public async Task ExportJson_RedirectToIndex()
        {
            Mock <PostService> mock       = new Mock <PostService>();
            PostController     controller = GetNewPostControllerWithControllerContext(mock.Object, null, null);

            FilePathResult result = (await controller.ExportJson()) as FilePathResult;

            Assert.AreEqual("application/json", result.ContentType);
            Assert.AreEqual("Posts.json", result.FileDownloadName);
            Assert.AreEqual("./DiplomMSSQLApp.WEB/Results/Posts.json", result.FileName);
        }