test_diceware.py

import os
import pytest
import sys
from diceware import (
    SRC_DIR, RE_LANG_CODE, SPECIAL_CHARS, get_wordlist, get_wordlist_path,
    insert_special_char, get_passphrase, handle_options, main,
    )


class FakeRandom(object):
    # a very, very bad random generator.
    # Very handy for tests, though :-)

    nums_to_draw = [0] * 100

    def choice(self, elems):
        num, self.nums_to_draw = self.nums_to_draw[0], self.nums_to_draw[1:]
        return elems[num]


@pytest.fixture(scope="function")
def argv_handler(request):
    """This fixture restores sys.argv after tests.
    """
    _argv_stored = sys.argv

    def teardown():
        sys.argv = _argv_stored
    request.addfinalizer(teardown)


class Test_GetWordList(object):

    def test_get_wordlist_en(self):
        # we can get a list of words out of english wordlist.
        en_src = os.path.join(SRC_DIR, 'wordlists', 'wordlist_en.txt')
        en_result = get_wordlist(en_src)
        assert en_result[0] == 'a'
        assert en_result[-1] == '@'
        assert len(en_result) == 8192

    def test_get_wordlist_simple(self, tmpdir):
        # simple wordlists can be created
        in_file = tmpdir.mkdir("work").join("mywordlist")
        in_file.write("a\nb\n")
        assert ['a', 'b'] == get_wordlist(in_file.strpath)

    def test_get_wordlist_ignore_empty_lines(self, tmpdir):
        # we ignore empty lines in wordlists
        in_file = tmpdir.mkdir("work").join("mywordlist")
        in_file.write("\n\na\n\n")
        assert ['a'] == get_wordlist(in_file.strpath)


class TestDicewareModule(object):

    def test_re_lang_code(self):
        # RE_LANG_CODE really works
        # valid stuff
        assert RE_LANG_CODE.match('de') is not None
        assert RE_LANG_CODE.match('DE') is not None
        assert RE_LANG_CODE.match('vb') is not None
        # invalid stuff
        assert RE_LANG_CODE.match('de_DE') is None
        assert RE_LANG_CODE.match('u1') is None
        assert RE_LANG_CODE.match('u') is None
        assert RE_LANG_CODE.match('dea') is None

    def test_get_wordlist_path(self):
        # we can get valid wordlist paths
        assert os.path.exists(get_wordlist_path('en'))
        assert not os.path.exists(get_wordlist_path('zz'))

    def test_get_wordlist_path_requires_ascii(self):
        # non ASCII alphabet chars are not accepted in language specifier
        with pytest.raises(ValueError) as exc_info:
            get_wordlist_path('../../tmp')
        assert exc_info.value.args[0].startswith(
            'Not a valid language code')

    def test_get_wordlist_path_loweres_country_code(self):
        # upper case country codes are lowered
        assert os.path.basename(get_wordlist_path('de')) == 'wordlist_de.txt'
        assert os.path.basename(get_wordlist_path('De')) == 'wordlist_de.txt'
        assert os.path.basename(get_wordlist_path('DE')) == 'wordlist_de.txt'

    def test_insert_special_char(self):
        # we can insert special chars in words.
        fake_rnd = FakeRandom()
        result1 = insert_special_char('foo', specials='bar', rnd=fake_rnd)
        assert result1 == 'boo'
        fake_rnd.nums_to_draw = [1, 1]
        result2 = insert_special_char('foo', specials='bar', rnd=fake_rnd)
        assert result2 == 'fao'
        fake_rnd.nums_to_draw = [2, 2]
        result3 = insert_special_char('foo', specials='bar', rnd=fake_rnd)
        assert result3 == 'for'
        fake_rnd.nums_to_draw = [0, 0]
        result4 = insert_special_char('foo', rnd=fake_rnd)
        assert result4 == '~oo'

    def test_insert_special_char_defaults(self):
        # defaults are respected
        expected_matrix = []
        for i in range(3):
            for j in range(len(SPECIAL_CHARS)):
                word = list('foo')
                word[i] = SPECIAL_CHARS[j]
                expected_matrix.append(''.join(word))
        for x in range(100):
            assert insert_special_char('foo') in expected_matrix

    def test_get_passphrase(self):
        # we can get passphrases
        r1 = get_passphrase()
        r2 = get_passphrase()
        assert r1 != r2

    def test_get_passphrase_capitals(self):
        # by default a passphrase contains upper case chars
        phrase = get_passphrase()
        assert phrase.lower() != phrase

    def test_get_passphrase_no_capitals(self):
        # we can turn capitals off
        phrase = get_passphrase(capitalized=False)
        assert phrase.lower() == phrase

    def test_handle_options(self):
        # we can get help
        with pytest.raises(SystemExit) as exc_info:
            handle_options(['--help'])
        assert exc_info.value.code == 0

    def test_handle_options_defaults(self):
        # defaults are correctly set
        options = handle_options([])
        assert options.num == 6
        assert options.capitalize is True
        assert options.specials == 0

    def test_main(self, capsys):
        # we can get a passphrase
        main([])  # call with default options in place
        out, err = capsys.readouterr()
        assert err == ''               # we got no errors
        assert out[-1] == '\n'         # output ends with liebreak
        assert not ('\n' in out[:-1])  # we get one line
        assert len(out) > 5            # we get at least some chars

    def test_main_help(self, capsys):
        # we can get help
        with pytest.raises(SystemExit) as exc_info:
            main(['--help'])
        assert exc_info.value.code == 0
        out, err = capsys.readouterr()
        out = out.replace(
            os.path.basename(sys.argv[0]), 'diceware')
        assert out == (
     'usage: diceware [-h] [-n NUM] [-c | --no-caps] [-s NUM]\n'
     '\n'
     'Create a passphrase\n'
     '\n'
     'optional arguments:\n'
     '  -h, --help            show this help message and exit\n'
     '  -n NUM, --num NUM     number of words to concatenate. Default: 6\n'
     '  -c, --caps            Capitalize words. This is the default.\n'
     '  --no-caps             Turn off capitalization.\n'
     '  -s NUM, --specials NUM\n'
     '                        Insert NUM special chars into generated word.\n'
            )

    def test_main_argv(self, argv_handler):
        # main() handles sys.argv if nothing is provided
        sys.argv = ['diceware', '--help']
        with pytest.raises(SystemExit) as exc_info:
            main()
        assert exc_info.value.code == 0