internal async Task Non_Generic_Async_Event_Should_Run_Asynchronously()
{
var notifier = new NonGenericNotifier();
var tcs = new TaskCompletionSource <object>();
var eventFired = false;
async Task RespondToSomethingHappening(object sender, EventArgs eventArgs)
{
await tcs.Task;
eventFired = true;
}
notifier.SomethingHappened += RespondToSomethingHappening;
var eventTask = notifier.OnSomethingHappening();
await Task.Delay(100);
eventFired.ShouldBeFalse();
tcs.SetResult(null);
await eventTask;
eventFired.ShouldBeTrue();
}
internal async Task All_Handlers_Should_Finish_Before_Event_Task_Completes()
{
var notifier = new NonGenericNotifier();
IEnumerable <TaskCompletionSource <object> > CreateAndSubscribeHandlers()
{
while (true)
{
var tcs = new TaskCompletionSource <object>();
Task RespondToSomethingHappening(object sender, EventArgs eventArgs) => tcs.Task;
notifier.SomethingHappened += RespondToSomethingHappening;
yield return(tcs);
}
}
// Reversing the order that the handlers signal completion ensures that we test that the event task
// completes only when _all_ handlers finish, and not just the last one subscribed.
var tcsArray = CreateAndSubscribeHandlers().Take(5).Reverse().ToArray();
var eventTask = notifier.OnSomethingHappening();
foreach (var tcs in tcsArray.Reverse())
{
await Task.Delay(10);
eventTask.IsCompleted.ShouldBeFalse();
tcs.SetResult(null);
}
await eventTask;
}
internal async Task Exceptions_That_Occur_During_Event_Handling_Should_Be_Propagated()
{
var notifier = new NonGenericNotifier();
Task FaultyHandler(object sender, EventArgs eventArgs) => throw new InvalidOperationException();
notifier.SomethingHappened += FaultyHandler;
await Should.ThrowAsync <InvalidOperationException>(async() => await notifier.OnSomethingHappening());
}
internal async Task Non_Generic_Synchronous_Event_Handlers_Should_Be_Convertible_To_Equivalent_Asynchronous_Handlers()
{
var notifier = new NonGenericNotifier();
var eventFired = false;
notifier.SomethingHappened += Async((sender, args) => eventFired = true);
await notifier.OnSomethingHappening();
eventFired.ShouldBeTrue();
}
internal void Invoke_Async_Should_Return_Completed_Task_If_No_Handlers_Are_Subscribed()
{
var notifier = new NonGenericNotifier();
notifier.OnSomethingHappening().IsCompleted.ShouldBeTrue();
}
