Integration test #

This page is still in its early stages.

Integration tests verify the behavior of the entire app. And can be run on real device.

Integrations tests can look very similar to widget tests. Here is a comparison table to help set them apart.

To create an integration test you first need to add the integration_test dependency.

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

Integration tests are written the same way as widget tests, except that you must call IntegrationTestWidgetsFlutterBinding.ensureInitialized() before executing any tests.

Adding integration tests #

Let’s try to convert widget test for the calculator into an integration test. You can either use your own solution, or mine by cloning the solution branch.

git clone -b separate-logic https://github.com/fluttered-book/quiz.git

Open the project in Android Studio.

Make a copy of your widget test (in my solution it is test/calculator_app_test.dart) to integration_test/calculator_app_test.dart.

As the first line of the main method in the test file you should add IntegrationTestWidgetsFlutterBinding.ensureInitialized().

void main() {
  IntegrationTestWidgetsFlutterBinding.ensureInitialized();

  // All `widgetTest` must be below.
}

Running the tests #

Mobile (iOS, Android) #

My solution only supports web platform. So, you will need to add support for mobile.

You can do that by running:

flutter create . --platforms=web,android,ios

For iOS you need to set up code signing in Xcode. Refer back to the installation guide for iPhone to find instructions.

Make sure your device is connected. Then run:

flutter test integration_test

You can also run tests on Android emulator. Start the device from Device Manager in Android Studio. Then rerun the command above.

Notice that you can see the app run and all the interactions animate. It is running the full app on a real device, the only thing that is simulated is tapping on button.

Even though interactions happen pretty quick, it is still a lot slower running this way compared to running widget tests.

You can use breakpoints in Android Studio to pause the app for debugging. A nice thing about integration tests compared to widget tests, is that you can actually see what the app looks like when execution is paused.