public async Task GetByIdShouldReturn404NotFound() { var basketServiceMock = new Mock <IBasketService>(MockBehavior.Strict); basketServiceMock.Setup(service => service.GetById(null)).ReturnsAsync((Basket)null); var productServiceMock = new Mock <IProductService>(MockBehavior.Strict); var controller = new BasketsController(basketServiceMock.Object, productServiceMock.Object); var result = await controller.GetById(null); Assert.IsType <NotFoundResult>(result); productServiceMock.VerifyAll(); basketServiceMock.Verify(service => service.GetById(null), Times.Once); basketServiceMock.VerifyAll(); }