86532


_****やりたいこととできないこと****_  
インテグレーションテストで画面遷移後にTextwidgetがあることを確認しようとしていますが、発見できていないというエラーが出ます。

### エラー文

[code]

    (The following exception is now available via WidgetTester.takeException:)
    ══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK ╞════════════════════════════════════════════════════
    The following TestFailure object was thrown running a test:
      Expected: exactly one matching node in the widget tree
      Actual: _TextFinder:<zero widgets with text "ホーム" (ignoring offstage widgets)>
       Which: means none were found but one was expected
    
    When the exception was thrown, this was the stack:
    
[/code]

_****何を・どのように調べたのか****_  
上記を解決するために、以下のキーワードで検索しました。

  * flutter integration_test 画面遷移した時のwidgetを確認するやり方
  * flutter integration_test How to check the widget at screen transition.

参考にした記事のURLは以下です。

[Flutterの新しいIntegration
Testの導入](https://zenn.dev/sakusin/articles/4a3a5f0510438e)

* * *

### ソースコード

[code]

    // main.dart
    
    import 'package:flutter/material.dart';
    import 'package:integration_test_sample/first_page.dart';
    
    void main() {
      runApp(MyApp());
    }
    
    class MyApp extends StatelessWidget {
      // This widget is the root of your application.
      @override
      Widget build(BuildContext context) {
        return MaterialApp(
          title: 'Flutter Demo',
          theme: ThemeData(    
            primarySwatch: Colors.blue,
          ),
          home: MyHomePage(title: 'Flutter Demo Home Page'),
        );
      }
    }
    
    class MyHomePage extends StatefulWidget {
      MyHomePage({Key? key, required this.title}) : super(key: key);
    
    
      final String title;
    
      @override
      _MyHomePageState createState() => _MyHomePageState();
    }
    
    class _MyHomePageState extends State<MyHomePage> {
      int _counter = 0;
    
      void _incrementCounter() {
        setState(() {
          _counter++;
        });
      }
    
      @override
      Widget build(BuildContext context) {
    
        return Scaffold(
          appBar: AppBar(
            // Here we take the value from the MyHomePage object that was created by
            // the App.build method, and use it to set our appbar title.
            title: Text(widget.title),
          ),
          body: Center(
            // Center is a layout widget. It takes a single child and positions it
            // in the middle of the parent.
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                Text(
                  'You have pushed the button this many times:',
                ),
                Text(
                  '$_counter',
                  style: Theme.of(context).textTheme.headline4,
                ),
                ElevatedButton(onPressed: (){
                  // Navigator.push(context, MaterialPageRoute(builder: builder));
                  Navigator.push(context, MaterialPageRoute(
                      builder: (context) => FirstPage()
                  ));
                }, child: Text('移動')),
              ],
            ),
          ),
          floatingActionButton: FloatingActionButton(
            onPressed: _incrementCounter,
            tooltip: 'Increment',
            child: Icon(Icons.add),
          ), // This trailing comma makes auto-formatting nicer for build methods.
        );
      }
    }
    
[/code]

[code]

    // first_page.dart
    
    import 'package:flutter/material.dart';
    
    class FirstPage extends StatelessWidget {
      @override
      Widget build(BuildContext context) {
        return Scaffold(
          appBar: AppBar(
            title: Text("ホーム"),
          ),
          body: Column(
            children: [
              Text('テスト'),         
            ],
          ),
        );
      }
    }
    
[/code]

[code]

    // integration_test.dart
    
    import 'package:flutter/material.dart';
    import 'package:flutter_test/flutter_test.dart';
    import 'package:integration_test/integration_test.dart';
    
    import 'package:integration_test_sample/main.dart' as app;
    
    void main() {
      IntegrationTestWidgetsFlutterBinding.ensureInitialized();
    
      group('group', () {
        testWidgets('start', (WidgetTester tester) async {
          app.main();
          await tester.pumpAndSettle();
    
          expect(find.byType(FloatingActionButton), findsOneWidget);
    
          expect(find.text('0'), findsOneWidget);
          expect(find.text('1'), findsNothing);
    
          await tester.tap(find.byType(ElevatedButton));
          await tester.pump();
          
          expect(find.text('ホーム'), findsOneWidget);
          expect(find.text('0'), findsNothing);
        });
      });
    }
    
[/code]


CC BY-SA 4.0
2022-02-09T22:15:53.680
86235
2022-02-23T09:43:08.447
2022-02-11T17:27:53.803
36424
36424
question
flutter テスト dart
インテグレーションテストで画面遷移後のwidgetがあるかどうかをテストするとエラーになる。


integration_test.dart 内の `await tester.pump();` を `await
tester.pumpAndSettle();` に変更します。


CC BY-SA 4.0
2022-02-23T09:43:08.447
86532
2022-02-23T09:43:08.447
32959
86235
answer