public async Task GetStockItems_Returns_OkObjectResult()
        {
            //Arrange
            _fixture.MockStockItemRepository.Setup(x => x.GetStockItemsAsync())
            .ReturnsAsync(_fixture.StockItems);

            var controller = new StockItemController(_fixture.MockStockItemRepository.Object);

            //Act
            var result = await controller.GetStockItems();

            //Assert
            var okResult   = result.Should().BeOfType <OkObjectResult>().Subject;
            var stockItems = okResult.Value.Should().BeAssignableTo <IEnumerable <GetStockItemDto> >().Subject;

            okResult.StatusCode.Should().Be(200);
            stockItems.Should().HaveCount(3);
        }