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Editing: comparison.py
from collections import OrderedDict from collections.abc import Iterable as IterableABC from decimal import Decimal from difflib import unified_diff from functools import partial as partial_type, reduce from operator import __or__ from pprint import pformat from typing import ( Dict, Any, Optional, Sequence, Generator, TypeVar, List, Mapping, Pattern, Union, Callable, Iterable ) from types import GeneratorType import re from testfixtures import not_there, singleton from testfixtures.resolve import resolve from testfixtures.utils import indent from testfixtures.mock import parent_name, mock_call from unittest.mock import call as unittest_mock_call # Some common types that are immutable, for optimisation purposes within CompareContext IMMUTABLE_TYPEs = str, bytes, int, float, tuple, type(None) def diff(x: str, y: str, x_label: str = '', y_label: str = ''): """ A shorthand function that uses :mod:`difflib` to return a string representing the differences between the two string arguments. Most useful when comparing multi-line strings. """ return '\n'.join( unified_diff( x.split('\n'), y.split('\n'), x_label or 'first', y_label or 'second', lineterm='') ) def compare_simple(x, y, context: 'CompareContext'): """ Returns a very simple textual difference between the two supplied objects. """ if x != y: repr_x = repr(x) repr_y = repr(y) if repr_x == repr_y: if type(x) is not type(y): return compare_with_type(x, y, context) x_attrs = _extract_attrs(x) y_attrs = _extract_attrs(y) diff_ = None if not (x_attrs is None or y_attrs is None): diff_ = _compare_mapping(x_attrs, y_attrs, context, x, 'attributes ', '.%s') if diff_: return diff_ return 'Both %s and %s appear as %r, but are not equal!' % ( context.x_label or 'x', context.y_label or 'y', repr_x ) return context.label('x', repr_x) + ' != ' + context.label('y', repr_y) def _extract_attrs(obj, ignore: Iterable[str] = None) -> Optional[Dict[str, Any]]: try: attrs = vars(obj).copy() except TypeError: attrs = None else: if isinstance(obj, BaseException): attrs['args'] = obj.args has_slots = getattr(obj, '__slots__', not_there) is not not_there if has_slots: slots = set() for cls in type(obj).__mro__: slots.update(getattr(cls, '__slots__', ())) if slots and attrs is None: attrs = {} for n in slots: value = getattr(obj, n, not_there) if value is not not_there: attrs[n] = value if attrs is None: return None if ignore is not None: for attr in ignore: attrs.pop(attr, None) return attrs def _attrs_to_ignore( context: 'CompareContext', ignore_attributes: Iterable[str], obj ) -> Iterable[str]: ignore = context.get_option('ignore_attributes', ()) if isinstance(ignore, dict): ignore = ignore.get(type(obj), ()) ignore = set(ignore) ignore.update(ignore_attributes) return ignore def compare_object( x, y, context: 'CompareContext', ignore_attributes: Iterable[str] = () ) -> Optional[str]: """ Compare the two supplied objects based on their type and attributes. :param ignore_attributes: Either a sequence of strings containing attribute names to be ignored when comparing or a mapping of type to sequence of strings containing attribute names to be ignored when comparing that type. This may be specified as either a parameter to this function or in the ``context``. If specified in both, they will both apply with precedence given to whatever is specified is specified as a parameter. If specified as a parameter to this function, it may only be a list of strings. """ if type(x) is not type(y) or isinstance(x, type): return compare_simple(x, y, context) x_attrs = _extract_attrs(x, _attrs_to_ignore(context, ignore_attributes, x)) y_attrs = _extract_attrs(y, _attrs_to_ignore(context, ignore_attributes, y)) if x_attrs is None or y_attrs is None or not (x_attrs and y_attrs): return compare_simple(x, y, context) if context.ignore_eq or x_attrs != y_attrs: return _compare_mapping(x_attrs, y_attrs, context, x, 'attributes ', '.%s') def compare_exception( x: Exception, y: Exception, context: 'CompareContext' ) -> Optional[str]: """ Compare the two supplied exceptions based on their message, type and attributes. """ if x.args != y.args: return compare_simple(x, y, context) return compare_object(x, y, context) def compare_with_type(x, y, context: 'CompareContext') -> str: """ Return a textual description of the difference between two objects including information about their types. """ if type(x) is AlreadySeen and type(x.obj) is type(y) and x.obj == y: return '' source = locals() to_render = {} for name in 'x', 'y': obj = source[name] to_render[name] = context.label( name, '{0} ({1!r})'.format(_short_repr(obj), type(obj)) ) return '{x} != {y}'.format(**to_render) def compare_sequence( x: Sequence, y: Sequence, context: 'CompareContext', prefix: bool = True ) -> Optional[str]: """ Returns a textual description of the differences between the two supplied sequences. """ l_x = len(x) l_y = len(y) i = 0 while i < l_x and i < l_y: if context.different(x[i], y[i], '[%i]' % i): break i += 1 if l_x == l_y and i == l_x: return return (('sequence not as expected:\n\n' if prefix else '')+ 'same:\n%s\n\n' '%s:\n%s\n\n' '%s:\n%s') % (pformat(x[:i]), context.x_label or 'first', pformat(x[i:]), context.y_label or 'second', pformat(y[i:]), ) def compare_generator(x: Generator, y: Generator, context: 'CompareContext') -> Optional[str]: """ Returns a textual description of the differences between the two supplied generators. This is done by first unwinding each of the generators supplied into tuples and then passing those tuples to :func:`compare_sequence`. """ x = tuple(x) y = tuple(y) if not context.ignore_eq and x == y: return return compare_sequence(x, y, context) def compare_tuple(x: tuple, y: tuple, context: 'CompareContext') -> Optional[str]: """ Returns a textual difference between two tuples or :func:`collections.namedtuple` instances. The presence of a ``_fields`` attribute on a tuple is used to decide whether or not it is a :func:`~collections.namedtuple`. """ x_fields = getattr(x, '_fields', None) y_fields = getattr(y, '_fields', None) if x_fields and y_fields: if x_fields == y_fields: return _compare_mapping(dict(zip(x_fields, x)), dict(zip(y_fields, y)), context, x) else: return compare_with_type(x, y, context) return compare_sequence(x, y, context) def compare_dict(x: dict, y: dict, context: 'CompareContext') -> Optional[str]: """ Returns a textual description of the differences between the two supplied dictionaries. """ return _compare_mapping(x, y, context, x) Item = TypeVar('Item') def sorted_by_repr(sequence: Iterable[Item]) -> List[Item]: return sorted(sequence, key=lambda o: repr(o)) def _compare_mapping( x: Mapping, y: Mapping, context: 'CompareContext', obj_for_class: Any, prefix: str = '', breadcrumb: str = '[%r]', check_y_not_x: bool = True ) -> Optional[str]: x_keys = set(x.keys()) y_keys = set(y.keys()) x_not_y = x_keys - y_keys y_not_x = y_keys - x_keys same = [] diffs = [] for key in sorted_by_repr(x_keys.intersection(y_keys)): if context.different(x[key], y[key], breadcrumb % (key, )): diffs.append('%r: %s != %s' % ( key, context.label('x', pformat(x[key])), context.label('y', pformat(y[key])), )) else: same.append(key) if not (x_not_y or (check_y_not_x and y_not_x) or diffs): return if obj_for_class is not_there: lines = [] else: lines = ['%s not as expected:' % obj_for_class.__class__.__name__] if same: try: same = sorted(same) except TypeError: pass lines.extend(('', '%ssame:' % prefix, repr(same))) x_label = context.x_label or 'first' y_label = context.y_label or 'second' if x_not_y: lines.extend(('', '%sin %s but not %s:' % (prefix, x_label, y_label))) for key in sorted_by_repr(x_not_y): lines.append('%r: %s' % ( key, pformat(x[key]) )) if y_not_x: lines.extend(('', '%sin %s but not %s:' % (prefix, y_label, x_label))) for key in sorted_by_repr(y_not_x): lines.append('%r: %s' % ( key, pformat(y[key]) )) if diffs: lines.extend(('', '%sdiffer:' % (prefix or 'values '))) lines.extend(diffs) return '\n'.join(lines) def compare_set(x: set, y: set, context: 'CompareContext') -> Optional[str]: """ Returns a textual description of the differences between the two supplied sets. """ x_not_y = x - y y_not_x = y - x if not (y_not_x or x_not_y): return lines = ['%s not as expected:' % x.__class__.__name__, ''] x_label = context.x_label or 'first' y_label = context.y_label or 'second' if x_not_y: lines.extend(( 'in %s but not %s:' % (x_label, y_label), pformat(sorted_by_repr(x_not_y)), '', )) if y_not_x: lines.extend(( 'in %s but not %s:' % (y_label, x_label), pformat(sorted_by_repr(y_not_x)), '', )) return '\n'.join(lines)+'\n' trailing_whitespace_re: Pattern = re.compile(r'\s+$', re.MULTILINE) def strip_blank_lines(text: str) -> str: result = [] for line in text.split('\n'): if line and not line.isspace(): result.append(line) return '\n'.join(result) def split_repr(text: str) -> str: parts = text.split('\n') for i, part in enumerate(parts[:-1]): parts[i] = repr(part + '\n') parts[-1] = repr(parts[-1]) return '\n'.join(parts) def compare_text(x: str, y: str, context: 'CompareContext'): """ Returns an informative string describing the differences between the two supplied strings. The way in which this comparison is performed can be controlled using the following parameters: :param blanklines: If `False`, then when comparing multi-line strings, any blank lines in either argument will be ignored. :param trailing_whitespace: If `False`, then when comparing multi-line strings, trailing whilespace on lines will be ignored. :param show_whitespace: If `True`, then whitespace characters in multi-line strings will be replaced with their representations. """ blanklines = context.get_option('blanklines', True) trailing_whitespace = context.get_option('trailing_whitespace', True) show_whitespace = context.get_option('show_whitespace', False) if not trailing_whitespace: x = trailing_whitespace_re.sub('', x) y = trailing_whitespace_re.sub('', y) if not blanklines: x = strip_blank_lines(x) y = strip_blank_lines(y) if x == y: return labelled_x = context.label('x', repr(x)) labelled_y = context.label('y', repr(y)) if len(x) > 10 or len(y) > 10: if '\n' in x or '\n' in y: if show_whitespace: x = split_repr(x) y = split_repr(y) message = '\n' + diff(x, y, context.x_label, context.y_label) else: message = '\n%s\n!=\n%s' % (labelled_x, labelled_y) else: message = labelled_x+' != '+labelled_y return message def compare_bytes(x: bytes, y: bytes, context: 'CompareContext') -> Optional[str]: if x == y: return labelled_x = context.label('x', repr(x)) labelled_y = context.label('y', repr(y)) return '\n%s\n!=\n%s' % (labelled_x, labelled_y) def compare_call(x, y, context: 'CompareContext') -> Optional[str]: if x == y: return def extract(call): try: name, args, kwargs = call except ValueError: name = None args, kwargs = call return name, args, kwargs x_name, x_args, x_kw = extract(x) y_name, y_args, y_kw = extract(y) if x_name == y_name and x_args == y_args and x_kw == y_kw: return compare_call(getattr(x, parent_name), getattr(y, parent_name), context) if repr(x) != repr(y): return compare_text(repr(x), repr(y), context) different = ( context.different(x_name, y_name, ' function name') or context.different(x_args, y_args, ' args') or context.different(x_kw, y_kw, ' kw') ) if not different: return return 'mock.call not as expected:' def compare_partial(x: partial_type, y: partial_type, context: 'CompareContext') -> Optional[str]: x_attrs = dict(func=x.func, args=x.args, keywords=x.keywords) y_attrs = dict(func=y.func, args=y.args, keywords=y.keywords) if x_attrs != y_attrs: return _compare_mapping(x_attrs, y_attrs, context, x, 'attributes ', '.%s') def _short_repr(obj) -> str: repr_ = repr(obj) if len(repr_) > 30: repr_ = repr_[:30] + '...' return repr_ Comparer = Callable[[Any, Any, 'CompareContext'], Optional[str]] Registry = Dict[type, Comparer] _registry: Registry = { dict: compare_dict, set: compare_set, list: compare_sequence, tuple: compare_tuple, str: compare_text, bytes: compare_bytes, int: compare_simple, float: compare_simple, Decimal: compare_simple, GeneratorType: compare_generator, mock_call.__class__: compare_call, unittest_mock_call.__class__: compare_call, BaseException: compare_exception, partial_type: compare_partial, } def register(type_: type, comparer: Comparer): """ Register the supplied comparer for the specified type. This registration is global and will be in effect from the point this function is called until the end of the current process. """ _registry[type_] = comparer def _shared_mro(x, y): y_mro = set(type(y).__mro__) for class_ in type(x).__mro__: if class_ in y_mro: yield class_ _unsafe_iterables = str, bytes, dict class AlreadySeen: def __init__(self, id_, obj, breadcrumb): self.id = id_ self.obj = obj self.breadcrumb = breadcrumb def __repr__(self): return f'<AlreadySeen for {self.obj!r} at {self.breadcrumb} with id {self.id}>' def __eq__(self, other): if isinstance(other, AlreadySeen): return self.breadcrumb == other.breadcrumb else: return self.obj == other class CompareContext(object): """ Stores the context of the current comparison in process during a call to :func:`testfixtures.compare`. """ def __init__( self, x_label: Optional[str], y_label: Optional[str], recursive: bool = True, strict: bool = False, ignore_eq: bool = False, comparers: Registry = None, options: Dict[str, Any] = None, ): self.registries = [] if comparers: self.registries.append(comparers) self.registries.append(_registry) self.x_label = x_label self.y_label = y_label self.recursive: bool = recursive self.strict: bool = strict self.ignore_eq: bool = ignore_eq self.options: Dict[str, Any] = options or {} self.message: str = '' self.breadcrumbs: List[str] = [] self._seen = {} def extract_args(self, args: tuple, x: Any, y: Any, expected: Any, actual: Any) -> List: possible = [] def append_if_specified(source): if source is not unspecified: possible.append(source) append_if_specified(expected) possible.extend(args) append_if_specified(actual) append_if_specified(x) append_if_specified(y) if len(possible) != 2: message = 'Exactly two objects needed, you supplied:' if possible: message += ' {}'.format(possible) if self.options: message += ' {}'.format(self.options) raise TypeError(message) return possible def get_option(self, name: str, default=None): return self.options.get(name, default) def label(self, side: str, value: Any) -> str: r = str(value) label = getattr(self, side+'_label') if label: r += ' ('+label+')' return r def _lookup(self, x: Any, y: Any) -> Comparer: if self.strict and type(x) is not type(y): return compare_with_type for class_ in _shared_mro(x, y): for registry in self.registries: comparer = registry.get(class_) if comparer: return comparer # fallback for iterables if ((isinstance(x, IterableABC) and isinstance(y, IterableABC)) and not (isinstance(x, _unsafe_iterables) or isinstance(y, _unsafe_iterables))): return compare_generator # special handling for Comparisons: if isinstance(x, Comparison) or isinstance(y, Comparison): return compare_simple return compare_object def _separator(self) -> str: return '\n\nWhile comparing %s: ' % ''.join(self.breadcrumbs[1:]) def _break_loops(self, obj, breadcrumb): # Don't bother with this process for simple, immutable types: if isinstance(obj, IMMUTABLE_TYPEs): return obj id_ = id(obj) breadcrumb_ = self._seen.get(id_) if breadcrumb_ is not None: return AlreadySeen(id_, obj, breadcrumb_) else: self._seen[id_] = breadcrumb return obj def different(self, x: Any, y: Any, breadcrumb: str) -> Union[bool, Optional[str]]: x = self._break_loops(x, breadcrumb) y = self._break_loops(y, breadcrumb) recursed = bool(self.breadcrumbs) self.breadcrumbs.append(breadcrumb) existing_message = self.message self.message = '' current_message = '' try: if type(y) is AlreadySeen or not (self.strict or self.ignore_eq): try: if x == y: return False except RecursionError: pass comparer: Comparer = self._lookup(x, y) result = comparer(x, y, self) specific_comparer = comparer is not compare_simple if result: if specific_comparer and recursed: current_message = self._separator() if specific_comparer or not recursed: current_message += result if self.recursive: current_message += self.message return result finally: self.message = existing_message + current_message self.breadcrumbs.pop() def _resolve_lazy(source): return str(source() if callable(source) else source) unspecified = singleton('unspecified') def compare( *args, x: Any = unspecified, y: Any = unspecified, expected: Any = unspecified, actual: Any = unspecified, prefix: str = None, suffix: str = None, x_label: str = None, y_label: str = None, raises: bool = True, recursive: bool = True, strict: bool = False, ignore_eq: bool = False, comparers: Registry = None, **options: Any ) -> Optional[str]: """ Compare two objects, raising an :class:`AssertionError` if they are not the same. The :class:`AssertionError` raised will attempt to provide descriptions of the differences found. The two objects to compare can be passed either positionally or using explicit keyword arguments named ``x`` and ``y``, or ``expected`` and ``actual``, or a mixture of these. :param prefix: If provided, in the event of an :class:`AssertionError` being raised, the prefix supplied will be prepended to the message in the :class:`AssertionError`. This may be a callable, in which case it will only be resolved if needed. :param suffix: If provided, in the event of an :class:`AssertionError` being raised, the suffix supplied will be appended to the message in the :class:`AssertionError`. This may be a callable, in which case it will only be resolved if needed. :param x_label: If provided, in the event of an :class:`AssertionError` being raised, the object passed as the first positional argument, or ``x`` keyword argument, will be labelled with this string in the message in the :class:`AssertionError`. :param y_label: If provided, in the event of an :class:`AssertionError` being raised, the object passed as the second positional argument, or ``y`` keyword argument, will be labelled with this string in the message in the :class:`AssertionError`. :param raises: If ``False``, the message that would be raised in the :class:`AssertionError` will be returned instead of the exception being raised. :param recursive: If ``True``, when a difference is found in a nested data structure, attempt to highlight the location of the difference. :param strict: If ``True``, objects will only compare equal if they are of the same type as well as being equal. :param ignore_eq: If ``True``, object equality, which relies on ``__eq__`` being correctly implemented, will not be used. Instead, comparers will be looked up and used and, if no suitable comparer is found, objects will be considered equal if their hash is equal. :param comparers: If supplied, should be a dictionary mapping types to comparer functions for those types. These will be added to the comparer registry for the duration of this call. Any other keyword parameters supplied will be passed to the functions that end up doing the comparison. See the :mod:`API documentation below <testfixtures.comparison>` for details of these. """ __tracebackhide__ = True if not (expected is unspecified and actual is unspecified): x_label = x_label or 'expected' y_label = y_label or 'actual' context = CompareContext(x_label, y_label, recursive, strict, ignore_eq, comparers, options) x, y = context.extract_args(args, x, y, expected, actual) if not context.different(x, y, ''): return message = context.message if prefix: message = _resolve_lazy(prefix) + ': ' + message if suffix: message += '\n' + _resolve_lazy(suffix) if raises: raise AssertionError(message) return message class StatefulComparison(object): """ A base class for stateful comparison objects. """ failed: str = '' expected: Any = None name_attrs: Sequence[str] = () def __eq__(self, other): return not(self != other) def name(self) -> str: name = type(self).__name__ if self.name_attrs: name += '(%s)' % ', '.join('%s=%r' % (n, getattr(self, n)) for n in self.name_attrs) return name def body(self) -> str: return pformat(self.expected)[1:-1] def __repr__(self) -> str: name = self.name() body = self.failed or self.body() prefix = '<%s%s>' % (name, self.failed and '(failed)' or '') if '\n' in body: return '\n'+prefix+'\n'+body.strip('\n')+'\n'+'</%s>' % name elif body: return prefix + body + '</>' return prefix class Comparison(StatefulComparison): """ These are used when you need to compare an object's type, a subset of its attributes or make equality checks with objects that do not natively support comparison. :param object_or_type: The object or class from which to create the :class:`Comparison`. :param attribute_dict: An optional dictionary containing attributes to place on the :class:`Comparison`. :param partial: If true, only the specified attributes will be checked and any extra attributes of the object being compared with will be ignored. :param attributes: Any other keyword parameters passed will placed as attributes on the :class:`Comparison`. """ def __init__(self, object_or_type, attribute_dict: Dict[str, Any] = None, partial: bool = False, **attributes: Any): self.partial = partial if attributes: if attribute_dict is None: attribute_dict = attributes else: attribute_dict.update(attributes) if isinstance(object_or_type, str): c = resolve(object_or_type).found if c is not_there: raise AttributeError( '%r could not be resolved' % object_or_type ) elif isinstance(object_or_type, type): c = object_or_type else: c = object_or_type.__class__ if attribute_dict is None: attribute_dict = _extract_attrs(object_or_type) self.expected_type = c self.expected_attributes = attribute_dict def __ne__(self, other: Any) -> bool: if self.expected_type is not other.__class__: self.failed = 'wrong type' return True if self.expected_attributes is None: return False attribute_names = set(self.expected_attributes.keys()) if self.partial: actual_attributes = {} else: actual_attributes = _extract_attrs(other) attribute_names -= set(actual_attributes) for name in attribute_names: try: actual_attributes[name] = getattr(other, name) except AttributeError: pass context = CompareContext(x_label='Comparison', y_label='actual') self.failed = _compare_mapping(self.expected_attributes, actual_attributes, context, obj_for_class=not_there, prefix='attributes ', breadcrumb='.%s', check_y_not_x=not self.partial) return bool(self.failed) def name(self) -> str: name = 'C:' module = getattr(self.expected_type, '__module__', None) if module: name = name + module + '.' name += (getattr(self.expected_type, '__name__', None) or repr(self.expected_type)) return name def body(self) -> str: if self.expected_attributes: # if we're not failed, show what we will expect: lines = [] for k, v in sorted(self.expected_attributes.items()): rv = repr(v) if '\n' in rv: rv = indent(rv) lines.append('%s: %s' % (k, rv)) return '\n'.join(lines) return '' class SequenceComparison(StatefulComparison): """ An object that can be used in comparisons of expected and actual sequences. :param expected: The items expected to be in the sequence. :param ordered: If ``True``, then the items are expected to be in the order specified. If ``False``, they may be in any order. Defaults to ``True``. :param partial: If ``True``, then any keys not expected will be ignored. Defaults to ``False``. :param recursive: If a difference is found, recursively compare the item where the difference was found to highlight exactly what was different. Defaults to ``False``. """ name_attrs = ('ordered', 'partial') def __init__( self, *expected, ordered: bool = True, partial: bool = False, recursive: bool = False ): self.expected = expected self.ordered = ordered self.partial = partial self.recursive = recursive self.checked_indices = set() def __ne__(self, other) -> bool: try: actual = original_actual = list(other) except TypeError: self.failed = 'bad type' return True expected = list(self.expected) actual = list(actual) matched = [] matched_expected_indices = [] matched_actual_indices = [] missing_from_expected = actual missing_from_expected_indices = actual_indices = list(range(len(actual))) missing_from_actual = [] missing_from_actual_indices = [] start = 0 for e_i, e in enumerate(expected): try: i = actual.index(e, start) a_i = actual_indices.pop(i) except ValueError: missing_from_actual.append(e) missing_from_actual_indices.append(e_i) else: matched.append(missing_from_expected.pop(i)) matched_expected_indices.append(e_i) matched_actual_indices.append(a_i) self.checked_indices.add(a_i) if self.ordered: start = i matches_in_order = matched_actual_indices == sorted(matched_actual_indices) all_matched = not (missing_from_actual or missing_from_expected) partial_match = self.partial and not missing_from_actual if (matches_in_order or not self.ordered) and (all_matched or partial_match): return False expected_indices = matched_expected_indices+missing_from_actual_indices actual_indices = matched_actual_indices if self.partial: # try to give a clue as to what didn't match: if self.recursive and self.ordered and missing_from_expected: actual_indices.append(missing_from_expected_indices.pop(0)) missing_from_expected.pop(0) ignored = missing_from_expected missing_from_expected = None else: actual_indices += missing_from_expected_indices ignored = None message = [] def add_section(name, content): if content: message.append(name+':\n'+pformat(content)) add_section('ignored', ignored) if self.ordered: message.append(compare( expected=[self.expected[i] for i in sorted(expected_indices)], actual=[original_actual[i] for i in sorted(actual_indices)], recursive=self.recursive, raises=False ).split('\n\n', 1)[1]) else: add_section('same', matched) add_section('in expected but not actual', missing_from_actual) add_section('in actual but not expected', missing_from_expected) self.failed = '\n\n'.join(message) return True class Subset(SequenceComparison): """ A shortcut for :class:`SequenceComparison` that checks if the specified items are present in the sequence. """ name_attrs = () def __init__(self, *expected): super(Subset, self).__init__(*expected, ordered=False, partial=True) class Permutation(SequenceComparison): """ A shortcut for :class:`SequenceComparison` that checks if the set of items in the sequence is as expected, but without checking ordering. """ def __init__(self, *expected): super(Permutation, self).__init__(*expected, ordered=False, partial=False) class MappingComparison(StatefulComparison): """ An object that can be used in comparisons of expected and actual mappings. :param expected_mapping: The mapping that should be matched expressed as either a sequence of ``(key, value)`` tuples or a mapping. :param expected_items: The items that should be matched. :param ordered: If ``True``, then the keys in the mapping are expected to be in the order specified. Defaults to ``False``. :param partial: If ``True``, then any keys not expected will be ignored. Defaults to ``False``. :param recursive: If a difference is found, recursively compare the value where the difference was found to highlight exactly what was different. Defaults to ``False``. """ name_attrs = ('ordered', 'partial') def __init__(self, *expected_mapping, **expected_items): # py2 :-( self.ordered = expected_items.pop('ordered', False) self.partial = expected_items.pop('partial', False) self.recursive = expected_items.pop('recursive', False) if len(expected_mapping) == 1: expected = OrderedDict(*expected_mapping) else: expected = OrderedDict(expected_mapping) expected.update(expected_items) self.expected = expected def body(self) -> str: # this can all go away and use the super class once py2 is gone :'( parts = [] text_length = 0 for key, value in self.expected.items(): part = repr(key)+': '+pformat(value) text_length += len(part) parts.append(part) if text_length > 60: sep = ',\n' else: sep = ', ' return sep.join(parts) def __ne__(self, other) -> bool: try: actual_keys = other.keys() actual_mapping = dict(other.items()) except AttributeError: self.failed = 'bad type' return True expected_keys = self.expected.keys() expected_mapping = self.expected if self.partial: ignored_keys = set(actual_keys) - set(expected_keys) for key in ignored_keys: del actual_mapping[key] # preserve the order: actual_keys = [k for k in actual_keys if k not in ignored_keys] else: ignored_keys = None mapping_differences = compare( expected=expected_mapping, actual=actual_mapping, recursive=self.recursive, raises=False ) if self.ordered: key_differences = compare( expected=list(expected_keys), actual=list(actual_keys), recursive=self.recursive, raises=False ) else: key_differences = None if key_differences or mapping_differences: message = [] if ignored_keys: message.append('ignored:\n'+pformat(sorted(ignored_keys))) if mapping_differences: message.append(mapping_differences.split('\n\n', 1)[1]) if key_differences: message.append('wrong key order:\n\n'+key_differences.split('\n\n', 1)[1]) self.failed = '\n\n'.join(message) return True return False class StringComparison: """ An object that can be used in comparisons of expected and actual strings where the string expected matches a pattern rather than a specific concrete string. :param regex_source: A string containing the source for a regular expression that will be used whenever this :class:`StringComparison` is compared with any :class:`str` instance. :param flags: Flags passed to :func:`re.compile`. :param flag_names: See the :ref:`examples <stringcomparison>`. """ def __init__(self, regex_source: str, flags: int = None, **flag_names: str): args = [regex_source] flags_ = [] if flags: flags_.append(flags) flags_.extend(getattr(re, f.upper()) for f in flag_names) if flags_: args.append(reduce(__or__, flags_)) self.re = re.compile(*args) def __eq__(self, other) -> bool: if not isinstance(other, str): return False if self.re.match(other): return True return False def __ne__(self, other) -> bool: return not self == other def __repr__(self) -> str: return '<S:%s>' % self.re.pattern def __lt__(self, other) -> bool: return self.re.pattern < other def __gt__(self, other) -> bool: return self.re.pattern > other class RoundComparison: """ An object that can be used in comparisons of expected and actual numerics to a specified precision. :param value: numeric to be compared. :param precision: Number of decimal places to round to in order to perform the comparison. """ def __init__(self, value: float, precision: int): self.rounded = round(value, precision) self.precision = precision def __eq__(self, other) -> bool: other_rounded = round(other, self.precision) if type(self.rounded) is not type(other_rounded): raise TypeError('Cannot compare %r with %r' % (self, type(other))) return self.rounded == other_rounded def __ne__(self, other) -> bool: return not self == other def __repr__(self) -> str: return '<R:%s to %i digits>' % (self.rounded, self.precision) class RangeComparison: """ An object that can be used in comparisons of orderable types to check that a value specified within the given range. :param lower_bound: the inclusive lower bound for the acceptable range. :param upper_bound: the inclusive upper bound for the acceptable range. """ def __init__(self, lower_bound, upper_bound): self.lower_bound = lower_bound self.upper_bound = upper_bound def __eq__(self, other) -> bool: return self.lower_bound <= other <= self.upper_bound def __ne__(self, other) -> bool: return not self == other def __repr__(self) -> str: return '<Range: [%s, %s]>' % (self.lower_bound, self.upper_bound)
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