testing.md

Testing

Goldens

To generate golden tests in the project, the golden_toolkit library has been added.

By opening the file flutter_test_config.dart, you can configure the strictness of golden comparisons and the set of devices for which they will be generated.

To save time on writing goldens, you can use the function testWidget. This function allows you to:

• Test the functionality of a widget (e.g., interactions with elements, element presence, etc.), including for ElementaryWidget's.
• Generate goldens for both light and dark themes.

Warning

Always specify the generic type of the widget you are testing (e.g.,testWidget<TestableScreen>), as the golden's name generation is based on the widget class name.

Example usage:

class MockTestableScreenWM extends Mock implements ITestableScreenWM {}

void main() {
  final mockData = MockData('test data');
  final widget = TestableScreen(mockData);
  final wm = MockTestableScreenWM();

  testWidget<TestableScreen>(
    'Test screen',
    widgetBuilder: (_) => widget.build(wm),
    setup: (theme) {
      when(() => wm.data).thenReturn(EntityValueNotifier(mockData));
      when(() => wm.theme).thenReturn(theme);
      when(wm.onSubmitPressed).thenAnswer((_) => Future.value())
      when(wm.onCancelPressed).thenReturn(null);
    },
    test: (tester, theme) async {
        final submitButton = find.widgetWithText(PrimaryButton, CommonStrings.submitButton);
        final cancelButton = find.widgetWithText(SecondaryButton, CommonStrings.cancelButton);
        
        expect(submitButton, findsOneWidget);
        expect(cancelButton, findsOneWidget);
        expect(finder, findsOneWidget);

        await tester.tap(submitButton);
        verify(wm.onSubmitPressed);

        await tester.tap(cancelButton);
        verify(wm.onCancelPressed);
    },
  );

  /// Nothing to test, just want to generate the golden.
  testWidget<TestableScreen>(
    'Test screen - loading',
    widgetBuilder: (_) => widget.build(wm),
    /// Since we are testing a specific widget state, we fill in the [screenState] property.
    screenState: 'loading',
    setup: (theme) {
      when(() => wm.data).thenReturn(EntityValueNotifier.loading());
      when(() => wm.theme).thenReturn(theme);
    }
  );
}