public void PutTags(int id) { var updateEntity = _fixture.Build <TagModel>().With(x => x.Id, id).Create(); // Act var controller = new TagsController(_logger, _entityBL, _commonBL); var result = controller.PutTags(id, updateEntity) as OkNegotiatedContentResult <JsonResponse>; // Assert var resultEntity = result.Content.Data as Tag; Assert.That(resultEntity.LastActivityDate, Is.Not.EqualTo(DateTime.MinValue)); Assert.That(resultEntity.Id, Is.EqualTo(1)); // hasn't changed }