Moq: How to get to a parameter passed to a method of a mocked service

Question

Imagine this class

public class Foo {      private Handler _h;      public Foo(Handler h)     {         _h = h;     }      public void Bar(int i)     {         _h.AsyncHandle(CalcOn(i));     }      private SomeResponse CalcOn(int i)     {         ...;     } } 

Mo(q)cking Handler in a test of Foo, how would I be able to check what Bar() has passed to _h.AsyncHandle?

Answer 1

You can use the Mock.Callback-method:

var mock = new Mock<Handler>(); SomeResponse result = null; mock.Setup(h => h.AsyncHandle(It.IsAny<SomeResponse>()))     .Callback<SomeResponse>(r => result = r);  // do your test new Foo(mock.Object).Bar(22); Assert.NotNull(result); 

If you only want to check something simple on the passed in argument, you also can do it directly:

mock.Setup(h => h.AsyncHandle(It.Is<SomeResponse>(response => response != null)));