public static void Callback()
{
var queue = new ManualEventQueue();
var evnt = new TestEvent();
bool handled = false;
queue.Enqueue(
evnt,
onHandled: e =>
{
Assert.True(ReferenceEquals(e, evnt));
handled = true;
});
// handled original event
Assert.False(handled);
Assert.True(queue.HandleNext());
Assert.False(handled);
// handle second event, implicitly added
Assert.True(queue.HandleNext());
Assert.True(handled);
// no other events were added
Assert.False(queue.HandleNext());
}
public static void StatelessHandler()
{
var queue = new ManualEventQueue();
// create subscriber
TestEvent lastEventHandled = null;
var subscriber = DelegateEventHandler.On <TestEvent>(evnt => lastEventHandled = evnt);
queue.Subscribers.Add(subscriber);
// enqueue and handle event
queue.Enqueue(new TestEvent()
{
Value = 3
});
Assert.Null(lastEventHandled);
Assert.True(queue.HandleNext());
// test subscriber
Assert.NotNull(lastEventHandled);
Assert.AreEqual(3, lastEventHandled.Value);
// queue is empty again (no unhandled exceptions or anything else)
Assert.False(queue.HandleNext());
}
public static void IsShutDown()
{
// initially open
var queue = new ManualEventQueue();
Assert.False(queue.IsShutDown);
// removing all subscribers does not shut down the queue
queue.Subscribers.AddAll(new TestEventHandler(), weakRef: false);
queue.Subscribers.Clear();
Assert.False(queue.IsShutDown);
// adding the shutting down event is not enough
queue.BeginShutdown();
Assert.False(queue.IsShutDown);
// handling the shutting down event is not enough...
queue.Subscribers.Add(
DelegateEventHandler.OnShuttingDown(
e => queue.Enqueue(new NamedEvent("shutting down event handler"))),
weakRef: false);
Assert.True(queue.HandleNext());
Assert.False(queue.IsShutDown);
// handling the NamedEvent added in the ShuttingDownEvent handler, is not enough
Assert.True(queue.HandleNext());
Assert.False(queue.IsShutDown);
// ... but handling the ShutDownEvent is
Assert.True(queue.HandleNext());
Assert.True(queue.IsShutDown);
Assert.False(queue.HandleNext());
}
public static void HandleSupportsEventInheritance()
{
var queue = new ManualEventQueue();
var subscriber = new AncestorEventHandler();
queue.Subscribers.AddAll(subscriber);
// subscriber does not handle events not in it's inheritance tree
Assert.True(queue.Enqueue(new TestEvent()));
Assert.True(queue.HandleNext());
Assert.Null(subscriber.LastEventHandled);
// subscriber accepts event type it explicitly stated it would handle
var namedEvent = new NamedEvent("name");
Assert.True(queue.Enqueue(namedEvent));
Assert.True(queue.HandleNext());
Assert.AreSame(namedEvent, subscriber.LastEventHandled);
// subscriber accepts event that inherit what it declared it would handle
var derivedEvent = new DescendantEvent();
Assert.True(queue.Enqueue(derivedEvent));
Assert.True(queue.HandleNext());
Assert.AreSame(derivedEvent, subscriber.LastEventHandled);
}
public static void EnqueueReturnValue()
{
var queue = new ManualEventQueue();
var evnt = new TestEvent();
Assert.True(queue.Enqueue(evnt));
// adding the same event a second time
Assert.False(queue.Enqueue(evnt));
// handling it and adding it again is fine however
Assert.True(queue.HandleNext());
Assert.False(queue.HandleNext()); // verify that we only added it once
Assert.True(queue.Enqueue(evnt));
// adding suspension
queue.EventAdding.Suspend();
Assert.False(queue.Enqueue(new TestEvent()));
queue.EventAdding.Resume();
Assert.True(queue.Enqueue(new TestEvent()));
// handle all events
while (queue.HandleNext())
{
;
}
// add and handle shutting down event
Assert.True(queue.Enqueue(new ShuttingDownEvent()));
Assert.False(queue.Enqueue(new ShuttingDownEvent())); // another shutting down event is already enqueued
Assert.True(queue.HandleNext());
Assert.False(queue.Enqueue(new TestEvent())); // no more events of any kind can be added
}
public static void ShutdownRequest_AfterShuttingDown()
{
// can not enqueue after shutting down event was enqueued
var queue = new ManualEventQueue();
Assert.True(queue.BeginShutdown());
Assert.False(queue.Enqueue(new ShutdownRequestEvent()));
// handling is skipped, if a shutting down event is enqueued beforehand
queue = new ManualEventQueue();
bool requestDetected = false;
queue.Subscribers.Add(
DelegateEventHandler.OnShutdownRequest(
e => requestDetected = true),
weakRef: false);
Assert.True(queue.Enqueue(new ShutdownRequestEvent())); // enqueueing succeeds
Assert.True(queue.Enqueue(new ShuttingDownEvent())); // shutting down event added
Assert.False(requestDetected);
Assert.True(queue.HandleNext()); // the request was "handled" successfully
Assert.False(requestDetected); // but the handler was not actually invoked
// ensure there are no unexpected events in the queue, that could have shifted the position of the request event
Assert.True(queue.HandleNext()); // shutting down event
Assert.True(queue.HandleNext()); // shut down event
Assert.False(queue.HandleNext());
Assert.True(queue.IsShutDown);
}
public static void NullCallback()
{
var queue = new ManualEventQueue();
Assert.True(queue.Enqueue(new TestEvent(), onHandled: null)); // no exception, successful call
Assert.True(queue.HandleNext());
Assert.False(queue.HandleNext()); // no secondary event added
}
public static void NoNewSubscriptionsAfterShutdown()
{
var queue = new ManualEventQueue();
var handler = new TestEventHandler();
queue.Subscribers.AddAll(handler);
queue.BeginShutdown();
Assert.True(queue.HandleNext()); // shutting down event
Assert.True(queue.HandleNext()); // shut down event
Assert.True(queue.IsShutDown);
Assert.False(queue.Subscribers.RemoveAll(handler)); // a shutdown queue has no subscribers
Assert.False(queue.Subscribers.AddAll(new TestEventHandler(), weakRef: false));
}
private static void Constructor(out ManualEventQueue queue)
{
// try to pass a null event queue
Assert.Throws <ArgumentNullException>(() => TestApp.Initialize(null));
// try to pass an event queue that's already shut down
var manualQueue = new ManualEventQueue();
manualQueue.BeginShutdown();
while (manualQueue.HandleNext())
{
;
}
Assert.Throws <ArgumentException>(() => TestApp.Initialize(manualQueue));
// pass a proper event queue
manualQueue = new ManualEventQueue();
TestApp.Initialize(manualQueue);
Assert.NotNull(AppBase.MainEventQueue);
Assert.AreSame(manualQueue, AppBase.MainEventQueue.BaseEventQueue);
Assert.AreSame(manualQueue.Subscribers, AppBase.MainEventQueue.Subscribers);
Assert.AreSame(manualQueue.EventAdding, AppBase.MainEventQueue.EventAdding);
Assert.AreSame(manualQueue.EventHandling, AppBase.MainEventQueue.EventHandling);
Assert.AreSame(manualQueue.RaiseUnhandledEvents, AppBase.MainEventQueue.RaiseUnhandledEvents);
Assert.AreEqual(AppState.Shutdown, AppBase.CurrentState);
queue = manualQueue;
}
private static void ShutdownEventTriggersShutdownState(ManualEventQueue manualQueue)
{
TestApp.MoveToState(AppState.Running);
while (manualQueue.HandleNext())
{
;
}
manualQueue.BeginShutdown();
while (manualQueue.HandleNext())
{
;
}
Assert.True(manualQueue.IsShutDown);
Assert.AreEqual(AppState.Shutdown, TestApp.CurrentState);
}
public static void EventsCanNotBeEnqueuedTwice()
{
var queue = new ManualEventQueue();
var evnt = new TestEvent();
// the same instance twice won't work
queue.Enqueue(evnt);
queue.Enqueue(evnt);
Assert.True(queue.HandleNext());
Assert.False(queue.HandleNext());
// .. but two separate instances of the same event are fine
queue.Enqueue(new TestEvent());
queue.Enqueue(new TestEvent());
Assert.True(queue.HandleNext());
Assert.True(queue.HandleNext());
}
public static void EventsCanNotBeEnqueuedAfterShuttingDown()
{
var queue = new ManualEventQueue();
var testListener = new TestEventHandler();
queue.Subscribers.AddAll(testListener);
queue.Subscribers.Add(
DelegateEventHandler.OnShuttingDown(
e => queue.Enqueue(new NamedEvent("shutting down event handler"))),
weakRef: false);
// enqueue shutting down event
queue.BeginShutdown();
// can enqueue, after the shutting down event is enqueued, but before it is handled
Assert.True(queue.Enqueue(new TestEvent()
{
Value = 1
}));
// handle shutting down event
Assert.True(queue.HandleNext());
Assert.Null(testListener.LastEventHandled);
// try to enqueue another event, after the shutting down event is handled:
// it should have no effect
Assert.False(queue.Enqueue(new TestEvent()
{
Value = 2
}));
// handle first test event
Assert.True(queue.HandleNext());
Assert.AreEqual(1, ((TestEvent)testListener.LastEventHandled).Value);
// handle the event added in the shutting down event handler
Assert.True(queue.HandleNext());
Assert.IsInstanceOf <NamedEvent>(testListener.LastEventHandled); // false for null
// handle shut down event
Assert.True(queue.HandleNext(out var shutDownEvent));
Assert.IsInstanceOf <ShutDownEvent>(shutDownEvent);
// nothing more to handle
Assert.True(queue.IsShutDown);
}
public static void ShuttingDownHandler()
{
var queue = new ManualEventQueue();
// create subscriber
ShuttingDownEvent lastEventHandled = null;
var subscriber = DelegateEventHandler.OnShuttingDown(evnt => lastEventHandled = evnt);
queue.Subscribers.Add(subscriber);
// enqueue and handle event
queue.BeginShutdown();
Assert.Null(lastEventHandled);
Assert.True(queue.HandleNext()); // shutting down event
// test subscriber
Assert.NotNull(lastEventHandled);
Assert.True(queue.HandleNext()); // shut down event
Assert.True(queue.IsShutDown);
}
public static void StatefulHandler()
{
var queue = new ManualEventQueue();
// create subscriber
TestEvent lastEventHandled = null;
var subscriber = DelegateEventHandler.On(
(int currentState, TestEvent evnt) =>
{
lastEventHandled = evnt;
evnt.Value += currentState;
return(currentState + 1);
},
initialState: 10);
queue.Subscribers.Add(subscriber);
// enqueue events
queue.Enqueue(new TestEvent()
{
Value = 3
});
queue.Enqueue(new TestEvent()
{
Value = 4
});
Assert.Null(lastEventHandled);
// handle first event
Assert.True(queue.HandleNext());
Assert.NotNull(lastEventHandled);
Assert.AreEqual(13, lastEventHandled.Value);
// handle second event
Assert.True(queue.HandleNext());
Assert.NotNull(lastEventHandled);
Assert.AreEqual(15, lastEventHandled.Value);
// queue is empty again (no unhandled exceptions or anything else)
Assert.False(queue.HandleNext());
}
public static void HandleNextInvokesHandler()
{
var queue = new ManualEventQueue();
var evnt = new TestEvent();
var subscriber = new TestEventHandler();
// queue empty
Assert.False(queue.HandleNext());
// enqueueing does not invoke handlers
queue.Subscribers.AddAll(subscriber);
Assert.True(queue.Enqueue(evnt));
Assert.Null(subscriber.LastEventHandled);
// invoking handlers is successful
Assert.True(queue.HandleNext());
Assert.AreSame(evnt, subscriber.LastEventHandled);
// queue is empty again
Assert.False(queue.HandleNext());
}
public static void ShutdownRequest_NotCancelled()
{
var queue = new ManualEventQueue();
bool shuttingDownDetected = false;
queue.Subscribers.Add(
DelegateEventHandler.OnShuttingDown(
e => shuttingDownDetected = true),
weakRef: false);
// requests are granted by default (Cancel is false)
Assert.True(queue.RequestShutdown());
Assert.True(queue.HandleNext()); // request event
Assert.False(shuttingDownDetected);
Assert.True(queue.HandleNext()); // shutting down event
Assert.True(shuttingDownDetected);
Assert.True(queue.HandleNext()); // shut down event
Assert.False(queue.HandleNext());
Assert.True(queue.IsShutDown);
}
public static void EventAddingSuspension()
{
var queue = new ManualEventQueue();
Assert.False(queue.EventHandling.IsSuspended);
var testListener = new TestEventHandler();
queue.Subscribers.AddAll(testListener);
var evnt = new TestEvent();
queue.EventAdding.Suspend();
Assert.False(queue.Enqueue(evnt));
Assert.False(queue.HandleNext());
Assert.Null(testListener.LastEventHandled);
queue.EventAdding.Resume();
Assert.True(queue.Enqueue(evnt));
Assert.True(queue.HandleNext());
Assert.AreSame(evnt, testListener.LastEventHandled);
}
public static void ExceptionHandler()
{
var queue = new ManualEventQueue();
// create subscriber
UnhandledExceptionEvent lastEventHandled = null;
var subscriber = DelegateEventHandler.OnException(evnt => lastEventHandled = evnt);
queue.Subscribers.Add(subscriber);
// enqueue and handle event
queue.Enqueue(new UnhandledExceptionEvent(new UnauthorizedAccessException()));
Assert.Null(lastEventHandled);
Assert.True(queue.HandleNext());
// test subscriber
Assert.NotNull(lastEventHandled);
Test.OrdinalEquals(lastEventHandled.Type, typeof(UnauthorizedAccessException).ToString());
// queue is empty again (no unhandled exceptions or anything else)
Assert.False(queue.HandleNext());
}
public static void ShutdownRequest_Cancelled()
{
var queue = new ManualEventQueue();
queue.Subscribers.Add(
DelegateEventHandler.OnShutdownRequest(
e => e.Cancel = true),
weakRef: false);
// you can only add one request at a time
Assert.True(queue.RequestShutdown());
Assert.False(queue.RequestShutdown());
// cancel the request
Assert.True(queue.HandleNext());
// no shutting down event
Assert.False(queue.HandleNext());
// you can add another request, once the previous one is out of the queue
Assert.True(queue.RequestShutdown());
Assert.True(queue.HandleNext());
Assert.False(queue.HandleNext());
}
private static void ChangeToSameState(ManualEventQueue manualQueue)
{
AppStateChangedEvent.Critical criticalEvent = null;
var subscriber = DelegateEventHandler.On <AppStateChangedEvent.Critical>(
e =>
{
criticalEvent = e;
});
TestApp.MainEventQueue.Subscribers.Add(subscriber);
var currentState = TestApp.CurrentState;
TestApp.MoveToState(currentState);
Assert.AreEqual(currentState, TestApp.CurrentState); // no state change
Assert.Null(criticalEvent); // no critical event
Assert.False(manualQueue.HandleNext()); // no regular event
TestApp.MainEventQueue.Subscribers.Remove(subscriber);
}
public static void EventHandlerExceptions()
{
var queue = new ManualEventQueue();
queue.Subscribers.Add(
DelegateEventHandler.On <TestEvent>(
e => throw new ArgumentOutOfRangeException()),
weakRef: false);
queue.Subscribers.Add(
DelegateEventHandler.On <TestEvent>(
e => throw new MissingMemberException()),
weakRef: false);
bool argumentExceptionFound = false;
bool memberExceptionFound = false;
bool unhandledExceptionEventHandled = false;
queue.Subscribers.Add(
DelegateEventHandler.On <UnhandledExceptionEvent>(
e =>
{
unhandledExceptionEventHandled = true;
if (e.Type.IndexOf(nameof(ArgumentOutOfRangeException), StringComparison.Ordinal) != -1)
{
argumentExceptionFound = true;
}
else if (e.Type.IndexOf(nameof(MissingMemberException), StringComparison.Ordinal) != -1)
{
memberExceptionFound = true;
}
}),
weakRef: false);
// unhandled exception events are generated by default
queue.Enqueue(new TestEvent());
Assert.False(argumentExceptionFound);
Assert.False(memberExceptionFound);
Assert.False(unhandledExceptionEventHandled);
Assert.True(queue.HandleNext()); // test event
Assert.True(queue.HandleNext()); // argument exception
Assert.True(queue.HandleNext()); // missing member exception
Assert.True(argumentExceptionFound);
Assert.True(memberExceptionFound);
Assert.True(unhandledExceptionEventHandled);
// unhandled exception event suppression
queue.Enqueue(new TestEvent());
argumentExceptionFound = false;
memberExceptionFound = false;
unhandledExceptionEventHandled = false;
queue.RaiseUnhandledEvents.Suspend();
Assert.True(queue.HandleNext());
Assert.False(queue.HandleNext());
queue.RaiseUnhandledEvents.Resume();
Assert.False(argumentExceptionFound);
Assert.False(memberExceptionFound);
Assert.False(unhandledExceptionEventHandled);
// event addition suppression
queue.Enqueue(new TestEvent());
queue.EventAdding.Suspend();
Assert.True(queue.HandleNext());
Assert.False(queue.HandleNext());
queue.EventAdding.Resume();
Assert.False(argumentExceptionFound);
Assert.False(memberExceptionFound);
Assert.False(unhandledExceptionEventHandled);
}