public async void AddMakeAsync_Returns_Maker() { Guid guid = Guid.NewGuid(); var maker = new Mock <IVehicleMake>(); maker.Setup(s => s.Id).Returns(guid); repoMock.Setup(s => s.AddAsync(It.IsAny <IVehicleMake>())).Returns(Task.FromResult(maker.Object)); uowMock.SetupGet(s => s.Makers).Returns(repoMock.Object); var makeService = new VehicleMakeService(uowMock.Object); var make = await makeService.AddMakeAsync(maker.Object); //Assert Assert.NotNull(make); Assert.Equal(guid, make.Id); }