e2e #

This package enables self-driving testing of Flutter code on devices and emulators. It adapts flutter_test results into a format that is compatible with flutter drive and native Android instrumentation testing.

iOS support is not available yet, but is planned in the future.

Usage #

Add a dependency on the e2e package in the dev_dependencies section of pubspec.yaml. For plugins, do this in the pubspec.yaml of the example app.

Invoke E2EWidgetsFlutterBinding.ensureInitialized() at the start of a test file, e.g.

import 'package:e2e/e2e.dart';

void main() {
  E2EWidgetsFlutterBinding.ensureInitialized();
  testWidgets("failing test example", (WidgetTester tester) async {
    expect(2 + 2, equals(5));
  });
  exit(result == 'pass' ? 0 : 1);
}

Test locations #

It is recommended to put e2e tests in the test/ folder of the app or package. For example apps, if the e2e test references example app code, it should go in example/test/. It is also acceptable to put e2e tests in test_driver/ folder so that they're alongside the runner app (see below).

Using Flutter driver to run tests #

E2EWidgetsTestBinding supports launching the on-device tests with flutter drive. Note that the tests don't use the FlutterDriver API, they use testWidgets instead.

Put the a file named <package_name>_e2e_test.dart in the app' test_driver directory:

import 'dart:async';
import 'dart:io';
import 'package:flutter_driver/flutter_driver.dart';

Future<void> main() async {
  final FlutterDriver driver = await FlutterDriver.connect();
  final String result =
      await driver.requestData(null, timeout: const Duration(minutes: 1));
  await driver.close();
  exit(result == 'pass' ? 0 : 1);
}

To run a example app test with Flutter driver:

cd example
flutter drive test/<package_name>_e2e.dart

To test plugin APIs using Flutter driver:

cd example
flutter drive --driver=test_driver/<package_name>_test.dart test/<package_name>_e2e.dart

Android device testing #

Create an instrumentation test file in your application's android/app/src/androidTest/java/com/example/myapp/ directory (replacing com, example, and myapp with values from your app's package name). You can name this test file MainActivityTest.java or another name of your choice.

package com.example.myapp;

import androidx.test.rule.ActivityTestRule;
import dev.flutter.plugins.e2e.FlutterRunner;
import org.junit.Rule;
import org.junit.runner.RunWith;

@RunWith(FlutterRunner.class)
public class MainActivityTest {
  @Rule
  public ActivityTestRule<MainActivity> rule = new ActivityTestRule<>(MainActivity.class);
}

Update your application's myapp/android/app/build.gradle to make sure it uses androidx's version of AndroidJUnitRunner and has androidx libraries as a dependency.

android {
  ...
  defaultConfig {
    ...
    testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
  }
}

dependencies {
    testImplementation 'junit:junit:4.12'

    // https://developer.android.com/jetpack/androidx/releases/test/#1.2.0
    androidTestImplementation 'androidx.test:runner:1.2.0'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}

To e2e test on a local Android device (emulated or physical):

./gradlew app:connectedAndroidTest -Ptarget=`pwd`/../test_driver/<package_name>_e2e.dart

Firebase Test Lab #

If this is your first time testing with Firebase Test Lab, you'll need to follow the guides in the Firebase test lab documentation to set up a project.

To run an e2e test on Android devices using Firebase Test Lab, use gradle commands to build an instrumentation test for Android.

pushd android
./gradlew app:assembleAndroidTest
./gradlew app:assembleDebug -Ptarget=<path_to_test>.dart
popd

Upload the build apks Firebase Test Lab, making sure to replace <PATH_TO_KEY_FILE>, <PROJECT_NAME>, <RESULTS_BUCKET>, and <RESULTS_DIRECTORY> with your values.

gcloud auth activate-service-account --key-file=<PATH_TO_KEY_FILE>
gcloud --quiet config set project <PROJECT_NAME>
gcloud firebase test android run --type instrumentation \
  --app build/app/outputs/apk/debug/app-debug.apk \
  --test build/app/outputs/apk/androidTest/debug/app-debug-androidTest.apk\
  --timeout 2m \
  --results-bucket=<RESULTS_BUCKET> \
  --results-dir=<RESULTS_DIRECTORY>

You can pass additional parameters on the command line, such as the devices you want to test on. See gcloud firebase test android run.

iOS device testing #

You need to change iOS/Podfile to avoid test target statically linking to the plugins. One way is to link all of the plugins dynamically:

target 'Runner' do
  use_frameworks!
  ...
end

To e2e test on your iOS device (simulator or real), rebuild your iOS targets with Flutter tool.

flutter build ios -t test_driver/<package_name>_e2e.dart (--simulator)

Open Xcode project (by default, it's ios/Runner.xcodeproj). Create a test target (navigating File > New > Target... and set up the values) and a test file RunnerTests.m and change the code. You can change RunnerTests.m to the name of your choice.

#import <XCTest/XCTest.h>
#import <e2e/E2EIosTest.h>

E2E_IOS_RUNNER(RunnerTests)

Now you can start RunnerTests to kick out e2e tests!