public async Task Put_Change_Basket_Item_Quanitity() { // Arrange var basketItemDbSetMock = Builder <BasketItem> .CreateListOfSize(5).Build(); _iBasketServiceMock.Setup(m => m.ChangeBasketItemQuantityAsync(1, 2)).Returns(Task.FromResult(basketItemDbSetMock)); // Act var result = await _shoppingCartController.ChangeItemQuantity(1, 2); // Assert Assert.NotNull(result); var objectResult = result as OkObjectResult; Assert.NotNull(objectResult); var content = objectResult.Value as IList <BasketItem>; Assert.NotNull(content); }