import py
from vt102 import VT102


def check(vt, expected):
    expected = '\n'.join(expected)
    assert vt.screenshot() == expected


def test_simple_scrolling():
    vt = VT102(16, 3)
    vt.terminal_input('hello')
    check(vt, ['hello',
               '',
               ''])
    vt.terminal_input('\r\nworld\r\n')
    check(vt, ['hello',
               'world',
               ''])
    vt.terminal_input('bla\r')
    check(vt, ['hello',
               'world',
               'bla'])
    vt.terminal_input('\n')
    check(vt, ['world',
               'bla',
               ''])

def test_wraparound():
    vt = VT102(5, 3)
    vt.terminal_input('12345abcdefghij')
    check(vt, ['12345',
               'abcde',
               'fghij'])
    vt.terminal_input('k')
    check(vt, ['abcde',
               'fghij',
               'k'])