integration_test

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.

Usage

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

Create a integration_test/ directory for your package. In this directory, create a <name>_test.dart, using the following as a starting point to make assertions.

import 'package:flutter_test/flutter_test.dart';
import 'package:integration_test/integration_test.dart';

void main() => run(_testMain);

void _testMain() {
  testWidgets("failing test example", (WidgetTester tester) async {
    expect(2 + 2, equals(5));
  });
}

Driver Entrypoint

An accompanying driver script will be needed that can be shared across all integration tests. Create a file named integration_test.dart in the test_driver/ directory with the following contents:

import 'package:integration_test/integration_test_driver.dart';

Future<void> main() => integrationDriver();

You can also use different driver scripts to customize the behavior of the app under test. For example, FlutterDriver can also be parameterized with different options. See the extended driver for an example.

Package Structure

Your package should have a structure that looks like this:

lib/
  ...
integration_test/
  foo_test.dart
  bar_test.dart
test/
  # Other unit tests go here.
test_driver/
  integration_test.dart

Example

Using Flutter Driver to Run Tests

These tests can be launched with the flutter drive command.

To run the integration_test/foo_test.dart test with the test_driver/integration_test.dart driver, use the following command:

flutter drive \
  --driver=test_driver/integration_test.dart \
  --target=integration_test/foo_test.dart

Web

Make sure you have enabled web support then download and run the web driver in another process.

Use following command to execute the tests:

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

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.integration_test.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 run integration_test/foo_test.dart on a local Android device (emulated or physical):

./gradlew app:connectedAndroidTest -Ptarget=`pwd`/../integration_test/foo_test.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 a test on Android devices using Firebase Test Lab, use gradle commands to build an instrumentation test for Android, after creating androidTest as suggested in the last section.

pushd android
# flutter build generates files in android/ for building the app
flutter build apk
./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

Open ios/Runner.xcworkspace in Xcode. Create a test target if you do not already have one via File > New > Target... and select Unit Testing Bundle. Change the Product Name to RunnerTests. Make sure Target to be Tested is set to Runner. Select Finish.

Add the new test target to ios/Podfile by embedding in the existing Runner target.

target 'Runner' do
  # Do not change existing lines.
  ...

  target 'RunnerTests' do
    inherit! :search_paths
  end
end

Run flutter build ios from your project file to hook up the new settings.

In Xcode, add a test file called RunnerTests.m (or any name of your choice) to the new target and replace the file:

@import XCTest;
@import integration_test;

INTEGRATION_TEST_IOS_RUNNER(RunnerTests)

Run Product > Tests to run the integration tests on your selected device.

To build integration_test/foo_test.dart from the command line, run:

# Pass --simulator if building for the simulator.
flutter build ios integration_test/foo_test.dart