public async Task GetById_SpecificSupplier_ShouldReturnASupplier() { // Arrange var supplier = _supplierFixture.GetValidSupplier(); var supplierId = supplier.Id; var mock = new Mock <ISupplierService>(); mock.Setup(service => service.GetSupplierAndAddressAndProducts(supplierId)).ReturnsAsync(supplier); // Act SupplierController controller = new SupplierController(mock.Object); var actionResult = await controller.GetById(supplierId); var result = Assert.IsType <ActionResult <SupplierDTO> >(actionResult).Result; var okResult = result as OkObjectResult; // Assert okResult.Value.Should().BeSameAs(supplier); okResult.StatusCode.Equals(HttpStatusCode.OK); }