public void BookPenaltyTest()
{
LibraryLogic logic = new LibraryLogic(new Library());
DateTime pastDate = new DateTime(2020, 10, 30);
TimeSpan diff = DateTime.Today - pastDate;
var b = new Book("Dune", "Herbert", BType.SciFi, 1, 1);
b.ReturnDate = pastDate;
Assert.AreEqual(logic.BookPenalty(b), diff.Days);
var b2 = new Book("Dune", "Herbert", BType.SciFi, 1, 1);
Assert.AreEqual(logic.BookPenalty(b2), 0);
}
