public void ShouldGetAuthorById() { //Arrange CAuthor testAuthor = new CAuthor { Id = 2, Name = "Alfred Vaino Aho", BooksIds = new Int32[] { 2, 5 } }; //Act CAuthor authorFromMock = interactorUnderTest.GetAuthorById(2); //Assert testAuthor.Should().BeEquivalentTo(authorFromMock); }