///
+  /// It is assumed that all input files (e.g. [templateArbFile], arb files
+  /// for translated messages) and output files (e.g. The localizations
+  /// [outputFile], `messages_<locale>.dart` and `messages_all.dart`)
+  /// will reside here.
+  ///
+  /// This directory is specified with the [initialize] method.
+  Directory l10nDirectory;
+
+  /// The input arb file which defines all of the messages that will be
+  /// exported by the generated class that's written to [outputFile].
+  ///
+  /// This file is specified with the [initialize] method.
+  File templateArbFile;
+
+  /// The file to write the generated localizations and localizations delegate
+  /// classes to.
+  ///
+  /// This file is specified with the [initialize] method.
+  File outputFile;
+
+  /// The class name to be used for the localizations class in [outputFile].
+  ///
+  /// For example, if 'AppLocalizations' is passed in, a class named
+  /// AppLocalizations will be used for localized message lookups.
+  ///
+  /// The class name is specified with the [initialize] method.
+  String get className => _className;
+  String _className;
+  /// Sets the [className] for the localizations and localizations delegate
+  /// classes.
+
+  /// The list of all arb files in [l10nDirectory].
+  final List<String> arbFilenames = <String>[];
 
-  final String arbPathString = results['arb-dir'] as String;
-  final String outputFileString = results['output-localization-file'] as String;
+  /// The supported language codes as found in the arb files located in
+  /// [l10nDirectory].
+  final Set<String> supportedLanguageCodes = <String>{};
+
+  /// The supported locales as found in the arb files located in
+  /// [l10nDirectory].
+  final Set<LocaleInfo> supportedLocales = <LocaleInfo>{};
 
-  final Directory l10nDirectory = Directory(arbPathString);
-  final File templateArbFile = File(path.join(l10nDirectory.path, results['template-arb-file'] as String));
-  final File outputFile = File(path.join(l10nDirectory.path, outputFileString));
-  final String stringsClassName = results['output-class'] as String;
+  /// The class methods that will be generated in the localizations class
+  /// based on messages found in the template arb file.
+  final List<String> classMethods = <String>[];
 
+  /// Initializes [l10nDirectory], [templateArbFile], [outputFile] and [className].
+  ///
+  /// Throws an [L10nException] when a provided configuration is not allowed
+  /// by [LocalizationsGenerator].
+  ///
+  /// Throws a [FileSystemException] when a file operation necessary for setting
+  /// up the [LocalizationsGenerator] cannot be completed.
+  void initialize({
+    String l10nDirectoryPath,
+    String templateArbFileName,
+    String outputFileString,
+    String classNameString,
+  }) {
+    setL10nDirectory(l10nDirectoryPath);
+    setTemplateArbFile(templateArbFileName);
+    setOutputFile(outputFileString);
+    className = classNameString;
+  }
+
+  /// Sets the reference [Directory] for [l10nDirectory].
+  @visibleForTesting
+  void setL10nDirectory(String arbPathString) {
+    if (arbPathString == null)
+      throw L10nException('arbPathString argument cannot be null');
+    l10nDirectory = _fs.directory(arbPathString);
     if (!l10nDirectory.existsSync())
-    exitWithError(
+      throw FileSystemException(
         "The 'arb-dir' directory, $l10nDirectory, does not exist.\n"
         'Make sure that the correct path was provided.'
       );
-  final String l10nDirectoryStatModeString = l10nDirectory.statSync().modeString();
-  if (!_isDirectoryReadableAndWritable(l10nDirectoryStatModeString))
-    exitWithError(
+
+    final FileStat fileStat = l10nDirectory.statSync();
+    if (_isNotReadable(fileStat) || _isNotWritable(fileStat))
+      throw FileSystemException(
         "The 'arb-dir' directory, $l10nDirectory, doesn't allow reading and writing.\n"
         'Please ensure that the user has read and write permissions.'
       );
+  }
+
+  /// Sets the reference [File] for [templateArbFile].
+  @visibleForTesting
+  void setTemplateArbFile(String templateArbFileName) {
+    if (templateArbFileName == null)
+      throw L10nException('templateArbFileName argument cannot be null');
+    if (l10nDirectory == null)
+      throw L10nException('l10nDirectory cannot be null when setting template arb file');
+
+    templateArbFile = _fs.file(path.join(l10nDirectory.path, templateArbFileName));
     final String templateArbFileStatModeString = templateArbFile.statSync().modeString();
-  if (templateArbFileStatModeString[0] == '-')
-    exitWithError(
+    if (templateArbFileStatModeString[0] == '-' && templateArbFileStatModeString[3] == '-')
+      throw FileSystemException(
         "The 'template-arb-file', $templateArbFile, is not readable.\n"
         'Please ensure that the user has read permissions.'
       );
-  if (!_isValidClassName(stringsClassName))
-    exitWithError(
-      "The 'output-class', $stringsClassName, is not valid Dart class name.\n"
-    );
-
-  final List<String> arbFilenames = <String>[];
-  final Set<String> supportedLanguageCodes = <String>{};
-  final Set<LocaleInfo> supportedLocales = <LocaleInfo>{};
+  }
 
-  for (FileSystemEntity entity in l10nDirectory.listSync().toList()..sort(sortFilesByPath)) {
-    final String entityPath = entity.path;
+  /// Sets the reference [File] for the localizations delegate [outputFile].
+  @visibleForTesting
+  void setOutputFile(String outputFileString) {
+    if (outputFileString == null)
+      throw L10nException('outputFileString argument cannot be null');
+    outputFile = _fs.file(path.join(l10nDirectory.path, outputFileString));
+  }
 
-    if (FileSystemEntity.isFileSync(entityPath)) {
-      final RegExp arbFilenameRE = RegExp(r'(\w+)\.arb$');
-      if (arbFilenameRE.hasMatch(entityPath)) {
-        final File arbFile = File(entityPath);
-        final Map<String, dynamic> arbContents = json.decode(arbFile.readAsStringSync()) as Map<String, dynamic>;
-        String localeString = arbContents['@@locale'] as String;
+  @visibleForTesting
+  set className(String classNameString) {
+    if (classNameString == null)
+      throw L10nException('classNameString argument cannot be null');
+    if (!_isValidClassName(classNameString))
+      throw L10nException(
+        "The 'output-class', $classNameString, is not a valid Dart class name.\n"
+      );
+    _className = classNameString;
+  }
 
+  /// Scans [l10nDirectory] for arb files and parses them for language and locale
+  /// information.
+  void parseArbFiles() {
+    final List<File> fileSystemEntityList = l10nDirectory
+      .listSync()
+      .whereType<File>()
+      .toList();
+    final List<LocaleInfo> localeInfoList = <LocaleInfo>[];
+
+    for (File file in fileSystemEntityList) {
+      final String filePath = file.path;
+      if (arbFilenameRE.hasMatch(filePath)) {
+        final Map<String, dynamic> arbContents = json.decode(file.readAsStringSync());
+        String localeString = arbContents['@@locale'];
         if (localeString == null) {
-          final RegExp arbFilenameLocaleRE = RegExp(r'^[^_]*_(\w+)\.arb$');
-          final RegExpMatch arbFileMatch = arbFilenameLocaleRE.firstMatch(entityPath);
+          final RegExpMatch arbFileMatch = arbFilenameLocaleRE.firstMatch(filePath);
           if (arbFileMatch == null) {
-            exitWithError(
+            throw L10nException(
               "The following .arb file's locale could not be determined: \n"
-              '$entityPath \n'
+              '$filePath \n'
               "Make sure that the locale is specified in the '@@locale' "
-              'property or as part of the filename (ie. file_en.arb)'
+              'property or as part of the filename (e.g. file_en.arb)'
             );
           }
 
-          localeString = arbFilenameLocaleRE.firstMatch(entityPath)[1];
+          localeString = arbFilenameLocaleRE.firstMatch(filePath)[1];
         }
 
-        arbFilenames.add(entityPath);
+        arbFilenames.add(filePath);
         final LocaleInfo localeInfo = LocaleInfo.fromString(localeString);
-        if (supportedLocales.contains(localeInfo))
-          exitWithError(
+        if (localeInfoList.contains(localeInfo))
+          throw L10nException(
             'Multiple arb files with the same locale detected. \n'
             'Ensure that there is exactly one arb file for each locale.'
           );
-        supportedLocales.add(localeInfo);
-        supportedLanguageCodes.add('\'${localeInfo.languageCode}\'');
-      }
+        localeInfoList.add(localeInfo);
       }
     }
 
-  final List<String> classMethods = <String>[];
+    localeInfoList.sort();
+    supportedLocales.addAll(localeInfoList);
+    supportedLanguageCodes.addAll(localeInfoList.map((LocaleInfo localeInfo) {
+      return '\'${localeInfo.languageCode}\'';
+    }));
+  }
 
+  /// Generates the methods for the localizations class.
+  ///
+  /// The method parses [templateArbFile] and uses its resource ids as the
+  /// Dart method and getter names. It then uses each resource id's
+  /// corresponding resource value to figure out how to define these getters.
+  ///
+  /// For example, a message with plurals will be handled differently from
+  /// a simple, singular message.
+  ///
+  /// Throws an [L10nException] when a provided configuration is not allowed
+  /// by [LocalizationsGenerator].
+  ///
+  /// Throws a [FileSystemException] when a file operation necessary for setting
+  /// up the [LocalizationsGenerator] cannot be completed.
+  ///
+  /// Throws a [FormatException] when parsing the arb file is unsuccessful.
+  void generateClassMethods() {
     Map<String, dynamic> bundle;
     try {
-    bundle = json.decode(templateArbFile.readAsStringSync()) as Map<String, dynamic>;
+      bundle = json.decode(templateArbFile.readAsStringSync());
     } on FileSystemException catch (e) {
-    exitWithError('Unable to read input arb file: $e');
+      throw FileSystemException('Unable to read input arb file: $e');
     } on FormatException catch (e) {
-    exitWithError('Unable to parse arb file: $e');
+      throw FormatException('Unable to parse arb file: $e');
     }
 
-  final RegExp pluralValueRE = RegExp(r'^\s*\{[\w\s,]*,\s*plural\s*,');
-
-  for (String key in bundle.keys.toList()..sort()) {
+    final List<String> sortedArbKeys = bundle.keys.toList()..sort();
+    for (String key in sortedArbKeys) {
       if (key.startsWith('@'))
         continue;
       if (!_isValidGetterAndMethodName(key))
-      exitWithError(
+        throw L10nException(
           'Invalid key format: $key \n It has to be in camel case, cannot start '
           'with a number, and cannot contain non-alphanumeric characters.'
         );
-    if (pluralValueRE.hasMatch(bundle[key] as String))
+      if (pluralValueRE.hasMatch(bundle[key]))
         classMethods.add(genPluralMethod(bundle, key));
       else
         classMethods.add(genSimpleMethod(bundle, key));
     }
+  }
 
+  /// Generates a file that contains the localizations class and the
+  /// LocalizationsDelegate class.
+  void generateOutputFile() {
+    final String directory = path.basename(l10nDirectory.path);
+    final String outputFileName = path.basename(outputFile.path);
     outputFile.writeAsStringSync(
       defaultFileTemplate
-      .replaceAll('@className', stringsClassName)
+        .replaceAll('@className', className)
         .replaceAll('@classMethods', classMethods.join('\n'))
-      .replaceAll('@importFile', _importFilePath(arbPathString, outputFileString))
+        .replaceAll('@importFile', '$directory/$outputFileName')
         .replaceAll('@supportedLocales', genSupportedLocaleProperty(supportedLocales))
         .replaceAll('@supportedLanguageCodes', supportedLanguageCodes.toList().join(', '))
     );
-
-  final ProcessResult pubGetResult = await Process.run('flutter', <String>['pub', 'get']);
-  if (pubGetResult.exitCode != 0) {
-    stderr.write(pubGetResult.stderr);
-    exit(1);
   }
+}
 
-  final ProcessResult generateFromArbResult = await Process.run('flutter', <String>[
-    'pub',
-    'pub',
-    'run',
-    'intl_translation:generate_from_arb',
-    '--output-dir=${l10nDirectory.path}',
-    '--no-use-deferred-loading',
-    outputFile.path,
-    ...arbFilenames,
-  ]);
-  if (generateFromArbResult.exitCode != 0) {
-    stderr.write(generateFromArbResult.stderr);
-    exit(1);
-  }
+class L10nException implements Exception {
+  L10nException(this.message);
+
+  final String message;
 }

dev/tools/pubspec.yaml

@@ -29,12 +29,44 @@ dependencies:
   typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
 dev_dependencies:
+  test: 1.9.4
   test_api: 0.2.11
   mockito: 4.1.1
 
+  analyzer: 0.38.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   boolean_selector: 1.0.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  coverage: 0.13.3+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  csslib: 0.16.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  front_end: 0.1.27 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  glob: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  html: 0.14.0+3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  http_multi_server: 2.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  io: 0.3.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  js: 0.6.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  kernel: 0.3.27 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  logging: 0.11.3+2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   matcher: 0.12.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  mime: 0.9.6+3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  multi_server_socket: 1.0.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  node_interop: 1.0.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  node_io: 1.0.1+2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  node_preamble: 1.4.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  package_config: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  package_resolver: 1.0.10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pool: 1.4.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pub_semver: 1.4.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf: 0.7.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_packages_handler: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_static: 0.2.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_web_socket: 0.2.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  source_map_stack_trace: 1.1.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  source_maps: 0.10.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   stack_trace: 1.9.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   stream_channel: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.15 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  vm_service: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  watcher: 0.9.7+13 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  web_socket_channel: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  yaml: 2.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
-# PUBSPEC CHECKSUM: a9e9
+# PUBSPEC CHECKSUM: 3590

dev/tools/test/common.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:io';
+
+import 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
+import 'package:test/test.dart' as test_package show TypeMatcher;
+
+export 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
+
+// Defines a 'package:test' shim.
+// TODO(ianh): Remove this file once https://github.com/dart-lang/matcher/issues/98 is fixed
+
+/// A matcher that compares the type of the actual value to the type argument T.
+Matcher isInstanceOf<T>() => test_package.TypeMatcher<T>();
+
+void tryToDelete(Directory directory) {
+  // This should not be necessary, but it turns out that
+  // on Windows it's common for deletions to fail due to
+  // bogus (we think) "access denied" errors.
+  try {
+    directory.deleteSync(recursive: true);
+  } on FileSystemException catch (error) {
+    print('Failed to delete ${directory.path}: $error');
+  }
+}

dev/tools/test/localization/gen_l10n_test.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:io';
+
+import 'package:file/file.dart';
+import 'package:file/memory.dart';
+import 'package:path/path.dart' as path;
+
+import '../../localization/gen_l10n.dart';
+import '../../localization/localizations_utils.dart';
+
+import '../common.dart';
+
+final String defaultArbPathString = path.join('lib', 'l10n');
+const String defaultTemplateArbFileName = 'app_en_US.arb';
+const String defaultOutputFileString = 'output-localization-file';
+const String defaultClassNameString = 'AppLocalizations';
+const String singleMessageArbFileString = '''{
+  "title": "Stocks",
+  "@title": {
+    "description": "Title for the Stocks application"
+  }
+}''';
+
+const String esArbFileName = 'app_es.arb';
+const String singleEsMessageArbFileString = '''{
+  "title": "Acciones"
+}''';
+
+void _standardFlutterDirectoryL10nSetup(FileSystem fs) {
+  final Directory l10nDirectory = fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+    ..createSync(recursive: true);
+  l10nDirectory.childFile(defaultTemplateArbFileName)
+    .writeAsStringSync(singleMessageArbFileString);
+  l10nDirectory.childFile(esArbFileName)
+    .writeAsStringSync(singleEsMessageArbFileString);
+}
+
+void main() {
+  MemoryFileSystem fs;
+
+  setUp(() {
+    fs = MemoryFileSystem(
+      style: Platform.isWindows ? FileSystemStyle.windows : FileSystemStyle.posix
+    );
+  });
+
+  group('LocalizationsGenerator setters:', () {
+    test('happy path', () {
+      _standardFlutterDirectoryL10nSetup(fs);
+      expect(() {
+        final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: defaultTemplateArbFileName,
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+      }, returnsNormally);
+    });
+
+    test('setL10nDirectory fails if the directory does not exist', () {
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.setL10nDirectory('lib');
+      } on FileSystemException catch (e) {
+        expect(e.message, contains('Make sure that the correct path was provided'));
+        return;
+      }
+
+      fail(
+        'Attempting to set LocalizationsGenerator.setL10nDirectory should fail if the '
+        'directory does not exist.'
+      );
+    });
+
+    test('setL10nDirectory fails if input string is null', () {
+      _standardFlutterDirectoryL10nSetup(fs);
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.setL10nDirectory(null);
+      } on L10nException catch (e) {
+        expect(e.message, contains('cannot be null'));
+        return;
+      }
+
+      fail(
+        'Attempting to set LocalizationsGenerator.setL10nDirectory should fail if the '
+        'the input string is null.'
+      );
+    });
+
+    test('setTemplateArbFile fails if l10nDirectory is null', () {
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.setTemplateArbFile(defaultTemplateArbFileName);
+      } on L10nException catch (e) {
+        expect(e.message, contains('cannot be null'));
+        return;
+      }
+
+      fail(
+        'Attempting to set LocalizationsGenerator.setTemplateArbFile should fail if the '
+        'the l10nDirectory is null.'
+      );
+    });
+
+    test('setTemplateArbFile fails if templateArbFileName is null', () {
+      _standardFlutterDirectoryL10nSetup(fs);
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.setTemplateArbFile(null);
+      } on L10nException catch (e) {
+        expect(e.message, contains('cannot be null'));
+        return;
+      }
+
+      fail(
+        'Attempting to set LocalizationsGenerator.setTemplateArbFile should fail if the '
+        'the l10nDirectory is null.'
+      );
+    });
+
+    test('setTemplateArbFile fails if input string is null', () {
+      _standardFlutterDirectoryL10nSetup(fs);
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.setTemplateArbFile(null);
+      } on L10nException catch (e) {
+        expect(e.message, contains('cannot be null'));
+        return;
+      }
+
+      fail(
+        'Attempting to set LocalizationsGenerator.setTemplateArbFile should fail if the '
+        'the input string is null.'
+      );
+    });
+
+    test('setOutputFile fails if input string is null', () {
+      _standardFlutterDirectoryL10nSetup(fs);
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.setOutputFile(null);
+      } on L10nException catch (e) {
+        expect(e.message, contains('cannot be null'));
+        return;
+      }
+
+      fail(
+        'Attempting to set LocalizationsGenerator.setOutputFile should fail if the '
+        'the input string is null.'
+      );
+    });
+
+    test('setting className fails if input string is null', () {
+      _standardFlutterDirectoryL10nSetup(fs);
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.className = null;
+      } on L10nException catch (e) {
+        expect(e.message, contains('cannot be null'));
+        return;
+      }
+
+      fail(
+        'Attempting to set LocalizationsGenerator.className should fail if the '
+        'the input string is null.'
+      );
+    });
+
+    group('className should only take valid Dart class names:', () {
+      LocalizationsGenerator generator;
+      setUp(() {
+        _standardFlutterDirectoryL10nSetup(fs);
+        generator = LocalizationsGenerator(fs);
+        try {
+          generator.setL10nDirectory(defaultArbPathString);
+          generator.setTemplateArbFile(defaultTemplateArbFileName);
+          generator.setOutputFile(defaultOutputFileString);
+        } on L10nException catch (e) {
+          throw TestFailure('Unexpected failure during test setup: ${e.message}');
+        }
+      });
+
+      test('fails on string with spaces', () {
+        try {
+          generator.className = 'String with spaces';
+        } on L10nException catch (e) {
+          expect(e.message, contains('is not a valid Dart class name'));
+          return;
+        }
+        fail(
+          'Attempting to set LocalizationsGenerator.className should fail if the '
+          'the input string is not a valid Dart class name.'
+        );
+      });
+
+      test('fails on non-alphanumeric symbols', () {
+        try {
+          generator.className = 'TestClass@123';
+        } on L10nException catch (e) {
+          expect(e.message, contains('is not a valid Dart class name'));
+          return;
+        }
+        fail(
+          'Attempting to set LocalizationsGenerator.className should fail if the '
+          'the input string is not a valid Dart class name.'
+        );
+      });
+
+      test('fails on camel-case', () {
+        try {
+          generator.className = 'camelCaseClassName';
+        } on L10nException catch (e) {
+          expect(e.message, contains('is not a valid Dart class name'));
+          return;
+        }
+        fail(
+          'Attempting to set LocalizationsGenerator.className should fail if the '
+          'the input string is not a valid Dart class name.'
+        );
+      });
+
+      test('fails when starting with a number', () {
+        try {
+          generator.className = '123ClassName';
+        } on L10nException catch (e) {
+          expect(e.message, contains('is not a valid Dart class name'));
+          return;
+        }
+        fail(
+          'Attempting to set LocalizationsGenerator.className should fail if the '
+          'the input string is not a valid Dart class name.'
+        );
+      });
+    });
+  });
+
+  group('LocalizationsGenerator.parseArbFiles:', () {
+    test('correctly initializes supportedLocales and supportedLanguageCodes properties', () {
+      _standardFlutterDirectoryL10nSetup(fs);
+
+      LocalizationsGenerator generator;
+      try {
+        generator = LocalizationsGenerator(fs);
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: defaultTemplateArbFileName,
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+        generator.parseArbFiles();
+      } on L10nException catch (e) {
+        fail('Setting language and locales should not fail: \n$e');
+      }
+
+      expect(generator.supportedLocales.contains(LocaleInfo.fromString('en_US')), true);
+      expect(generator.supportedLocales.contains(LocaleInfo.fromString('es')), true);
+    });
+
+    test('correctly parses @@locale property in arb file', () {
+      const String arbFileWithEnLocale = '''{
+  "@@locale": "en",
+  "title": "Stocks",
+  "@title": {
+    "description": "Title for the Stocks application"
+  }
+}''';
+
+      const String arbFileWithZhLocale = '''{
+  "@@locale": "zh",
+  "title": "Stocks",
+  "@title": {
+    "description": "Title for the Stocks application"
+  }
+}''';
+
+      final Directory l10nDirectory = fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+        ..createSync(recursive: true);
+      l10nDirectory.childFile('first_file.arb')
+        .writeAsStringSync(arbFileWithEnLocale);
+      l10nDirectory.childFile('second_file.arb')
+        .writeAsStringSync(arbFileWithZhLocale);
+
+      LocalizationsGenerator generator;
+      try {
+        generator = LocalizationsGenerator(fs);
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: 'first_file.arb',
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+        generator.parseArbFiles();
+      } on L10nException catch (e) {
+        fail('Setting language and locales should not fail: \n$e');
+      }
+
+      expect(generator.supportedLocales.contains(LocaleInfo.fromString('en')), true);
+      expect(generator.supportedLocales.contains(LocaleInfo.fromString('zh')), true);
+    });
+
+    test('correctly parses @@locale property in arb file', () {
+      const String arbFileWithEnLocale = '''{
+  "@@locale": "en",
+  "title": "Stocks",
+  "@title": {
+    "description": "Title for the Stocks application"
+  }
+}''';
+
+      const String arbFileWithZhLocale = '''{
+  "@@locale": "zh",
+  "title": "Stocks",
+  "@title": {
+    "description": "Title for the Stocks application"
+  }
+}''';
+
+      final Directory l10nDirectory = fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+        ..createSync(recursive: true);
+      l10nDirectory.childFile('app_es.arb')
+        .writeAsStringSync(arbFileWithEnLocale);
+      l10nDirectory.childFile('app_am.arb')
+        .writeAsStringSync(arbFileWithZhLocale);
+
+      LocalizationsGenerator generator;
+      try {
+        generator = LocalizationsGenerator(fs);
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: 'app_es.arb',
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+        generator.parseArbFiles();
+      } on L10nException catch (e) {
+        fail('Setting language and locales should not fail: \n$e');
+      }
+
+      // @@locale property should hold higher priority
+      expect(generator.supportedLocales.contains(LocaleInfo.fromString('en')), true);
+      expect(generator.supportedLocales.contains(LocaleInfo.fromString('zh')), true);
+      // filename should not be used since @@locale is specified
+      expect(generator.supportedLocales.contains(LocaleInfo.fromString('es')), false);
+      expect(generator.supportedLocales.contains(LocaleInfo.fromString('am')), false);
+    });
+
+    test('throws when arb file\'s locale could not be determined', () {
+      fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+        ..createSync(recursive: true)
+        ..childFile('app.arb')
+        .writeAsStringSync(singleMessageArbFileString);
+      try {
+        final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: 'app.arb',
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+        generator.parseArbFiles();
+      } on L10nException catch (e) {
+        expect(e.message, contains('locale could not be determined'));
+        return;
+      }
+      fail(
+        'Since locale is not specified, setting languages and locales '
+        'should fail'
+      );
+    });
+    test('throws when the same locale is detected more than once', () {
+      const String secondMessageArbFileString = '''{
+  "market": "MARKET",
+  "@market": {
+    "description": "Label for the Market tab"
+  }
+}''';
+
+      final Directory l10nDirectory = fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+        ..createSync(recursive: true);
+      l10nDirectory.childFile('app_en.arb')
+        .writeAsStringSync(singleMessageArbFileString);
+      l10nDirectory.childFile('app2_en.arb')
+        .writeAsStringSync(secondMessageArbFileString);
+
+      try {
+        final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: 'app_en.arb',
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+        generator.parseArbFiles();
+      } on L10nException catch (e) {
+        expect(e.message, contains('Multiple arb files with the same locale detected'));
+        return;
+      }
+
+      fail(
+        'Since en locale is specified twice, setting languages and locales '
+        'should fail'
+      );
+    });
+  });
+
+  group('LocalizationsGenerator.generateClassMethods:', () {
+    test('correctly generates a simple message with getter:', () {
+      _standardFlutterDirectoryL10nSetup(fs);
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: defaultTemplateArbFileName,
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+        generator.parseArbFiles();
+        generator.generateClassMethods();
+      } on Exception catch (e) {
+        fail('Parsing template arb file should succeed: \n$e');
+      }
+
+      expect(generator.classMethods, isNotEmpty);
+      expect(
+        generator.classMethods.first,
+        '''  String get title {
+    return Intl.message(
+      r'Stocks',
+      locale: _localeName,
+      name: 'title',
+      desc: r'Title for the Stocks application'
+    );
+  }
+''');
+    });
+
+    test('correctly generates simple message method with parameters', () {
+      const String singleSimpleMessageWithPlaceholderArbFileString = '''{
+  "itemNumber": "Item {value}",
+  "@itemNumber": {
+    "description": "Item placement in list.",
+    "placeholders": {
+      "value": {
+        "example": "1"
+      }
+    }
+  }
+}''';
+      final Directory l10nDirectory = fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+        ..createSync(recursive: true);
+      l10nDirectory.childFile(defaultTemplateArbFileName)
+        .writeAsStringSync(singleSimpleMessageWithPlaceholderArbFileString);
+
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: defaultTemplateArbFileName,
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+        generator.parseArbFiles();
+        generator.generateClassMethods();
+      } on Exception catch (e) {
+        fail('Parsing template arb file should succeed: \n$e');
+      }
+
+      expect(generator.classMethods, isNotEmpty);
+      expect(
+        generator.classMethods.first,
+        '''  String itemNumber(Object value) {
+    return Intl.message(
+      r\'Item \$value\',
+      locale: _localeName,
+      name: 'itemNumber',
+      desc: r\'Item placement in list.\',
+      args: <Object>[value]
+    );
+  }
+''');
+    });
+
+    test('correctly generates a plural message:', () {
+      const String singlePluralMessageArbFileString = '''{
+  "helloWorlds": "{count,plural, =0{Hello}=1{Hello World}=2{Hello two worlds}few{Hello {count} worlds}many{Hello all {count} worlds}other{Hello other {count} worlds}}",
+  "@helloWorlds": {
+    "placeholders": {
+      "count": {}
+    }
+  }
+}''';
+      final Directory l10nDirectory = fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+        ..createSync(recursive: true);
+      l10nDirectory.childFile(defaultTemplateArbFileName)
+        .writeAsStringSync(singlePluralMessageArbFileString);
+
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: defaultTemplateArbFileName,
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+        generator.parseArbFiles();
+        generator.generateClassMethods();
+      } on Exception catch (e) {
+        fail('Parsing template arb file should succeed: \n$e');
+      }
+
+      expect(generator.classMethods, isNotEmpty);
+      expect(
+        generator.classMethods.first,
+        '''  String helloWorlds(int count) {
+    return Intl.plural(
+      count,
+      locale: _localeName,
+      name: 'helloWorlds',
+      args: <Object>[count],
+      zero: 'Hello',
+      one: 'Hello World',
+      two: 'Hello two worlds',
+      few: 'Hello \$count worlds',
+      many: 'Hello all \$count worlds',
+      other: 'Hello other \$count worlds'
+    );
+  }
+'''
+      );
+    });
+
+    test('should throw when failing to parse the arb file:', () {
+      const String arbFileWithTrailingComma = '''{
+  "title": "Stocks",
+  "@title": {
+    "description": "Title for the Stocks application"
+  },
+}''';
+      final Directory l10nDirectory = fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+        ..createSync(recursive: true);
+      l10nDirectory.childFile(defaultTemplateArbFileName)
+        .writeAsStringSync(arbFileWithTrailingComma);
+
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: defaultTemplateArbFileName,
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+        generator.parseArbFiles();
+        generator.generateClassMethods();
+      } on FormatException catch (e) {
+        expect(e.message, contains('Unexpected character'));
+        return;
+      }
+
+      fail(
+        'should fail with a FormatException due to a trailing comma in the '
+        'arb file.'
+      );
+    });
+
+    test('should throw when resource is is missing resource attribute:', () {
+      const String arbFileWithMissingResourceAttribute = '''{
+  "title": "Stocks"
+}''';
+      final Directory l10nDirectory = fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+        ..createSync(recursive: true);
+      l10nDirectory.childFile(defaultTemplateArbFileName)
+        .writeAsStringSync(arbFileWithMissingResourceAttribute);
+
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: defaultTemplateArbFileName,
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+        generator.parseArbFiles();
+        generator.generateClassMethods();
+      } on L10nException catch (e) {
+        expect(e.message, contains('Resource attribute "@title" was not found'));
+        return;
+      }
+
+      fail(
+        'should fail with a FormatException due to a trailing comma in the '
+        'arb file.'
+      );
+    });
+
+    group('checks for method/getter formatting', () {
+      test('cannot contain non-alphanumeric symbols', () {
+        const String nonAlphaNumericArbFile = '''{
+    "title!!": "Stocks",
+    "@title!!": {
+      "description": "Title for the Stocks application"
+    }
+  }''';
+        final Directory l10nDirectory = fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+          ..createSync(recursive: true);
+        l10nDirectory.childFile(defaultTemplateArbFileName)
+          .writeAsStringSync(nonAlphaNumericArbFile);
+
+        final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+        try {
+          generator.initialize(
+            l10nDirectoryPath: defaultArbPathString,
+            templateArbFileName: defaultTemplateArbFileName,
+            outputFileString: defaultOutputFileString,
+            classNameString: defaultClassNameString,
+          );
+          generator.parseArbFiles();
+          generator.generateClassMethods();
+        } on L10nException catch (e) {
+          expect(e.message, contains('Invalid key format'));
+          return;
+        }
+
+        fail('should fail due to non-alphanumeric character.');
+      });
+
+      test('must start with lowercase character', () {
+        const String nonAlphaNumericArbFile = '''{
+    "Title": "Stocks",
+    "@Title": {
+      "description": "Title for the Stocks application"
+    }
+  }''';
+        final Directory l10nDirectory = fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+          ..createSync(recursive: true);
+        l10nDirectory.childFile(defaultTemplateArbFileName)
+          .writeAsStringSync(nonAlphaNumericArbFile);
+
+        final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+        try {
+          generator.initialize(
+            l10nDirectoryPath: defaultArbPathString,
+            templateArbFileName: defaultTemplateArbFileName,
+            outputFileString: defaultOutputFileString,
+            classNameString: defaultClassNameString,
+          );
+          generator.parseArbFiles();
+          generator.generateClassMethods();
+        } on L10nException catch (e) {
+          expect(e.message, contains('Invalid key format'));
+          return;
+        }
+
+        fail('should fail since key starts with a non-lowercase.');
+      });
+
+      test('cannot start with a number', () {
+        const String nonAlphaNumericArbFile = '''{
+    "123title": "Stocks",
+    "@123title": {
+      "description": "Title for the Stocks application"
+    }
+  }''';
+        final Directory l10nDirectory = fs.currentDirectory.childDirectory('lib').childDirectory('l10n')
+          ..createSync(recursive: true);
+        l10nDirectory.childFile(defaultTemplateArbFileName)
+          .writeAsStringSync(nonAlphaNumericArbFile);
+
+        final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+        try {
+          generator.initialize(
+            l10nDirectoryPath: defaultArbPathString,
+            templateArbFileName: defaultTemplateArbFileName,
+            outputFileString: defaultOutputFileString,
+            classNameString: defaultClassNameString,
+          );
+          generator.parseArbFiles();
+          generator.generateClassMethods();
+        } on L10nException catch (e) {
+          expect(e.message, contains('Invalid key format'));
+          return;
+        }
+
+        fail('should fail since key starts with a number.');
+      });
+    });
+  });
+
+  group('LocalizationsGenerator.generateOutputFile:', () {
+    test('correctly generates the localizations classes:', () {
+      _standardFlutterDirectoryL10nSetup(fs);
+      final LocalizationsGenerator generator = LocalizationsGenerator(fs);
+      try {
+        generator.initialize(
+          l10nDirectoryPath: defaultArbPathString,
+          templateArbFileName: defaultTemplateArbFileName,
+          outputFileString: defaultOutputFileString,
+          classNameString: defaultClassNameString,
+        );
+        generator.parseArbFiles();
+        generator.generateClassMethods();
+        generator.generateOutputFile();
+      } on Exception catch (e) {
+        fail('Generating output localization file should succeed: \n$e');
+      }
+
+      final String outputFileString = generator.outputFile.readAsStringSync();
+      expect(outputFileString, contains('class AppLocalizations'));
+      expect(outputFileString, contains('class _AppLocalizationsDelegate extends LocalizationsDelegate<AppLocalizations>'));
+    });
+  });
+}

examples/stocks/lib/i18n/regenerate.md

@@ -15,7 +15,7 @@ for more info.
 `messages_all.dart`, and `stock_strings.dart` with the following command:
 
 ```dart
-dart ${FLUTTER_PATH}/dev/tools/localization/gen_l10n.dart --arb-dir=lib/i18n \
+dart ${FLUTTER_PATH}/dev/tools/localization/bin/gen_l10n.dart --arb-dir=lib/i18n \
     --template-arb-file=stocks_en_US.arb --output-localization-file=stock_strings.dart \
     --output-class=StockStrings
 ```