public void ShouldAddCommentLikeWhenCommentNotYetLikedByUser() { var commentLike = new CommentLike { CommentLikeId = 4, CommentId = 1, UserId = 1, User = new User { UserId = 1, UserName = "******" } }; _commentLikeRepository = new Mock<ICommentLikeRepository>(); _commentLikeRepository.Setup(a => a.Find(It.IsAny<Expression<Func<CommentLike, bool>>>(), false)) .Returns(new List<CommentLike>()); _commentLikeRepository.Setup(a => a.Add(It.IsAny<CommentLike>())) .Returns(commentLike); _commentLikesLogic = new CommentLikesLogic(_commentLikeRepository.Object); var result = _commentLikesLogic.Add(new Common.Contracts.CommentLike { CommentId = 1, UserId = 1 }); Assert.NotNull(result); Assert.AreEqual(4, result.CommentLikeId); }