diff options
Diffstat (limited to 'lib/testtools/testtools/matchers/_dict.py')
| -rw-r--r-- | lib/testtools/testtools/matchers/_dict.py | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/lib/testtools/testtools/matchers/_dict.py b/lib/testtools/testtools/matchers/_dict.py new file mode 100644 index 0000000000..ff05199e6c --- /dev/null +++ b/lib/testtools/testtools/matchers/_dict.py @@ -0,0 +1,259 @@ +# Copyright (c) 2009-2012 testtools developers. See LICENSE for details. + +__all__ = [ + 'KeysEqual', + ] + +from ..helpers import ( + dict_subtract, + filter_values, + map_values, + ) +from ._higherorder import ( + AnnotatedMismatch, + PrefixedMismatch, + MismatchesAll, + ) +from ._impl import Matcher, Mismatch + + +def LabelledMismatches(mismatches, details=None): + """A collection of mismatches, each labelled.""" + return MismatchesAll( + (PrefixedMismatch(k, v) for (k, v) in sorted(mismatches.items())), + wrap=False) + + +class MatchesAllDict(Matcher): + """Matches if all of the matchers it is created with match. + + A lot like ``MatchesAll``, but takes a dict of Matchers and labels any + mismatches with the key of the dictionary. + """ + + def __init__(self, matchers): + super(MatchesAllDict, self).__init__() + self.matchers = matchers + + def __str__(self): + return 'MatchesAllDict(%s)' % (_format_matcher_dict(self.matchers),) + + def match(self, observed): + mismatches = {} + for label in self.matchers: + mismatches[label] = self.matchers[label].match(observed) + return _dict_to_mismatch( + mismatches, result_mismatch=LabelledMismatches) + + +class DictMismatches(Mismatch): + """A mismatch with a dict of child mismatches.""" + + def __init__(self, mismatches, details=None): + super(DictMismatches, self).__init__(None, details=details) + self.mismatches = mismatches + + def describe(self): + lines = ['{'] + lines.extend( + [' %r: %s,' % (key, mismatch.describe()) + for (key, mismatch) in sorted(self.mismatches.items())]) + lines.append('}') + return '\n'.join(lines) + + +def _dict_to_mismatch(data, to_mismatch=None, + result_mismatch=DictMismatches): + if to_mismatch: + data = map_values(to_mismatch, data) + mismatches = filter_values(bool, data) + if mismatches: + return result_mismatch(mismatches) + + +class _MatchCommonKeys(Matcher): + """Match on keys in a dictionary. + + Given a dictionary where the values are matchers, this will look for + common keys in the matched dictionary and match if and only if all common + keys match the given matchers. + + Thus:: + + >>> structure = {'a': Equals('x'), 'b': Equals('y')} + >>> _MatchCommonKeys(structure).match({'a': 'x', 'c': 'z'}) + None + """ + + def __init__(self, dict_of_matchers): + super(_MatchCommonKeys, self).__init__() + self._matchers = dict_of_matchers + + def _compare_dicts(self, expected, observed): + common_keys = set(expected.keys()) & set(observed.keys()) + mismatches = {} + for key in common_keys: + mismatch = expected[key].match(observed[key]) + if mismatch: + mismatches[key] = mismatch + return mismatches + + def match(self, observed): + mismatches = self._compare_dicts(self._matchers, observed) + if mismatches: + return DictMismatches(mismatches) + + +class _SubDictOf(Matcher): + """Matches if the matched dict only has keys that are in given dict.""" + + def __init__(self, super_dict, format_value=repr): + super(_SubDictOf, self).__init__() + self.super_dict = super_dict + self.format_value = format_value + + def match(self, observed): + excess = dict_subtract(observed, self.super_dict) + return _dict_to_mismatch( + excess, lambda v: Mismatch(self.format_value(v))) + + +class _SuperDictOf(Matcher): + """Matches if all of the keys in the given dict are in the matched dict. + """ + + def __init__(self, sub_dict, format_value=repr): + super(_SuperDictOf, self).__init__() + self.sub_dict = sub_dict + self.format_value = format_value + + def match(self, super_dict): + return _SubDictOf(super_dict, self.format_value).match(self.sub_dict) + + +def _format_matcher_dict(matchers): + return '{%s}' % ( + ', '.join(sorted('%r: %s' % (k, v) for k, v in matchers.items()))) + + +class _CombinedMatcher(Matcher): + """Many matchers labelled and combined into one uber-matcher. + + Subclass this and then specify a dict of matcher factories that take a + single 'expected' value and return a matcher. The subclass will match + only if all of the matchers made from factories match. + + Not **entirely** dissimilar from ``MatchesAll``. + """ + + matcher_factories = {} + + def __init__(self, expected): + super(_CombinedMatcher, self).__init__() + self._expected = expected + + def format_expected(self, expected): + return repr(expected) + + def __str__(self): + return '%s(%s)' % ( + self.__class__.__name__, self.format_expected(self._expected)) + + def match(self, observed): + matchers = dict( + (k, v(self._expected)) for k, v in self.matcher_factories.items()) + return MatchesAllDict(matchers).match(observed) + + +class MatchesDict(_CombinedMatcher): + """Match a dictionary exactly, by its keys. + + Specify a dictionary mapping keys (often strings) to matchers. This is + the 'expected' dict. Any dictionary that matches this must have exactly + the same keys, and the values must match the corresponding matchers in the + expected dict. + """ + + matcher_factories = { + 'Extra': _SubDictOf, + 'Missing': lambda m: _SuperDictOf(m, format_value=str), + 'Differences': _MatchCommonKeys, + } + + format_expected = lambda self, expected: _format_matcher_dict(expected) + + +class ContainsDict(_CombinedMatcher): + """Match a dictionary for that contains a specified sub-dictionary. + + Specify a dictionary mapping keys (often strings) to matchers. This is + the 'expected' dict. Any dictionary that matches this must have **at + least** these keys, and the values must match the corresponding matchers + in the expected dict. Dictionaries that have more keys will also match. + + In other words, any matching dictionary must contain the dictionary given + to the constructor. + + Does not check for strict sub-dictionary. That is, equal dictionaries + match. + """ + + matcher_factories = { + 'Missing': lambda m: _SuperDictOf(m, format_value=str), + 'Differences': _MatchCommonKeys, + } + + format_expected = lambda self, expected: _format_matcher_dict(expected) + + +class ContainedByDict(_CombinedMatcher): + """Match a dictionary for which this is a super-dictionary. + + Specify a dictionary mapping keys (often strings) to matchers. This is + the 'expected' dict. Any dictionary that matches this must have **only** + these keys, and the values must match the corresponding matchers in the + expected dict. Dictionaries that have fewer keys can also match. + + In other words, any matching dictionary must be contained by the + dictionary given to the constructor. + + Does not check for strict super-dictionary. That is, equal dictionaries + match. + """ + + matcher_factories = { + 'Extra': _SubDictOf, + 'Differences': _MatchCommonKeys, + } + + format_expected = lambda self, expected: _format_matcher_dict(expected) + + +class KeysEqual(Matcher): + """Checks whether a dict has particular keys.""" + + def __init__(self, *expected): + """Create a `KeysEqual` Matcher. + + :param expected: The keys the dict is expected to have. If a dict, + then we use the keys of that dict, if a collection, we assume it + is a collection of expected keys. + """ + super(KeysEqual, self).__init__() + try: + self.expected = expected.keys() + except AttributeError: + self.expected = list(expected) + + def __str__(self): + return "KeysEqual(%s)" % ', '.join(map(repr, self.expected)) + + def match(self, matchee): + from ._basic import _BinaryMismatch, Equals + expected = sorted(self.expected) + matched = Equals(expected).match(sorted(matchee.keys())) + if matched: + return AnnotatedMismatch( + 'Keys not equal', + _BinaryMismatch(expected, 'does not match', matchee)) + return None |