Verifying a delegate was called with Moq

Question

i got a class that gets by argument a delegate. This class invokes that delegate, and i want to unit test it with Moq. how do i verify that this method was called ?

exam

Answer 1

Moq does not support mocking delegates. But you can create some interface, with method, which matches your delegate signature:

public interface IBar
{
    void M(int number);
}

Then create mock, which implements this interface, and use this mock object to create delegate:

Mock bar = new Mock();
Foo foo = new Foo(bar.Object.M); 
A a = new A(foo);
bar.Verify(x => x.M(5));   

After exercising your sut, you will be able to verify expectations on your mocked object.

UPDATE: Actually you can simply pass bar.Object.M to your sut, without Foo delegate instance creation. But anyway, mocking delegates requires interface creation.