public async Task Get_WhenCarWithGivenIdExists_ShouldBeReturned() { //Arrange var id = 1; var expected = "B2001ABC"; var car = new Car { Id = id, Plate = expected, }; _mockCarRepository .Setup(x => x.Get(id)) .Returns(Task.FromResult(CarHelper.GetDomainModels().FirstOrDefault(x => x.Id == id))) .Verifiable(); _mockUnitOfWork. Setup(x => x.Cars). Returns(_mockCarRepository.Object); ICarService service = new CarService(_mockUnitOfWork.Object); //Act var actual = await service.Get(id); //Assert _mockCarRepository.Verify(); Assert.IsNotNull(actual); Assert.AreEqual(expected, actual.Plate); }