testWidget<T extends Widget> function

@isTest void testWidget<T extends Widget>({ required Widget widgetBuilder(BuildContext, ThemeType), String? desc, TestFunctionWithTheme? test, void setup(BuildContext, ThemeMode)?, bool withGolden = true, bool deviceMatters = true, bool autoHeight = false, bool? skip, String? screenState, Future<void> customPump(WidgetTester)?, Future<void> deviceSetup(TestDevice, WidgetTester)?, List<Device>? devices, bool onlyOneTheme = false, bool onlyOneLocale = false, })

Performs testing of the widget of type T.

• widgetBuilder - function that returns the widget to be tested.
• desc - test description.
• setup - function that sets up configurations before the test. It provides the application theme.
• test - function containing the actual test. It provides WidgetTester and the application theme. No need to call WidgetTester.pumpWidgetBuilder.
• withGolden - flag to determine if golden file updates should be performed for this widget.
• deviceMatters - flag to determine if golden files should be generated for different devices.
• screenState - string that allows specifying the screen state (e.g., loading, error).
• skip - Allows skipping the test.
• onlyOneTheme - Uses only one of the themes for the test (the first one from the list).
• onlyOneLocale - Uses only one of the locales for the test (the first one from the list).
• customPump - Allows customizing the pump function.
• devices - Allows specifying the devices for which the golden files should be generated.
• autoHeight - Allows specifying if the height of the golden file should be automatically adjusted.
• deviceSetup - Allows specifying the setup function for each device.

Implementation

@isTest
void testWidget<T extends Widget>({
  required Widget Function(BuildContext, ThemeType) widgetBuilder,
  String? desc,
  TestFunctionWithTheme? test,
  void Function(BuildContext, ThemeMode)? setup,
  bool withGolden = true,
  bool deviceMatters = true,
  bool autoHeight = false,
  bool? skip,
  String? screenState,
  Future<void> Function(WidgetTester)? customPump,
  Future<void> Function(TestDevice, WidgetTester)? deviceSetup,
  List<Device>? devices,
  bool onlyOneTheme = false,
  bool onlyOneLocale = false,
}) =>
    testGoldens(
      desc ?? 'Golden for $T',
      skip: skip,
      (tester) async {
        await loadAppFonts();

        // If the theme is not important for the test, the first one from the list will be used.
        final themesForTest = onlyOneTheme
            ? [themesForTesting.firstOrNull].whereNotNull()
            : themesForTesting;

        final localesForTest = onlyOneLocale
            ? [localesForTesting.firstOrNull].whereNotNull()
            : localesForTesting;

        assert(
          themesForTest.isNotEmpty,
          'At least one theme should be provided for the test.',
        );

        assert(
          localesForTest.isNotEmpty,
          'At least one locale should be provided for the test.',
        );

        /// Iterate over each theme.
        for (final theme in themesForTest) {
          /// Iterate over each locale.
          for (final locale in localesForTest) {
            /// Call setup if available.
            await tester.pumpWidgetBuilder(
              const SizedBox.shrink(),
              wrapper: (_) => widgetWrapper(
                (context) {
                  setup?.call(context, theme.type.toThemeMode);
                  return ColoredBox(
                    color: getBackgroundColor(theme.data),
                    child: widgetBuilder(context, theme.type),
                  );
                },
                theme.type,
                theme.data,
                localizationsForTesting,
                [locale],
              ),
            );

            /// Call the test if available.
            await test?.call(tester, theme.data);

            if (withGolden) {
              /// Generate golden files.
              await multiScreenGolden(
                tester,
                _getGoldenName<T>(
                  theme,
                  screenState,
                  locale: localesForTest.length == 1 ? null : locale,
                  includeThemeName: !onlyOneTheme,
                ),
                devices: deviceMatters ? null : [Device.phone],
                autoHeight: autoHeight,
              );

              await tester.pumpWidget(Container());
            }
          }
        }
      },
    );