sxchnge/frontend/app/test/localization_test.dart

import 'dart:convert';
import 'dart:io';

import 'package:flutter/material.dart';

import 'package:flutter_test/flutter_test.dart';

import 'package:shared_preferences/shared_preferences.dart';

import 'package:sxchnge_app/main.dart';
import 'package:sxchnge_app/providers/locale.dart';

void main() {
  TestWidgetsFlutterBinding.ensureInitialized();

  setUp(() => SharedPreferences.setMockInitialValues({}));

  test('saved choice overrides system locale, with English fallback', () async {
    expect(
      LocaleProvider.resolve(null, [const Locale('ru', 'RU')]),
      const Locale('ru'),
    );
    expect(
      LocaleProvider.resolve('en', [const Locale('ru')]),
      const Locale('en'),
    );
    expect(
      LocaleProvider.resolve('ru-RU', [const Locale('en')]),
      const Locale('ru'),
    );
    expect(
      LocaleProvider.resolve('de', [const Locale('ru')]),
      const Locale('en'),
    );
    expect(
      LocaleProvider.resolve(null, [const Locale('fr')]),
      const Locale('en'),
    );
    expect(LocaleProvider.resolve(null, []), const Locale('en'));
    final first = await LocaleProvider.load([const Locale('en')]);
    await first.setLocale(const Locale('ru'));
    final restarted = await LocaleProvider.load([const Locale('en')]);
    expect(restarted.locale, const Locale('ru'));
    await Future.wait([
      first.setLocale(const Locale('en')),
      first.setLocale(const Locale('ru')),
    ]);
    expect(
      (await SharedPreferences.getInstance()).getString(
        LocaleProvider.storageKey,
      ),
      'ru',
    );
    first.dispose();
    restarted.dispose();
  });

  test('catalogs have equal keys and no empty translations', () {
    final en = jsonDecode(File('lib/l10n/en.arb').readAsStringSync()) as Map;
    final ru = jsonDecode(File('lib/l10n/ru.arb').readAsStringSync()) as Map;
    expect(ru.keys.toSet(), en.keys.toSet());
    expect(
      ru.values.every((value) => value is String && value.trim().isNotEmpty),
      isTrue,
    );
  });

  testWidgets(
    'switching language updates errors and keeps form data and mode',
    (tester) async {
      tester.view.physicalSize = const Size(1440, 1200);
      tester.view.devicePixelRatio = 1;
      addTearDown(tester.view.resetPhysicalSize);
      addTearDown(tester.view.resetDevicePixelRatio);
      final locale = await LocaleProvider.load([const Locale('en')]);
      await tester.pumpWidget(SxchngeApp(localeProvider: locale));
      await tester.pumpAndSettle();
      await tester.tap(find.text('Sign up'));
      await tester.pumpAndSettle();
      await tester.enterText(find.byKey(const ValueKey('name')), 'Алексей');
      await tester.enterText(find.byKey(const ValueKey('email')), 'invalid');
      await tester.ensureVisible(find.byKey(const ValueKey('submit')));
      await tester.tap(find.byKey(const ValueKey('submit')));
      await tester.pumpAndSettle();
      expect(find.text('Enter a valid email address.'), findsOneWidget);
      await tester.ensureVisible(find.byKey(const ValueKey('locale-selector')));
      await tester.tap(find.byKey(const ValueKey('locale-selector')));
      await tester.pumpAndSettle();
      await tester.tap(
        find.ancestor(
          of: find.text('Русский'),
          matching: find.byType(CheckedPopupMenuItem<Locale>),
        ),
      );
      await tester.pumpAndSettle();
      expect(find.text('Введите корректный адрес почты.'), findsOneWidget);
      expect(find.text('Алексей'), findsOneWidget);
      expect(find.text('invalid'), findsOneWidget);
      expect(find.byKey(const ValueKey('confirmation')), findsOneWidget);
      expect(find.byTooltip('Показать пароль'), findsOneWidget);
      expect(
        (await SharedPreferences.getInstance()).getString(
          LocaleProvider.storageKey,
        ),
        'ru',
      );
      expect(tester.takeException(), isNull);
    },
  );

  for (final width in [320.0, 1440.0]) {
    testWidgets('Russian forms fit at width $width with 200% text', (
      tester,
    ) async {
      tester.view.physicalSize = Size(width, 1000);
      tester.view.devicePixelRatio = 1;
      tester.platformDispatcher.textScaleFactorTestValue = 2;
      addTearDown(tester.view.resetPhysicalSize);
      addTearDown(tester.view.resetDevicePixelRatio);
      addTearDown(tester.platformDispatcher.clearTextScaleFactorTestValue);
      await tester.pumpWidget(
        SxchngeApp(
          localeProvider: LocaleProvider(initialLocale: const Locale('ru')),
        ),
      );
      await tester.pumpAndSettle();
      expect(tester.takeException(), isNull);
      await tester.ensureVisible(find.text('Регистрация'));
      await tester.tap(find.text('Регистрация'));
      await tester.pumpAndSettle();
      await tester.ensureVisible(find.byKey(const ValueKey('submit')));
      await tester.tap(find.byKey(const ValueKey('submit')));
      await tester.pumpAndSettle();
      expect(find.text('Введите ваше имя.'), findsOneWidget);
      expect(tester.takeException(), isNull);
    });
  }
}