public async Task AsyncOperationCancelledIfRequestedAsync()
{
await _taskFactory.SwitchToMainThreadAsync();
var asyncOperationStarted = new AsyncManualResetEvent();
var taskCancelled = new AsyncManualResetEvent();
var source = new CancellationTokenSource();
Task asyncOperation = _taskExecutor.SubmitAsync(async() =>
{
asyncOperationStarted.Set();
await taskCancelled.WaitAsync();
Assert.Throws <OperationCanceledException>(
() => _taskExecutor.CancelAsyncOperationIfRequested());
}, source.Token, _dummyMethodName, _dummyType);
await asyncOperationStarted.WaitAsync();
source.Cancel();
taskCancelled.Set();
Assert.ThrowsAsync <TaskCanceledException>(async() => await asyncOperation);
}