public void testBooksGetAuthorByBookId()
{
//Arrange
var BookRepoMockClass = new Mock <IBookRepo>();
string expected = "Huma";
BookRepoMockClass.Setup(x => x.GetAuthorByBookId(2)).Returns(expected);
var booksController = new BooksController(BookRepoMockClass.Object);
//Act
IHttpActionResult result = booksController.GetAuthorByBookId(2);
var resultBook = result as OkNegotiatedContentResult <string>;
//Assert
Assert.AreEqual(resultBook.Content, expected);
}