public void GetBookByIdReturnsBook(int id)
{
var books = GetBooks();
var mockBook = new Mock <IRepository <Book> >();
mockBook.Setup(x => x.Get(It.Is <int>(y => y < 0 || y > 13)))
.Throws(new InvalidOperationException());
mockBook.Setup(x => x.Get(It.Is <int>(y => y >= 0 && y <= 13)))
.Returns(books[id]);
var mockCarousel = new Mock <IRepository <Carousel> >();
var sysut = new LandingPageHelper(mockBook.Object, mockCarousel.Object);
var result = sysut.GetBookById(id);
Assert.True(result != null);
Assert.Throws <InvalidOperationException>(() => sysut.GetBookById(20));
}
