tests/test_cadenus.py

   1 import pytest
   2 import string
   3
   4 from szyfrow.cadenus import *
   5 from szyfrow.support.utilities import *
   6
   7 def test_keycolumn():
   8     assert make_cadenus_keycolumn()['a'] == 0
   9     assert make_cadenus_keycolumn()['b'] == 1
  10     assert make_cadenus_keycolumn()['c'] == 2
  11     assert make_cadenus_keycolumn()['v'] == 21
  12     assert make_cadenus_keycolumn()['w'] == 21
  13     assert make_cadenus_keycolumn()['z'] == 24
  14     assert make_cadenus_keycolumn(doubled_letters='ij', start='b',
  15         reverse=True)['a'] == 1
  16     assert make_cadenus_keycolumn(doubled_letters='ij', start='b',
  17         reverse=True)['b'] == 0
  18     assert make_cadenus_keycolumn(doubled_letters='ij', start='b',
  19         reverse=True)['c'] == 24
  20     assert make_cadenus_keycolumn(doubled_letters='ij', start='b',
  21         reverse=True)['i'] == 18
  22     assert make_cadenus_keycolumn(doubled_letters='ij', start='b',
  23         reverse=True)['j'] == 18
  24     assert make_cadenus_keycolumn(doubled_letters='ij', start='b',
  25         reverse=True)['v'] == 6
  26     assert make_cadenus_keycolumn(doubled_letters='ij', start='b',
  27         reverse=True)['z'] == 2
  28
  29
  30 def test_encipher_message():
  31     plaintext = sanitise('''Whoever has made a voyage up the Hudson must
  32         remember the Kaatskill mountains. They are a dismembered branch of
  33         the great''')
  34     keycol = make_cadenus_keycolumn(doubled_letters='vw', start='a', reverse=True)
  35     ciphertext = cadenus_encipher(plaintext, 'wink', keycol)
  36     expected = 'antodeleeeuhrsidrbhmhdrrhnimefmthgeaetakseomehetyaasuvoyegrastmmuuaeenabbtpchehtarorikswosmvaleatned'
  37     assert ciphertext == expected
  38
  39     plaintext = sanitise('''a severe limitation on the usefulness of the
  40         cadenus is that every message must be a multiple of twenty-five
  41         letters long''')
  42     ciphertext = cadenus_encipher(plaintext, 'easy', keycol)
  43     expected = 'systretomtattlusoatleeesfiyheasdfnmschbhneuvsnpmtofarenuseieeieltarlmentieetogevesitfaisltngeeuvowul'
  44     assert ciphertext == expected
  45
  46
  47 def test_decipher_message():
  48     plaintext = sanitise('''Whoever has made a voyage up the Hudson must
  49         remember the Kaatskill mountains. They are a dismembered branch of
  50         the great''')
  51     keycol = make_cadenus_keycolumn(doubled_letters='vw', start='a', reverse=True)
  52     for key in ['wink', 'easy']:
  53         enciphered = cadenus_encipher(plaintext, key, keycol)
  54         deciphered = cadenus_decipher(enciphered, key, keycol)
  55         assert deciphered == plaintext
  56
  57
  58 def test_cadenus_break():
  59     plaintext = sanitise('''It is a truth universally acknowledged, that a single man in
  60              possession of a good fortune, must be in want of a wife. However
  61              little known the feelings or views of such a man may be on his
  62              first entering a neighbourhood, this truth is so well fixed in
  63              the minds of the surrounding families, that he is considered the
  64              rightful property of some one or other of their daughters.''')
  65     expected_key = 'swashbuckling'
  66     expected_score = Ptrigrams(plaintext)
  67     expected_keycol = make_cadenus_keycolumn(doubled_letters='vw', start='a',
  68         reverse=True)
  69
  70     ciphertext = cadenus_encipher(plaintext, expected_key, expected_keycol)
  71
  72     # dictionary = ['clearinghouse', 'computerising', 'counterclaims',
  73     #     'housewarmings',  'intravenously', 'liquefactions', 'somersaulting',
  74     #     'sportsmanlike', 'swashbuckling']
  75
  76     dictionary = ['swashbuckling']
  77
  78     (key, keycol), score = cadenus_break(ciphertext, words=dictionary,
  79         fitness=Ptrigrams)
  80
  81     assert key == expected_key
  82     assert keycol == expected_keycol
  83     assert score == pytest.approx(expected_score)