Verifying a delegate was called with Moq

c# unit-testing delegates moq
Lironess picture Lironess · Jun 12, 2012 · Viewed 12.5k times · Source

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 ?

example class :

public delegate void Foo(int number);

public class A
{
   int a = 5;

   public A(Foo myFoo)
   {
      myFoo(a);
   }
}

and I want to check that Foo was called. Thank you.

Answer

Lukazoid picture Lukazoid · Sep 11, 2014

As of this commit Moq now supports the mocking of delegates, for your situation you would do it like so:

var fooMock = new Mock<Foo>();
var a = new A(fooMock.Object);

Then you can verify the delegate was invoked:

fooMock.Verify(f => f(5), Times.Once);

Or:

fooMock.Verify(f => f(It.IsAny<int>()), Times.Once);

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