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);
}