blob: e6f4560057023de23a1284f4dd159691bf35c604 [file] [log] [blame]
// 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:convert' show json;
import 'dart:io';
import 'localizations_utils.dart';
// The first suffix in kPluralSuffixes must be "Other". "Other" is special
// because it's the only one that is required.
const List<String> kPluralSuffixes = <String>['Other', 'Zero', 'One', 'Two', 'Few', 'Many'];
final RegExp kPluralRegexp = RegExp(r'(\w*)(' + kPluralSuffixes.skip(1).join(r'|') + r')$');
class ValidationError implements Exception {
ValidationError(this. message);
final String message;
String toString() => message;
/// Sanity checking of the @foo metadata in the English translations, *_en.arb.
/// - For each foo, resource, there must be a corresponding @foo.
/// - For each @foo resource, there must be a corresponding foo, except
/// for plurals, for which there must be a fooOther.
/// - Each @foo resource must have a Map value with a String valued
/// description entry.
/// Throws an exception upon failure.
void validateEnglishLocalizations(File file) {
final StringBuffer errorMessages = StringBuffer();
if (!file.existsSync()) {
errorMessages.writeln('English localizations do not exist: $file');
throw ValidationError(errorMessages.toString());
final Map<String, dynamic> bundle = json.decode(file.readAsStringSync()) as Map<String, dynamic>;
for (final String resourceId in bundle.keys) {
if (resourceId.startsWith('@'))
if (bundle['@$resourceId'] != null)
bool checkPluralResource(String suffix) {
final int suffixIndex = resourceId.indexOf(suffix);
return suffixIndex != -1 && bundle['@${resourceId.substring(0, suffixIndex)}'] != null;
if (kPluralSuffixes.any(checkPluralResource))
errorMessages.writeln('A value was not specified for @$resourceId');
for (final String atResourceId in bundle.keys) {
if (!atResourceId.startsWith('@'))
final dynamic atResourceValue = bundle[atResourceId];
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');
final String description = atResource['description'] as String;
if (description == null)
errorMessages.writeln('No description specified for $atResourceId');
final String plural = atResource['plural'] as String;
final String resourceId = atResourceId.substring(1);
if (plural != null) {
final String resourceIdOther = '${resourceId}Other';
if (!bundle.containsKey(resourceIdOther))
errorMessages.writeln('Default plural resource $resourceIdOther undefined');
} else {
if (!bundle.containsKey(resourceId))
errorMessages.writeln('No matching $resourceId defined for $atResourceId');
if (errorMessages.isNotEmpty)
throw ValidationError(errorMessages.toString());
/// Enforces the following invariants in our localizations:
/// - Resource keys are valid, i.e. they appear in the canonical list.
/// - Resource keys are complete for language-level locales, e.g. "es", "he".
/// Uses "en" localizations as the canonical source of locale keys that other
/// locales are compared against.
/// If validation fails, throws an exception.
void validateLocalizations(
Map<LocaleInfo, Map<String, String>> localeToResources,
Map<LocaleInfo, Map<String, dynamic>> localeToAttributes,
) {
final Map<String, String> canonicalLocalizations = localeToResources[LocaleInfo.fromString('en')];
final Set<String> canonicalKeys = Set<String>.from(canonicalLocalizations.keys);
final StringBuffer errorMessages = StringBuffer();
bool explainMissingKeys = false;
for (final LocaleInfo locale in localeToResources.keys) {
final Map<String, String> resources = localeToResources[locale];
// Whether `key` corresponds to one of the plural variations of a key with
// the same prefix and suffix "Other".
// Many languages require only a subset of these variations, so we do not
// require them so long as the "Other" variation exists.
bool isPluralVariation(String key) {
final Match pluralMatch = kPluralRegexp.firstMatch(key);
if (pluralMatch == null)
return false;
final String prefix = pluralMatch[1];
return resources.containsKey('${prefix}Other');
final Set<String> keys = Set<String>.from(
resources.keys.where((String key) => !isPluralVariation(key))
// Make sure keys are valid (i.e. they also exist in the canonical
// localizations)
final Set<String> invalidKeys = keys.difference(canonicalKeys);
if (invalidKeys.isNotEmpty)
errorMessages.writeln('Locale "$locale" contains invalid resource keys: ${invalidKeys.join(', ')}');
// For language-level locales only, check that they have a complete list of
// keys, or opted out of using certain ones.
if (locale.length == 1) {
final Map<String, dynamic> attributes = localeToAttributes[locale];
final List<String> missingKeys = <String>[];
for (final String missingKey in canonicalKeys.difference(keys)) {
final dynamic attribute = attributes[missingKey];
final bool intentionallyOmitted = attribute is Map && attribute.containsKey('notUsed');
if (!intentionallyOmitted && !isPluralVariation(missingKey))
if (missingKeys.isNotEmpty) {
explainMissingKeys = true;
errorMessages.writeln('Locale "$locale" is missing the following resource keys: ${missingKeys.join(', ')}');
if (errorMessages.isNotEmpty) {
if (explainMissingKeys) {
'If a resource key is intentionally omitted, add an attribute corresponding '
'to the key name with a "notUsed" property explaining why. Example:'
..writeln('"@anteMeridiemAbbreviation": {')
..writeln(' "notUsed": "Sindhi time format does not use a.m. indicator"')
throw ValidationError(errorMessages.toString());