flutter-add-widget-test

Use testWidgets with a WidgetTester callback, call pumpWidget to render the widget, locate elements with Finder objects like find.text or find.byType, then assert with expect and matchers such as findsOneWidget. Wrap widgets in MaterialApp when they need theme or directionality.

Call await tester.tap(finder) to simulate taps and await tester.enterText(finder, 'text') for text fields. After the interaction, call await tester.pump() to rebuild the tree, then verify the updated state with expect.

Use pump() to trigger a single frame rebuild after standard state changes like button taps. Use pumpAndSettle() when testing animations, transitions, or asynchronous updates, since it repeatedly pumps frames until no more are scheduled.

Items in lazy lists are not rendered until visible. Call await tester.scrollUntilVisible(itemFinder, 500.0, scrollable: listFinder) to scroll the target into view before interacting with or asserting on it.

Place test files in the test/ directory at the project root and suffix filenames with _test.dart, such as widget_test.dart. Add flutter_test to dev_dependencies in pubspec.yaml, then run tests with flutter test.