How to test Flutter widgets on different screen sizes?

Question

I have a Flutter widget which shows extra data depending on the screen size. Does anyone know a way of testing this widget on multiple different screen sizes?

I\'ve

Answer 1

Not sure why but solution of @rémi-rousselet didn't work for me. I've had to specify screen size using binding.window.physicalSizeTestValue and binding.window.devicePixelRatioTestValue so that output is fully deterministic

I've added a little bit more code for flutter beginners like me. Check this:

void main() {

  final TestWidgetsFlutterBinding binding =
    TestWidgetsFlutterBinding.ensureInitialized();

  testWidgets("Basic layout test (mobile device)", (tester) async {
    binding.window.physicalSizeTestValue = Size(400, 200);
    binding.window.devicePixelRatioTestValue = 1.0;

    await tester.pumpWidget(new MyApp());

    expect(find.byType(MyHomePage), findsOneWidget);
    // etc.
  });
}