Check app functionality with an integration test

This recipe describes how to use the integration_test package to run integration tests. The Flutter SDK includes the integration_test package. Integration tests using this package have the following properties.

  • Use the flutter drive command to run tests on a physical device or emulator.
  • Run on Firebase Test Lab, to automate testing on a variety of devices.
  • Use flutter_test APIs to enable tests to be written in a style similar to widget tests

In this recipe, learn how to test a counter app.

  • how to set up integration tests
  • how to verify if an app displays specific text
  • how to tap specific widgets
  • how to run integration tests

This recipe uses the following steps:

  1. Create an app to test.
  2. Add the integration_test dependency.
  3. Create the test files.
  4. Write the integration test.
  5. Run the integration test.

Create a new app to test

#

Integration testing requires an app to test. This example uses the built-in Counter App example that Flutter produces when you run the flutter create command. The counter app allows a user to tap on a button to increase a counter.

  1. To create an instance of the built-in Flutter app, run the following command in your terminal:

    flutter create counter_app
  2. Change into the counter_app directory.

  3. Open lib/main.dart in your preferred IDE.

  4. Add a key parameter to the floatingActionButton() widget with an instance of a Key class with a string value of increment.

    dart
     floatingActionButton: FloatingActionButton(
       key: const ValueKey('increment'),
       onPressed: _incrementCounter,
       tooltip: 'Increment',
       child: const Icon(Icons.add),
     ),
  5. Save your lib/main.dart file.

After these changes, the lib/main.dart file should resemble the following code.

lib/main.dart
dart
import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: 'Counter App',
      home: MyHomePage(title: 'Counter App Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        // Provide a Key to this button. This allows finding this
        // specific button inside the test suite, and tapping it.
        key: const Key('increment'),
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}

Add the integration_test dependency

#

You need to add the testing packages to your new app.

To add integration_test and flutter_test packages as dev_dependencies using sdk: flutter, run following command.

flutter pub add 'dev:integration_test:{"sdk":"flutter"}'

Output:

Building flutter tool...
Resolving dependencies... 
Got dependencies.
Resolving dependencies... 
+ file 7.0.0
+ flutter_driver 0.0.0 from sdk flutter
+ fuchsia_remote_debug_protocol 0.0.0 from sdk flutter
+ integration_test 0.0.0 from sdk flutter
...
  test_api 0.6.1 (0.7.1 available)
  vm_service 13.0.0 (14.2.1 available)
+ webdriver 3.0.3
Changed 8 dependencies!
7 packages have newer versions incompatible with dependency constraints.
Try `flutter pub outdated` for more information.

Updated pubspec.yaml file:

pubspec.yaml
yaml
# ...
dev_dependencies:
  # ... added dependencies
  flutter_test:
    sdk: flutter
  flutter_lints: ^5.0.0
  integration_test:
    sdk: flutter
# ...

Create the integration test files

#

Integration tests reside in a separate directory inside your Flutter project.

  1. Create a new directory named integration_test.
  2. Add empty file named app_test.dart in that directory.

The resulting directory tree should resemble the following:

counter_app/
  lib/
    main.dart
  integration_test/
    app_test.dart

Write the integration test

#

The integration test file consists of a Dart code file with dependencies on integration_test, flutter_test, and your app's Dart file.

  1. Open your integration_test/app_test.dart file in your preferred IDE.

  2. Copy the following code and paste it into your integration_test/app_test.dart file. The last import should point to the main.dart file of your counter_app. (This import points to the example app called introduction.)

    integration_test/counter_test.dart
    dart
    import 'package:flutter/material.dart';
    import 'package:flutter_test/flutter_test.dart';
    import 'package:how_to/main.dart';
    import 'package:integration_test/integration_test.dart';
    
    void main() {
      IntegrationTestWidgetsFlutterBinding.ensureInitialized();
    
      group('end-to-end test', () {
        testWidgets('tap on the floating action button, verify counter',
            (tester) async {
          // Load app widget.
          await tester.pumpWidget(const MyApp());
    
          // Verify the counter starts at 0.
          expect(find.text('0'), findsOneWidget);
    
          // Finds the floating action button to tap on.
          final fab = find.byKey(const ValueKey('increment'));
    
          // Emulate a tap on the floating action button.
          await tester.tap(fab);
    
          // Trigger a frame.
          await tester.pumpAndSettle();
    
          // Verify the counter increments by 1.
          expect(find.text('1'), findsOneWidget);
        });
      });
    }

This example goes through three steps:

  1. Initialize IntegrationTestWidgetsFlutterBinding. This singleton service executes tests on a physical device.

  2. Interact and test widgets using the WidgetTester class.

  3. Test the important scenarios.

Run integration tests

#

The integration tests that run vary depending on the platform on which you test.

  • To test a desktop platform, use the command line or a CI system.
  • To test a mobile platform, use the command line or Firebase Test Lab.
  • To test in a web browser, use the command line.

Test on a desktop platform

#
Expand if you test Linux apps using a CI system

To test a Linux app, your CI system must invoke an X server first. In the GitHub Action, GitLab Runner, or similar configuration file, set the integration test to work with the xvfb-run tool.

Doing this invokes an X Window system into which Flutter can launch and test your Linux app.

As an example using GitHub Actions, your jobs.setup.steps should include a step resembling the following:

yaml
      - name: Run Integration Tests
        uses: username/xvfb-action@v1.1.2
        with:
          run: flutter test integration_test -d linux -r github

This starts the integration test within an X Window.

If you don't configure your integration in this way, Flutter returns an error.

Building Linux application...
Error waiting for a debug connection: The log reader stopped unexpectedly, or never started.

To test on a macOS, Windows, or Linux platform, complete the following tasks.

  1. Run the following command from the root of the project.

    flutter test integration_test/app_test.dart
  2. If offered a choice of platform to test, choose the desktop platform. Type 1 to choose the desktop platform.

Based on platform, the command result should resemble the following output.

PS C:\path\to\counter_app> flutter test .\integration_test\app_test.dart
Resolving dependencies...
Downloading packages...
  flutter_lints 3.0.2 (4.0.0 available)
  leak_tracker 10.0.4 (10.0.5 available)
  leak_tracker_flutter_testing 3.0.3 (3.0.5 available)
  lints 3.0.0 (4.0.0 available)
  material_color_utilities 0.8.0 (0.11.1 available)
  meta 1.12.0 (1.15.0 available)
  test_api 0.7.0 (0.7.1 available)
  vm_service 14.2.1 (14.2.2 available)
Got dependencies!
8 packages have newer versions incompatible with dependency constraints.
Try `flutter pub outdated` for more information.

Connected devices:

Windows (desktop) • windows • windows-x64    • Microsoft Windows [Version 10.0.22631.3593]
Chrome (web)      • chrome  • web-javascript • Google Chrome 124.0.6367.207
Edge (web)        • edge    • web-javascript • Microsoft Edge 124.0.2478.97

[1]: Windows (windows)
[2]: Chrome (chrome)
[3]: Edge (edge)

Please choose one (or "q" to quit): 1

00:00 +0: loading C:/path/to/counter_app/integration_test/app_test.dart               B
00:29 +0: loading C:/path/to/counter_app/counter_app/integration_test/app_test.dart   29.1s
√ Built build\windows\x64\runner\Debug\counter_app.exe
00:31 +1: All tests passed!
flutter test integration_test
Resolving dependencies... 
Downloading packages... 
  flutter_lints 3.0.2 (4.0.0 available)
> leak_tracker 10.0.4 (was 10.0.0) (10.0.5 available)
> leak_tracker_flutter_testing 3.0.3 (was 2.0.1) (3.0.5 available)
> leak_tracker_testing 3.0.1 (was 2.0.1)
  lints 3.0.0 (4.0.0 available)
  material_color_utilities 0.8.0 (0.11.1 available)
> meta 1.12.0 (was 1.11.0) (1.15.0 available)
> test_api 0.7.0 (was 0.6.1) (0.7.1 available)
> vm_service 14.2.1 (was 13.0.0) (14.2.2 available)
Changed 6 dependencies!
8 packages have newer versions incompatible with dependency constraints.
Try `flutter pub outdated` for more information.

Connected devices:

macOS (desktop)                 • macos                 • darwin-arm64   • macOS 14.4.1 23E224 darwin-arm64
Mac Designed for iPad (desktop) • mac-designed-for-ipad • darwin         • macOS 14.4.1 23E224 darwin-arm64
Chrome (web)                    • chrome                • web-javascript • Google Chrome 124.0.6367.208

No wireless devices were found.

[1]: macOS (macos)
[2]: Mac Designed for iPad (mac-designed-for-ipad)
[3]: Chrome (chrome)
Please choose one (or "q" to quit): 1

00:01 +0: loading /path/to/counter_app/integration_test/app_test.dart        R
00:02 +0: loading /path/to/counter_app/integration_test/app_test.dart    846ms
00:03 +0: loading /path/to/counter_app/integration_test/app_test.dart        B

Building macOS application...
✓ Built build/macos/Build/Products/Debug/counter_app.app
00:32 +1: All tests passed!
flutter test integration_test/app_test.dart

Connected devices:

Linux (desktop) • linux  • linux-x64      • Ubuntu 22.04.4 LTS 6.5.0-35-generic
Chrome (web)    • chrome • web-javascript • Google Chrome 104.0.5112.101

[1]: Linux (linux)
[2]: Chrome (chrome)

Please choose one (or "q" to quit): 1

00:00 +0: /path/to/counter_app/integration_test/app_test.dart     B
00:16 +0: /path/to/counter_app/integration_test/app_test.dart

✓ Built build/linux/x64/debug/bundle/counter_app

Test on a mobile device

#

To test on a real iOS or Android device, complete the following tasks.

  1. Connect the device.

  2. Run the following command from the root of the project.

    flutter test integration_test/app_test.dart

    The result should resemble the following output. This example uses iOS.

    flutter test integration_test/app_test.dart
    00:04 +0: loading /path/to/counter_app/integration_test/app_test.dart
    00:15 +0: loading /path/to/counter_app/integration_test/app_test.dart
    00:18 +0: loading /path/to/counter_app/integration_test/app_test.dart   2,387ms
    Xcode build done.                                           13.5s
    00:21 +1: All tests passed!
  3. Verify that the test removed the Counter App when it finished. If not, subsequent tests fail. If needed, press on the app and choose Remove App from the context menu.


Test in a web browser

#

To test in a web browser, perform the following steps.

  1. Install ChromeDriver into the directory of your choice.

    npx @puppeteer/browsers install chromedriver@stable

    To simplify the install, this command uses the @puppeteer/browsers Node library.

  2. Add the path to ChromeDriver to your $PATH environment variable.

  3. Verify the ChromeDriver install succeeded.

    chromedriver --version
    ChromeDriver 124.0.6367.60 (8771130bd84f76d855ae42fbe02752b03e352f17-refs/branch-heads/6367@{#798})
  4. In your counter_app project directory, create a new directory named test_driver.

    mkdir test_driver
  5. In this directory, create a new file named integration_test.dart.

  6. Copy the following code and paste it into your integration_test.dart file.

    test_driver/integration_test.dart
    dart
    import 'package:integration_test/integration_test_driver.dart';
    
    Future<void> main() => integrationDriver();
  7. Launch chromedriver as follows:

    chromedriver --port=4444
  8. From the root of the project, run the following command:

    flutter drive \
      --driver=test_driver/integration_test.dart \
      --target=integration_test/app_test.dart \
      -d chrome

    The response should resemble the following output:

    Resolving dependencies...
      leak_tracker 10.0.0 (10.0.5 available)
      leak_tracker_flutter_testing 2.0.1 (3.0.5 available)
      leak_tracker_testing 2.0.1 (3.0.1 available)
      material_color_utilities 0.8.0 (0.11.1 available)
      meta 1.11.0 (1.14.0 available)
      test_api 0.6.1 (0.7.1 available)
      vm_service 13.0.0 (14.2.1 available)
    Got dependencies!
    7 packages have newer versions incompatible with dependency constraints.
    Try `flutter pub outdated` for more information.
    Launching integration_test/app_test.dart on Chrome in debug mode...
    Waiting for connection from debug service on Chrome...             10.9s
    This app is linked to the debug service: ws://127.0.0.1:51523/3lofIjIdmbs=/ws
    Debug service listening on ws://127.0.0.1:51523/3lofIjIdmbs=/ws
    00:00 +0: end-to-end test tap on the floating action button, verify counter
    00:01 +1: (tearDownAll)
    00:01 +2: All tests passed!
    All tests passed.
    Application finished.

    To run this as a headless test, run flutter drive with -d web-server option:

    flutter drive \
      --driver=test_driver/integration_test.dart \
      --target=integration_test/app_test.dart \
      -d web-server

To learn more, see the Running Flutter driver tests with web wiki page.


Test using the Firebase Test Lab

#

To test both Android and iOS targets, you can use the Firebase Test Lab.

Android setup

#

Follow the instructions in the Android Device Testing section of the README.

iOS setup

#

Follow the instructions in the iOS Device Testing section of the README.

Test Lab project setup

#
  1. Launch your Firebase Console.

  2. Create a new Firebase project if necessary.

  3. Navigate to Quality > Test Lab.

    Firebase Test Lab Console

Upload an Android APK

#
  1. Create an APK using Gradle.

    pushd android
    # flutter build generates files in android/ for building the app
    flutter build apk
    ./gradlew app:assembleAndroidTest
    ./gradlew app:assembleDebug -Ptarget=integration_test/<name>_test.dart
    popd

    Where <name>_test.dart is the file created in the Project Setup section.

To start a Robo test and run other tests, drag the "debug" APK from <flutter_project_directory>/build/app/outputs/apk/debug into the Android Robo Test target on the web page.

Firebase Test Lab upload
  1. Click Run a test.

  2. Select the Instrumentation test type.

  3. Add the App APK to the App APK or AAB box.

    <flutter_project_directory>/build/app/outputs/apk/debug/<file>.apk

  4. Add the Test APK to the Test APK box.

    <flutter_project_directory>/build/app/outputs/apk/androidTest/debug/<file>.apk

Firebase Test Lab upload two APKs

If a failure occurs, click the red icon to view the output:

Firebase Test Lab test results

Upload an Android APK from the command line

#

See the Firebase Test Lab section of the README for instructions on uploading the APKs from the command line.

Upload Xcode tests

#

To learn how to upload the .zip file, consult the Firebase TestLab iOS instructions on the Firebase TestLab section of the Firebase Console.

Upload Xcode tests from the command line

#

To learn how to upload the .zip file from the command line, consult the iOS Device Testing section in the README.