public void NullDelegateThrows()
{
Assert.Throws<ArgumentNullException>(() =>
{
var action = new DelegateReference(null, true);
});
}
public void NotKeepAliveAllowsDelegateToBeCollected()
{
var delegates = new SomeClassHandler();
var delegateReference = new DelegateReference((Action<string>)delegates.DoEvent, false);
delegates = null;
GC.Collect();
Assert.Null(delegateReference.Target);
}
public void KeepAlivePreventsDelegateFromBeingCollected()
{
var delegates = new SomeClassHandler();
var delegateReference = new DelegateReference((Action<string>)delegates.DoEvent, true);
delegates = null;
GC.Collect();
Assert.NotNull(delegateReference.Target);
}
public void ShouldReturnNullIfTargetNotAlive()
{
SomeClassHandler handler = new SomeClassHandler();
var weakHandlerRef = new WeakReference(handler);
var action = new DelegateReference((Action<string>)handler.DoEvent, false);
handler = null;
GC.Collect();
Assert.False(weakHandlerRef.IsAlive);
Assert.Null(action.Target);
}
public void ShouldAllowCollectionOfOriginalDelegate()
{
var classHandler = new SomeClassHandler();
Action<string> myAction = new Action<string>(classHandler.MyAction);
var weakAction = new DelegateReference(myAction, false);
var originalAction = new WeakReference(myAction);
myAction = null;
GC.Collect();
Assert.False(originalAction.IsAlive);
((Action<string>)weakAction.Target)("payload");
Assert.Equal("payload", classHandler.MyActionArg);
}
public void NotKeepAliveKeepsDelegateIfStillAlive()
{
var delegates = new SomeClassHandler();
var delegateReference = new DelegateReference((Action<string>)delegates.DoEvent, false);
GC.Collect();
Assert.NotNull(delegateReference.Target);
GC.KeepAlive(delegates); //Makes delegates ineligible for garbage collection until this point (to prevent oompiler optimizations that may release the referenced object prematurely).
delegates = null;
GC.Collect();
Assert.Null(delegateReference.Target);
}
public void TargetShouldReturnAction()
{
var classHandler = new SomeClassHandler();
Action<string> myAction = new Action<string>(classHandler.MyAction);
var weakAction = new DelegateReference(myAction, false);
((Action<string>)weakAction.Target)("payload");
Assert.Equal("payload", classHandler.MyActionArg);
}
public void WeakDelegateWorksWithStaticMethodDelegates()
{
var action = new DelegateReference((Action)SomeClassHandler.StaticMethod, false);
Assert.NotNull(action.Target);
}
