public void AddAuthor()
        {
            // Arrange
            //var context = new BookRankingDbContext(DbConnectionFactory.CreateTransient());
            var context       = new Mock <IBookRankingDbContext>();
            var mockMapper    = new Mock <IMapper>();
            var authorDTOMock = new Mock <AuthorDTO>();
            var authorMock    = new Mock <Author>();

            mockMapper.Setup(m => m.Map <Author>(authorDTOMock.Object)).Returns(authorMock.Object);
            var authors = new FakeDbSet <Author>();

            context.Setup(c => c.Authors).Returns(authors);

            var service = new AuthorService(context.Object, mockMapper.Object);

            // Act
            service.AddAuthor(authorDTOMock.Object);

            // Assert
            Assert.IsTrue(context.Object.Authors.Contains(authorMock.Object));
        }