Rhino Mocks: How do I mock a method call within a method call?

Question

I have a really simple class with two methods; One that will be called and the other that it will call. The idea is to call the OuterMockMethod method BUT mock the InnerMockMethod. Right now I can only seem to mock the OuterMockMethod method.

public class MockClass : IMockInterface
{         
    public virtual MockClass InnerMockMethod()
    {
      MockClass returnValue;

      returnValue = new MockClass();
      returnValue.SomeMessage = "Not mocked";

      return returnValue;
    }

    public virtual MockClass OuterMockMethod()
    {
      MockClass mock;

      mock = new MockClass();

      return mock.MockedMethod();
    }
}

Now this works, but it isn't the method I want to mock:

 public void MockTest_Internal()
 {
     MockClass returnedClass;
     MockClass mockProvider;

     mockProvider = repository.StrictMock<MockClass>();
     mockProvider.Expect(item => item.OuterMockMethod())
       .Return(new MockClass { SomeMessage = "Mocked" });
     repository.Replay(mockProvider);

     returnedClass = mockProvider.OuterMockMethod();

     Assert.IsTrue(returnedClass.SomeMessage == "Mocked");
 }

As you can see, it calls the OuterMockMethod which it likes but I don't want that. I want to mock the InnerMockMethod so that when it's called by the OuterMockMethod it will return what I want it to.

 public void MockTest_Internal()
 {
     MockClass returnedClass;
     MockClass mockProvider;

     mockProvider = repository.StrictMock<MockClass>();
     mockProvider.Expect(item => item.InnerMockMethod())
       .Return(new MockClass { SomeMessage = "Mocked" });
     repository.Replay(mockProvider);

     returnedClass = mockProvider.OuterMockMethod();  //Boom angry Rhino

     Assert.IsTrue(returnedClass.SomeMessage == "Mocked");
 }

Answer 1

In this case you need to put the mock on the returned object:

MockClass returnedMock = MockRepository.GenerateMock<MockClass>();
returnedMock.Expect( rm => rm.InnerMockMethod() )
            .Return( new MockClass { SomeMessage = "Mocked" } );
mockProvider.Expect( mp => mp.OuterMockMethod() ).Return (returnedMock );

returnedClass = mockProvider.OuterMockMethod();

...

Note that StrictMock has been deprecated. The preferred pattern is now AAA (Arrange, Act, Assert). You can find more info here.