public void ShouldGetTagsByName()
{
const string tagName = "ipsum";
var tags = _tags.Where(a => a.TagName.Contains(tagName)).ToList();
_tagRepository = new Mock<ITagRepository>();
_tagRepository.Setup(a => a.Find(It.IsAny<Expression<Func<Tag, bool>>>(), true))
.Returns(tags);
_postRepository = new Mock<IPostRepository>();
_tagsLogic = new TagsLogic(_tagRepository.Object, _postRepository.Object);
var result = _tagsLogic.GetTagsByName(tagName);
Assert.AreEqual(2, result.Count);
}