public void DeleteOffer_WhenInValidParametersArePased_ShouldReturnNull() { // Arrange var autoMapperConfig = new AutoMapperConfig(); autoMapperConfig.Execute(typeof(OffersController).Assembly); var carOffer = new CarOffer(); var guid = Guid.NewGuid(); var userServiceMock = new Mock <IUserService>(); var carOffersServiceMock = new Mock <ICarOffersService>(); carOffersServiceMock.Setup(x => x.GetAll()) .Returns(() => new List <CarOffer> { carOffer }.AsQueryable()); carOffersServiceMock.Setup(x => x.Delete(carOffer)); OffersController offersController = new OffersController(carOffersServiceMock.Object, userServiceMock.Object); // Act ViewResult result = offersController.DeleteOffer(guid) as ViewResult; // Assert Assert.IsNull(result); }