migrate localization to null safety (#84064)

migrate localization to null safety

dev/tools/localization/bin/encode_kn_arb_files.dart

@@ -13,8 +13,6 @@
 // This utility is run by `gen_localizations.dart` if --overwrite is passed
 // in as an option.
 
-// @dart = 2.8
-
 import 'dart:convert';
 import 'dart:io';
 

dev/tools/localization/bin/gen_date_localizations.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
 /// This program extracts localized date symbols and patterns from the intl
 /// package for the subset of locales supported by the flutter_localizations
 /// package.
@@ -42,7 +40,7 @@ const String _kCommandName = 'gen_date_localizations.dart';
 // Date symbols for the Kannada locale ('kn') are handled specially because
 // some of the strings contain characters that can crash Emacs on Linux.
 // See packages/flutter_localizations/lib/src/l10n/README for more information.
-String currentLocale;
+String? currentLocale;
 
 Future<void> main(List<String> rawArgs) async {
   checkCwdIsRepoRoot(_kCommandName);
@@ -66,7 +64,7 @@ Future<void> main(List<String> rawArgs) async {
       (String line) => line.startsWith('intl:'),
       orElse: () {
         exitWithError('intl dependency not found in ${dotPackagesFile.path}');
-        return null; // unreachable
+        return ''; // unreachable
       },
     )
     .split(':')
@@ -143,7 +141,7 @@ String _jsonToMap(dynamic json) {
     return '$json';
 
   if (json is String)
-    return generateEncodedString(currentLocale, json);
+    return generateEncodedString(currentLocale!, json);
 
   if (json is Iterable) {
     final StringBuffer buffer = StringBuffer('<dynamic>[');
@@ -180,7 +178,7 @@ Set<String> _supportedLocales() {
   for (final FileSystemEntity entity in supportedLocalesDirectory.listSync()) {
     final String filePath = entity.path;
     if (FileSystemEntity.isFileSync(filePath) && filenameRE.hasMatch(filePath)) {
-      supportedLocales.add(filenameRE.firstMatch(filePath)[1]);
+      supportedLocales.add(filenameRE.firstMatch(filePath)![1]!);
     }
   }
 
@@ -200,5 +198,5 @@ Map<String, File> _listIntlData(Directory directory) {
 
   final List<String> locales = localeFiles.keys.toList(growable: false);
   locales.sort();
-  return Map<String, File>.fromIterable(locales, value: (dynamic locale) => localeFiles[locale]);
+  return Map<String, File>.fromIterable(locales, value: (dynamic locale) => localeFiles[locale]!);
 }

dev/tools/localization/bin/gen_missing_localizations.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
 // This program updates the language locale arb files with any missing resource
 // entries that are included in the English arb files. This is useful when
 // adding new resources for localization. You can just add the appropriate
@@ -68,10 +66,10 @@ bool intentionallyOmitted(String key, Map<String, dynamic> bundle) {
 /// Whether `key` corresponds to one of the plural variations of a key with
 /// the same prefix and suffix "Other".
 bool isPluralVariation(String key, Map<String, dynamic> bundle) {
-  final Match pluralMatch = kPluralRegexp.firstMatch(key);
+  final Match? pluralMatch = kPluralRegexp.firstMatch(key);
   if (pluralMatch == null)
     return false;
-  final String prefix = pluralMatch[1];
+  final String prefix = pluralMatch[1]!;
   return bundle.containsKey('${prefix}Other');
 }
 
@@ -85,7 +83,7 @@ void updateMissingResources(String localizationPath, String groupPrefix) {
   for (final FileSystemEntity entity in localizationDir.listSync().toList()..sort(sortFilesByPath)) {
     final String entityPath = entity.path;
     if (FileSystemEntity.isFileSync(entityPath) && filenamePattern.hasMatch(entityPath)) {
-      final String localeString = filenamePattern.firstMatch(entityPath)[1];
+      final String localeString = filenamePattern.firstMatch(entityPath)![1]!;
       final LocaleInfo locale = LocaleInfo.fromString(localeString);
 
       // Only look at top-level language locales

dev/tools/localization/gen_cupertino_localizations.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
 import 'localizations_utils.dart';
 
 String generateCupertinoHeader(String regenerateInstructions) {

dev/tools/localization/gen_material_localizations.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
 import 'localizations_utils.dart';
 
 String generateMaterialHeader(String regenerateInstructions) {

dev/tools/localization/localizations_utils.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
 import 'dart:convert';
 import 'dart:io';
 
@@ -23,11 +21,11 @@ int sortFilesByPath (FileSystemEntity a, FileSystemEntity b) {
 @immutable
 class LocaleInfo implements Comparable<LocaleInfo> {
   const LocaleInfo({
-    this.languageCode,
+    required this.languageCode,
     this.scriptCode,
     this.countryCode,
-    this.length,
-    this.originalString,
+    required this.length,
+    required this.originalString,
   });
 
   /// Simple parser. Expects the locale string to be in the form of 'language_script_COUNTRY'
@@ -42,8 +40,8 @@ class LocaleInfo implements Comparable<LocaleInfo> {
     final List<String> codes = locale.split('_'); // [language, script, country]
     assert(codes.isNotEmpty && codes.length < 4);
     final String languageCode = codes[0];
-    String scriptCode;
-    String countryCode;
+    String? scriptCode;
+    String? countryCode;
     int length = codes.length;
     String originalString = locale;
     if (codes.length == 2) {
@@ -111,8 +109,8 @@ class LocaleInfo implements Comparable<LocaleInfo> {
   }
 
   final String languageCode;
-  final String scriptCode;
-  final String countryCode;
+  final String? scriptCode;
+  final String? countryCode;
   final int length;             // The number of fields. Ranges from 1-3.
   final String originalString;  // Original un-parsed locale string.
 
@@ -148,10 +146,10 @@ class LocaleInfo implements Comparable<LocaleInfo> {
 /// Parse the data for a locale from a file, and store it in the [attributes]
 /// and [resources] keys.
 void loadMatchingArbsIntoBundleMaps({
-  @required Directory directory,
-  @required RegExp filenamePattern,
-  @required Map<LocaleInfo, Map<String, String>> localeToResources,
-  @required Map<LocaleInfo, Map<String, dynamic>> localeToResourceAttributes,
+  required Directory directory,
+  required RegExp filenamePattern,
+  required Map<LocaleInfo, Map<String, String>> localeToResources,
+  required Map<LocaleInfo, Map<String, dynamic>> localeToResourceAttributes,
 }) {
   assert(directory != null);
   assert(filenamePattern != null);
@@ -169,13 +167,13 @@ void loadMatchingArbsIntoBundleMaps({
   for (final FileSystemEntity entity in directory.listSync().toList()..sort(sortFilesByPath)) {
     final String entityPath = entity.path;
     if (FileSystemEntity.isFileSync(entityPath) && filenamePattern.hasMatch(entityPath)) {
-      final String localeString = filenamePattern.firstMatch(entityPath)[1];
+      final String localeString = filenamePattern.firstMatch(entityPath)![1]!;
       final File arbFile = File(entityPath);
 
       // Helper method to fill the maps with the correct data from file.
       void populateResources(LocaleInfo locale, File file) {
-        final Map<String, String> resources = localeToResources[locale];
-        final Map<String, dynamic> attributes = localeToResourceAttributes[locale];
+        final Map<String, String> resources = localeToResources[locale]!;
+        final Map<String, dynamic> attributes = localeToResourceAttributes[locale]!;
         final Map<String, dynamic> bundle = json.decode(file.readAsStringSync()) as Map<String, dynamic>;
         for (final String key in bundle.keys) {
           // The ARB file resource "attributes" for foo are called @foo.
@@ -258,9 +256,9 @@ GeneratorOptions parseArgs(List<String> rawArgs) {
 
 class GeneratorOptions {
   GeneratorOptions({
-    @required this.writeToFile,
-    @required this.materialOnly,
-    @required this.cupertinoOnly,
+    required this.writeToFile,
+    required this.materialOnly,
+    required this.cupertinoOnly,
   });
 
   final bool writeToFile;
@@ -271,7 +269,7 @@ class GeneratorOptions {
 // See also //master/tools/gen_locale.dart in the engine repo.
 Map<String, List<String>> _parseSection(String section) {
   final Map<String, List<String>> result = <String, List<String>>{};
-  List<String> lastHeading;
+  late List<String> lastHeading;
   for (final String line in section.split('\n')) {
     if (line == '')
       continue;
@@ -285,7 +283,7 @@ Map<String, List<String>> _parseSection(String section) {
     final String name = line.substring(0, colon);
     final String value = line.substring(colon + 2);
     lastHeading = result.putIfAbsent(name, () => <String>[]);
-    result[name].add(value);
+    result[name]!.add(value);
   }
   return result;
 }
@@ -304,11 +302,11 @@ void precacheLanguageAndRegionTags() {
       languageSubtagRegistry.split('%%').skip(1).map<Map<String, List<String>>>(_parseSection).toList();
   for (final Map<String, List<String>> section in sections) {
     assert(section.containsKey('Type'), section.toString());
-    final String type = section['Type'].single;
+    final String type = section['Type']!.single;
     if (type == 'language' || type == 'region' || type == 'script') {
       assert(section.containsKey('Subtag') && section.containsKey('Description'), section.toString());
-      final String subtag = section['Subtag'].single;
-      String description = section['Description'].join(' ');
+      final String subtag = section['Subtag']!.single;
+      String description = section['Description']!.join(' ');
       if (description.startsWith('United '))
         description = 'the $description';
       if (description.contains(kParentheticalPrefix))
@@ -336,10 +334,10 @@ String describeLocale(String tag) {
   final List<String> subtags = tag.split('_');
   assert(subtags.isNotEmpty);
   assert(_languages.containsKey(subtags[0]));
-  final String language = _languages[subtags[0]];
+  final String language = _languages[subtags[0]]!;
   String output = language;
-  String region;
-  String script;
+  String? region;
+  String? script;
   if (subtags.length == 2) {
     region = _regions[subtags[1]];
     script = _scripts[subtags[1]];

dev/tools/localization/localizations_validator.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
-
 import 'dart:convert' show json;
 import 'dart:io';
 
@@ -62,7 +60,7 @@ void validateEnglishLocalizations(File file) {
       continue;
 
     final dynamic atResourceValue = bundle[atResourceId];
-    final Map<String, dynamic> atResource =
+    final Map<String, dynamic>? atResource =
         atResourceValue is Map<String, dynamic> ? atResourceValue : null;
     if (atResource == null) {
       errorMessages.writeln('A map value was not specified for $atResourceId');
@@ -103,12 +101,12 @@ void validateLocalizations(
   Map<LocaleInfo, Map<String, String>> localeToResources,
   Map<LocaleInfo, Map<String, dynamic>> localeToAttributes,
 ) {
-  final Map<String, String> canonicalLocalizations = localeToResources[LocaleInfo.fromString('en')];
+  final Map<String, String> canonicalLocalizations = localeToResources[LocaleInfo.fromString('en')]!;
   final Set<String> canonicalKeys = Set<String>.from(canonicalLocalizations.keys);
   final StringBuffer errorMessages = StringBuffer();
   bool explainMissingKeys = false;
   for (final LocaleInfo locale in localeToResources.keys) {
-    final Map<String, String> resources = localeToResources[locale];
+    final Map<String, String> resources = localeToResources[locale]!;
 
     // Whether `key` corresponds to one of the plural variations of a key with
     // the same prefix and suffix "Other".
@@ -116,10 +114,10 @@ void validateLocalizations(
     // Many languages require only a subset of these variations, so we do not
     // require them so long as the "Other" variation exists.
     bool isPluralVariation(String key) {
-      final Match pluralMatch = kPluralRegexp.firstMatch(key);
+      final Match? pluralMatch = kPluralRegexp.firstMatch(key);
       if (pluralMatch == null)
         return false;
-      final String prefix = pluralMatch[1];
+      final String? prefix = pluralMatch[1];
       return resources.containsKey('${prefix}Other');
     }
 
@@ -135,10 +133,10 @@ void validateLocalizations(
     // For language-level locales only, check that they have a complete list of
     // keys, or opted out of using certain ones.
     if (locale.length == 1) {
-      final Map<String, dynamic> attributes = localeToAttributes[locale];
-      final List<String> missingKeys = <String>[];
+      final Map<String, dynamic>? attributes = localeToAttributes[locale];
+      final List<String?> missingKeys = <String?>[];
        for (final String missingKey in canonicalKeys.difference(keys)) {
-        final dynamic attribute = attributes[missingKey];
+        final dynamic attribute = attributes?[missingKey];
         final bool intentionallyOmitted = attribute is Map && attribute.containsKey('notUsed');
         if (!intentionallyOmitted && !isPluralVariation(missingKey))
           missingKeys.add(missingKey);