How do I raise an event when a method is called using Moq?

Question

I\'ve got an interface like this:

public interface IMyInterface
{
    event EventHandler Triggered;
    void Trigger();
}

And I

Answer 1

Your pseudo-code was almost spot on. You needed to use Raises instead of Raise. Check the Moq Quickstart: Events for versions Moq 4.x and you will see where you made the mistake.

_mockedObject.Setup(i => i.Trigger()).Raises(i => i.Triggered += null, this, true);

Here is the snippet form GitHub

// Raising an event on the mock
mock.Raise(m => m.FooEvent += null, new FooEventArgs(fooValue));

// Raising an event on a descendant down the hierarchy
mock.Raise(m => m.Child.First.FooEvent += null, new FooEventArgs(fooValue));

// Causing an event to raise automatically when Submit is invoked
mock.Setup(foo => foo.Submit()).Raises(f => f.Sent += null, EventArgs.Empty);
// The raised event would trigger behavior on the object under test, which 
// you would make assertions about later (how its state changed as a consequence, typically)

// Raising a custom event which does not adhere to the EventHandler pattern
public delegate void MyEventHandler(int i, bool b);
public interface IFoo
{
  event MyEventHandler MyEvent; 
}

var mock = new Mock();
...
// Raise passing the custom arguments expected by the event delegate
mock.Raise(foo => foo.MyEvent += null, 25, true);