public void Save_New_MD_Creates_It() { IMemberRepository repo = Substitute.For<IMemberRepository>(); repo.GetDirector().Returns(d => null); MembersController controller = new MembersController(repo); MusicalDirector director = new MusicalDirector {Name = "Fred", Description = "Fred's Description"}; var result = controller.EditMD(director); repo.Received().Save(director); }