public async Task PostSupplier_Should_Return_Bad_Request() { var delivery = SampleData.GetDeliveries()[1]; deliveryController.ModelState.AddModelError("", "Invalid Date"); var result = await deliveryController.PostDelivery(delivery); var statusCodeResult = (IStatusCodeActionResult)result.Result; Assert.IsNull(result.Value); Assert.AreEqual(statusCodeResult.StatusCode, StatusCodes.Status400BadRequest); }