public void ShouldGetTagsByPostId()
{
const int postId = 1;
var tags = _tags.Where(a => a.TagId != 3).ToList();
var post = _posts.Where(a => a.PostId == 1).ToList();
_tagRepository = new Mock<ITagRepository>();
_tagRepository.Setup(a => a.Find(It.IsAny<Expression<Func<Tag, bool>>>(), null, string.Empty))
.Returns(tags);
_postRepository = new Mock<IPostRepository>();
_postRepository.Setup(a => a.Find(It.IsAny<Expression<Func<Post, bool>>>(),
It.IsAny<Func<IQueryable<Post>, IOrderedQueryable<Post>>>(), It.IsAny<string>()))
.Returns(post);
_tagsLogic = new TagsLogic(_tagRepository.Object, _postRepository.Object);
var result = _tagsLogic.GetByPostId(postId);
Assert.AreEqual(2, result.Count);
}