Edit File: mock.py
# mock.py # Test tools for mocking and patching. # Maintained by Michael Foord # Backport for other versions of Python available from # https://pypi.org/project/mock __all__ = ( 'Mock', 'MagicMock', 'patch', 'sentinel', 'DEFAULT', 'ANY', 'call', 'create_autospec', 'FILTER_DIR', 'NonCallableMock', 'NonCallableMagicMock', 'mock_open', 'PropertyMock', ) __version__ = '1.0' import inspect import pprint import sys import builtins from types import ModuleType from functools import wraps, partial _builtins = {name for name in dir(builtins) if not name.startswith('_')} BaseExceptions = (BaseException,) if 'java' in sys.platform: # jython import java BaseExceptions = (BaseException, java.lang.Throwable) FILTER_DIR = True # Workaround for issue #12370 # Without this, the __class__ properties wouldn't be set correctly _safe_super = super def _is_instance_mock(obj): # can't use isinstance on Mock objects because they override __class__ # The base class for all mocks is NonCallableMock return issubclass(type(obj), NonCallableMock) def _is_exception(obj): return ( isinstance(obj, BaseExceptions) or isinstance(obj, type) and issubclass(obj, BaseExceptions) ) def _get_signature_object(func, as_instance, eat_self): """ Given an arbitrary, possibly callable object, try to create a suitable signature object. Return a (reduced func, signature) tuple, or None. """ if isinstance(func, type) and not as_instance: # If it's a type and should be modelled as a type, use __init__. try: func = func.__init__ except AttributeError: return None # Skip the `self` argument in __init__ eat_self = True elif not isinstance(func, FunctionTypes): # If we really want to model an instance of the passed type, # __call__ should be looked up, not __init__. try: func = func.__call__ except AttributeError: return None if eat_self: sig_func = partial(func, None) else: sig_func = func try: return func, inspect.signature(sig_func) except ValueError: # Certain callable types are not supported by inspect.signature() return None def _check_signature(func, mock, skipfirst, instance=False): sig = _get_signature_object(func, instance, skipfirst) if sig is None: return func, sig = sig def checksig(_mock_self, *args, **kwargs): sig.bind(*args, **kwargs) _copy_func_details(func, checksig) type(mock)._mock_check_sig = checksig def _copy_func_details(func, funcopy): funcopy.__name__ = func.__name__ funcopy.__doc__ = func.__doc__ try: funcopy.__text_signature__ = func.__text_signature__ except AttributeError: pass # we explicitly don't copy func.__dict__ into this copy as it would # expose original attributes that should be mocked try: funcopy.__module__ = func.__module__ except AttributeError: pass try: funcopy.__defaults__ = func.__defaults__ except AttributeError: pass try: funcopy.__kwdefaults__ = func.__kwdefaults__ except AttributeError: pass def _callable(obj): if isinstance(obj, type): return True if getattr(obj, '__call__', None) is not None: return True return False def _is_list(obj): # checks for list or tuples # XXXX badly named! return type(obj) in (list, tuple) def _instance_callable(obj): """Given an object, return True if the object is callable. For classes, return True if instances would be callable.""" if not isinstance(obj, type): # already an instance return getattr(obj, '__call__', None) is not None # *could* be broken by a class overriding __mro__ or __dict__ via # a metaclass for base in (obj,) + obj.__mro__: if base.__dict__.get('__call__') is not None: return True return False def _set_signature(mock, original, instance=False): # creates a function with signature (*args, **kwargs) that delegates to a # mock. It still does signature checking by calling a lambda with the same # signature as the original. if not _callable(original): return skipfirst = isinstance(original, type) result = _get_signature_object(original, instance, skipfirst) if result is None: return mock func, sig = result def checksig(*args, **kwargs): sig.bind(*args, **kwargs) _copy_func_details(func, checksig) name = original.__name__ if not name.isidentifier(): name = 'funcopy' context = {'_checksig_': checksig, 'mock': mock} src = """def %s(*args, **kwargs): _checksig_(*args, **kwargs) return mock(*args, **kwargs)""" % name exec (src, context) funcopy = context[name] _setup_func(funcopy, mock) return funcopy def _setup_func(funcopy, mock): funcopy.mock = mock # can't use isinstance with mocks if not _is_instance_mock(mock): return def assert_called_with(*args, **kwargs): return mock.assert_called_with(*args, **kwargs) def assert_called(*args, **kwargs): return mock.assert_called(*args, **kwargs) def assert_not_called(*args, **kwargs): return mock.assert_not_called(*args, **kwargs) def assert_called_once(*args, **kwargs): return mock.assert_called_once(*args, **kwargs) def assert_called_once_with(*args, **kwargs): return mock.assert_called_once_with(*args, **kwargs) def assert_has_calls(*args, **kwargs): return mock.assert_has_calls(*args, **kwargs) def assert_any_call(*args, **kwargs): return mock.assert_any_call(*args, **kwargs) def reset_mock(): funcopy.method_calls = _CallList() funcopy.mock_calls = _CallList() mock.reset_mock() ret = funcopy.return_value if _is_instance_mock(ret) and not ret is mock: ret.reset_mock() funcopy.called = False funcopy.call_count = 0 funcopy.call_args = None funcopy.call_args_list = _CallList() funcopy.method_calls = _CallList() funcopy.mock_calls = _CallList() funcopy.return_value = mock.return_value funcopy.side_effect = mock.side_effect funcopy._mock_children = mock._mock_children funcopy.assert_called_with = assert_called_with funcopy.assert_called_once_with = assert_called_once_with funcopy.assert_has_calls = assert_has_calls funcopy.assert_any_call = assert_any_call funcopy.reset_mock = reset_mock funcopy.assert_called = assert_called funcopy.assert_not_called = assert_not_called funcopy.assert_called_once = assert_called_once mock._mock_delegate = funcopy def _is_magic(name): return '__%s__' % name[2:-2] == name class _SentinelObject(object): "A unique, named, sentinel object." def __init__(self, name): self.name = name def __repr__(self): return 'sentinel.%s' % self.name class _Sentinel(object): """Access attributes to return a named object, usable as a sentinel.""" def __init__(self): self._sentinels = {} def __getattr__(self, name): if name == '__bases__': # Without this help(unittest.mock) raises an exception raise AttributeError return self._sentinels.setdefault(name, _SentinelObject(name)) sentinel = _Sentinel() DEFAULT = sentinel.DEFAULT _missing = sentinel.MISSING _deleted = sentinel.DELETED def _copy(value): if type(value) in (dict, list, tuple, set): return type(value)(value) return value _allowed_names = { 'return_value', '_mock_return_value', 'side_effect', '_mock_side_effect', '_mock_parent', '_mock_new_parent', '_mock_name', '_mock_new_name' } def _delegating_property(name): _allowed_names.add(name) _the_name = '_mock_' + name def _get(self, name=name, _the_name=_the_name): sig = self._mock_delegate if sig is None: return getattr(self, _the_name) return getattr(sig, name) def _set(self, value, name=name, _the_name=_the_name): sig = self._mock_delegate if sig is None: self.__dict__[_the_name] = value else: setattr(sig, name, value) return property(_get, _set) class _CallList(list): def __contains__(self, value): if not isinstance(value, list): return list.__contains__(self, value) len_value = len(value) len_self = len(self) if len_value > len_self: return False for i in range(0, len_self - len_value + 1): sub_list = self[i:i+len_value] if sub_list == value: return True return False def __repr__(self): return pprint.pformat(list(self)) def _check_and_set_parent(parent, value, name, new_name): if not _is_instance_mock(value): return False if ((value._mock_name or value._mock_new_name) or (value._mock_parent is not None) or (value._mock_new_parent is not None)): return False _parent = parent while _parent is not None: # setting a mock (value) as a child or return value of itself # should not modify the mock if _parent is value: return False _parent = _parent._mock_new_parent if new_name: value._mock_new_parent = parent value._mock_new_name = new_name if name: value._mock_parent = parent value._mock_name = name return True # Internal class to identify if we wrapped an iterator object or not. class _MockIter(object): def __init__(self, obj): self.obj = iter(obj) def __iter__(self): return self def __next__(self): return next(self.obj) class Base(object): _mock_return_value = DEFAULT _mock_side_effect = None def __init__(self, *args, **kwargs): pass class NonCallableMock(Base): """A non-callable version of `Mock`""" def __new__(cls, *args, **kw): # every instance has its own class # so we can create magic methods on the # class without stomping on other mocks new = type(cls.__name__, (cls,), {'__doc__': cls.__doc__}) instance = object.__new__(new) return instance def __init__( self, spec=None, wraps=None, name=None, spec_set=None, parent=None, _spec_state=None, _new_name='', _new_parent=None, _spec_as_instance=False, _eat_self=None, unsafe=False, **kwargs ): if _new_parent is None: _new_parent = parent __dict__ = self.__dict__ __dict__['_mock_parent'] = parent __dict__['_mock_name'] = name __dict__['_mock_new_name'] = _new_name __dict__['_mock_new_parent'] = _new_parent if spec_set is not None: spec = spec_set spec_set = True if _eat_self is None: _eat_self = parent is not None self._mock_add_spec(spec, spec_set, _spec_as_instance, _eat_self) __dict__['_mock_children'] = {} __dict__['_mock_wraps'] = wraps __dict__['_mock_delegate'] = None __dict__['_mock_called'] = False __dict__['_mock_call_args'] = None __dict__['_mock_call_count'] = 0 __dict__['_mock_call_args_list'] = _CallList() __dict__['_mock_mock_calls'] = _CallList() __dict__['method_calls'] = _CallList() __dict__['_mock_unsafe'] = unsafe if kwargs: self.configure_mock(**kwargs) _safe_super(NonCallableMock, self).__init__( spec, wraps, name, spec_set, parent, _spec_state ) def attach_mock(self, mock, attribute): """ Attach a mock as an attribute of this one, replacing its name and parent. Calls to the attached mock will be recorded in the `method_calls` and `mock_calls` attributes of this one.""" mock._mock_parent = None mock._mock_new_parent = None mock._mock_name = '' mock._mock_new_name = None setattr(self, attribute, mock) def mock_add_spec(self, spec, spec_set=False): """Add a spec to a mock. `spec` can either be an object or a list of strings. Only attributes on the `spec` can be fetched as attributes from the mock. If `spec_set` is True then only attributes on the spec can be set.""" self._mock_add_spec(spec, spec_set) def _mock_add_spec(self, spec, spec_set, _spec_as_instance=False, _eat_self=False): _spec_class = None _spec_signature = None if spec is not None and not _is_list(spec): if isinstance(spec, type): _spec_class = spec else: _spec_class = _get_class(spec) res = _get_signature_object(spec, _spec_as_instance, _eat_self) _spec_signature = res and res[1] spec = dir(spec) __dict__ = self.__dict__ __dict__['_spec_class'] = _spec_class __dict__['_spec_set'] = spec_set __dict__['_spec_signature'] = _spec_signature __dict__['_mock_methods'] = spec def __get_return_value(self): ret = self._mock_return_value if self._mock_delegate is not None: ret = self._mock_delegate.return_value if ret is DEFAULT: ret = self._get_child_mock( _new_parent=self, _new_name='()' ) self.return_value = ret return ret def __set_return_value(self, value): if self._mock_delegate is not None: self._mock_delegate.return_value = value else: self._mock_return_value = value _check_and_set_parent(self, value, None, '()') __return_value_doc = "The value to be returned when the mock is called." return_value = property(__get_return_value, __set_return_value, __return_value_doc) @property def __class__(self): if self._spec_class is None: return type(self) return self._spec_class called = _delegating_property('called') call_count = _delegating_property('call_count') call_args = _delegating_property('call_args') call_args_list = _delegating_property('call_args_list') mock_calls = _delegating_property('mock_calls') def __get_side_effect(self): delegated = self._mock_delegate if delegated is None: return self._mock_side_effect sf = delegated.side_effect if (sf is not None and not callable(sf) and not isinstance(sf, _MockIter) and not _is_exception(sf)): sf = _MockIter(sf) delegated.side_effect = sf return sf def __set_side_effect(self, value): value = _try_iter(value) delegated = self._mock_delegate if delegated is None: self._mock_side_effect = value else: delegated.side_effect = value side_effect = property(__get_side_effect, __set_side_effect) def reset_mock(self, visited=None,*, return_value=False, side_effect=False): "Restore the mock object to its initial state." if visited is None: visited = [] if id(self) in visited: return visited.append(id(self)) self.called = False self.call_args = None self.call_count = 0 self.mock_calls = _CallList() self.call_args_list = _CallList() self.method_calls = _CallList() if return_value: self._mock_return_value = DEFAULT if side_effect: self._mock_side_effect = None for child in self._mock_children.values(): if isinstance(child, _SpecState) or child is _deleted: continue child.reset_mock(visited) ret = self._mock_return_value if _is_instance_mock(ret) and ret is not self: ret.reset_mock(visited) def configure_mock(self, **kwargs): """Set attributes on the mock through keyword arguments. Attributes plus return values and side effects can be set on child mocks using standard dot notation and unpacking a dictionary in the method call: >>> attrs = {'method.return_value': 3, 'other.side_effect': KeyError} >>> mock.configure_mock(**attrs)""" for arg, val in sorted(kwargs.items(), # we sort on the number of dots so that # attributes are set before we set attributes on # attributes key=lambda entry: entry[0].count('.')): args = arg.split('.') final = args.pop() obj = self for entry in args: obj = getattr(obj, entry) setattr(obj, final, val) def __getattr__(self, name): if name in {'_mock_methods', '_mock_unsafe'}: raise AttributeError(name) elif self._mock_methods is not None: if name not in self._mock_methods or name in _all_magics: raise AttributeError("Mock object has no attribute %r" % name) elif _is_magic(name): raise AttributeError(name) if not self._mock_unsafe: if name.startswith(('assert', 'assret')): raise AttributeError(name) result = self._mock_children.get(name) if result is _deleted: raise AttributeError(name) elif result is None: wraps = None if self._mock_wraps is not None: # XXXX should we get the attribute without triggering code # execution? wraps = getattr(self._mock_wraps, name) result = self._get_child_mock( parent=self, name=name, wraps=wraps, _new_name=name, _new_parent=self ) self._mock_children[name] = result elif isinstance(result, _SpecState): result = create_autospec( result.spec, result.spec_set, result.instance, result.parent, result.name ) self._mock_children[name] = result return result def __repr__(self): _name_list = [self._mock_new_name] _parent = self._mock_new_parent last = self dot = '.' if _name_list == ['()']: dot = '' seen = set() while _parent is not None: last = _parent _name_list.append(_parent._mock_new_name + dot) dot = '.' if _parent._mock_new_name == '()': dot = '' _parent = _parent._mock_new_parent # use ids here so as not to call __hash__ on the mocks if id(_parent) in seen: break seen.add(id(_parent)) _name_list = list(reversed(_name_list)) _first = last._mock_name or 'mock' if len(_name_list) > 1: if _name_list[1] not in ('()', '().'): _first += '.' _name_list[0] = _first name = ''.join(_name_list) name_string = '' if name not in ('mock', 'mock.'): name_string = ' name=%r' % name spec_string = '' if self._spec_class is not None: spec_string = ' spec=%r' if self._spec_set: spec_string = ' spec_set=%r' spec_string = spec_string % self._spec_class.__name__ return "<%s%s%s id='%s'>" % ( type(self).__name__, name_string, spec_string, id(self) ) def __dir__(self): """Filter the output of `dir(mock)` to only useful members.""" if not FILTER_DIR: return object.__dir__(self) extras = self._mock_methods or [] from_type = dir(type(self)) from_dict = list(self.__dict__) from_type = [e for e in from_type if not e.startswith('_')] from_dict = [e for e in from_dict if not e.startswith('_') or _is_magic(e)] return sorted(set(extras + from_type + from_dict + list(self._mock_children))) def __setattr__(self, name, value): if name in _allowed_names: # property setters go through here return object.__setattr__(self, name, value) elif (self._spec_set and self._mock_methods is not None and name not in self._mock_methods and name not in self.__dict__): raise AttributeError("Mock object has no attribute '%s'" % name) elif name in _unsupported_magics: msg = 'Attempting to set unsupported magic method %r.' % name raise AttributeError(msg) elif name in _all_magics: if self._mock_methods is not None and name not in self._mock_methods: raise AttributeError("Mock object has no attribute '%s'" % name) if not _is_instance_mock(value): setattr(type(self), name, _get_method(name, value)) original = value value = lambda *args, **kw: original(self, *args, **kw) else: # only set _new_name and not name so that mock_calls is tracked # but not method calls _check_and_set_parent(self, value, None, name) setattr(type(self), name, value) self._mock_children[name] = value elif name == '__class__': self._spec_class = value return else: if _check_and_set_parent(self, value, name, name): self._mock_children[name] = value return object.__setattr__(self, name, value) def __delattr__(self, name): if name in _all_magics and name in type(self).__dict__: delattr(type(self), name) if name not in self.__dict__: # for magic methods that are still MagicProxy objects and # not set on the instance itself return if name in self.__dict__: object.__delattr__(self, name) obj = self._mock_children.get(name, _missing) if obj is _deleted: raise AttributeError(name) if obj is not _missing: del self._mock_children[name] self._mock_children[name] = _deleted def _format_mock_call_signature(self, args, kwargs): name = self._mock_name or 'mock' return _format_call_signature(name, args, kwargs) def _format_mock_failure_message(self, args, kwargs): message = 'Expected call: %s\nActual call: %s' expected_string = self._format_mock_call_signature(args, kwargs) call_args = self.call_args if len(call_args) == 3: call_args = call_args[1:] actual_string = self._format_mock_call_signature(*call_args) return message % (expected_string, actual_string) def _call_matcher(self, _call): """ Given a call (or simply an (args, kwargs) tuple), return a comparison key suitable for matching with other calls. This is a best effort method which relies on the spec's signature, if available, or falls back on the arguments themselves. """ sig = self._spec_signature if sig is not None: if len(_call) == 2: name = '' args, kwargs = _call else: name, args, kwargs = _call try: return name, sig.bind(*args, **kwargs) except TypeError as e: return e.with_traceback(None) else: return _call def assert_not_called(_mock_self): """assert that the mock was never called. """ self = _mock_self if self.call_count != 0: msg = ("Expected '%s' to not have been called. Called %s times." % (self._mock_name or 'mock', self.call_count)) raise AssertionError(msg) def assert_called(_mock_self): """assert that the mock was called at least once """ self = _mock_self if self.call_count == 0: msg = ("Expected '%s' to have been called." % self._mock_name or 'mock') raise AssertionError(msg) def assert_called_once(_mock_self): """assert that the mock was called only once. """ self = _mock_self if not self.call_count == 1: msg = ("Expected '%s' to have been called once. Called %s times." % (self._mock_name or 'mock', self.call_count)) raise AssertionError(msg) def assert_called_with(_mock_self, *args, **kwargs): """assert that the mock was called with the specified arguments. Raises an AssertionError if the args and keyword args passed in are different to the last call to the mock.""" self = _mock_self if self.call_args is None: expected = self._format_mock_call_signature(args, kwargs) raise AssertionError('Expected call: %s\nNot called' % (expected,)) def _error_message(): msg = self._format_mock_failure_message(args, kwargs) return msg expected = self._call_matcher((args, kwargs)) actual = self._call_matcher(self.call_args) if expected != actual: cause = expected if isinstance(expected, Exception) else None raise AssertionError(_error_message()) from cause def assert_called_once_with(_mock_self, *args, **kwargs): """assert that the mock was called exactly once and that that call was with the specified arguments.""" self = _mock_self if not self.call_count == 1: msg = ("Expected '%s' to be called once. Called %s times." % (self._mock_name or 'mock', self.call_count)) raise AssertionError(msg) return self.assert_called_with(*args, **kwargs) def assert_has_calls(self, calls, any_order=False): """assert the mock has been called with the specified calls. The `mock_calls` list is checked for the calls. If `any_order` is False (the default) then the calls must be sequential. There can be extra calls before or after the specified calls. If `any_order` is True then the calls can be in any order, but they must all appear in `mock_calls`.""" expected = [self._call_matcher(c) for c in calls] cause = expected if isinstance(expected, Exception) else None all_calls = _CallList(self._call_matcher(c) for c in self.mock_calls) if not any_order: if expected not in all_calls: raise AssertionError( 'Calls not found.\nExpected: %r\n' 'Actual: %r' % (_CallList(calls), self.mock_calls) ) from cause return all_calls = list(all_calls) not_found = [] for kall in expected: try: all_calls.remove(kall) except ValueError: not_found.append(kall) if not_found: raise AssertionError( '%r not all found in call list' % (tuple(not_found),) ) from cause def assert_any_call(self, *args, **kwargs): """assert the mock has been called with the specified arguments. The assert passes if the mock has *ever* been called, unlike `assert_called_with` and `assert_called_once_with` that only pass if the call is the most recent one.""" expected = self._call_matcher((args, kwargs)) actual = [self._call_matcher(c) for c in self.call_args_list] if expected not in actual: cause = expected if isinstance(expected, Exception) else None expected_string = self._format_mock_call_signature(args, kwargs) raise AssertionError( '%s call not found' % expected_string ) from cause def _get_child_mock(self, **kw): """Create the child mocks for attributes and return value. By default child mocks will be the same type as the parent. Subclasses of Mock may want to override this to customize the way child mocks are made. For non-callable mocks the callable variant will be used (rather than any custom subclass).""" _type = type(self) if not issubclass(_type, CallableMixin): if issubclass(_type, NonCallableMagicMock): klass = MagicMock elif issubclass(_type, NonCallableMock) : klass = Mock else: klass = _type.__mro__[1] return klass(**kw) def _try_iter(obj): if obj is None: return obj if _is_exception(obj): return obj if _callable(obj): return obj try: return iter(obj) except TypeError: # XXXX backwards compatibility # but this will blow up on first call - so maybe we should fail early? return obj class CallableMixin(Base): def __init__(self, spec=None, side_effect=None, return_value=DEFAULT, wraps=None, name=None, spec_set=None, parent=None, _spec_state=None, _new_name='', _new_parent=None, **kwargs): self.__dict__['_mock_return_value'] = return_value _safe_super(CallableMixin, self).__init__( spec, wraps, name, spec_set, parent, _spec_state, _new_name, _new_parent, **kwargs ) self.side_effect = side_effect def _mock_check_sig(self, *args, **kwargs): # stub method that can be replaced with one with a specific signature pass def __call__(_mock_self, *args, **kwargs): # can't use self in-case a function / method we are mocking uses self # in the signature _mock_self._mock_check_sig(*args, **kwargs) return _mock_self._mock_call(*args, **kwargs) def _mock_call(_mock_self, *args, **kwargs): self = _mock_self self.called = True self.call_count += 1 # handle call_args _call = _Call((args, kwargs), two=True) self.call_args = _call self.call_args_list.append(_call) seen = set() # initial stuff for method_calls: do_method_calls = self._mock_parent is not None method_call_name = self._mock_name # initial stuff for mock_calls: mock_call_name = self._mock_new_name is_a_call = mock_call_name == '()' self.mock_calls.append(_Call(('', args, kwargs))) # follow up the chain of mocks: _new_parent = self._mock_new_parent while _new_parent is not None: # handle method_calls: if do_method_calls: _new_parent.method_calls.append(_Call((method_call_name, args, kwargs))) do_method_calls = _new_parent._mock_parent is not None if do_method_calls: method_call_name = _new_parent._mock_name + '.' + method_call_name # handle mock_calls: this_mock_call = _Call((mock_call_name, args, kwargs)) _new_parent.mock_calls.append(this_mock_call) if _new_parent._mock_new_name: if is_a_call: dot = '' else: dot = '.' is_a_call = _new_parent._mock_new_name == '()' mock_call_name = _new_parent._mock_new_name + dot + mock_call_name # follow the parental chain: _new_parent = _new_parent._mock_new_parent # check we're not in an infinite loop: # ( use ids here so as not to call __hash__ on the mocks) _new_parent_id = id(_new_parent) if _new_parent_id in seen: break seen.add(_new_parent_id) effect = self.side_effect if effect is not None: if _is_exception(effect): raise effect elif not _callable(effect): result = next(effect) if _is_exception(result): raise result else: result = effect(*args, **kwargs) if result is not DEFAULT: return result if self._mock_return_value is not DEFAULT: return self.return_value if self._mock_wraps is not None: return self._mock_wraps(*args, **kwargs) return self.return_value class Mock(CallableMixin, NonCallableMock): """ Create a new `Mock` object. `Mock` takes several optional arguments that specify the behaviour of the Mock object: * `spec`: This can be either a list of strings or an existing object (a class or instance) that acts as the specification for the mock object. If you pass in an object then a list of strings is formed by calling dir on the object (excluding unsupported magic attributes and methods). Accessing any attribute not in this list will raise an `AttributeError`. If `spec` is an object (rather than a list of strings) then `mock.__class__` returns the class of the spec object. This allows mocks to pass `isinstance` tests. * `spec_set`: A stricter variant of `spec`. If used, attempting to *set* or get an attribute on the mock that isn't on the object passed as `spec_set` will raise an `AttributeError`. * `side_effect`: A function to be called whenever the Mock is called. See the `side_effect` attribute. Useful for raising exceptions or dynamically changing return values. The function is called with the same arguments as the mock, and unless it returns `DEFAULT`, the return value of this function is used as the return value. If `side_effect` is an iterable then each call to the mock will return the next value from the iterable. If any of the members of the iterable are exceptions they will be raised instead of returned. * `return_value`: The value returned when the mock is called. By default this is a new Mock (created on first access). See the `return_value` attribute. * `wraps`: Item for the mock object to wrap. If `wraps` is not None then calling the Mock will pass the call through to the wrapped object (returning the real result). Attribute access on the mock will return a Mock object that wraps the corresponding attribute of the wrapped object (so attempting to access an attribute that doesn't exist will raise an `AttributeError`). If the mock has an explicit `return_value` set then calls are not passed to the wrapped object and the `return_value` is returned instead. * `name`: If the mock has a name then it will be used in the repr of the mock. This can be useful for debugging. The name is propagated to child mocks. Mocks can also be called with arbitrary keyword arguments. These will be used to set attributes on the mock after it is created. """ def _dot_lookup(thing, comp, import_path): try: return getattr(thing, comp) except AttributeError: __import__(import_path) return getattr(thing, comp) def _importer(target): components = target.split('.') import_path = components.pop(0) thing = __import__(import_path) for comp in components: import_path += ".%s" % comp thing = _dot_lookup(thing, comp, import_path) return thing def _is_started(patcher): # XXXX horrible return hasattr(patcher, 'is_local') class _patch(object): attribute_name = None _active_patches = [] def __init__( self, getter, attribute, new, spec, create, spec_set, autospec, new_callable, kwargs ): if new_callable is not None: if new is not DEFAULT: raise ValueError( "Cannot use 'new' and 'new_callable' together" ) if autospec is not None: raise ValueError( "Cannot use 'autospec' and 'new_callable' together" ) self.getter = getter self.attribute = attribute self.new = new self.new_callable = new_callable self.spec = spec self.create = create self.has_local = False self.spec_set = spec_set self.autospec = autospec self.kwargs = kwargs self.additional_patchers = [] def copy(self): patcher = _patch( self.getter, self.attribute, self.new, self.spec, self.create, self.spec_set, self.autospec, self.new_callable, self.kwargs ) patcher.attribute_name = self.attribute_name patcher.additional_patchers = [ p.copy() for p in self.additional_patchers ] return patcher def __call__(self, func): if isinstance(func, type): return self.decorate_class(func) return self.decorate_callable(func) def decorate_class(self, klass): for attr in dir(klass): if not attr.startswith(patch.TEST_PREFIX): continue attr_value = getattr(klass, attr) if not hasattr(attr_value, "__call__"): continue patcher = self.copy() setattr(klass, attr, patcher(attr_value)) return klass def decorate_callable(self, func): if hasattr(func, 'patchings'): func.patchings.append(self) return func @wraps(func) def patched(*args, **keywargs): extra_args = [] entered_patchers = [] exc_info = tuple() try: for patching in patched.patchings: arg = patching.__enter__() entered_patchers.append(patching) if patching.attribute_name is not None: keywargs.update(arg) elif patching.new is DEFAULT: extra_args.append(arg) args += tuple(extra_args) return func(*args, **keywargs) except: if (patching not in entered_patchers and _is_started(patching)): # the patcher may have been started, but an exception # raised whilst entering one of its additional_patchers entered_patchers.append(patching) # Pass the exception to __exit__ exc_info = sys.exc_info() # re-raise the exception raise finally: for patching in reversed(entered_patchers): patching.__exit__(*exc_info) patched.patchings = [self] return patched def get_original(self): target = self.getter() name = self.attribute original = DEFAULT local = False try: original = target.__dict__[name] except (AttributeError, KeyError): original = getattr(target, name, DEFAULT) else: local = True if name in _builtins and isinstance(target, ModuleType): self.create = True if not self.create and original is DEFAULT: raise AttributeError( "%s does not have the attribute %r" % (target, name) ) return original, local def __enter__(self): """Perform the patch.""" new, spec, spec_set = self.new, self.spec, self.spec_set autospec, kwargs = self.autospec, self.kwargs new_callable = self.new_callable self.target = self.getter() # normalise False to None if spec is False: spec = None if spec_set is False: spec_set = None if autospec is False: autospec = None if spec is not None and autospec is not None: raise TypeError("Can't specify spec and autospec") if ((spec is not None or autospec is not None) and spec_set not in (True, None)): raise TypeError("Can't provide explicit spec_set *and* spec or autospec") original, local = self.get_original() if new is DEFAULT and autospec is None: inherit = False if spec is True: # set spec to the object we are replacing spec = original if spec_set is True: spec_set = original spec = None elif spec is not None: if spec_set is True: spec_set = spec spec = None elif spec_set is True: spec_set = original if spec is not None or spec_set is not None: if original is DEFAULT: raise TypeError("Can't use 'spec' with create=True") if isinstance(original, type): # If we're patching out a class and there is a spec inherit = True Klass = MagicMock _kwargs = {} if new_callable is not None: Klass = new_callable elif spec is not None or spec_set is not None: this_spec = spec if spec_set is not None: this_spec = spec_set if _is_list(this_spec): not_callable = '__call__' not in this_spec else: not_callable = not callable(this_spec) if not_callable: Klass = NonCallableMagicMock if spec is not None: _kwargs['spec'] = spec if spec_set is not None: _kwargs['spec_set'] = spec_set # add a name to mocks if (isinstance(Klass, type) and issubclass(Klass, NonCallableMock) and self.attribute): _kwargs['name'] = self.attribute _kwargs.update(kwargs) new = Klass(**_kwargs) if inherit and _is_instance_mock(new): # we can only tell if the instance should be callable if the # spec is not a list this_spec = spec if spec_set is not None: this_spec = spec_set if (not _is_list(this_spec) and not _instance_callable(this_spec)): Klass = NonCallableMagicMock _kwargs.pop('name') new.return_value = Klass(_new_parent=new, _new_name='()', **_kwargs) elif autospec is not None: # spec is ignored, new *must* be default, spec_set is treated # as a boolean. Should we check spec is not None and that spec_set # is a bool? if new is not DEFAULT: raise TypeError( "autospec creates the mock for you. Can't specify " "autospec and new." ) if original is DEFAULT: raise TypeError("Can't use 'autospec' with create=True") spec_set = bool(spec_set) if autospec is True: autospec = original new = create_autospec(autospec, spec_set=spec_set, _name=self.attribute, **kwargs) elif kwargs: # can't set keyword args when we aren't creating the mock # XXXX If new is a Mock we could call new.configure_mock(**kwargs) raise TypeError("Can't pass kwargs to a mock we aren't creating") new_attr = new self.temp_original = original self.is_local = local setattr(self.target, self.attribute, new_attr) if self.attribute_name is not None: extra_args = {} if self.new is DEFAULT: extra_args[self.attribute_name] = new for patching in self.additional_patchers: arg = patching.__enter__() if patching.new is DEFAULT: extra_args.update(arg) return extra_args return new def __exit__(self, *exc_info): """Undo the patch.""" if not _is_started(self): raise RuntimeError('stop called on unstarted patcher') if self.is_local and self.temp_original is not DEFAULT: setattr(self.target, self.attribute, self.temp_original) else: delattr(self.target, self.attribute) if not self.create and (not hasattr(self.target, self.attribute) or self.attribute in ('__doc__', '__module__', '__defaults__', '__annotations__', '__kwdefaults__')): # needed for proxy objects like django settings setattr(self.target, self.attribute, self.temp_original) del self.temp_original del self.is_local del self.target for patcher in reversed(self.additional_patchers): if _is_started(patcher): patcher.__exit__(*exc_info) def start(self): """Activate a patch, returning any created mock.""" result = self.__enter__() self._active_patches.append(self) return result def stop(self): """Stop an active patch.""" try: self._active_patches.remove(self) except ValueError: # If the patch hasn't been started this will fail pass return self.__exit__() def _get_target(target): try: target, attribute = target.rsplit('.', 1) except (TypeError, ValueError): raise TypeError("Need a valid target to patch. You supplied: %r" % (target,)) getter = lambda: _importer(target) return getter, attribute def _patch_object( target, attribute, new=DEFAULT, spec=None, create=False, spec_set=None, autospec=None, new_callable=None, **kwargs ): """ patch the named member (`attribute`) on an object (`target`) with a mock object. `patch.object` can be used as a decorator, class decorator or a context manager. Arguments `new`, `spec`, `create`, `spec_set`, `autospec` and `new_callable` have the same meaning as for `patch`. Like `patch`, `patch.object` takes arbitrary keyword arguments for configuring the mock object it creates. When used as a class decorator `patch.object` honours `patch.TEST_PREFIX` for choosing which methods to wrap. """ getter = lambda: target return _patch( getter, attribute, new, spec, create, spec_set, autospec, new_callable, kwargs ) def _patch_multiple(target, spec=None, create=False, spec_set=None, autospec=None, new_callable=None, **kwargs): """Perform multiple patches in a single call. It takes the object to be patched (either as an object or a string to fetch the object by importing) and keyword arguments for the patches:: with patch.multiple(settings, FIRST_PATCH='one', SECOND_PATCH='two'): ... Use `DEFAULT` as the value if you want `patch.multiple` to create mocks for you. In this case the created mocks are passed into a decorated function by keyword, and a dictionary is returned when `patch.multiple` is used as a context manager. `patch.multiple` can be used as a decorator, class decorator or a context manager. The arguments `spec`, `spec_set`, `create`, `autospec` and `new_callable` have the same meaning as for `patch`. These arguments will be applied to *all* patches done by `patch.multiple`. When used as a class decorator `patch.multiple` honours `patch.TEST_PREFIX` for choosing which methods to wrap. """ if type(target) is str: getter = lambda: _importer(target) else: getter = lambda: target if not kwargs: raise ValueError( 'Must supply at least one keyword argument with patch.multiple' ) # need to wrap in a list for python 3, where items is a view items = list(kwargs.items()) attribute, new = items[0] patcher = _patch( getter, attribute, new, spec, create, spec_set, autospec, new_callable, {} ) patcher.attribute_name = attribute for attribute, new in items[1:]: this_patcher = _patch( getter, attribute, new, spec, create, spec_set, autospec, new_callable, {} ) this_patcher.attribute_name = attribute patcher.additional_patchers.append(this_patcher) return patcher def patch( target, new=DEFAULT, spec=None, create=False, spec_set=None, autospec=None, new_callable=None, **kwargs ): """ `patch` acts as a function decorator, class decorator or a context manager. Inside the body of the function or with statement, the `target` is patched with a `new` object. When the function/with statement exits the patch is undone. If `new` is omitted, then the target is replaced with a `MagicMock`. If `patch` is used as a decorator and `new` is omitted, the created mock is passed in as an extra argument to the decorated function. If `patch` is used as a context manager the created mock is returned by the context manager. `target` should be a string in the form `'package.module.ClassName'`. The `target` is imported and the specified object replaced with the `new` object, so the `target` must be importable from the environment you are calling `patch` from. The target is imported when the decorated function is executed, not at decoration time. The `spec` and `spec_set` keyword arguments are passed to the `MagicMock` if patch is creating one for you. In addition you can pass `spec=True` or `spec_set=True`, which causes patch to pass in the object being mocked as the spec/spec_set object. `new_callable` allows you to specify a different class, or callable object, that will be called to create the `new` object. By default `MagicMock` is used. A more powerful form of `spec` is `autospec`. If you set `autospec=True` then the mock will be created with a spec from the object being replaced. All attributes of the mock will also have the spec of the corresponding attribute of the object being replaced. Methods and functions being mocked will have their arguments checked and will raise a `TypeError` if they are called with the wrong signature. For mocks replacing a class, their return value (the 'instance') will have the same spec as the class. Instead of `autospec=True` you can pass `autospec=some_object` to use an arbitrary object as the spec instead of the one being replaced. By default `patch` will fail to replace attributes that don't exist. If you pass in `create=True`, and the attribute doesn't exist, patch will create the attribute for you when the patched function is called, and delete it again afterwards. This is useful for writing tests against attributes that your production code creates at runtime. It is off by default because it can be dangerous. With it switched on you can write passing tests against APIs that don't actually exist! Patch can be used as a `TestCase` class decorator. It works by decorating each test method in the class. This reduces the boilerplate code when your test methods share a common patchings set. `patch` finds tests by looking for method names that start with `patch.TEST_PREFIX`. By default this is `test`, which matches the way `unittest` finds tests. You can specify an alternative prefix by setting `patch.TEST_PREFIX`. Patch can be used as a context manager, with the with statement. Here the patching applies to the indented block after the with statement. If you use "as" then the patched object will be bound to the name after the "as"; very useful if `patch` is creating a mock object for you. `patch` takes arbitrary keyword arguments. These will be passed to the `Mock` (or `new_callable`) on construction. `patch.dict(...)`, `patch.multiple(...)` and `patch.object(...)` are available for alternate use-cases. """ getter, attribute = _get_target(target) return _patch( getter, attribute, new, spec, create, spec_set, autospec, new_callable, kwargs ) class _patch_dict(object): """ Patch a dictionary, or dictionary like object, and restore the dictionary to its original state after the test. `in_dict` can be a dictionary or a mapping like container. If it is a mapping then it must at least support getting, setting and deleting items plus iterating over keys. `in_dict` can also be a string specifying the name of the dictionary, which will then be fetched by importing it. `values` can be a dictionary of values to set in the dictionary. `values` can also be an iterable of `(key, value)` pairs. If `clear` is True then the dictionary will be cleared before the new values are set. `patch.dict` can also be called with arbitrary keyword arguments to set values in the dictionary:: with patch.dict('sys.modules', mymodule=Mock(), other_module=Mock()): ... `patch.dict` can be used as a context manager, decorator or class decorator. When used as a class decorator `patch.dict` honours `patch.TEST_PREFIX` for choosing which methods to wrap. """ def __init__(self, in_dict, values=(), clear=False, **kwargs): if isinstance(in_dict, str): in_dict = _importer(in_dict) self.in_dict = in_dict # support any argument supported by dict(...) constructor self.values = dict(values) self.values.update(kwargs) self.clear = clear self._original = None def __call__(self, f): if isinstance(f, type): return self.decorate_class(f) @wraps(f) def _inner(*args, **kw): self._patch_dict() try: return f(*args, **kw) finally: self._unpatch_dict() return _inner def decorate_class(self, klass): for attr in dir(klass): attr_value = getattr(klass, attr) if (attr.startswith(patch.TEST_PREFIX) and hasattr(attr_value, "__call__")): decorator = _patch_dict(self.in_dict, self.values, self.clear) decorated = decorator(attr_value) setattr(klass, attr, decorated) return klass def __enter__(self): """Patch the dict.""" self._patch_dict() def _patch_dict(self): values = self.values in_dict = self.in_dict clear = self.clear try: original = in_dict.copy() except AttributeError: # dict like object with no copy method # must support iteration over keys original = {} for key in in_dict: original[key] = in_dict[key] self._original = original if clear: _clear_dict(in_dict) try: in_dict.update(values) except AttributeError: # dict like object with no update method for key in values: in_dict[key] = values[key] def _unpatch_dict(self): in_dict = self.in_dict original = self._original _clear_dict(in_dict) try: in_dict.update(original) except AttributeError: for key in original: in_dict[key] = original[key] def __exit__(self, *args): """Unpatch the dict.""" self._unpatch_dict() return False start = __enter__ stop = __exit__ def _clear_dict(in_dict): try: in_dict.clear() except AttributeError: keys = list(in_dict) for key in keys: del in_dict[key] def _patch_stopall(): """Stop all active patches. LIFO to unroll nested patches.""" for patch in reversed(_patch._active_patches): patch.stop() patch.object = _patch_object patch.dict = _patch_dict patch.multiple = _patch_multiple patch.stopall = _patch_stopall patch.TEST_PREFIX = 'test' magic_methods = ( "lt le gt ge eq ne " "getitem setitem delitem " "len contains iter " "hash str sizeof " "enter exit " # we added divmod and rdivmod here instead of numerics # because there is no idivmod "divmod rdivmod neg pos abs invert " "complex int float index " "trunc floor ceil " "bool next " ) numerics = ( "add sub mul matmul div floordiv mod lshift rshift and xor or pow truediv" ) inplace = ' '.join('i%s' % n for n in numerics.split()) right = ' '.join('r%s' % n for n in numerics.split()) # not including __prepare__, __instancecheck__, __subclasscheck__ # (as they are metaclass methods) # __del__ is not supported at all as it causes problems if it exists _non_defaults = { '__get__', '__set__', '__delete__', '__reversed__', '__missing__', '__reduce__', '__reduce_ex__', '__getinitargs__', '__getnewargs__', '__getstate__', '__setstate__', '__getformat__', '__setformat__', '__repr__', '__dir__', '__subclasses__', '__format__', '__getnewargs_ex__', } def _get_method(name, func): "Turns a callable object (like a mock) into a real function" def method(self, *args, **kw): return func(self, *args, **kw) method.__name__ = name return method _magics = { '__%s__' % method for method in ' '.join([magic_methods, numerics, inplace, right]).split() } _all_magics = _magics | _non_defaults _unsupported_magics = { '__getattr__', '__setattr__', '__init__', '__new__', '__prepare__', '__instancecheck__', '__subclasscheck__', '__del__' } _calculate_return_value = { '__hash__': lambda self: object.__hash__(self), '__str__': lambda self: object.__str__(self), '__sizeof__': lambda self: object.__sizeof__(self), } _return_values = { '__lt__': NotImplemented, '__gt__': NotImplemented, '__le__': NotImplemented, '__ge__': NotImplemented, '__int__': 1, '__contains__': False, '__len__': 0, '__exit__': False, '__complex__': 1j, '__float__': 1.0, '__bool__': True, '__index__': 1, } def _get_eq(self): def __eq__(other): ret_val = self.__eq__._mock_return_value if ret_val is not DEFAULT: return ret_val if self is other: return True return NotImplemented return __eq__ def _get_ne(self): def __ne__(other): if self.__ne__._mock_return_value is not DEFAULT: return DEFAULT if self is other: return False return NotImplemented return __ne__ def _get_iter(self): def __iter__(): ret_val = self.__iter__._mock_return_value if ret_val is DEFAULT: return iter([]) # if ret_val was already an iterator, then calling iter on it should # return the iterator unchanged return iter(ret_val) return __iter__ _side_effect_methods = { '__eq__': _get_eq, '__ne__': _get_ne, '__iter__': _get_iter, } def _set_return_value(mock, method, name): fixed = _return_values.get(name, DEFAULT) if fixed is not DEFAULT: method.return_value = fixed return return_calulator = _calculate_return_value.get(name) if return_calulator is not None: try: return_value = return_calulator(mock) except AttributeError: # XXXX why do we return AttributeError here? # set it as a side_effect instead? return_value = AttributeError(name) method.return_value = return_value return side_effector = _side_effect_methods.get(name) if side_effector is not None: method.side_effect = side_effector(mock) class MagicMixin(object): def __init__(self, *args, **kw): self._mock_set_magics() # make magic work for kwargs in init _safe_super(MagicMixin, self).__init__(*args, **kw) self._mock_set_magics() # fix magic broken by upper level init def _mock_set_magics(self): these_magics = _magics if getattr(self, "_mock_methods", None) is not None: these_magics = _magics.intersection(self._mock_methods) remove_magics = set() remove_magics = _magics - these_magics for entry in remove_magics: if entry in type(self).__dict__: # remove unneeded magic methods delattr(self, entry) # don't overwrite existing attributes if called a second time these_magics = these_magics - set(type(self).__dict__) _type = type(self) for entry in these_magics: setattr(_type, entry, MagicProxy(entry, self)) class NonCallableMagicMock(MagicMixin, NonCallableMock): """A version of `MagicMock` that isn't callable.""" def mock_add_spec(self, spec, spec_set=False): """Add a spec to a mock. `spec` can either be an object or a list of strings. Only attributes on the `spec` can be fetched as attributes from the mock. If `spec_set` is True then only attributes on the spec can be set.""" self._mock_add_spec(spec, spec_set) self._mock_set_magics() class MagicMock(MagicMixin, Mock): """ MagicMock is a subclass of Mock with default implementations of most of the magic methods. You can use MagicMock without having to configure the magic methods yourself. If you use the `spec` or `spec_set` arguments then *only* magic methods that exist in the spec will be created. Attributes and the return value of a `MagicMock` will also be `MagicMocks`. """ def mock_add_spec(self, spec, spec_set=False): """Add a spec to a mock. `spec` can either be an object or a list of strings. Only attributes on the `spec` can be fetched as attributes from the mock. If `spec_set` is True then only attributes on the spec can be set.""" self._mock_add_spec(spec, spec_set) self._mock_set_magics() class MagicProxy(object): def __init__(self, name, parent): self.name = name self.parent = parent def __call__(self, *args, **kwargs): m = self.create_mock() return m(*args, **kwargs) def create_mock(self): entry = self.name parent = self.parent m = parent._get_child_mock(name=entry, _new_name=entry, _new_parent=parent) setattr(parent, entry, m) _set_return_value(parent, m, entry) return m def __get__(self, obj, _type=None): return self.create_mock() class _ANY(object): "A helper object that compares equal to everything." def __eq__(self, other): return True def __ne__(self, other): return False def __repr__(self): return '<ANY>' ANY = _ANY() def _format_call_signature(name, args, kwargs): message = '%s(%%s)' % name formatted_args = '' args_string = ', '.join([repr(arg) for arg in args]) kwargs_string = ', '.join([ '%s=%r' % (key, value) for key, value in sorted(kwargs.items()) ]) if args_string: formatted_args = args_string if kwargs_string: if formatted_args: formatted_args += ', ' formatted_args += kwargs_string return message % formatted_args class _Call(tuple): """ A tuple for holding the results of a call to a mock, either in the form `(args, kwargs)` or `(name, args, kwargs)`. If args or kwargs are empty then a call tuple will compare equal to a tuple without those values. This makes comparisons less verbose:: _Call(('name', (), {})) == ('name',) _Call(('name', (1,), {})) == ('name', (1,)) _Call(((), {'a': 'b'})) == ({'a': 'b'},) The `_Call` object provides a useful shortcut for comparing with call:: _Call(((1, 2), {'a': 3})) == call(1, 2, a=3) _Call(('foo', (1, 2), {'a': 3})) == call.foo(1, 2, a=3) If the _Call has no name then it will match any name. """ def __new__(cls, value=(), name='', parent=None, two=False, from_kall=True): args = () kwargs = {} _len = len(value) if _len == 3: name, args, kwargs = value elif _len == 2: first, second = value if isinstance(first, str): name = first if isinstance(second, tuple): args = second else: kwargs = second else: args, kwargs = first, second elif _len == 1: value, = value if isinstance(value, str): name = value elif isinstance(value, tuple): args = value else: kwargs = value if two: return tuple.__new__(cls, (args, kwargs)) return tuple.__new__(cls, (name, args, kwargs)) def __init__(self, value=(), name=None, parent=None, two=False, from_kall=True): self._mock_name = name self._mock_parent = parent self._mock_from_kall = from_kall def __eq__(self, other): if other is ANY: return True try: len_other = len(other) except TypeError: return False self_name = '' if len(self) == 2: self_args, self_kwargs = self else: self_name, self_args, self_kwargs = self if (getattr(self, '_mock_parent', None) and getattr(other, '_mock_parent', None) and self._mock_parent != other._mock_parent): return False other_name = '' if len_other == 0: other_args, other_kwargs = (), {} elif len_other == 3: other_name, other_args, other_kwargs = other elif len_other == 1: value, = other if isinstance(value, tuple): other_args = value other_kwargs = {} elif isinstance(value, str): other_name = value other_args, other_kwargs = (), {} else: other_args = () other_kwargs = value elif len_other == 2: # could be (name, args) or (name, kwargs) or (args, kwargs) first, second = other if isinstance(first, str): other_name = first if isinstance(second, tuple): other_args, other_kwargs = second, {} else: other_args, other_kwargs = (), second else: other_args, other_kwargs = first, second else: return False if self_name and other_name != self_name: return False # this order is important for ANY to work! return (other_args, other_kwargs) == (self_args, self_kwargs) __ne__ = object.__ne__ def __call__(self, *args, **kwargs): if self._mock_name is None: return _Call(('', args, kwargs), name='()') name = self._mock_name + '()' return _Call((self._mock_name, args, kwargs), name=name, parent=self) def __getattr__(self, attr): if self._mock_name is None: return _Call(name=attr, from_kall=False) name = '%s.%s' % (self._mock_name, attr) return _Call(name=name, parent=self, from_kall=False) def count(self, *args, **kwargs): return self.__getattr__('count')(*args, **kwargs) def index(self, *args, **kwargs): return self.__getattr__('index')(*args, **kwargs) def __repr__(self): if not self._mock_from_kall: name = self._mock_name or 'call' if name.startswith('()'): name = 'call%s' % name return name if len(self) == 2: name = 'call' args, kwargs = self else: name, args, kwargs = self if not name: name = 'call' elif not name.startswith('()'): name = 'call.%s' % name else: name = 'call%s' % name return _format_call_signature(name, args, kwargs) def call_list(self): """For a call object that represents multiple calls, `call_list` returns a list of all the intermediate calls as well as the final call.""" vals = [] thing = self while thing is not None: if thing._mock_from_kall: vals.append(thing) thing = thing._mock_parent return _CallList(reversed(vals)) call = _Call(from_kall=False) def create_autospec(spec, spec_set=False, instance=False, _parent=None, _name=None, **kwargs): """Create a mock object using another object as a spec. Attributes on the mock will use the corresponding attribute on the `spec` object as their spec. Functions or methods being mocked will have their arguments checked to check that they are called with the correct signature. If `spec_set` is True then attempting to set attributes that don't exist on the spec object will raise an `AttributeError`. If a class is used as a spec then the return value of the mock (the instance of the class) will have the same spec. You can use a class as the spec for an instance object by passing `instance=True`. The returned mock will only be callable if instances of the mock are callable. `create_autospec` also takes arbitrary keyword arguments that are passed to the constructor of the created mock.""" if _is_list(spec): # can't pass a list instance to the mock constructor as it will be # interpreted as a list of strings spec = type(spec) is_type = isinstance(spec, type) _kwargs = {'spec': spec} if spec_set: _kwargs = {'spec_set': spec} elif spec is None: # None we mock with a normal mock without a spec _kwargs = {} if _kwargs and instance: _kwargs['_spec_as_instance'] = True _kwargs.update(kwargs) Klass = MagicMock if inspect.isdatadescriptor(spec): # descriptors don't have a spec # because we don't know what type they return _kwargs = {} elif not _callable(spec): Klass = NonCallableMagicMock elif is_type and instance and not _instance_callable(spec): Klass = NonCallableMagicMock _name = _kwargs.pop('name', _name) _new_name = _name if _parent is None: # for a top level object no _new_name should be set _new_name = '' mock = Klass(parent=_parent, _new_parent=_parent, _new_name=_new_name, name=_name, **_kwargs) if isinstance(spec, FunctionTypes): # should only happen at the top level because we don't # recurse for functions mock = _set_signature(mock, spec) else: _check_signature(spec, mock, is_type, instance) if _parent is not None and not instance: _parent._mock_children[_name] = mock if is_type and not instance and 'return_value' not in kwargs: mock.return_value = create_autospec(spec, spec_set, instance=True, _name='()', _parent=mock) for entry in dir(spec): if _is_magic(entry): # MagicMock already does the useful magic methods for us continue # XXXX do we need a better way of getting attributes without # triggering code execution (?) Probably not - we need the actual # object to mock it so we would rather trigger a property than mock # the property descriptor. Likewise we want to mock out dynamically # provided attributes. # XXXX what about attributes that raise exceptions other than # AttributeError on being fetched? # we could be resilient against it, or catch and propagate the # exception when the attribute is fetched from the mock try: original = getattr(spec, entry) except AttributeError: continue kwargs = {'spec': original} if spec_set: kwargs = {'spec_set': original} if not isinstance(original, FunctionTypes): new = _SpecState(original, spec_set, mock, entry, instance) mock._mock_children[entry] = new else: parent = mock if isinstance(spec, FunctionTypes): parent = mock.mock skipfirst = _must_skip(spec, entry, is_type) kwargs['_eat_self'] = skipfirst new = MagicMock(parent=parent, name=entry, _new_name=entry, _new_parent=parent, **kwargs) mock._mock_children[entry] = new _check_signature(original, new, skipfirst=skipfirst) # so functions created with _set_signature become instance attributes, # *plus* their underlying mock exists in _mock_children of the parent # mock. Adding to _mock_children may be unnecessary where we are also # setting as an instance attribute? if isinstance(new, FunctionTypes): setattr(mock, entry, new) return mock def _must_skip(spec, entry, is_type): """ Return whether we should skip the first argument on spec's `entry` attribute. """ if not isinstance(spec, type): if entry in getattr(spec, '__dict__', {}): # instance attribute - shouldn't skip return False spec = spec.__class__ for klass in spec.__mro__: result = klass.__dict__.get(entry, DEFAULT) if result is DEFAULT: continue if isinstance(result, (staticmethod, classmethod)): return False elif isinstance(getattr(result, '__get__', None), MethodWrapperTypes): # Normal method => skip if looked up on type # (if looked up on instance, self is already skipped) return is_type else: return False # shouldn't get here unless function is a dynamically provided attribute # XXXX untested behaviour return is_type def _get_class(obj): try: return obj.__class__ except AttributeError: # it is possible for objects to have no __class__ return type(obj) class _SpecState(object): def __init__(self, spec, spec_set=False, parent=None, name=None, ids=None, instance=False): self.spec = spec self.ids = ids self.spec_set = spec_set self.parent = parent self.instance = instance self.name = name FunctionTypes = ( # python function type(create_autospec), # instance method type(ANY.__eq__), ) MethodWrapperTypes = ( type(ANY.__eq__.__get__), ) file_spec = None def _iterate_read_data(read_data): # Helper for mock_open: # Retrieve lines from read_data via a generator so that separate calls to # readline, read, and readlines are properly interleaved sep = b'\n' if isinstance(read_data, bytes) else '\n' data_as_list = [l + sep for l in read_data.split(sep)] if data_as_list[-1] == sep: # If the last line ended in a newline, the list comprehension will have an # extra entry that's just a newline. Remove this. data_as_list = data_as_list[:-1] else: # If there wasn't an extra newline by itself, then the file being # emulated doesn't have a newline to end the last line remove the # newline that our naive format() added data_as_list[-1] = data_as_list[-1][:-1] for line in data_as_list: yield line def mock_open(mock=None, read_data=''): """ A helper function to create a mock to replace the use of `open`. It works for `open` called directly or used as a context manager. The `mock` argument is the mock object to configure. If `None` (the default) then a `MagicMock` will be created for you, with the API limited to methods or attributes available on standard file handles. `read_data` is a string for the `read` methoddline`, and `readlines` of the file handle to return. This is an empty string by default. """ def _readlines_side_effect(*args, **kwargs): if handle.readlines.return_value is not None: return handle.readlines.return_value return list(_state[0]) def _read_side_effect(*args, **kwargs): if handle.read.return_value is not None: return handle.read.return_value return type(read_data)().join(_state[0]) def _readline_side_effect(): if handle.readline.return_value is not None: while True: yield handle.readline.return_value for line in _state[0]: yield line while True: yield type(read_data)() global file_spec if file_spec is None: import _io file_spec = list(set(dir(_io.TextIOWrapper)).union(set(dir(_io.BytesIO)))) if mock is None: mock = MagicMock(name='open', spec=open) handle = MagicMock(spec=file_spec) handle.__enter__.return_value = handle _state = [_iterate_read_data(read_data), None] handle.write.return_value = None handle.read.return_value = None handle.readline.return_value = None handle.readlines.return_value = None handle.read.side_effect = _read_side_effect _state[1] = _readline_side_effect() handle.readline.side_effect = _state[1] handle.readlines.side_effect = _readlines_side_effect def reset_data(*args, **kwargs): _state[0] = _iterate_read_data(read_data) if handle.readline.side_effect == _state[1]: # Only reset the side effect if the user hasn't overridden it. _state[1] = _readline_side_effect() handle.readline.side_effect = _state[1] return DEFAULT mock.side_effect = reset_data mock.return_value = handle return mock class PropertyMock(Mock): """ A mock intended to be used as a property, or other descriptor, on a class. `PropertyMock` provides `__get__` and `__set__` methods so you can specify a return value when it is fetched. Fetching a `PropertyMock` instance from an object calls the mock, with no args. Setting it calls the mock with the value being set. """ def _get_child_mock(self, **kwargs): return MagicMock(**kwargs) def __get__(self, obj, obj_type): return self() def __set__(self, obj, val): self(val)
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