public async Task TestUpdateStory_NotFound() { //Arrange string expectedTitle = "LoremIpsum"; string userId = "akash"; DBStatus status = DBStatus.NotFound; RequestStoryDTO storyDTO = new RequestStoryDTO { Title = expectedTitle }; storiesService.Setup(x => x.ReplaceStoryAsync(storyDTO, userId)).ReturnsAsync(status); storiesController.ControllerContext = httpContext; //Act var result = await storiesController.UpdateStory(storyDTO) as NotFoundResult; //Assert Assert.NotNull(result); Assert.Equal(404, result.StatusCode); }