runTest method Null safety

  1. @override
Future<void> runTest(
  1. Future<void> testBody(
    1. VoidCallback invariantTester,
    2. {String description = '',
    3. @Deprecated('This parameter has no effect. Use the `timeout` parameter on `testWidgets` instead. ' 'This feature was deprecated after v2.6.0-1.0.pre.') Duration? timeout}

    Call the testBody inside a FakeAsync scope on which pump can advance time.

    Returns a future which completes when the test has run.

    Called by the testWidgets and benchmarkWidgets functions to run a test.

    The invariantTester argument is called after the testBody's Future completes. If it throws, then the test is marked as failed.

    The description is used by the LiveTestWidgetsFlutterBinding to show a label on the screen during the test. The description comes from the value passed to testWidgets. It must not be null.


    Future<void> runTest(
      Future<void> Function() testBody,
      VoidCallback invariantTester, {
      String description = '',
        'This parameter has no effect. Use the `timeout` parameter on `testWidgets` instead. '
        'This feature was deprecated after v2.6.0-1.0.pre.'
      Duration? timeout,
    }) {
      assert(description != null);
      assert(_currentFakeAsync == null);
      assert(_clock == null);
      final FakeAsync fakeAsync = FakeAsync();
      _currentFakeAsync = fakeAsync; // reset in postTest
      _clock = fakeAsync.getClock(DateTime.utc(2015));
      late Future<void> testBodyResult; localFakeAsync) {
        assert(fakeAsync == _currentFakeAsync);
        assert(fakeAsync == localFakeAsync);
        testBodyResult = _runTest(testBody, invariantTester, description);
      return Future<void>.microtask(() async {
        // testBodyResult is a Future that was created in the Zone of the
        // fakeAsync. This means that if we await it here, it will register a
        // microtask to handle the future _in the fake async zone_. We avoid this
        // by calling '.then' in the current zone. While flushing the microtasks
        // of the fake-zone below, the new future will be completed and can then
        // be used without fakeAsync.
        final Future<void> resultFuture = testBodyResult.then<void>((_) {
          // Do nothing.
        // Resolve interplay between fake async and real async calls.
        while (_pendingAsyncTasks != null) {
          await _pendingAsyncTasks!.future;
        return resultFuture;