stupid_simple_testing.dart

extension on WidgetTester {
  Future<void> launchApp() async {
    await app.main();
    await pumpAndSettle();
  }

  Future<void> clearState() async {
    await SharedPreferences.getInstance().then((it) => it.clear());
  }

  Future<void> tapFinder(Finder finder,
      {int index = 0, bool scrollTo = false}) async {
    expect(finder, findsWidgets);
    final maxIndex = min(index, finder.evaluate().length - 1);
    final honedFinder = finder.at(maxIndex);
    if (scrollTo) await ensureVisible(honedFinder);
    await tap(honedFinder, warnIfMissed: false);
    await pumpAndSettle();
  }

  Future<void> tapText(String text,
      {int index = 0, bool scrollTo = false}) async {
    final finder = find.text(text);
    await tapFinder(finder, index: index, scrollTo: scrollTo);
  }

  Future<void> tapIcon(IconData icon,
      {int index = 0, bool scrollTo = false}) async {
    final finder = find.byIcon(icon);
    await tapFinder(finder, index: index, scrollTo: scrollTo);
  }

  Future<void> tapBackButton() async {
    final finder = find.byType(BackButton);
    await tapFinder(finder);
  }

  Future<void> wait(int ms) async {
    await Future.delayed(Duration(milliseconds: ms));
  }

  Future<void> waitForText(
    String text, {
    Duration interval = const Duration(milliseconds: 50),
    Duration timeout = const Duration(seconds: 10),
  }) async {
    var stopwatch = Stopwatch()..start();

    while (stopwatch.elapsed < timeout) {
      await Future.delayed(interval);
      await pump();
      final finder = find.text(text);
      final foundSomething = finder.evaluate().isNotEmpty;
      if (foundSomething) {
        expect(finder, findsWidgets);
        stopwatch.stop();
        return;
      }
    }

    final finder = find.text(text);
    expect(finder, findsWidgets);
  }

  Future<void> input(String text, {int index = 0}) async {
    final finder = find.byType(EditableText);
    expect(finder, findsWidgets);
    final maxIndex = max(index, finder.evaluate().length - 1);
    await enterText(finder.at(maxIndex), text);
    await pumpAndSettle();
  }
}

@KoalityJustin Justin took this concept further, it can be found here: https://gist.github.com/KoalityJustin/910c9a5dd1ddb43c34de9770f4dac11f