widgets_test.dart 50 KB
Newer Older
Ian Hickson's avatar
Ian Hickson committed
1
// Copyright 2014 The Flutter Authors. All rights reserved.
2 3 4
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

5 6
import 'dart:ui' as ui;

7 8
import 'package:flutter/foundation.dart';
import 'package:flutter/widgets.dart';
9
import 'package:flutter_localizations/flutter_localizations.dart';
10
import 'package:flutter_test/flutter_test.dart';
11 12 13 14 15

class TestLocalizations {
  TestLocalizations(this.locale, this.prefix);

  final Locale locale;
16
  final String? prefix;
17

18
  static Future<TestLocalizations> loadSync(Locale locale, String? prefix) {
19
    return SynchronousFuture<TestLocalizations>(TestLocalizations(locale, prefix));
20 21
  }

22 23 24 25 26
  static Future<TestLocalizations> loadAsync(Locale locale, String? prefix) {
    return Future<TestLocalizations>.delayed(
      const Duration(milliseconds: 100),
      () => TestLocalizations(locale, prefix)
    );
27 28 29
  }

  static TestLocalizations of(BuildContext context) {
30
    return Localizations.of<TestLocalizations>(context, TestLocalizations)!;
31 32 33 34 35 36 37 38
  }

  String get message => '${prefix ?? ""}$locale';
}

class SyncTestLocalizationsDelegate extends LocalizationsDelegate<TestLocalizations> {
  SyncTestLocalizationsDelegate([this.prefix]);

39
  final String? prefix; // Changing this value triggers a rebuild
40 41
  final List<bool> shouldReloadValues = <bool>[];

42 43 44
  @override
  bool isSupported(Locale locale) => true;

45 46 47 48 49 50 51 52
  @override
  Future<TestLocalizations> load(Locale locale) => TestLocalizations.loadSync(locale, prefix);

  @override
  bool shouldReload(SyncTestLocalizationsDelegate old) {
    shouldReloadValues.add(prefix != old.prefix);
    return prefix != old.prefix;
  }
53 54

  @override
Ian Hickson's avatar
Ian Hickson committed
55
  String toString() => '${objectRuntimeType(this, 'SyncTestLocalizationsDelegate')}($prefix)';
56 57 58 59 60
}

class AsyncTestLocalizationsDelegate extends LocalizationsDelegate<TestLocalizations> {
  AsyncTestLocalizationsDelegate([this.prefix]);

61
  final String? prefix; // Changing this value triggers a rebuild
62 63
  final List<bool> shouldReloadValues = <bool>[];

64 65 66
  @override
  bool isSupported(Locale locale) => true;

67 68 69 70 71 72 73 74
  @override
  Future<TestLocalizations> load(Locale locale) => TestLocalizations.loadAsync(locale, prefix);

  @override
  bool shouldReload(AsyncTestLocalizationsDelegate old) {
    shouldReloadValues.add(prefix != old.prefix);
    return prefix != old.prefix;
  }
75 76

  @override
Ian Hickson's avatar
Ian Hickson committed
77
  String toString() => '${objectRuntimeType(this, 'AsyncTestLocalizationsDelegate')}($prefix)';
78 79 80 81 82 83 84 85
}

class MoreLocalizations {
  MoreLocalizations(this.locale);

  final Locale locale;

  static Future<MoreLocalizations> loadSync(Locale locale) {
86
    return SynchronousFuture<MoreLocalizations>(MoreLocalizations(locale));
87 88 89
  }

  static Future<MoreLocalizations> loadAsync(Locale locale) {
90 91 92 93
    return Future<MoreLocalizations>.delayed(
      const Duration(milliseconds: 100),
      () => MoreLocalizations(locale)
    );
94 95 96
  }

  static MoreLocalizations of(BuildContext context) {
97
    return Localizations.of<MoreLocalizations>(context, MoreLocalizations)!;
98 99 100 101 102 103 104 105 106
  }

  String get message => '$locale';
}

class SyncMoreLocalizationsDelegate extends LocalizationsDelegate<MoreLocalizations> {
  @override
  Future<MoreLocalizations> load(Locale locale) => MoreLocalizations.loadSync(locale);

107 108 109
  @override
  bool isSupported(Locale locale) => true;

110 111 112 113 114 115 116 117
  @override
  bool shouldReload(SyncMoreLocalizationsDelegate old) => false;
}

class AsyncMoreLocalizationsDelegate extends LocalizationsDelegate<MoreLocalizations> {
  @override
  Future<MoreLocalizations> load(Locale locale) => MoreLocalizations.loadAsync(locale);

118 119 120
  @override
  bool isSupported(Locale locale) => true;

121 122 123 124
  @override
  bool shouldReload(AsyncMoreLocalizationsDelegate old) => false;
}

125 126 127 128 129 130 131 132
class OnlyRTLDefaultWidgetsLocalizations extends DefaultWidgetsLocalizations {
  @override
  TextDirection get textDirection => TextDirection.rtl;
}

class OnlyRTLDefaultWidgetsLocalizationsDelegate extends LocalizationsDelegate<WidgetsLocalizations> {
  const OnlyRTLDefaultWidgetsLocalizationsDelegate();

133 134 135
  @override
  bool isSupported(Locale locale) => true;

136 137
  @override
  Future<WidgetsLocalizations> load(Locale locale) {
138
    return SynchronousFuture<WidgetsLocalizations>(OnlyRTLDefaultWidgetsLocalizations());
139 140 141 142 143 144
  }

  @override
  bool shouldReload(OnlyRTLDefaultWidgetsLocalizationsDelegate old) => false;
}

145
Widget buildFrame({
146 147 148 149
  Locale? locale,
  Iterable<LocalizationsDelegate<dynamic>>? delegates,
  required WidgetBuilder buildContent,
  LocaleResolutionCallback? localeResolutionCallback,
150
  List<Locale> supportedLocales = const <Locale>[
151 152
    Locale('en', 'US'),
    Locale('en', 'GB'),
153
  ],
154
}) {
155
  return WidgetsApp(
156 157 158
    color: const Color(0xFFFFFFFF),
    locale: locale,
    localizationsDelegates: delegates,
159 160
    localeResolutionCallback: localeResolutionCallback,
    supportedLocales: supportedLocales,
161
    onGenerateRoute: (RouteSettings settings) {
162
      return PageRouteBuilder<void>(
163 164 165 166 167 168 169 170
        pageBuilder: (BuildContext context, Animation<double> _, Animation<double> __) {
          return buildContent(context);
        }
      );
    },
  );
}

171
class SyncLoadTest extends StatefulWidget {
172
  const SyncLoadTest({Key? key}) : super(key: key);
173 174

  @override
175
  SyncLoadTestState createState() => SyncLoadTestState();
176 177 178 179 180
}

class SyncLoadTestState extends State<SyncLoadTest> {
  @override
  Widget build(BuildContext context) {
181
    return Text(
182 183 184 185 186 187
      TestLocalizations.of(context).message,
      textDirection: TextDirection.rtl,
    );
  }
}

188 189
void main() {
  testWidgets('Localizations.localeFor in a WidgetsApp with system locale', (WidgetTester tester) async {
190
    late BuildContext pageContext;
191 192 193 194 195

    await tester.pumpWidget(
      buildFrame(
        buildContent: (BuildContext context) {
          pageContext = context;
Ian Hickson's avatar
Ian Hickson committed
196
          return const Text('Hello World', textDirection: TextDirection.ltr);
197 198 199 200 201 202 203 204 205 206 207 208 209 210
        }
      )
    );

    await tester.binding.setLocale('en', 'GB');
    await tester.pump();
    expect(Localizations.localeOf(pageContext), const Locale('en', 'GB'));

    await tester.binding.setLocale('en', 'US');
    await tester.pump();
    expect(Localizations.localeOf(pageContext), const Locale('en', 'US'));
  });

  testWidgets('Localizations.localeFor in a WidgetsApp with an explicit locale', (WidgetTester tester) async {
211
    const Locale locale = Locale('en', 'US');
212
    late BuildContext pageContext;
213 214 215 216 217 218

    await tester.pumpWidget(
      buildFrame(
        locale: locale,
        buildContent: (BuildContext context) {
          pageContext = context;
219
          return const Text('Hello World');
220 221 222 223 224 225 226 227 228 229 230 231 232 233
        },
      )
    );

    expect(Localizations.localeOf(pageContext), locale);

    await tester.binding.setLocale('en', 'GB');
    await tester.pump();

    // The WidgetApp's explicit locale overrides the system's locale.
    expect(Localizations.localeOf(pageContext), locale);
  });

  testWidgets('Synchronously loaded localizations in a WidgetsApp', (WidgetTester tester) async {
234
    final List<LocalizationsDelegate<dynamic>> delegates = <LocalizationsDelegate<dynamic>>[
235
      SyncTestLocalizationsDelegate(),
236
      DefaultWidgetsLocalizations.delegate,
237 238
    ];

239
    Future<void> pumpTest(Locale locale) async {
240
      await tester.pumpWidget(Localizations(
241 242 243 244 245
        locale: locale,
        delegates: delegates,
        child: const SyncLoadTest(),
      ));
    }
246

247
    await pumpTest(const Locale('en', 'US'));
248
    expect(find.text('en_US'), findsOneWidget);
249

250
    await pumpTest(const Locale('en', 'GB'));
251 252 253
    await tester.pump();
    expect(find.text('en_GB'), findsOneWidget);

254
    await pumpTest(const Locale('en', 'US'));
255 256 257 258 259 260 261 262
    await tester.pump();
    expect(find.text('en_US'), findsOneWidget);
  });

  testWidgets('Asynchronously loaded localizations in a WidgetsApp', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
263
          AsyncTestLocalizationsDelegate(),
264 265
        ],
        buildContent: (BuildContext context) {
266
          return Text(TestLocalizations.of(context).message);
267
        },
268 269 270
      )
    );
    await tester.pump(const Duration(milliseconds: 50)); // TestLocalizations.loadAsync() takes 100ms
271
    expect(find.text('en_US'), findsNothing); // TestLocalizations hasn't been loaded yet
272 273 274

    await tester.pump(const Duration(milliseconds: 50)); // TestLocalizations.loadAsync() completes
    await tester.pumpAndSettle();
275
    expect(find.text('en_US'), findsOneWidget); // default test locale is US english
276

277
    await tester.binding.setLocale('en', 'GB');
278 279
    await tester.pump(const Duration(milliseconds: 100));
    await tester.pumpAndSettle();
280
    expect(find.text('en_GB'), findsOneWidget);
281

282
    await tester.binding.setLocale('en', 'US');
283 284 285
    await tester.pump(const Duration(milliseconds: 50));
    // TestLocalizations.loadAsync() hasn't completed yet so the old text
    // localization is still displayed
286
    expect(find.text('en_GB'), findsOneWidget);
287 288
    await tester.pump(const Duration(milliseconds: 50)); // finish the async load
    await tester.pumpAndSettle();
289
    expect(find.text('en_US'), findsOneWidget);
290 291 292 293 294 295
  });

  testWidgets('Localizations with multiple sync delegates', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
296 297
          SyncTestLocalizationsDelegate(),
          SyncMoreLocalizationsDelegate(),
298 299 300
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
301
          return Column(
302
            children: <Widget>[
303 304
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
305 306
            ],
          );
307
        },
308 309 310
      )
    );

Josh Soref's avatar
Josh Soref committed
311
    // All localizations were loaded synchronously
312 313 314 315 316 317 318 319
    expect(find.text('A: en_US'), findsOneWidget);
    expect(find.text('B: en_US'), findsOneWidget);
  });

  testWidgets('Localizations with multiple delegates', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
320 321
          SyncTestLocalizationsDelegate(),
          AsyncMoreLocalizationsDelegate(), // No resources until this completes
322 323 324
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
325
          return Column(
326
            children: <Widget>[
327 328
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
329 330
            ],
          );
331
        },
332 333 334 335 336 337 338 339 340 341 342 343 344 345
      )
    );

    await tester.pump(const Duration(milliseconds: 50));
    expect(find.text('A: en_US'), findsNothing); // MoreLocalizations.load() hasn't completed yet
    expect(find.text('B: en_US'), findsNothing);

    await tester.pump(const Duration(milliseconds: 50));
    await tester.pumpAndSettle();

    expect(find.text('A: en_US'), findsOneWidget);
    expect(find.text('B: en_US'), findsOneWidget);
  });

Josh Soref's avatar
Josh Soref committed
346
  testWidgets('Multiple Localizations', (WidgetTester tester) async {
347 348 349
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
350
          SyncTestLocalizationsDelegate(),
351 352 353
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
354
          return Column(
355
            children: <Widget>[
356 357
              Text('A: ${TestLocalizations.of(context).message}'),
              Localizations(
358 359
                locale: const Locale('en', 'GB'),
                delegates: <LocalizationsDelegate<dynamic>>[
360
                  SyncTestLocalizationsDelegate(),
361
                  DefaultWidgetsLocalizations.delegate,
362 363
                ],
                // Create a new context within the en_GB Localization
364
                child: Builder(
365
                  builder: (BuildContext context) {
366
                    return Text('B: ${TestLocalizations.of(context).message}');
367 368 369 370 371
                  },
                ),
              ),
            ],
          );
372
        },
373 374 375 376 377 378 379 380 381 382 383
      )
    );

    expect(find.text('A: en_US'), findsOneWidget);
    expect(find.text('B: en_GB'), findsOneWidget);
  });

  // If both the locale and the length and type of a Localizations delegate list
  // stays the same BUT one of its delegate.shouldReload() methods returns true,
  // then the dependent widgets should rebuild.
  testWidgets('Localizations sync delegate shouldReload returns true', (WidgetTester tester) async {
384
    final SyncTestLocalizationsDelegate originalDelegate = SyncTestLocalizationsDelegate();
385 386 387 388
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
          originalDelegate,
389
          SyncMoreLocalizationsDelegate(),
390 391 392
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
393
          return Column(
394
            children: <Widget>[
395 396
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
397 398
            ],
          );
399
        },
400 401 402 403 404 405 406 407 408
      )
    );

    await tester.pumpAndSettle();
    expect(find.text('A: en_US'), findsOneWidget);
    expect(find.text('B: en_US'), findsOneWidget);
    expect(originalDelegate.shouldReloadValues, <bool>[]);


409
    final SyncTestLocalizationsDelegate modifiedDelegate = SyncTestLocalizationsDelegate('---');
410 411 412 413
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
          modifiedDelegate,
414
          SyncMoreLocalizationsDelegate(),
415 416 417
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
418
          return Column(
419
            children: <Widget>[
420 421
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
422 423
            ],
          );
424
        },
425 426 427 428 429 430 431
      )
    );

    await tester.pumpAndSettle();
    expect(find.text('A: ---en_US'), findsOneWidget);
    expect(find.text('B: en_US'), findsOneWidget);
    expect(modifiedDelegate.shouldReloadValues, <bool>[true]);
432
    expect(originalDelegate.shouldReloadValues, <bool>[]);
433 434 435 436 437 438
  });

  testWidgets('Localizations async delegate shouldReload returns true', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
439 440
          AsyncTestLocalizationsDelegate(),
          AsyncMoreLocalizationsDelegate(),
441 442 443
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
444
          return Column(
445
            children: <Widget>[
446 447
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
448 449
            ],
          );
450
        },
451 452 453 454 455 456 457
      )
    );

    await tester.pumpAndSettle();
    expect(find.text('A: en_US'), findsOneWidget);
    expect(find.text('B: en_US'), findsOneWidget);

458
    final AsyncTestLocalizationsDelegate modifiedDelegate = AsyncTestLocalizationsDelegate('---');
459 460 461 462
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
          modifiedDelegate,
463
          AsyncMoreLocalizationsDelegate(),
464 465 466
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
467
          return Column(
468
            children: <Widget>[
469 470
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
471 472
            ],
          );
473
        },
474 475 476 477 478 479 480 481 482
      )
    );

    await tester.pumpAndSettle();
    expect(find.text('A: ---en_US'), findsOneWidget);
    expect(find.text('B: en_US'), findsOneWidget);
    expect(modifiedDelegate.shouldReloadValues, <bool>[true]);
  });

483
  testWidgets('Directionality tracks system locale', (WidgetTester tester) async {
484
    late BuildContext pageContext;
485 486 487

    await tester.pumpWidget(
      buildFrame(
488 489 490
        delegates: const <LocalizationsDelegate<dynamic>>[
          GlobalWidgetsLocalizations.delegate,
        ],
491
        supportedLocales: const <Locale>[
492 493
          Locale('en', 'GB'),
          Locale('ar', 'EG'),
494
        ],
495 496 497
        buildContent: (BuildContext context) {
          pageContext = context;
          return const Text('Hello World');
498
        },
499 500 501 502 503 504 505 506 507 508 509
      )
    );

    await tester.binding.setLocale('en', 'GB');
    await tester.pump();
    expect(Directionality.of(pageContext), TextDirection.ltr);

    await tester.binding.setLocale('ar', 'EG');
    await tester.pump();
    expect(Directionality.of(pageContext), TextDirection.rtl);
  });
510 511 512 513

  testWidgets('localeResolutionCallback override', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
514
        localeResolutionCallback: (Locale? newLocale, Iterable<Locale> supportedLocales) {
515 516 517
          return const Locale('foo', 'BAR');
        },
        buildContent: (BuildContext context) {
518
          return Text(Localizations.localeOf(context).toString());
519
        },
520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535
      )
    );

    await tester.pumpAndSettle();
    expect(find.text('foo_BAR'), findsOneWidget);

    await tester.binding.setLocale('en', 'GB');
    await tester.pumpAndSettle();
    expect(find.text('foo_BAR'), findsOneWidget);
  });


  testWidgets('supportedLocales and defaultLocaleChangeHandler', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
536 537 538
          Locale('zh', 'CN'),
          Locale('en', 'GB'),
          Locale('en', 'CA'),
539 540
        ],
        buildContent: (BuildContext context) {
541
          return Text(Localizations.localeOf(context).toString());
542
        },
543 544 545 546
      )
    );

    await tester.pumpAndSettle();
547
    expect(find.text('en_GB'), findsOneWidget);
548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563

    // defaultLocaleChangedHandler prefers exact supported locale match
    await tester.binding.setLocale('en', 'CA');
    await tester.pumpAndSettle();
    expect(find.text('en_CA'), findsOneWidget);

    // defaultLocaleChangedHandler chooses 1st matching supported locale.languageCode
    await tester.binding.setLocale('en', 'US');
    await tester.pumpAndSettle();
    expect(find.text('en_GB'), findsOneWidget);

    // defaultLocaleChangedHandler: no matching supported locale, so use the 1st one
    await tester.binding.setLocale('da', 'DA');
    await tester.pumpAndSettle();
    expect(find.text('zh_CN'), findsOneWidget);
  });
564

565
  testWidgets("Localizations.override widget tracks parent's locale and delegates", (WidgetTester tester) async {
566 567 568
    await tester.pumpWidget(
      buildFrame(
        // Accept whatever locale we're given
569
        localeResolutionCallback: (Locale? locale, Iterable<Locale> supportedLocales) => locale,
570 571 572
        delegates: const <LocalizationsDelegate<dynamic>>[
          GlobalWidgetsLocalizations.delegate,
        ],
573
        buildContent: (BuildContext context) {
574
          return Localizations.override(
575
            context: context,
576
            child: Builder(
577
              builder: (BuildContext context) {
578
                final Locale locale = Localizations.localeOf(context);
579
                final TextDirection direction = WidgetsLocalizations.of(context).textDirection;
580
                return Text('$locale $direction');
581 582 583
              },
            ),
          );
584
        },
585 586
      )
    );
587

588
    // Initial WidgetTester locale is `en_US`.
589
    await tester.pumpAndSettle();
590
    expect(find.text('en_US TextDirection.ltr'), findsOneWidget);
591 592 593 594 595 596 597 598 599 600 601 602 603 604

    await tester.binding.setLocale('en', 'CA');
    await tester.pumpAndSettle();
    expect(find.text('en_CA TextDirection.ltr'), findsOneWidget);

    await tester.binding.setLocale('ar', 'EG');
    await tester.pumpAndSettle();
    expect(find.text('ar_EG TextDirection.rtl'), findsOneWidget);

    await tester.binding.setLocale('da', 'DA');
    await tester.pumpAndSettle();
    expect(find.text('da_DA TextDirection.ltr'), findsOneWidget);
  });

605
  testWidgets("Localizations.override widget overrides parent's DefaultWidgetLocalizations", (WidgetTester tester) async {
606 607 608
    await tester.pumpWidget(
      buildFrame(
        // Accept whatever locale we're given
609
        localeResolutionCallback: (Locale? locale, Iterable<Locale> supportedLocales) => locale,
610
        buildContent: (BuildContext context) {
611
          return Localizations.override(
612
            context: context,
613
            delegates: const <OnlyRTLDefaultWidgetsLocalizationsDelegate>[
614
              // Override: no matter what the locale, textDirection is always RTL.
615
              OnlyRTLDefaultWidgetsLocalizationsDelegate(),
616
            ],
617
            child: Builder(
618
              builder: (BuildContext context) {
619
                final Locale locale = Localizations.localeOf(context);
620
                final TextDirection direction = WidgetsLocalizations.of(context).textDirection;
621
                return Text('$locale $direction');
622 623 624
              },
            ),
          );
625
        },
626 627 628
      )
    );

629
    // Initial WidgetTester locale is `en_US`.
630
    await tester.pumpAndSettle();
631
    expect(find.text('en_US TextDirection.rtl'), findsOneWidget);
632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649

    await tester.binding.setLocale('en', 'CA');
    await tester.pumpAndSettle();
    expect(find.text('en_CA TextDirection.rtl'), findsOneWidget);

    await tester.binding.setLocale('ar', 'EG');
    await tester.pumpAndSettle();
    expect(find.text('ar_EG TextDirection.rtl'), findsOneWidget);

    await tester.binding.setLocale('da', 'DA');
    await tester.pumpAndSettle();
    expect(find.text('da_DA TextDirection.rtl'), findsOneWidget);
  });

  testWidgets('WidgetsApp overrides DefaultWidgetLocalizations', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        // Accept whatever locale we're given
650
        localeResolutionCallback: (Locale? locale, Iterable<Locale> supportedLocales) => locale,
651 652 653 654
        delegates: <OnlyRTLDefaultWidgetsLocalizationsDelegate>[
          const OnlyRTLDefaultWidgetsLocalizationsDelegate(),
        ],
        buildContent: (BuildContext context) {
655
          final Locale locale = Localizations.localeOf(context);
656
          final TextDirection direction = WidgetsLocalizations.of(context).textDirection;
657
          return Text('$locale $direction');
658
        },
659 660 661
      )
    );

662
    // Initial WidgetTester locale is `en_US`.
663
    await tester.pumpAndSettle();
664
    expect(find.text('en_US TextDirection.rtl'), findsOneWidget);
665 666 667 668 669 670 671 672 673 674 675 676 677

    await tester.binding.setLocale('en', 'CA');
    await tester.pumpAndSettle();
    expect(find.text('en_CA TextDirection.rtl'), findsOneWidget);

    await tester.binding.setLocale('ar', 'EG');
    await tester.pumpAndSettle();
    expect(find.text('ar_EG TextDirection.rtl'), findsOneWidget);

    await tester.binding.setLocale('da', 'DA');
    await tester.pumpAndSettle();
    expect(find.text('da_DA TextDirection.rtl'), findsOneWidget);
  });
678

679 680 681 682 683 684 685 686
  // We provide <Locale>[Locale('en', 'US'), Locale('zh', 'CN')] as ui.window.locales
  // for flutter tester so that the behavior of tests match that of production
  // environments. Here, we test the default locales.
  testWidgets('WidgetsApp DefaultWidgetLocalizations', (WidgetTester tester) async {
    await tester.pumpAndSettle();
    await tester.pumpWidget(
      buildFrame(
        // Accept whatever locale we're given
687
        localeResolutionCallback: (Locale? locale, Iterable<Locale> supportedLocales) => locale,
688 689 690 691
        delegates: <OnlyRTLDefaultWidgetsLocalizationsDelegate>[
          const OnlyRTLDefaultWidgetsLocalizationsDelegate(),
        ],
        buildContent: (BuildContext context) {
692 693
          final Locale locale1 = ui.window.locales.first;
          final Locale locale2 = ui.window.locales[1];
694
          return Text('$locale1 $locale2');
695
        },
696 697 698 699 700 701
      )
    );
     // Initial WidgetTester default locales is `en_US` and `zh_CN`.
    await tester.pumpAndSettle();
    expect(find.text('en_US zh_CN'), findsOneWidget);
  });
702 703 704 705 706 707 708 709 710 711 712 713

  testWidgets('WidgetsApp.locale is resolved against supportedLocales', (WidgetTester tester) async {
    // app locale matches a supportedLocale
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale('zh', 'CN'),
          Locale('en', 'US'),
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
          return Text(Localizations.localeOf(context).toString());
714
        },
715 716 717 718 719 720 721 722 723 724 725 726 727 728 729
      )
    );
    await tester.pumpAndSettle();
    expect(find.text('en_US'), findsOneWidget);

    // app locale matches a supportedLocale's language
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale('zh', 'CN'),
          Locale('en', 'GB'),
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
          return Text(Localizations.localeOf(context).toString());
730
        },
731 732 733 734 735 736 737 738 739 740 741 742 743 744 745
      )
    );
    await tester.pumpAndSettle();
    expect(find.text('en_GB'), findsOneWidget);

    // app locale matches no supportedLocale
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale('zh', 'CN'),
          Locale('en', 'US'),
        ],
        locale: const Locale('ab', 'CD'),
        buildContent: (BuildContext context) {
          return Text(Localizations.localeOf(context).toString());
746
        },
747 748 749 750 751
      )
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_CN'), findsOneWidget);
  });
752 753 754 755 756 757 758 759 760 761 762

  // Example from http://unicode.org/reports/tr35/#LanguageMatching
  testWidgets('WidgetsApp Unicode tr35 1', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale('de'),
          Locale('fr'),
          Locale('ja'),
        ],
        buildContent: (BuildContext context) {
763
          final Locale locale = Localizations.localeOf(context);
764
          return Text('$locale');
765
        },
766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785
      )
    );
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'de', countryCode: 'AT'),
      Locale.fromSubtags(languageCode: 'fr'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('de'), findsOneWidget);
  });

  // Examples from http://unicode.org/reports/tr35/#LanguageMatching
  testWidgets('WidgetsApp Unicode tr35 2', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale('ja', 'JP'),
          Locale('de'),
          Locale('zh', 'TW'),
        ],
        buildContent: (BuildContext context) {
786
          final Locale locale = Localizations.localeOf(context);
787
          return Text('$locale');
788
        },
789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817
      )
    );
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_TW'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'de'),
      Locale.fromSubtags(languageCode: 'fr'),
      Locale.fromSubtags(languageCode: 'de', countryCode: 'SW'),
      Locale.fromSubtags(languageCode: 'it'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('de'), findsOneWidget);
  });

  testWidgets('WidgetsApp EdgeCase Chinese', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale.fromSubtags(languageCode: 'zh'),
          Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'CN'),
          Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant', countryCode: 'TW'),
          Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant', countryCode: 'HK'),
        ],
        buildContent: (BuildContext context) {
818
          final Locale locale = Localizations.localeOf(context);
819
          return Text('$locale');
820
        },
821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958
      )
    );

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'de'),
      Locale.fromSubtags(languageCode: 'fr'),
      Locale.fromSubtags(languageCode: 'de', countryCode: 'SW'),
      Locale.fromSubtags(languageCode: 'zh'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant', countryCode: 'US'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_TW'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_TW'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant', countryCode: 'TW'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_TW'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'TW'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_TW'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'HK'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_HK'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'HK'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'CN'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh'), findsOneWidget);

    // This behavior is up to the implementer to decide if a perfect scriptCode match
    // is better than a countryCode match.
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant', countryCode: 'CN'),
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'CN'),
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'CN'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_TW'), findsOneWidget);


    // languageCode only match is not enough to prevent resolving a perfect match
    // further down the preferredLocales list.
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'CN'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'JP'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'CN'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'CN'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    // When no language match, we try for country only, since it is likely users are
    // at least familiar with their country's language. This is a possible case only
    // on iOS, where countryCode can be selected independently from language and script.
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', scriptCode: 'Hans', countryCode: 'TW'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_TW'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'TW'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_TW'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'HK'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_HK'), findsOneWidget);
  });

  // Same as 'WidgetsApp EdgeCase Chinese' test except the supportedLocales order is
  // reversed.
  testWidgets('WidgetsApp EdgeCase ReverseChinese', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant', countryCode: 'HK'),
          Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant', countryCode: 'TW'),
          Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'CN'),
          Locale.fromSubtags(languageCode: 'zh'),
        ],
        buildContent: (BuildContext context) {
959
          final Locale locale = Localizations.localeOf(context);
960
          return Text('$locale');
961
        },
962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098
      )
    );

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'de'),
      Locale.fromSubtags(languageCode: 'fr'),
      Locale.fromSubtags(languageCode: 'de', countryCode: 'SW'),
      Locale.fromSubtags(languageCode: 'zh'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant', countryCode: 'US'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_HK'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_HK'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant', countryCode: 'TW'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_TW'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'TW'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_TW'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'HK'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_HK'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'HK'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'CN'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_HK'), findsOneWidget);

    // This behavior is up to the implementer to decide if a perfect scriptCode match
    // is better than a countryCode match.
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hant', countryCode: 'CN'),
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'CN'),
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'CN'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_HK'), findsOneWidget);

    // languageCode only match is not enough to prevent resolving a perfect match
    // further down the preferredLocales list.
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'CN'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'JP'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'zh', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'CN'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),
      Locale.fromSubtags(languageCode: 'zh', scriptCode: 'Hans', countryCode: 'CN'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hans_CN'), findsOneWidget);

    // When no language match, we try for country only, since it is likely users are
    // at least familiar with their country's language. This is a possible case only
    // on iOS, where countryCode can be selected independently from language and script.
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', scriptCode: 'Hans', countryCode: 'TW'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_TW'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'TW'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_TW'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'HK'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_Hant_HK'), findsOneWidget);
  });

  // Examples from https://developer.android.com/guide/topics/resources/multilingual-support
  testWidgets('WidgetsApp Android', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale('en'),
          Locale('de', 'DE'),
          Locale('es', 'ES'),
          Locale('fr', 'FR'),
          Locale('it', 'IT'),
        ],
        buildContent: (BuildContext context) {
1099
          final Locale locale = Localizations.localeOf(context);
1100
          return Text('$locale');
1101
        },
1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121
      )
    );
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'fr', countryCode: 'CH'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('fr_FR'), findsOneWidget);
  });

  // Examples from https://developer.android.com/guide/topics/resources/multilingual-support
  testWidgets('WidgetsApp Android', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale('en'),
          Locale('de', 'DE'),
          Locale('es', 'ES'),
          Locale('it', 'IT'),
        ],
        buildContent: (BuildContext context) {
1122
          final Locale locale = Localizations.localeOf(context);
1123
          return Text('$locale');
1124
        },
1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154
      )
    );
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'fr', countryCode: 'CH'),
      Locale.fromSubtags(languageCode: 'it', countryCode: 'CH'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('it_IT'), findsOneWidget);
  });

  testWidgets('WidgetsApp Country-only fallback', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale('en', 'US'),
          Locale('de', 'DE'),
          Locale('de', 'AU'),
          Locale('de', 'LU'),
          Locale('de', 'CH'),
          Locale('es', 'ES'),
          Locale('es', 'US'),
          Locale('it', 'IT'),
          Locale('zh', 'CN'),
          Locale('zh', 'TW'),
          Locale('fr', 'FR'),
          Locale('br', 'FR'),
          Locale('pt', 'BR'),
          Locale('pt', 'PT'),
        ],
        buildContent: (BuildContext context) {
1155
          final Locale locale = Localizations.localeOf(context);
1156
          return Text('$locale');
1157
        },
1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221
      )
    );
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'ar', countryCode: 'CH'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('de_CH'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'ar', countryCode: 'FR'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('fr_FR'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'ar', countryCode: 'US'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_US'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'es', countryCode: 'US'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('es_US'), findsOneWidget);

    // Strongly prefer matching first locale even if next one is perfect.
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'pt'),
      Locale.fromSubtags(languageCode: 'pt', countryCode: 'PT'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('pt_PT'), findsOneWidget);

    // Don't country match with any other available match. This behavior is
    // up for reconsideration.
    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'ar', countryCode: 'BR'),
      Locale.fromSubtags(languageCode: 'pt'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('pt_BR'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'ar', countryCode: 'BR'),
      Locale.fromSubtags(languageCode: 'pt', countryCode: 'PT'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('pt_PT'), findsOneWidget);
  });

  // Simulates a Chinese-default app that supports english in Canada but not
  // French. French-Canadian users should get 'en_CA' instead of Chinese.
  testWidgets('WidgetsApp Multilingual country', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale('zh', 'CN'),
          Locale('en', 'CA'),
          Locale('en', 'US'),
          Locale('en', 'AU'),
          Locale('de', 'DE'),
        ],
        buildContent: (BuildContext context) {
1222
          final Locale locale = Localizations.localeOf(context);
1223
          return Text('$locale');
1224
        },
1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285
      )
    );

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'fr', countryCode: 'CA'),
      Locale.fromSubtags(languageCode: 'fr'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_CA'), findsOneWidget);
  });


  testWidgets('WidgetsApp Common cases', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        // Decently well localized app.
        supportedLocales: const <Locale>[
          Locale('en', 'US'),
          Locale('en', 'GB'),
          Locale('en', 'AU'),
          Locale('en', 'CA'),
          Locale('zh', 'CN'),
          Locale('zh', 'TW'),
          Locale('de', 'DE'),
          Locale('de', 'CH'),
          Locale('es', 'MX'),
          Locale('es', 'ES'),
          Locale('es', 'AR'),
          Locale('es', 'CO'),
          Locale('ru', 'RU'),
          Locale('fr', 'FR'),
          Locale('fr', 'CA'),
          Locale('ar', 'SA'),
          Locale('ar', 'EG'),
          Locale('ar', 'IQ'),
          Locale('ar', 'MA'),
          Locale('af'),
          Locale('bg'),
          Locale('nl', 'NL'),
          Locale('pl'),
          Locale('cs'),
          Locale('fa'),
          Locale('el'),
          Locale('he'),
          Locale('hi'),
          Locale('pa'),
          Locale('ta'),
          Locale('id'),
          Locale('it', 'IT'),
          Locale('ja'),
          Locale('ko'),
          Locale('ms'),
          Locale('mn'),
          Locale('pt', 'BR'),
          Locale('pt', 'PT'),
          Locale('sv', 'SE'),
          Locale('th'),
          Locale('tr'),
          Locale('vi'),
        ],
        buildContent: (BuildContext context) {
1286
          final Locale locale = Localizations.localeOf(context);
1287
          return Text('$locale');
1288
        },
1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420
      )
    );

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_US'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_US'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'CA'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_CA'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'AU'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_AU'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'ar', countryCode: 'CH'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('ar_SA'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'ar'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('ar_SA'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'ar', countryCode: 'IQ'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('ar_IQ'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'es', countryCode: 'ES'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('es_ES'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'es'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('es_MX'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'pa', countryCode: 'US'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('pa'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'hi', countryCode: 'IN'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('hi'), findsOneWidget);

    // Multiple preferred locales:

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'NZ'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'AU'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'GB'),
      Locale.fromSubtags(languageCode: 'en'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_AU'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'ab'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'NZ'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'AU'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'GB'),
      Locale.fromSubtags(languageCode: 'en'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_AU'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'NZ'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'PH'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'ZA'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'CB'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_US'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'CA'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'AU'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'GB'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_CA'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'da'),
      Locale.fromSubtags(languageCode: 'en'),
      Locale.fromSubtags(languageCode: 'en', countryCode: 'CA'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_CA'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'da'),
      Locale.fromSubtags(languageCode: 'fo'),
      Locale.fromSubtags(languageCode: 'hr'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_US'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'da'),
      Locale.fromSubtags(languageCode: 'fo'),
      Locale.fromSubtags(languageCode: 'hr', countryCode: 'CA'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_CA'), findsOneWidget);
  });
1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431

  testWidgets('WidgetsApp invalid preferredLocales', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        supportedLocales: const <Locale>[
          Locale('zh', 'CN'),
          Locale('en', 'CA'),
          Locale('en', 'US'),
          Locale('en', 'AU'),
          Locale('de', 'DE'),
        ],
1432
        localeResolutionCallback: (Locale? locale, Iterable<Locale> supportedLocales) {
1433 1434 1435 1436 1437
          if (locale == null)
            return const Locale('und', 'US');
          return const Locale('en', 'US');
        },
        buildContent: (BuildContext context) {
1438
          final Locale locale = Localizations.localeOf(context);
1439
          return Text('$locale');
1440
        },
1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453
      )
    );

    await tester.binding.setLocales(const <Locale>[
      Locale.fromSubtags(languageCode: 'en', countryCode: 'US'),]
    );
    await tester.pumpAndSettle();
    expect(find.text('en_US'), findsOneWidget);

    await tester.binding.setLocales(const <Locale>[]);
    await tester.pumpAndSettle();
    expect(find.text('und_US'), findsOneWidget);
  });
1454
}