public void TestWeakEvent_Extension()
{
EventRaisingClass observed = new EventRaisingClass();
_eventRaised = false;
var handler = new EventHandler <EventArgs>(GetCallback()).MakeWeak(h => observed.Event -= h);
observed.Event += handler;
Assert.AreEqual(1, observed.SubscriptionCount);
// pull the WeakEventHandler instance out of the callback
var weakEventHandler = handler.Target as WeakEventHandler <EventArgs>;
Assert.IsNotNull(weakEventHandler);
// when target goes out of scope, event is not detached. the observer will be
// temporarily leaked until the event fires
InvalidateEventHandler(weakEventHandler);
Assert.AreEqual(1, observed.SubscriptionCount);
// if the target is no longer alive when the event is raised, the event handler should be
// automatically unregistered, which will cause the observer to unsubscribe from the source
observed.RaiseEvent(EventArgs.Empty);
Assert.AreEqual(0, observed.SubscriptionCount);
Assert.IsFalse(_eventRaised);
}
public void TestSubscription_Simple()
{
// subscription should not occur until handler is registered
EventRaisingClass observed = new EventRaisingClass();
Assert.AreEqual(0, observed.SubscriptionCount);
_eventRaised = false;
observed.Event += new WeakEventHandler <EventArgs>(GetCallback()).Handler;
// subscription should have occurred
Assert.AreEqual(1, observed.SubscriptionCount);
observed.RaiseEvent(EventArgs.Empty);
Assert.IsTrue(_eventRaised);
}