1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
"""
    babel.messages.checkers
    ~~~~~~~~~~~~~~~~~~~~~~~

    Various routines that help with validation of translations.

    :since: version 0.9

    :copyright: (c) 2013-2022 by the Babel Team.
    :license: BSD, see LICENSE for more details.
"""

from babel.messages.catalog import TranslationError, PYTHON_FORMAT


#: list of format chars that are compatible to each other
_string_format_compatibilities = [
    {'i', 'd', 'u'},
    {'x', 'X'},
    {'f', 'F', 'g', 'G'}
]


def num_plurals(catalog, message):
    """Verify the number of plurals in the translation."""
    if not message.pluralizable:
        if not isinstance(message.string, str):
            raise TranslationError("Found plural forms for non-pluralizable "
                                   "message")
        return

    # skip further tests if no catalog is provided.
    elif catalog is None:
        return

    msgstrs = message.string
    if not isinstance(msgstrs, (list, tuple)):
        msgstrs = (msgstrs,)
    if len(msgstrs) != catalog.num_plurals:
        raise TranslationError("Wrong number of plural forms (expected %d)" %
                               catalog.num_plurals)


def python_format(catalog, message):
    """Verify the format string placeholders in the translation."""
    if 'python-format' not in message.flags:
        return
    msgids = message.id
    if not isinstance(msgids, (list, tuple)):
        msgids = (msgids,)
    msgstrs = message.string
    if not isinstance(msgstrs, (list, tuple)):
        msgstrs = (msgstrs,)

    for msgid, msgstr in zip(msgids, msgstrs):
        if msgstr:
            _validate_format(msgid, msgstr)


def _validate_format(format, alternative):
    """Test format string `alternative` against `format`.  `format` can be the
    msgid of a message and `alternative` one of the `msgstr`\\s.  The two
    arguments are not interchangeable as `alternative` may contain less
    placeholders if `format` uses named placeholders.

    The behavior of this function is undefined if the string does not use
    string formattings.

    If the string formatting of `alternative` is compatible to `format` the
    function returns `None`, otherwise a `TranslationError` is raised.

    Examples for compatible format strings:

    >>> _validate_format('Hello %s!', 'Hallo %s!')
    >>> _validate_format('Hello %i!', 'Hallo %d!')

    Example for an incompatible format strings:

    >>> _validate_format('Hello %(name)s!', 'Hallo %s!')
    Traceback (most recent call last):
      ...
    TranslationError: the format strings are of different kinds

    This function is used by the `python_format` checker.

    :param format: The original format string
    :param alternative: The alternative format string that should be checked
                        against format
    :raises TranslationError: on formatting errors
    """

    def _parse(string):
        result = []
        for match in PYTHON_FORMAT.finditer(string):
            name, format, typechar = match.groups()
            if typechar == '%' and name is None:
                continue
            result.append((name, str(typechar)))
        return result

    def _compatible(a, b):
        if a == b:
            return True
        for set in _string_format_compatibilities:
            if a in set and b in set:
                return True
        return False

    def _check_positional(results):
        positional = None
        for name, char in results:
            if positional is None:
                positional = name is None
            else:
                if (name is None) != positional:
                    raise TranslationError('format string mixes positional '
                                           'and named placeholders')
        return bool(positional)

    a, b = map(_parse, (format, alternative))

    # now check if both strings are positional or named
    a_positional, b_positional = map(_check_positional, (a, b))
    if a_positional and not b_positional and not b:
        raise TranslationError('placeholders are incompatible')
    elif a_positional != b_positional:
        raise TranslationError('the format strings are of different kinds')

    # if we are operating on positional strings both must have the
    # same number of format chars and those must be compatible
    if a_positional:
        if len(a) != len(b):
            raise TranslationError('positional format placeholders are '
                                   'unbalanced')
        for idx, ((_, first), (_, second)) in enumerate(zip(a, b)):
            if not _compatible(first, second):
                raise TranslationError('incompatible format for placeholder '
                                       '%d: %r and %r are not compatible' %
                                       (idx + 1, first, second))

    # otherwise the second string must not have names the first one
    # doesn't have and the types of those included must be compatible
    else:
        type_map = dict(a)
        for name, typechar in b:
            if name not in type_map:
                raise TranslationError('unknown named placeholder %r' % name)
            elif not _compatible(typechar, type_map[name]):
                raise TranslationError('incompatible format for '
                                       'placeholder %r: '
                                       '%r and %r are not compatible' %
                                       (name, typechar, type_map[name]))


def _find_checkers():
    checkers = []
    try:
        from pkg_resources import working_set
    except ImportError:
        pass
    else:
        for entry_point in working_set.iter_entry_points('babel.checkers'):
            checkers.append(entry_point.load())
    if len(checkers) == 0:
        # if pkg_resources is not available or no usable egg-info was found
        # (see #230), just resort to hard-coded checkers
        return [num_plurals, python_format]
    return checkers


checkers = _find_checkers()