Integration tests work fine from flutter drive, but hang when entering text in Firebase Test Lab

Question

I have the following sign-in test set up for my app:

testWidgets('sign in with email and password', (WidgetTester tester) async {
  app.main();
  await tester.pumpAndSettle(Duration(seconds: 3));
  final emailInputFinder = find.byKey(Key('type-email'));
  final passwordInputFinder = find.byKey(Key('type-password'));
  final emailButtonFinder = find.byKey(Key('enter-email'));
  final passwordButtonFinder = find.byKey(Key('enter-password'));
  final dashboardFinder = find.byKey(Key('dashboard'));
  await tester.enterText(emailInputFinder, 'test.lab.user.01@...');
  await tester.pumpAndSettle(Duration(seconds: 3));
  await tester.tap(emailButtonFinder);
  await tester.pumpAndSettle(Duration(seconds: 3));
  await tester.enterText(passwordInputFinder, '...');
  await tester.pumpAndSettle(Duration(seconds: 3));
  await tester.tap(passwordButtonFinder);
  await tester.pumpAndSettle(Duration(seconds: 3));
  expect(dashboardFinder, findsOneWidget);
});

The hardcoded 3 second delay isn't ideal, but without it I can't run the tests using the driver.

Running on my local machine with the driver is fine. I use the command

flutter drive --driver=test_driver/integration_test.dart --target=integration_test/app_test.dart

But when I upload the Espresso test to Firebase Test Lab and review the video, the sign-in screen loads up, but the first enterText() command seems to have no effect. Nothing is added to the text field, and the test just times out.

I have tried various combinations of tester.tap() and tester.showKeyboard(), but so far, nothing is coming up.

How can I get enterText() to work correctly in the Espresso environment supported by TestLab?

Answer 1

Try calling binding.testTextInput.register():

  final binding = IntegrationTestWidgetsFlutterBinding.ensureInitialized() as IntegrationTestWidgetsFlutterBinding;

// Necessary for being able to enterText when not in debug mode 
  binding.testTextInput.register();

There is an issue in the flutter repo about documenting this. Basically if you're not in debug mode you have to call binding.testTextInput.register() in order for tester.enterText to work.