# Source code for mock.mock

    # mock.py
    # Test tools for mocking and patching.
    # E-mail: fuzzyman AT voidspace DOT org DOT uk
    #
    # mock 1.0.1
    # http://www.voidspace.org.uk/python/mock/
    #
    # Copyright (c) 2007-2013, Michael Foord & the mock team
    # All rights reserved.
    #
    # Redistribution and use in source and binary forms, with or without
    # modification, are permitted provided that the following conditions are
    # met:
    #
    #     * Redistributions of source code must retain the above copyright
    #       notice, this list of conditions and the following disclaimer.
    #
    #     * Redistributions in binary form must reproduce the above
    #       copyright notice, this list of conditions and the following
    #       disclaimer in the documentation and/or other materials provided
    #       with the distribution.
    #
    # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    from __future__ import absolute_import

    __all__ = (
        '__version__',
        'version_info',
        'Mock',
        'MagicMock',
        'patch',
        'sentinel',
        'DEFAULT',
        'ANY',
        'call',
        'create_autospec',
        'FILTER_DIR',
        'CallableMixin',
        'NonCallableMock',
        'NonCallableMagicMock',
        'mock_open',
        'PropertyMock',
    )

    from functools import partial
    import inspect
    import pprint
    import sys
    try:
        import builtins
    except ImportError:
        import __builtin__ as builtins
    from types import ModuleType

    import six
    from six import wraps
    from pbr.version import VersionInfo

    _v = VersionInfo('mock').semantic_version()
    __version__ = _v.release_string()
    version_info = _v.version_tuple()

    import mock

    try:
        inspectsignature = inspect.signature
    except AttributeError:
        import funcsigs
        inspectsignature = funcsigs.signature

    # TODO: use six.
    try:
        unicode
    except NameError:
        # Python 3
        basestring = unicode = str

    try:
        long
    except NameError:
        # Python 3
        long = int

    try:
        BaseException
    except NameError:
        # Python 2.4 compatibility
        BaseException = Exception

    if six.PY2:
        # Python 2's next() can't handle a non-iterator with a __next__ method.
        _next = next
        def next(obj, _next=_next):
            if getattr(obj, '__next__', None):
                return obj.__next__()
            return _next(obj)

        del _next

    _builtins = set(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)

    try:
        _isidentifier = str.isidentifier
    except AttributeError:
        # Python 2.X
        import keyword
        import re
        regex = re.compile(r'^[a-z_][a-z0-9_]*$', re.I)
        def _isidentifier(string):
            if string in keyword.kwlist:
                return False
            return regex.match(string)

    self = 'im_self'
    builtin = '__builtin__'
    if six.PY3:
        self = '__self__'
        builtin = 'builtins'

    # NOTE: This FILTER_DIR is not used. The binding in mock.FILTER_DIR is.
    FILTER_DIR = True

    # Workaround for Python 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, ClassTypes) and issubclass(obj, BaseExceptions)
        )

    class _slotted(object):
        __slots__ = ['a']

    DescriptorTypes = (
        type(_slotted.a),
        property,
    )

    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, ClassTypes) 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, inspectsignature(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
        if six.PY2:
            funcopy.func_defaults = func.func_defaults
            return

    def _callable(obj):
        if isinstance(obj, ClassTypes):
            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, ClassTypes):
            # already an instance
            return getattr(obj, '__call__', None) is not None

        if six.PY3:
            # *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
        else:
            klass = obj
            # uses __bases__ instead of __mro__ so that we work with old style classes
            if klass.__dict__.get('__call__') is not None:
                return True

            for base in klass.__bases__:
                if _instance_callable(base):
                    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, ClassTypes)
        result = _get_signature_object(original, instance, skipfirst)
        if result is None:
            return
        func, sig = result
        def checksig(*args, **kwargs):
            sig.bind(*args, **kwargs)
        _copy_func_details(func, checksig)

        name = original.__name__
        if not _isidentifier(name):
            name = 'funcopy'
        context = {'_checksig_': checksig, 'mock': mock}
        src = """def %s(*args, **kwargs):
        _checksig_(*args, **kwargs)
        return mock(*args, **kwargs)""" % name
        six.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_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

        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

    class OldStyleClass:
        pass
    ClassType = type(OldStyleClass)

    def _copy(value):
        if type(value) in (dict, list, tuple, set):
            return type(value)(value)
        return value

    ClassTypes = (type,)
    if six.PY2:
        ClassTypes = (type, ClassType)

    _allowed_names = set((
        '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, ClassTypes):
                    _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):
            "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()

            for child in self._mock_children.values():
                if isinstance(child, _SpecState):
                    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 mock.FILTER_DIR and getattr(object, '__dir__', None):
                # object.__dir__ is not in 2.7
                return object.__dir__(self)

            extras = self._mock_methods or []
            from_type = dir(type(self))
            from_dict = list(self.__dict__)

            if mock.FILTER_DIR:
                # object.__dir__ is not in 2.7
                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 a (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:
                    e.__traceback__ = None
                    return e
            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(cause):
                msg = self._format_mock_failure_message(args, kwargs)
                if six.PY2 and cause is not None:
                    # Tack on some diagnostics for Python without __cause__
                    msg = '%s\n%s' % (msg, str(cause))
                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
                six.raise_from(AssertionError(_error_message(cause)), cause)

        def assert_called_once_with(_mock_self, *args, **kwargs):
            """assert that the mock was called exactly once and 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:
                    six.raise_from(AssertionError(
                        'Calls not found.\nExpected: %r\n'
                        'Actual: %r' % (_CallList(calls), self.mock_calls)
                    ), 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:
                six.raise_from(AssertionError(
                    '%r not all found in call list' % (tuple(not_found),)
                ), 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)
                six.raise_from(AssertionError(
                    '%s call not found' % expected_string
                ), 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
            _new_name = self._mock_new_name
            _new_parent = self._mock_new_parent

            _call = _Call((args, kwargs), two=True)
            self.call_args = _call
            self.call_args_list.append(_call)
            self.mock_calls.append(_Call(('', args, kwargs)))

            seen = set()
            skip_next_dot = _new_name == '()'
            do_method_calls = self._mock_parent is not None
            name = self._mock_name
            while _new_parent is not None:
                this_mock_call = _Call((_new_name, args, kwargs))
                if _new_parent._mock_new_name:
                    dot = '.'
                    if skip_next_dot:
                        dot = ''

                    skip_next_dot = False
                    if _new_parent._mock_new_name == '()':
                        skip_next_dot = True

                    _new_name = _new_parent._mock_new_name + dot + _new_name

                if do_method_calls:
                    if _new_name == name:
                        this_method_call = this_mock_call
                    else:
                        this_method_call = _Call((name, args, kwargs))
                    _new_parent.method_calls.append(this_method_call)

                    do_method_calls = _new_parent._mock_parent is not None
                    if do_method_calls:
                        name = _new_parent._mock_name + '.' + name

                _new_parent.mock_calls.append(this_mock_call)
                _new_parent = _new_parent._mock_new_parent

                # 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)

            ret_val = DEFAULT
            effect = self.side_effect
            if effect is not None:
                if _is_exception(effect):
                    raise effect

                if not _callable(effect):
                    result = next(effect)
                    if _is_exception(result):
                        raise result
                    if result is DEFAULT:
                        result = self.return_value
                    return result

                ret_val = effect(*args, **kwargs)

            if (self._mock_wraps is not None and
                 self._mock_return_value is DEFAULT):
                return self._mock_wraps(*args, **kwargs)
            if ret_val is DEFAULT:
                ret_val = self.return_value
            return ret_val

    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.

          Alternatively `side_effect` can be an exception class or instance. In
          this case the exception will be raised when the mock is called.

          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, ClassTypes):
                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, ClassTypes):
                        # 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) in (unicode, 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, basestring):
                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, ClassTypes):
                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 "
    )

    numerics = (
        "add sub mul matmul div floordiv mod lshift rshift and xor or pow"
    )
    if six.PY3:
        numerics += ' truediv'
    inplace = ' '.join('i%s' % n for n in numerics.split())
    right = ' '.join('r%s' % n for n in numerics.split())
    extra = ''
    if six.PY3:
        extra = 'bool next '
    else:
        extra = 'unicode long nonzero oct hex truediv rtruediv '

    # 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 = set((
        '__cmp__', '__getslice__', '__setslice__', '__coerce__', # <3.x
        '__get__', '__set__', '__delete__', '__reversed__', '__missing__',
        '__reduce__', '__reduce_ex__', '__getinitargs__', '__getnewargs__',
        '__getstate__', '__setstate__', '__getformat__', '__setformat__',
        '__repr__', '__dir__', '__subclasses__', '__format__',
    ))

    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 = set(
        '__%s__' % method for method in
        ' '.join([magic_methods, numerics, inplace, right, extra]).split()
    )

    _all_magics = _magics | _non_defaults

    _unsupported_magics = set((
        '__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),
        '__unicode__': lambda self: unicode(object.__str__(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,
        '__nonzero__': True,
        '__oct__': '1',
        '__hex__': '0x1',
        '__long__': long(1),
        '__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
            return self is other
        return __eq__

    def _get_ne(self):
        def __ne__(other):
            if self.__ne__._mock_return_value is not DEFAULT:
                return DEFAULT
            return self is not other
        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])

        def encode_item(item):
            if six.PY2 and isinstance(item, unicode):
                return item.encode("utf-8")
            else:
                return item

        kwargs_string = ', '.join([
            '%s=%r' % (encode_item(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=None, parent=None, two=False,
                    from_kall=True):
            name = ''
            args = ()
            kwargs = {}
            _len = len(value)
            if _len == 3:
                name, args, kwargs = value
            elif _len == 2:
                first, second = value
                if isinstance(first, basestring):
                    name = first
                    if isinstance(second, tuple):
                        args = second
                    else:
                        kwargs = second
                else:
                    args, kwargs = first, second
            elif _len == 1:
                value, = value
                if isinstance(value, basestring):
                    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.name = name
            self.parent = parent
            self.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

            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, basestring):
                    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, basestring):
                    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)

        def __ne__(self, other):
            return not self.__eq__(other)

        def __call__(self, *args, **kwargs):
            if self.name is None:
                return _Call(('', args, kwargs), name='()')

            name = self.name + '()'
            return _Call((self.name, args, kwargs), name=name, parent=self)

        def __getattr__(self, attr):
            if self.name is None:
                return _Call(name=attr, from_kall=False)
            name = '%s.%s' % (self.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.from_kall:
                name = self.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.from_kall:
                    vals.append(thing)
                thing = thing.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, ClassTypes)

        _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 type(spec) in DescriptorTypes:
            # 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, ClassTypes):
            if entry in getattr(spec, '__dict__', {}):
                # instance attribute - shouldn't skip
                return False
            spec = spec.__class__
        if not hasattr(spec, '__mro__'):
            # old style class: can't have descriptors anyway
            return is_type

        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

        global file_spec
        if file_spec is None:
            # set on first use
            if six.PY3:
                import _io
                file_spec = list(set(dir(_io.TextIOWrapper)).union(set(dir(_io.BytesIO))))
            else:
                file_spec = file

        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)