tab_test.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/cupertino.dart';
import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';

void main() {
  testWidgets('Use home', (WidgetTester tester) async {
    await tester.pumpWidget(
      CupertinoApp(
        home: CupertinoTabView(
          builder: (BuildContext context) => const Text('home'),
        ),
      ),
    );

    expect(find.text('home'), findsOneWidget);
  });

  testWidgets('Use routes', (WidgetTester tester) async {
    await tester.pumpWidget(
      CupertinoApp(
        home: CupertinoTabView(
          routes: <String, WidgetBuilder>{
            '/': (BuildContext context) => const Text('first route'),
          },
        ),
      ),
    );

    expect(find.text('first route'), findsOneWidget);
  });

  testWidgets('Use home and named routes', (WidgetTester tester) async {
    await tester.pumpWidget(
      CupertinoApp(
        home: CupertinoTabView(
          builder: (BuildContext context) {
            return CupertinoButton(
              child: const Text('go to second page'),
              onPressed: () {
                Navigator.of(context).pushNamed('/2');
              },
            );
          },
          routes: <String, WidgetBuilder>{
            '/2': (BuildContext context) => const Text('second named route'),
          },
        ),
      ),
    );

    expect(find.text('go to second page'), findsOneWidget);
    await tester.tap(find.text('go to second page'));
    await tester.pump();
    await tester.pump(const Duration(milliseconds: 300));
    expect(find.text('second named route'), findsOneWidget);
  });

  testWidgets('Use onGenerateRoute', (WidgetTester tester) async {
    await tester.pumpWidget(
      CupertinoApp(
        home: CupertinoTabView(
          onGenerateRoute: (RouteSettings settings) {
            if (settings.name == Navigator.defaultRouteName) {
              return CupertinoPageRoute<void>(
                settings: settings,
                builder: (BuildContext context) {
                  return const Text('generated home');
                },
              );
            }
            return null;
          },
        ),
      ),
    );

    expect(find.text('generated home'), findsOneWidget);
  });

  testWidgets('Use onUnknownRoute', (WidgetTester tester) async {
    late String unknownForRouteCalled;
    await tester.pumpWidget(
      CupertinoApp(
        home: CupertinoTabView(
          onUnknownRoute: (RouteSettings settings) {
            unknownForRouteCalled = settings.name!;
            return null;
          },
        ),
      ),
    );

    expect(tester.takeException(), isFlutterError);
    expect(unknownForRouteCalled, '/');

    // Work-around for https://github.com/flutter/flutter/issues/65655.
    await tester.pumpWidget(Container());
    expect(tester.takeException(), isAssertionError);
  });

  testWidgets('Can use navigatorKey to navigate', (WidgetTester tester) async {
    final GlobalKey<NavigatorState> key = GlobalKey();
    await tester.pumpWidget(
      CupertinoApp(
        home: CupertinoTabView(
          navigatorKey: key,
          builder: (BuildContext context) => const Text('first route'),
          routes: <String, WidgetBuilder>{
            '/2': (BuildContext context) => const Text('second route'),
          },
        ),
      ),
    );

    key.currentState!.pushNamed('/2');

    await tester.pump();
    await tester.pump(const Duration(milliseconds: 300));
    expect(find.text('second route'), findsOneWidget);
  });

  testWidgets('Changing the key resets the navigator', (WidgetTester tester) async {
    final GlobalKey<NavigatorState> key = GlobalKey();
    await tester.pumpWidget(
      CupertinoApp(
        home: CupertinoTabView(
          builder: (BuildContext context) {
            return CupertinoButton(
              child: const Text('go to second page'),
              onPressed: () {
                Navigator.of(context).pushNamed('/2');
              },
            );
          },
          routes: <String, WidgetBuilder>{
            '/2': (BuildContext context) => const Text('second route'),
          },
        ),
      ),
    );

    expect(find.text('go to second page'), findsOneWidget);
    await tester.tap(find.text('go to second page'));
    await tester.pump();
    await tester.pump(const Duration(milliseconds: 300));
    expect(find.text('second route'), findsOneWidget);

    await tester.pumpWidget(
      CupertinoApp(
        home: CupertinoTabView(
          key: key,
          builder: (BuildContext context) {
            return CupertinoButton(
              child: const Text('go to second page'),
              onPressed: () {
                Navigator.of(context).pushNamed('/2');
              },
            );
          },
          routes: <String, WidgetBuilder>{
            '/2': (BuildContext context) => const Text('second route'),
          },
        ),
      ),
    );

    // The stack is gone and we're back to a re-built page 1.
    expect(find.text('go to second page'), findsOneWidget);
    expect(find.text('second route'), findsNothing);
  });

  testWidgets('Throws FlutterError when onUnknownRoute is null', (WidgetTester tester) async {
    final GlobalKey<NavigatorState> key = GlobalKey();
    await tester.pumpWidget(
      CupertinoApp(
        home: CupertinoTabView(
          navigatorKey: key,
          builder: (BuildContext context) => const Text('first route'),
        ),
      ),
    );
    late FlutterError error;
    try {
      key.currentState!.pushNamed('/2');
    } on FlutterError catch (e) {
      error = e;
    }
    expect(error, isNotNull);
    expect(
      error.toStringDeep(),
      equalsIgnoringHashCodes(
        'FlutterError\n'
        '   Could not find a generator for route RouteSettings("/2", null) in\n'
        '   the _CupertinoTabViewState.\n'
        '   Generators for routes are searched for in the following order:\n'
        '    1. For the "/" route, the "builder" property, if non-null, is\n'
        '   used.\n'
        '    2. Otherwise, the "routes" table is used, if it has an entry for\n'
        '   the route.\n'
        '    3. Otherwise, onGenerateRoute is called. It should return a\n'
        '   non-null value for any valid route not handled by "builder" and\n'
        '   "routes".\n'
        '    4. Finally if all else fails onUnknownRoute is called.\n'
        '   Unfortunately, onUnknownRoute was not set.\n',
      ),
    );
  });

  testWidgets('Throws FlutterError when onUnknownRoute returns null', (WidgetTester tester) async {
    final GlobalKey<NavigatorState> key = GlobalKey<NavigatorState>();
    await tester.pumpWidget(
      CupertinoApp(
        home: CupertinoTabView(
          navigatorKey: key,
          builder: (BuildContext context) => const Text('first route'),
          onUnknownRoute: (_) => null,
        ),
      ),
    );
    late FlutterError error;
    try {
      key.currentState!.pushNamed('/2');
    } on FlutterError catch (e) {
      error = e;
    }
    expect(error, isNotNull);
    expect(
      error.toStringDeep(),
      equalsIgnoringHashCodes(
        'FlutterError\n'
        '   The onUnknownRoute callback returned null.\n'
        '   When the _CupertinoTabViewState requested the route\n'
        '   RouteSettings("/2", null) from its onUnknownRoute callback, the\n'
        '   callback returned null. Such callbacks must never return null.\n',
      ),
    );
  });

  testWidgets('Navigator of CupertinoTabView restores state', (WidgetTester tester) async {
    await tester.pumpWidget(
      CupertinoApp(
        restorationScopeId: 'app',
        home: CupertinoTabView(
          restorationScopeId: 'tab',
          builder: (BuildContext context) => CupertinoButton(
            child: const Text('home'),
            onPressed: () {
              Navigator.of(context).restorablePushNamed('/2');
            },
          ),
          routes: <String, WidgetBuilder>{
            '/2' : (BuildContext context) => const Text('second route'),
          },
        ),
      ),
    );

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

    expect(find.text('home'), findsNothing);
    expect(find.text('second route'), findsOneWidget);

    final TestRestorationData data = await tester.getRestorationData();

    await tester.restartAndRestore();

    expect(find.text('home'), findsNothing);
    expect(find.text('second route'), findsOneWidget);

    Navigator.of(tester.element(find.text('second route'))).pop();
    await tester.pumpAndSettle();

    expect(find.text('home'), findsOneWidget);
    expect(find.text('second route'), findsNothing);

    await tester.restoreFrom(data);

    expect(find.text('home'), findsNothing);
    expect(find.text('second route'), findsOneWidget);

    Navigator.of(tester.element(find.text('second route'))).pop();
    await tester.pumpAndSettle();

    expect(find.text('home'), findsOneWidget);
    expect(find.text('second route'), findsNothing);
  });

  testWidgets('Handles Android back button', (WidgetTester tester) async {
    final GlobalKey<NavigatorState> key = GlobalKey<NavigatorState>();
    await tester.pumpWidget(
      CupertinoApp(
        home: CupertinoTabScaffold(
          tabBar: CupertinoTabBar(
            items: const <BottomNavigationBarItem>[
              BottomNavigationBarItem(label: '', icon: Text('1')),
              BottomNavigationBarItem(label: '', icon: Text('2'))
            ],
          ),
          tabBuilder: (_, int i) => PopScope(
            canPop: false,
            child: CupertinoTabView(
              navigatorKey: key,
              builder: (BuildContext context) => const Text('first route'),
            ),
          ),
        ),
      ),
    );

    expect(find.text('first route'), findsOneWidget);

    // Simulate android back button intent.
    final ByteData message = const JSONMethodCodec().encodeMethodCall(const MethodCall('popRoute'));
    await tester.binding.defaultBinaryMessenger.handlePlatformMessage('flutter/navigation', message, (_) {});
    await tester.pumpAndSettle();

    // Navigator didn't pop, so first route is still visible
    expect(find.text('first route'), findsOneWidget);
  });
}