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 5 6
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

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

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

  final Locale locale;
14
  final String? prefix;
15

16
  static Future<TestLocalizations> loadSync(Locale locale, String? prefix) {
17
    return SynchronousFuture<TestLocalizations>(TestLocalizations(locale, prefix));
18 19
  }

20 21 22 23 24
  static Future<TestLocalizations> loadAsync(Locale locale, String? prefix) {
    return Future<TestLocalizations>.delayed(
      const Duration(milliseconds: 100),
      () => TestLocalizations(locale, prefix)
    );
25 26 27
  }

  static TestLocalizations of(BuildContext context) {
28
    return Localizations.of<TestLocalizations>(context, TestLocalizations)!;
29 30 31 32 33 34 35 36
  }

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

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

37
  final String? prefix; // Changing this value triggers a rebuild
38 39
  final List<bool> shouldReloadValues = <bool>[];

40 41 42
  @override
  bool isSupported(Locale locale) => true;

43 44 45 46 47 48 49 50
  @override
  Future<TestLocalizations> load(Locale locale) => TestLocalizations.loadSync(locale, prefix);

  @override
  bool shouldReload(SyncTestLocalizationsDelegate old) {
    shouldReloadValues.add(prefix != old.prefix);
    return prefix != old.prefix;
  }
51 52

  @override
Ian Hickson's avatar
Ian Hickson committed
53
  String toString() => '${objectRuntimeType(this, 'SyncTestLocalizationsDelegate')}($prefix)';
54 55 56 57 58
}

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

59
  final String? prefix; // Changing this value triggers a rebuild
60 61
  final List<bool> shouldReloadValues = <bool>[];

62 63 64
  @override
  bool isSupported(Locale locale) => true;

65 66 67 68 69 70 71 72
  @override
  Future<TestLocalizations> load(Locale locale) => TestLocalizations.loadAsync(locale, prefix);

  @override
  bool shouldReload(AsyncTestLocalizationsDelegate old) {
    shouldReloadValues.add(prefix != old.prefix);
    return prefix != old.prefix;
  }
73 74

  @override
Ian Hickson's avatar
Ian Hickson committed
75
  String toString() => '${objectRuntimeType(this, 'AsyncTestLocalizationsDelegate')}($prefix)';
76 77 78 79 80 81 82 83
}

class MoreLocalizations {
  MoreLocalizations(this.locale);

  final Locale locale;

  static Future<MoreLocalizations> loadSync(Locale locale) {
84
    return SynchronousFuture<MoreLocalizations>(MoreLocalizations(locale));
85 86 87
  }

  static Future<MoreLocalizations> loadAsync(Locale locale) {
88 89 90 91
    return Future<MoreLocalizations>.delayed(
      const Duration(milliseconds: 100),
      () => MoreLocalizations(locale)
    );
92 93 94
  }

  static MoreLocalizations of(BuildContext context) {
95
    return Localizations.of<MoreLocalizations>(context, MoreLocalizations)!;
96 97 98 99 100 101 102 103 104
  }

  String get message => '$locale';
}

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

105 106 107
  @override
  bool isSupported(Locale locale) => true;

108 109 110 111 112 113 114 115
  @override
  bool shouldReload(SyncMoreLocalizationsDelegate old) => false;
}

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

116 117 118
  @override
  bool isSupported(Locale locale) => true;

119 120 121 122
  @override
  bool shouldReload(AsyncMoreLocalizationsDelegate old) => false;
}

123 124 125 126 127 128 129 130
class OnlyRTLDefaultWidgetsLocalizations extends DefaultWidgetsLocalizations {
  @override
  TextDirection get textDirection => TextDirection.rtl;
}

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

131 132 133
  @override
  bool isSupported(Locale locale) => true;

134 135
  @override
  Future<WidgetsLocalizations> load(Locale locale) {
136
    return SynchronousFuture<WidgetsLocalizations>(OnlyRTLDefaultWidgetsLocalizations());
137 138 139 140 141 142
  }

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

143
Widget buildFrame({
144 145 146 147
  Locale? locale,
  Iterable<LocalizationsDelegate<dynamic>>? delegates,
  required WidgetBuilder buildContent,
  LocaleResolutionCallback? localeResolutionCallback,
148
  List<Locale> supportedLocales = const <Locale>[
149 150
    Locale('en', 'US'),
    Locale('en', 'GB'),
151
  ],
152
}) {
153
  return WidgetsApp(
154 155 156
    color: const Color(0xFFFFFFFF),
    locale: locale,
    localizationsDelegates: delegates,
157 158
    localeResolutionCallback: localeResolutionCallback,
    supportedLocales: supportedLocales,
159
    onGenerateRoute: (RouteSettings settings) {
160
      return PageRouteBuilder<void>(
161 162 163 164 165 166 167 168
        pageBuilder: (BuildContext context, Animation<double> _, Animation<double> __) {
          return buildContent(context);
        }
      );
    },
  );
}

169
class SyncLoadTest extends StatefulWidget {
170
  const SyncLoadTest({super.key});
171 172

  @override
173
  SyncLoadTestState createState() => SyncLoadTestState();
174 175 176 177 178
}

class SyncLoadTestState extends State<SyncLoadTest> {
  @override
  Widget build(BuildContext context) {
179
    return Text(
180 181 182 183 184 185
      TestLocalizations.of(context).message,
      textDirection: TextDirection.rtl,
    );
  }
}

186 187
void main() {
  testWidgets('Localizations.localeFor in a WidgetsApp with system locale', (WidgetTester tester) async {
188
    late BuildContext pageContext;
189 190 191 192 193

    await tester.pumpWidget(
      buildFrame(
        buildContent: (BuildContext context) {
          pageContext = context;
Ian Hickson's avatar
Ian Hickson committed
194
          return const Text('Hello World', textDirection: TextDirection.ltr);
195 196 197 198 199 200 201 202 203 204 205 206 207 208
        }
      )
    );

    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 {
209
    const Locale locale = Locale('en', 'US');
210
    late BuildContext pageContext;
211 212 213 214 215 216

    await tester.pumpWidget(
      buildFrame(
        locale: locale,
        buildContent: (BuildContext context) {
          pageContext = context;
217
          return const Text('Hello World');
218 219 220 221 222 223 224 225 226 227 228 229 230 231
        },
      )
    );

    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 {
232
    final List<LocalizationsDelegate<dynamic>> delegates = <LocalizationsDelegate<dynamic>>[
233
      SyncTestLocalizationsDelegate(),
234
      DefaultWidgetsLocalizations.delegate,
235 236
    ];

237
    Future<void> pumpTest(Locale locale) async {
238
      await tester.pumpWidget(Localizations(
239 240 241 242 243
        locale: locale,
        delegates: delegates,
        child: const SyncLoadTest(),
      ));
    }
244

245
    await pumpTest(const Locale('en', 'US'));
246
    expect(find.text('en_US'), findsOneWidget);
247

248
    await pumpTest(const Locale('en', 'GB'));
249 250 251
    await tester.pump();
    expect(find.text('en_GB'), findsOneWidget);

252
    await pumpTest(const Locale('en', 'US'));
253 254 255 256 257 258 259 260
    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>>[
261
          AsyncTestLocalizationsDelegate(),
262 263
        ],
        buildContent: (BuildContext context) {
264
          return Text(TestLocalizations.of(context).message);
265
        },
266 267 268
      )
    );
    await tester.pump(const Duration(milliseconds: 50)); // TestLocalizations.loadAsync() takes 100ms
269
    expect(find.text('en_US'), findsNothing); // TestLocalizations hasn't been loaded yet
270 271 272

    await tester.pump(const Duration(milliseconds: 50)); // TestLocalizations.loadAsync() completes
    await tester.pumpAndSettle();
273
    expect(find.text('en_US'), findsOneWidget); // default test locale is US english
274

275
    await tester.binding.setLocale('en', 'GB');
276 277
    await tester.pump(const Duration(milliseconds: 100));
    await tester.pumpAndSettle();
278
    expect(find.text('en_GB'), findsOneWidget);
279

280
    await tester.binding.setLocale('en', 'US');
281 282 283
    await tester.pump(const Duration(milliseconds: 50));
    // TestLocalizations.loadAsync() hasn't completed yet so the old text
    // localization is still displayed
284
    expect(find.text('en_GB'), findsOneWidget);
285 286
    await tester.pump(const Duration(milliseconds: 50)); // finish the async load
    await tester.pumpAndSettle();
287
    expect(find.text('en_US'), findsOneWidget);
288 289 290 291 292 293
  });

  testWidgets('Localizations with multiple sync delegates', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
294 295
          SyncTestLocalizationsDelegate(),
          SyncMoreLocalizationsDelegate(),
296 297 298
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
299
          return Column(
300
            children: <Widget>[
301 302
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
303 304
            ],
          );
305
        },
306 307 308
      )
    );

Josh Soref's avatar
Josh Soref committed
309
    // All localizations were loaded synchronously
310 311 312 313 314 315 316 317
    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>>[
318 319
          SyncTestLocalizationsDelegate(),
          AsyncMoreLocalizationsDelegate(), // No resources until this completes
320 321 322
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
323
          return Column(
324
            children: <Widget>[
325 326
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
327 328
            ],
          );
329
        },
330 331 332 333 334 335 336 337 338 339 340 341 342 343
      )
    );

    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
344
  testWidgets('Multiple Localizations', (WidgetTester tester) async {
345 346 347
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
348
          SyncTestLocalizationsDelegate(),
349 350 351
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
352
          return Column(
353
            children: <Widget>[
354 355
              Text('A: ${TestLocalizations.of(context).message}'),
              Localizations(
356 357
                locale: const Locale('en', 'GB'),
                delegates: <LocalizationsDelegate<dynamic>>[
358
                  SyncTestLocalizationsDelegate(),
359
                  DefaultWidgetsLocalizations.delegate,
360 361
                ],
                // Create a new context within the en_GB Localization
362
                child: Builder(
363
                  builder: (BuildContext context) {
364
                    return Text('B: ${TestLocalizations.of(context).message}');
365 366 367 368 369
                  },
                ),
              ),
            ],
          );
370
        },
371 372 373 374 375 376 377 378 379 380 381
      )
    );

    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 {
382
    final SyncTestLocalizationsDelegate originalDelegate = SyncTestLocalizationsDelegate();
383 384 385 386
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
          originalDelegate,
387
          SyncMoreLocalizationsDelegate(),
388 389 390
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
391
          return Column(
392
            children: <Widget>[
393 394
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
395 396
            ],
          );
397
        },
398 399 400 401 402 403 404 405 406
      )
    );

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


407
    final SyncTestLocalizationsDelegate modifiedDelegate = SyncTestLocalizationsDelegate('---');
408 409 410 411
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
          modifiedDelegate,
412
          SyncMoreLocalizationsDelegate(),
413 414 415
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
416
          return Column(
417
            children: <Widget>[
418 419
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
420 421
            ],
          );
422
        },
423 424 425 426 427 428 429
      )
    );

    await tester.pumpAndSettle();
    expect(find.text('A: ---en_US'), findsOneWidget);
    expect(find.text('B: en_US'), findsOneWidget);
    expect(modifiedDelegate.shouldReloadValues, <bool>[true]);
430
    expect(originalDelegate.shouldReloadValues, <bool>[]);
431 432 433 434 435 436
  });

  testWidgets('Localizations async delegate shouldReload returns true', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
437 438
          AsyncTestLocalizationsDelegate(),
          AsyncMoreLocalizationsDelegate(),
439 440 441
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
442
          return Column(
443
            children: <Widget>[
444 445
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
446 447
            ],
          );
448
        },
449 450 451 452 453 454 455
      )
    );

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

456
    final AsyncTestLocalizationsDelegate modifiedDelegate = AsyncTestLocalizationsDelegate('---');
457 458 459 460
    await tester.pumpWidget(
      buildFrame(
        delegates: <LocalizationsDelegate<dynamic>>[
          modifiedDelegate,
461
          AsyncMoreLocalizationsDelegate(),
462 463 464
        ],
        locale: const Locale('en', 'US'),
        buildContent: (BuildContext context) {
465
          return Column(
466
            children: <Widget>[
467 468
              Text('A: ${TestLocalizations.of(context).message}'),
              Text('B: ${MoreLocalizations.of(context).message}'),
469 470
            ],
          );
471
        },
472 473 474 475 476 477 478 479 480
      )
    );

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

481
  testWidgets('Directionality tracks system locale', (WidgetTester tester) async {
482
    late BuildContext pageContext;
483 484 485

    await tester.pumpWidget(
      buildFrame(
486 487 488
        delegates: const <LocalizationsDelegate<dynamic>>[
          GlobalWidgetsLocalizations.delegate,
        ],
489
        supportedLocales: const <Locale>[
490 491
          Locale('en', 'GB'),
          Locale('ar', 'EG'),
492
        ],
493 494 495
        buildContent: (BuildContext context) {
          pageContext = context;
          return const Text('Hello World');
496
        },
497 498 499 500 501 502 503 504 505 506 507
      )
    );

    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);
  });
508 509 510 511

  testWidgets('localeResolutionCallback override', (WidgetTester tester) async {
    await tester.pumpWidget(
      buildFrame(
512
        localeResolutionCallback: (Locale? newLocale, Iterable<Locale> supportedLocales) {
513 514 515
          return const Locale('foo', 'BAR');
        },
        buildContent: (BuildContext context) {
516
          return Text(Localizations.localeOf(context).toString());
517
        },
518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533
      )
    );

    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>[
534 535 536
          Locale('zh', 'CN'),
          Locale('en', 'GB'),
          Locale('en', 'CA'),
537 538
        ],
        buildContent: (BuildContext context) {
539
          return Text(Localizations.localeOf(context).toString());
540
        },
541 542 543 544
      )
    );

    await tester.pumpAndSettle();
545
    expect(find.text('en_GB'), findsOneWidget);
546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561

    // 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);
  });
562

563
  testWidgets("Localizations.override widget tracks parent's locale and delegates", (WidgetTester tester) async {
564 565 566
    await tester.pumpWidget(
      buildFrame(
        // Accept whatever locale we're given
567
        localeResolutionCallback: (Locale? locale, Iterable<Locale> supportedLocales) => locale,
568 569 570
        delegates: const <LocalizationsDelegate<dynamic>>[
          GlobalWidgetsLocalizations.delegate,
        ],
571
        buildContent: (BuildContext context) {
572
          return Localizations.override(
573
            context: context,
574
            child: Builder(
575
              builder: (BuildContext context) {
576
                final Locale locale = Localizations.localeOf(context);
577
                final TextDirection direction = WidgetsLocalizations.of(context).textDirection;
578
                return Text('$locale $direction');
579 580 581
              },
            ),
          );
582
        },
583 584
      )
    );
585

586
    // Initial WidgetTester locale is `en_US`.
587
    await tester.pumpAndSettle();
588
    expect(find.text('en_US TextDirection.ltr'), findsOneWidget);
589 590 591 592 593 594 595 596 597 598 599 600 601 602

    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);
  });

603
  testWidgets("Localizations.override widget overrides parent's DefaultWidgetLocalizations", (WidgetTester tester) async {
604 605 606
    await tester.pumpWidget(
      buildFrame(
        // Accept whatever locale we're given
607
        localeResolutionCallback: (Locale? locale, Iterable<Locale> supportedLocales) => locale,
608
        buildContent: (BuildContext context) {
609
          return Localizations.override(
610
            context: context,
611
            delegates: const <OnlyRTLDefaultWidgetsLocalizationsDelegate>[
612
              // Override: no matter what the locale, textDirection is always RTL.
613
              OnlyRTLDefaultWidgetsLocalizationsDelegate(),
614
            ],
615
            child: Builder(
616
              builder: (BuildContext context) {
617
                final Locale locale = Localizations.localeOf(context);
618
                final TextDirection direction = WidgetsLocalizations.of(context).textDirection;
619
                return Text('$locale $direction');
620 621 622
              },
            ),
          );
623
        },
624 625 626
      )
    );

627
    // Initial WidgetTester locale is `en_US`.
628
    await tester.pumpAndSettle();
629
    expect(find.text('en_US TextDirection.rtl'), findsOneWidget);
630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647

    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
648
        localeResolutionCallback: (Locale? locale, Iterable<Locale> supportedLocales) => locale,
649 650 651 652
        delegates: <OnlyRTLDefaultWidgetsLocalizationsDelegate>[
          const OnlyRTLDefaultWidgetsLocalizationsDelegate(),
        ],
        buildContent: (BuildContext context) {
653
          final Locale locale = Localizations.localeOf(context);
654
          final TextDirection direction = WidgetsLocalizations.of(context).textDirection;
655
          return Text('$locale $direction');
656
        },
657 658 659
      )
    );

660
    // Initial WidgetTester locale is `en_US`.
661
    await tester.pumpAndSettle();
662
    expect(find.text('en_US TextDirection.rtl'), findsOneWidget);
663 664 665 666 667 668 669 670 671 672 673 674 675

    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);
  });
676

677 678 679 680 681 682 683 684
  // 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
685
        localeResolutionCallback: (Locale? locale, Iterable<Locale> supportedLocales) => locale,
686 687 688 689
        delegates: <OnlyRTLDefaultWidgetsLocalizationsDelegate>[
          const OnlyRTLDefaultWidgetsLocalizationsDelegate(),
        ],
        buildContent: (BuildContext context) {
690 691
          final Locale locale1 = WidgetsBinding.instance.platformDispatcher.locales.first;
          final Locale locale2 = WidgetsBinding.instance.platformDispatcher.locales[1];
692
          return Text('$locale1 $locale2');
693
        },
694 695 696 697 698 699
      )
    );
     // Initial WidgetTester default locales is `en_US` and `zh_CN`.
    await tester.pumpAndSettle();
    expect(find.text('en_US zh_CN'), findsOneWidget);
  });
700 701 702 703 704 705 706 707 708 709 710 711

  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());
712
        },
713 714 715 716 717 718 719 720 721 722 723 724 725 726 727
      )
    );
    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());
728
        },
729 730 731 732 733 734 735 736 737 738 739 740 741 742 743
      )
    );
    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());
744
        },
745 746 747 748 749
      )
    );
    await tester.pumpAndSettle();
    expect(find.text('zh_CN'), findsOneWidget);
  });
750 751 752 753 754 755 756 757 758 759 760

  // 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) {
761
          final Locale locale = Localizations.localeOf(context);
762
          return Text('$locale');
763
        },
764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783
      )
    );
    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) {
784
          final Locale locale = Localizations.localeOf(context);
785
          return Text('$locale');
786
        },
787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815
      )
    );
    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) {
816
          final Locale locale = Localizations.localeOf(context);
817
          return Text('$locale');
818
        },
819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956
      )
    );

    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) {
957
          final Locale locale = Localizations.localeOf(context);
958
          return Text('$locale');
959
        },
960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 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
      )
    );

    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) {
1097
          final Locale locale = Localizations.localeOf(context);
1098
          return Text('$locale');
1099
        },
1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119
      )
    );
    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) {
1120
          final Locale locale = Localizations.localeOf(context);
1121
          return Text('$locale');
1122
        },
1123 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
      )
    );
    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) {
1153
          final Locale locale = Localizations.localeOf(context);
1154
          return Text('$locale');
1155
        },
1156 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
      )
    );
    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) {
1220
          final Locale locale = Localizations.localeOf(context);
1221
          return Text('$locale');
1222
        },
1223 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
      )
    );

    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) {
1284
          final Locale locale = Localizations.localeOf(context);
1285
          return Text('$locale');
1286
        },
1287 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
      )
    );

    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);
  });
1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429

  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'),
        ],
1430
        localeResolutionCallback: (Locale? locale, Iterable<Locale> supportedLocales) {
1431
          if (locale == null) {
1432
            return const Locale('und', 'US');
1433
          }
1434 1435 1436
          return const Locale('en', 'US');
        },
        buildContent: (BuildContext context) {
1437
          final Locale locale = Localizations.localeOf(context);
1438
          return Text('$locale');
1439
        },
1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452
      )
    );

    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);
  });
1453
}