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 had a look through the widget_tester source code but can't find anything.

Answer 1

You can specify custom surface size by using WidgetTester

The following code will run a test with a screen size of 42x42

import 'package:flutter/widgets.dart'; import 'package:flutter_test/flutter_test.dart';  void main() {   testWidgets("foo", (tester) async {     tester.binding.window.physicalSizeTestValue = Size(42, 42);      // resets the screen to its original size after the test end     addTearDown(tester.binding.window.clearPhysicalSizeTestValue);      // TODO: do something   }); }