public void Add_ReturnsBadRequest()
{
// Arrange
var nameMissingItem = new InventoryItem()
{
Manufacturer = "Man",
Price = 100
};
_controller.ModelState.AddModelError("Name", "Required");
// Act
var badResponse = _controller.Post(nameMissingItem).Result;
// Assert
Assert.IsType <BadRequestResult>(badResponse);
}