public void AddReadertoRent()
{
// create a repository
DataRepository dr = new DataRepository();
// create data
Book book = new Book("Needful Things", "King, Stephen");
Reader reader = new Reader("xyz", "Ossowskiego 665", "1111111");
Reader reader1 = new Reader("zyx", "ulica01", "009");
Rent rent = new Rent(book, reader1, "03/06/2017");
// add reader to a rent
Assert.IsTrue(rent.AddReader(reader));
// add data to the repository
dr.CreateReader(reader);
dr.CreateRent(rent);
// expected value: true
Assert.AreEqual("xyz", dr.Rents[0].reader.nameSurname);
// expected NullReferenceException
Assert.AreEqual("Needful Things", dr.Rents[0].rentedBook.title);
}
