packages/flutter/test/widgets/navigator_replacement_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/material.dart';
import 'package:flutter_test/flutter_test.dart';

import 'observer_tester.dart';

void main() {
  testWidgets('Back during pushReplacement', (WidgetTester tester) async {
    await tester.pumpWidget(MaterialApp(
      home: const Material(child: Text('home')),
      routes: <String, WidgetBuilder>{
        '/a': (BuildContext context) => const Material(child: Text('a')),
        '/b': (BuildContext context) => const Material(child: Text('b')),
      },
    ));

    final NavigatorState navigator = tester.state(find.byType(Navigator));
    navigator.pushNamed('/a');
    await tester.pumpAndSettle();

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

    navigator.pushReplacementNamed('/b');
    await tester.pump();
    await tester.pump(const Duration(milliseconds: 10));

    expect(find.text('a'), findsOneWidget);
    expect(find.text('b'), findsOneWidget);
    expect(find.text('home'), findsNothing);

    navigator.pop();

    await tester.pumpAndSettle();

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

  group('pushAndRemoveUntil', () {
    testWidgets('notifies appropriately', (WidgetTester tester) async {
      final TestObserver observer = TestObserver();
      final Widget myApp = MaterialApp(
        home: const Material(child: Text('home')),
        routes: <String, WidgetBuilder>{
          '/a': (BuildContext context) => const Material(child: Text('a')),
          '/b': (BuildContext context) => const Material(child: Text('b')),
        },
        navigatorObservers: <NavigatorObserver>[observer],
      );

      await tester.pumpWidget(myApp);

      final NavigatorState navigator = tester.state(find.byType(Navigator));
      final List<String> log = <String>[];
      observer
        ..onPushed = (Route<dynamic>? route, Route<dynamic>? previousRoute) {
          log.add('${route!.settings.name} pushed, previous route: ${previousRoute!.settings.name}');
        }
        ..onRemoved = (Route<dynamic>? route, Route<dynamic>? previousRoute) {
          log.add('${route!.settings.name} removed, previous route: ${previousRoute?.settings.name}');
        };


      navigator.pushNamed('/a');
      await tester.pumpAndSettle();

      expect(find.text('home', skipOffstage: false), findsOneWidget);
      expect(find.text('a', skipOffstage: false), findsOneWidget);
      expect(find.text('b', skipOffstage: false), findsNothing);

      // Remove all routes below
      navigator.pushNamedAndRemoveUntil('/b', (Route<dynamic> route) => false);
      await tester.pumpAndSettle();

      expect(find.text('home', skipOffstage: false), findsNothing);
      expect(find.text('a', skipOffstage: false), findsNothing);
      expect(find.text('b', skipOffstage: false), findsOneWidget);
      expect(log, equals(<String>[
        '/a pushed, previous route: /',
        '/b pushed, previous route: /a',
        '/a removed, previous route: null',
        '/ removed, previous route: null',
      ]));

      log.clear();

      navigator.pushNamed('/');
      await tester.pumpAndSettle();

      expect(find.text('home', skipOffstage: false), findsOneWidget);
      expect(find.text('a', skipOffstage: false), findsNothing);
      expect(find.text('b', skipOffstage: false), findsOneWidget);

      // Remove only some routes below
      navigator.pushNamedAndRemoveUntil('/a', ModalRoute.withName('/b'));
      await tester.pumpAndSettle();

      expect(find.text('home', skipOffstage: false), findsNothing);
      expect(find.text('a', skipOffstage: false), findsOneWidget);
      expect(find.text('b', skipOffstage: false), findsOneWidget);
      expect(log, equals(<String>[
        '/ pushed, previous route: /b',
        '/a pushed, previous route: /',
        '/ removed, previous route: /b',
      ]));
    });

    testWidgets('triggers page transition animation for pushed route', (WidgetTester tester) async {
      final Widget myApp = MaterialApp(
        home: const Material(child: Text('home')),
        routes: <String, WidgetBuilder>{
          '/a': (BuildContext context) => const Material(child: Text('a')),
          '/b': (BuildContext context) => const Material(child: Text('b')),
        },
      );

      await tester.pumpWidget(myApp);
      final NavigatorState navigator = tester.state(find.byType(Navigator));

      navigator.pushNamed('/a');
      await tester.pumpAndSettle();

      navigator.pushNamedAndRemoveUntil('/b', (Route<dynamic> route) => false);
      await tester.pump();
      await tester.pump(const Duration(milliseconds: 100));

      // We are mid-transition, both pages are onstage
      expect(find.text('a'), findsOneWidget);
      expect(find.text('b'), findsOneWidget);

      // Complete transition
      await tester.pumpAndSettle();
      expect(find.text('a'), findsNothing);
      expect(find.text('b'), findsOneWidget);
    });

    testWidgets('Hero transition triggers when preceding route contains hero, and predicate route does not', (WidgetTester tester) async {
      const String kHeroTag = 'hero';
      final Widget myApp = MaterialApp(
        initialRoute: '/',
        routes: <String, WidgetBuilder>{
          '/': (BuildContext context) => const Material(child: Text('home')),
          '/a': (BuildContext context) => const Material(child: Hero(
            tag: kHeroTag,
            child: Text('a'),
          )),
          '/b': (BuildContext context) => const Material(child: Padding(
            padding: EdgeInsets.all(100.0),
            child: Hero(
              tag: kHeroTag,
              child: Text('b'),
            ),
          )),
        },
      );

      await tester.pumpWidget(myApp);
      final NavigatorState navigator = tester.state(find.byType(Navigator));

      navigator.pushNamed('/a');
      await tester.pumpAndSettle();

      navigator.pushNamedAndRemoveUntil('/b', ModalRoute.withName('/'));
      await tester.pump();
      await tester.pump(const Duration(milliseconds: 16));

      expect(find.text('b'), isOnstage);

      // 'b' text is heroing to its new location
      final Offset bOffset = tester.getTopLeft(find.text('b'));
      expect(bOffset.dx, greaterThan(0.0));
      expect(bOffset.dx, lessThan(100.0));
      expect(bOffset.dy, greaterThan(0.0));
      expect(bOffset.dy, lessThan(100.0));

      await tester.pump(const Duration(seconds: 1));

      expect(find.text('a'), findsNothing);
      expect(find.text('b'), isOnstage);
    });

    testWidgets('Hero transition does not trigger when preceding route does not contain hero, but predicate route does', (WidgetTester tester) async {
      const String kHeroTag = 'hero';
      final Widget myApp = MaterialApp(
        theme: ThemeData(
          pageTransitionsTheme: const PageTransitionsTheme(
            builders: <TargetPlatform, PageTransitionsBuilder>{
              TargetPlatform.android: FadeUpwardsPageTransitionsBuilder(),
            },
          ),
        ),
        initialRoute: '/',
        routes: <String, WidgetBuilder>{
          '/': (BuildContext context) => const Material(child: Hero(
            tag:kHeroTag,
            child: Text('home'),
          )),
          '/a': (BuildContext context) => const Material(child: Text('a')),
          '/b': (BuildContext context) => const Material(child: Padding(
            padding: EdgeInsets.all(100.0),
            child: Hero(
              tag: kHeroTag,
              child: Text('b'),
            ),
          )),
        },
      );

      await tester.pumpWidget(myApp);
      final NavigatorState navigator = tester.state(find.byType(Navigator));

      navigator.pushNamed('/a');
      await tester.pumpAndSettle();

      navigator.pushNamedAndRemoveUntil('/b', ModalRoute.withName('/'));
      await tester.pump();
      await tester.pump(const Duration(milliseconds: 16));

      expect(find.text('b'), isOnstage);

      // 'b' text is sliding in from the right, no hero transition
      final Offset bOffset = tester.getTopLeft(find.text('b'));
      expect(bOffset.dx, 100.0);
      expect(bOffset.dy, greaterThan(100.0));
    });
  });
}