public void AddProductToOrder() { // arrange OrderController oCtrl = new OrderController(); ProductController pCtrl = new ProductController(); int amount = 1; Product testProduct = new Product { _description = "Testprodukt", _name = "Testprodukt", _price = 13, _categoryId = 2, _supplierId = 2 }; // act int productId = pCtrl.Create(testProduct); testProduct._id = productId; UniqueProduct testUniqueProduct = new UniqueProduct { _product = testProduct, _serialNo = RandomString(9), _warranty = "forever" }; pCtrl.CreateUniqueProduct(testUniqueProduct); int orderId = oCtrl.CreateOrder(); oCtrl.AddProduct(orderId, productId, amount); // assert Assert.IsTrue(orderId != 0); }