def test_empty():
for rot in xrange(26):
assert mk_ceasar(rot)('') == ''
def test_rot_13():
assert mk_ceasar(13)('abc') == 'nop'
assert mk_ceasar(13)('nop') == 'abc'
assert mk_ceasar(13)('xyz ABC') == 'klm NOP'
assert mk_ceasar(13)('XYZ~abc') == 'KLM~nop'
def test_rot_13_undo():
rot13 = mk_ceasar(13)
tests = ['foo', 'BAR', 'baz', '', 'GG', ' yy ', 'The lonely wolf jumps on the moon.']
for test in tests:
assert rot13(rot13(test)) == test
def test_rot_1():
assert mk_ceasar(1)('abc') == 'bcd'
assert mk_ceasar(1)('xyz ABC') == 'yza BCD'
assert mk_ceasar(1)('XYZ~abc') == 'YZA~bcd'