    def test_scroll(self):
        """
        Check that scrolling works as expected.
        """
        def internal_checks(screen):
            # New screen is not scrolled.
            self.assertEqual(screen.start_line, 0)

            # Scroll and check it has moved
            screen.scroll()
            self.assertEqual(screen.start_line, 1)

            # Scroll to specific location and check it has moved
            screen.scroll_to(0)
            self.assertEqual(screen.start_line, 0)

        Screen.wrapper(internal_checks, height=15)
Check that scrolling works as expected.
tests/test_screen.py