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Flutter Android

Unit tests and flutter widget tests validate individual classes, functions, or widgets. You will not be able to validate how individual pieces work together in whole or capture the performance of an app running on real devices. To perform these tasks you could use Flutters' integration test solution.

Follow this guide to run integration tests for your Flutter app on Android.

What You'll Need​

Prepare Your Flutter Application For Integration Testing​

  1. Open your Flutter project in your favorite IDE.

  2. In your Flutter app's pubspec.yaml, add the following dependencies:

    dev_dependencies:
       integration_test:
          sdk: flutter
       flutter_test:
          sdk: flutter

  3. Create an instrumentation test file in your application’s android/app/src/androidTest/java/com/example/myapp directory. Replace com, example, and myApp with the values from your app’s package name.

    Then, name this test file as MainActivityTest.java or another name of your choice.

    package com.example.myApp;

    import androidx.test.rule.ActivityTestRule;
    import dev.flutter.plugins.integration_test.FlutterTestRunner;
    import org.junit.Rule;
    import org.junit.runner.RunWith;
    import com.example.myApp.MainActivity;

    @RunWith(FlutterTestRunner.class)
    public class MainActivityTest {
        @Rule
        public ActivityTestRule<MainActivity> rule = new ActivityTestRule<>(MainActivity.class, true, false);
    }

  4. Update your application’s myapp/android/app/build.gradle file to ensure it uses androidx’s version of AndroidJUnitRunner and includes androidx libraries as a dependency.

     android {
       ...
       defaultConfig {
         ...
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
       }
     }
     dependencies {
       testImplementation 'junit:junit:4.12'
       androidTestImplementation 'androidx.test:runner:1.2.0'
       androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
     }

  5. Create a directory called integration_test in the root of your Flutter project.

  6. Create a file called flutter_integration_test.dart in the integration_test directory.

  7. Update your testing dart file flutter_integration_test.dart to include the tearDownAll, The purpose for this is to make sure we close the connection to the driver after the tests have completed.

    import 'package:flutter/material.dart';
    import 'package:flutter_test/flutter_test.dart';
    import 'package:integration_test/integration_test.dart'; // Ensure you have this import
    // Add as app because we want to make sure the app loaded correctly on the device by calling the main function in the main dart file.
    import 'package:my_demo/main.dart' as app;
    void main() {

      // Ensure IntegrationTestWidgetsFlutterBinding is initialized
      final binding = IntegrationTestWidgetsFlutterBinding.ensureInitialized() as IntegrationTestWidgetsFlutterBinding;


      group('E2E Test With Flutter', (){
        tearDownAll(() async {
          // Signal that the test is complete
          binding.reportData = <String, dynamic>{
            'completed': true,
          };
        });

        testWidgets("First testing scenario increment 5 decrement 3", 
        (tester) async {
          app.main();
          await tester.pumpAndSettle(); // wait for app to be ready. 
          
          ...
        });
      });
    }

  8. Use the following Gradle commands to build an instrumentation test .apk file(test suite) using the MainActivityTest.java created in the androidTest directory as mentioned in step 3.

    Terminal Command
     # Go to the android folder which contains the "gradlew" script used for building Android apps from the terminal
     pushd android
     # Build an Android test APK (uses the MainActivityTest.java file created in step 1)
     ./gradlew app:assembleAndroidTest

     # Build a debug APK by passing the integration test file
     ./gradlew app:assembleDebug -Ptarget="..../integration_test/flutter_integration_test.dart"
     # Go back to the root of the project
     popd

  9. Configure saucectl to run the test.

    • Create a folder saucectl in your project root directory.
    • Inside this folder create a flutter_integration_test.yaml with the following content:
    apiVersion: v1alpha
    kind: espresso
    sauce:
       concurrency: 1
    espresso:
       app: ...../flutter/my-demo-app-flutter/build/app/outputs/flutter-apk/app-debug.apk
       testApp: ....../flutter/my-demo-app-flutter/build/app/outputs/apk/androidTest/debug/app-debug-androidTest.apk
    suites:
       - name: "Sauce Labs Espresso with flutter integration tests"
         testOptions:
           class:
             - com.example.my_demo_app_flutter.MainActivityTest
         devices:
           - name: "Google Pixel.*"
    artifacts:
       download:
         when: always
         match:
           - junit.xml
         directory: ./
    • Run the following commands to start the test on Sauce Labs
    Terminal Command
    saucectl configure -u USERNAME -a ACCESS_KEY
    saucectl run -c sauceconnect/flutter_integration_test.yaml
    • Check the status of you test on app.saucelabs.com
    saucectl run command output
    12:24:52 INF Running Espresso in Sauce Labs
                                          (.                          
                                           #.                           
                                           #.                           
                               .####################                    
                             #####////////*******/######                
                           .##///////*****************###/              
                          ,###////*********************###              
                          ####//***********************####             
                           ###/************************###              
                            ######********************###. ##           
                               (########################  ##     ##     
                                       ,######(#*         ##*   (##     
                                   /############*          #####        
                               (########(  #########(    ###            
                             .#######,    */  ############              
                          ,##########  %#### , ########*                
                        *### .#######/  ##  / ########                  
                       ###   .###########//###########                  
                   ######     ########################                  
                 (#(    *#(     #######.    (#######                    
                        ##,    /########    ########                    
                               *########    ########                    
     _____        _    _  _____ ______    _____ _      ____  _    _ _____  
    / ____|  /\  | |  | |/ ____|  ____|  / ____| |    / __ \| |  | |  __ \
    | (___   /  \ | |  | | |    | |__    | |    | |   | |  | | |  | | |  | |
    \___ \ / /\ \| |  | | |    |  __|   | |    | |   | |  | | |  | | |  | |
    ____) / ____ \ |__| | |____| |____  | |____| |___| |__| | |__| | |__| |
    |_____/_/    \_\____/ \_____|______|  \_____|______\____/ \____/|_____/
       
    12:24:52 INF Checking if ...../my-demo-app-flutter/build/app/outputs/flutter-apk/app-debug.apk has already been uploaded previously
    12:24:52 INF Checksum: 1df0b6684973536fef4ae653d89661d6c48d6f699091511515b69735d6a80fbd
    12:27:26 INF Application uploaded. durationMs=153173 storageId=6849a64a-3c51-4423-87f2-b3660c972a36
    12:27:26 INF Checking if ...../build/app/outputs/apk/androidTest/debug/app-debug-androidTest.apk has already been uploaded previously
    12:27:26 INF Checksum: b5b15cb741b78fe7a5df171406c17ec9ea8fd6ac52623abf7a8df519270e281d
    12:27:26 INF Skipping upload, using storage:635a7a46-c1fc-4c43-9a05-60e09a2163b8
    12:27:26 INF Launching workers. concurrency=1
    12:27:26 INF Starting suite. region=us-west-1 suite="Sauce Labs Espresso with flutter integration tests"
    12:27:27 INF Suite started. deviceId= deviceName="Google Pixel.*" platform=Android platformVersion= private=false suite="Sauce Labs Espresso with flutter integration tests" url=https://app.saucelabs.com/tests/4b52d0880d5d41579d669a66fdca2da0
    12:27:36 INF Suites in progress: 1
    12:27:46 INF Suites in progress: 1
    12:27:56 INF Suites in progress: 1
    12:28:06 INF Suites in progress: 1
    12:28:16 INF Suites in progress: 1
    12:28:26 INF Suites in progress: 1
    12:28:27 INF Suite finished. passed=true suite="Sauce Labs Espresso with flutter integration tests" url=https://app.saucelabs.com/tests/4b52d0880d5d41579d669a66fdca2da0
       
    Results:
           Name                                                  Duration    Status    Platform    Device            Attempts  
    ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
    ✔    Sauce Labs Espresso with flutter integration tests        1m0s    passed    Android     Google Pixel.*           1  
    ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
    ✔    All tests have passed                                     1m1s
       
    Build Link: https://app.saucelabs.com/builds/rdc/159d98f0223246e59dd172bad78573cc

Example Implementation​

For a practical example of how to set up and run integration tests for Flutter apps, you can refer to the Sauce Labs Flutter demo application repository. The steps outlined in this guide have already been implemented in that repository. You can follow along with the demo app to see how everything is configured and run your tests accordingly.

What's Next​

Next step

We're excited to share that Sauce Labs is actively working on expanding support for Flutter integration tests on iOS. Stay tuned for updates as we continue to develop this capability!