MyStory.Controllers.PostController.Edit C# (CSharp) Method

        public ActionResult Edit(PostInput input)
        {
            if (!ModelState.IsValid)
                return View("Edit", input);

            var post = DbContext.Posts.Single(p => p.Id == input.Id);

            if (TryUpdateModel(post, "", null, new string[]{"Tags"}))
            {
                post.DateModified = DateTime.Now;

                _tagService.UpdateTag(DbContext, input, post);

                DbContext.Entry(post).State = System.Data.EntityState.Modified;
                DbContext.SaveChanges();

                return RedirectToAction("Detail", "Post", new { id = input.Id });
            }

            return View("Edit", input);
        }

        public void Edit_Method_Should_Validate_Model()
        {
            // Arrange
            _controller = new PostController();
            _controller.ModelState.AddModelError("modelerror", "modelerror");

            var result = _controller.Edit(new PostInput()) as ViewResult;
            result.ViewName.SequenceEqual("Edit");
            result.ViewData.ModelState.IsValid.ShouldBeFalse();
        }