import org.junit.Before;
import org.junit.Test;

public class BookTest {
    private Book newBook;

    @Before
    public Book newBook() {
        newBook = new Book("TestTitle", "2017", "Smith", 1);
        return newBook;
    }

    @Test
    public void shouldLendBook_decreaseNumberOfCopies() {

        int expectedNumberOfCopies = 0;

        newBook.lendBook("Jones");

        assertEquals(expectedNumberOfCopies, newBook.getNumberOfCopies());

    }