Rhino Mocks: Mocked method returns null

I'm trying to mock a data repository object but after setting an expectation on my MockRepository, it returns null every time. My code is as follows:

    [Test]
    public void GetById_NotNull()
    {
        Person expectedPerson = new Person() { Id = 1, Name="Jon"};

        MockRepository MockRepository = new MockRepository();
        var FakePersonRepository = MockRepository.StrictMock<IRepository<Person>>();

        FakePersonRepository.Expect(action => action.Get(1)).IgnoreArguments().Return(expectedPerson);

        PersonService PersonService = new PersonService(FakePersonRepository);
        Person returnedPerson = PersonService.Get(1);

        Assert.IsNotNull(returnedPerson);
    }

    //and inside my person service
    public class PersonService
    {
         private IRepository<Person> _PersonRepository;
         public PersonService(IRepository<Person> PersonRepository)
         {
           this._PersonRepository = PersonRepository;
         }

         public Person Get(int Id)
         {
             Person p = _PersonRepository.Get(Id);
             return p;
          }
    }

The assertion at the bottom of the Test fails and returned person is always null. I know I must be doing something wrong with my mock....ideas?

From stackoverflow

• Try doing a

  mockRepository.ReplayAll()
  

  after the line where you set your Expect.

• I'm not super familiar with RhinoMocks (I've been using Moq), but couldn't:

  FakePersonRepository.Expect(action => action.Get(1)).IgnoreArguments().Return(expectedPerson);
  

  be

  FakePersonRepository.Expect(action => action.Get(1)).Return(expectedPerson);
  

  I also think you need a Replay() with RM.

  Dav Evans : Yeah the IgnoreArguments is superfluous. Its the replay I was missing.

• As others have said, I believe you will need a Replay somewhere with the style of tests you are using; As an alternative, you could use the newer AAA Syntax along with the static MockRepository.GenerateMock<>()/MockRepository.GenerateStub<>() methods which would not require a Replay.

• Chris is on the money here. The AAA syntax and using GenerateStub for this senario is best.

  var FakePersonRepository = MockRepository.GenerateStub<<IRepository<Person>>();
  FakePersonRepository.Stub(x => x.Get(1)).Returns(expectedPerson);
  
  PersonService PersonService = new PersonService(FakePersonRepository);
  Person returnedPerson = PersonService.Get(1);
  

• With the AAA syntax and GenerateMock you can also verify that PersonRepository is called with the correct parameter and correct number of times:

  Person expectedPerson = new Person() { Id = 1, Name="Jon"}; 
  
  MockRepository MockRepository = new MockRepository(); 
  var FakePersonRepository = MockRepository.GenerateMock<IRepository<Person>>(); 
  
  FakePersonRepository.Expect(action => action.Get(1)).Return(expectedPerson).Repeat.Once(); 
  PersonService PersonService = new PersonService(FakePersonRepository); 
  Person returnedPerson = PersonService.Get(1); 
  
  Assert.IsNotNull(returnedPerson); 
  FakePersonRepository.VerifyAllExpectations();