// ======================================
// tests: unit tests for the domain model
// ======================================


class CopyTest {

  void testCopyIsFreeIfUserIsNull() {
    def copy = new Copy();
    copy.user = null
    assertTrue(copy.isAvailable())
    copy.user = new User()
    assertFalse(copy.isAvailable())
  }
}

class BookTest {

  void testBookIsAvailableIfAnyCopyIsAvailable() {
    def book = new Book()
    book.copies = []
    assertFalse(book.isAvailable())


    // Variante 1: echtes Copy
    def copy = new Copy(book)

    // Variante 2: gemocktes Copy
    def copy = mock(Copy.class)
    when(copy.isAvailable()).thenReturn(true)


    book.copies = [copy]
    assertTrue(book.isAvailable())
  }
}