public void PutMethodReturnsModifiedItem() { // Arrange var mockRepository = new Mock <IRepository <ToDoItem> >(); mockRepository.SetReturnsDefault(new ToDoItem { Id = 10, Title = "Item", Description = "Description" }); var controller = new ToDoItemsController(mockRepository.Object, _mapper); var modifiedItem = new ToDoItemDTO { Title = "Updated Item", Description = "Updated Description" }; // Act IHttpActionResult actionResult = controller.Put(10, modifiedItem); var updatedResult = actionResult as OkNegotiatedContentResult <ToDoItemDTO>; // Assert Assert.IsNotNull(updatedResult); Assert.IsNotNull(updatedResult.Content); Assert.AreEqual(modifiedItem.Description, updatedResult.Content.Description); Assert.AreEqual(modifiedItem.Title, updatedResult.Content.Title); }