e2e

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));
  });
}

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 'package:e2e/e2e_driver.dart' as e2e;

Future<void> main() async => e2e.main();

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

You can run tests on web in release or profile mode.

First you need to make sure you have downloaded the driver for the browser.

cd example
flutter drive -v --target=test_driver/<package_name>dart -d web-server --release --browser-name=chrome

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.FlutterTestRunner;
import org.junit.Rule;
import org.junit.runner.RunWith;

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

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!