blob: c8fc5d1d2501284694043ba8849dba7eab102431 [file] [log] [blame]
# Test tools for mocking and patching.
# Copyright (C) 2007-2012 Michael Foord & the mock team
# E-mail: fuzzyman AT voidspace DOT org DOT uk
# mock 1.0
# Released subject to the BSD License
# Please see
# Scripts maintained at
# Comments, suggestions and bug reports welcome.
__all__ = (
__version__ = '1.0.1'
import pprint
import sys
import inspect
except ImportError:
# for alternative platforms that
# may not have inspect
inspect = None
from functools import wraps as original_wraps
except ImportError:
# Python 2.4 compatibility
def wraps(original):
def inner(f):
f.__name__ = original.__name__
f.__doc__ = original.__doc__
f.__module__ = original.__module__
f.__wrapped__ = original
return f
return inner
if sys.version_info[:2] >= (3, 3):
wraps = original_wraps
def wraps(func):
def inner(f):
f = original_wraps(func)(f)
f.__wrapped__ = func
return f
return inner
except NameError:
# Python 3
basestring = unicode = str
except NameError:
# Python 3
long = int
except NameError:
# Python 2.4 compatibility
BaseException = Exception
except NameError:
def next(obj):
BaseExceptions = (BaseException,)
if 'java' in sys.platform:
# jython
import java
BaseExceptions = (BaseException, java.lang.Throwable)
_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)
inPy3k = sys.version_info[0] == 3
# Needed to work around Python 3 bug where use of "super" interferes with
# defining __class__ as a descriptor
_super = super
self = 'im_self'
builtin = '__builtin__'
if inPy3k:
self = '__self__'
builtin = 'builtins'
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 = (
def _getsignature(func, skipfirst, instance=False):
if inspect is None:
raise ImportError('inspect module not available')
if isinstance(func, ClassTypes) and not instance:
func = func.__init__
except AttributeError:
skipfirst = True
elif not isinstance(func, FunctionTypes):
# for classes where instance is True we end up here too
func = func.__call__
except AttributeError:
if inPy3k:
argspec = inspect.getfullargspec(func)
except TypeError:
# C function / method, possibly inherited object().__init__
regargs, varargs, varkw, defaults, kwonly, kwonlydef, ann = argspec
regargs, varargs, varkwargs, defaults = inspect.getargspec(func)
except TypeError:
# C function / method, possibly inherited object().__init__
# instance methods and classmethods need to lose the self argument
if getattr(func, self, None) is not None:
regargs = regargs[1:]
if skipfirst:
# this condition and the above one are never both True - why?
regargs = regargs[1:]
if inPy3k:
signature = inspect.formatargspec(
regargs, varargs, varkw, defaults,
kwonly, kwonlydef, ann, formatvalue=lambda value: "")
signature = inspect.formatargspec(
regargs, varargs, varkwargs, defaults,
formatvalue=lambda value: "")
return signature[1:-1], func
def _check_signature(func, mock, skipfirst, instance=False):
if not _callable(func):
result = _getsignature(func, skipfirst, instance)
if result is None:
signature, func = result
# can't use self because "self" is common as an argument name
# unfortunately even not in the first place
src = "lambda _mock_self, %s: None" % signature
checksig = eval(src, {})
_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__
funcopy.__module__ = func.__module__
if not inPy3k:
funcopy.func_defaults = func.func_defaults
funcopy.__defaults__ = func.__defaults__
funcopy.__kwdefaults__ = func.__kwdefaults__
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
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):
skipfirst = isinstance(original, ClassTypes)
result = _getsignature(original, skipfirst, instance)
if result is None:
# was a C function (e.g. object().__init__ ) that can't be mocked
signature, func = result
src = "lambda %s: None" % signature
checksig = eval(src, {})
_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
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):
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()
ret = funcopy.return_value
if _is_instance_mock(ret) and not ret is 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): = name
def __repr__(self):
return 'sentinel.%s' %
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(mock) raises an exception
raise AttributeError
return self._sentinels.setdefault(name, _SentinelObject(name))
sentinel = _Sentinel()
_missing = sentinel.MISSING
_deleted = sentinel.DELETED
class OldStyleClass:
ClassType = type(OldStyleClass)
def _copy(value):
if type(value) in (dict, list, tuple, set):
return type(value)(value)
return value
ClassTypes = (type,)
if not inPy3k:
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):
_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
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
class Base(object):
_mock_return_value = DEFAULT
_mock_side_effect = None
def __init__(self, *args, **kwargs):
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,
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
self._mock_add_spec(spec, spec_set)
__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()
if kwargs:
_super(NonCallableMock, self).__init__(
spec, wraps, name, spec_set, parent,
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_class = None
if spec is not None and not _is_list(spec):
if isinstance(spec, ClassTypes):
_spec_class = spec
_spec_class = _get_class(spec)
spec = dir(spec)
__dict__ = self.__dict__
__dict__['_spec_class'] = _spec_class
__dict__['_spec_set'] = spec_set
__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
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,
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):
sig = self._mock_delegate
if sig is None:
return self._mock_side_effect
return sig.side_effect
def __set_side_effect(self, value):
value = _try_iter(value)
sig = self._mock_delegate
if sig is None:
self._mock_side_effect = value
sig.side_effect = value
side_effect = property(__get_side_effect, __set_side_effect)
def reset_mock(self):
"Restore the mock object to its initial state."
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):
ret = self._mock_return_value
if _is_instance_mock(ret) and ret is not self:
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 == '_mock_methods':
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)
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,
self._mock_children[name] = result
elif isinstance(result, _SpecState):
result = create_autospec(
result.spec, result.spec_set, result.instance,
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:
_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'>" % (
def __dir__(self):
"""Filter the output of `dir(mock)` to only useful members.
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
return sorted(set(extras + from_type + from_dict +
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)
# 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
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
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 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,))
if self.call_args != (args, kwargs):
msg = self._format_mock_failure_message(args, kwargs)
raise AssertionError(msg)
def assert_called_once_with(_mock_self, *args, **kwargs):
"""assert that the mock was called exactly once and with the specified
self = _mock_self
if not self.call_count == 1:
msg = ("Expected to be called once. Called %s times." %
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`."""
if not any_order:
if calls not in self.mock_calls:
raise AssertionError(
'Calls not found.\nExpected: %r\n'
'Actual: %r' % (calls, self.mock_calls)
all_calls = list(self.mock_calls)
not_found = []
for kall in calls:
except ValueError:
if not_found:
raise AssertionError(
'%r not all found in call list' % (tuple(not_found),)
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."""
kall = call(*args, **kwargs)
if kall not in self.call_args_list:
expected_string = self._format_mock_call_signature(args, kwargs)
raise AssertionError(
'%s call not found' % expected_string
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
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
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
_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
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
self.call_args = _Call((args, kwargs), two=True)
self.call_args_list.append(_Call((args, kwargs), two=True))
_new_name = self._mock_new_name
_new_parent = self._mock_new_parent
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
this_method_call = _Call((name, args, kwargs))
do_method_calls = _new_parent._mock_parent is not None
if do_method_calls:
name = _new_parent._mock_name + '.' + name
_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:
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
return result
ret_val = effect(*args, **kwargs)
if ret_val is DEFAULT:
ret_val = self.return_value
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
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 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):
return getattr(thing, comp)
except AttributeError:
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 = set()
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 = 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.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):
attr_value = getattr(klass, attr)
if not hasattr(attr_value, "__call__"):
patcher = self.copy()
setattr(klass, attr, patcher(attr_value))
return klass
def decorate_callable(self, func):
if hasattr(func, 'patchings'):
return func
def patched(*args, **keywargs):
# don't use a with here (backwards compatability with Python 2.4)
extra_args = []
entered_patchers = []
# can't use try...except...finally because of Python 2.4
# compatibility
exc_info = tuple()
for patching in patched.patchings:
arg = patching.__enter__()
if patching.attribute_name is not None:
elif is DEFAULT:
args += tuple(extra_args)
return func(*args, **keywargs)
if (patching not in entered_patchers and
# the patcher may have been started, but an exception
# raised whilst entering one of its additional_patchers
# Pass the exception to __exit__
exc_info = sys.exc_info()
# re-raise the exception
for patching in reversed(entered_patchers):
patched.patchings = [self]
if hasattr(func, 'func_code'):
# not in Python 3
patched.compat_co_firstlineno = getattr(
func, "compat_co_firstlineno",
return patched
def get_original(self):
target = self.getter()
name = self.attribute
original = DEFAULT
local = False
original = target.__dict__[name]
except (AttributeError, KeyError):
original = getattr(target, name, DEFAULT)
local = 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.spec, self.spec_set
autospec, kwargs = self.autospec, self.kwargs
new_callable = self.new_callable = 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
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
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
Klass = NonCallableMagicMock
new.return_value = Klass(_new_parent=new, _new_name='()',
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.attribute, new_attr)
if self.attribute_name is not None:
extra_args = {}
if is DEFAULT:
extra_args[self.attribute_name] = new
for patching in self.additional_patchers:
arg = patching.__enter__()
if is DEFAULT:
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.attribute, self.temp_original)
delattr(, self.attribute)
if not self.create and not hasattr(, self.attribute):
# needed for proxy objects like django settings
setattr(, self.attribute, self.temp_original)
del self.temp_original
del self.is_local
for patcher in reversed(self.additional_patchers):
if _is_started(patcher):
def start(self):
"""Activate a patch, returning any created mock."""
result = self.__enter__()
return result
def stop(self):
"""Stop an active patch."""
return self.__exit__()
def _get_target(target):
target, attribute = target.rsplit('.', 1)
except (TypeError, ValueError):
raise TypeError("Need a valid target to patch. You supplied: %r" %
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.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
`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)
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
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
A more powerful form of `spec` is `autospec`. If you set `autospec=True`
then the mock with 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 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.clear = clear
self._original = None
def __call__(self, f):
if isinstance(f, ClassTypes):
return self.decorate_class(f)
def _inner(*args, **kw):
return f(*args, **kw)
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."""
def _patch_dict(self):
values = self.values
in_dict = self.in_dict
clear = self.clear
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:
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
except AttributeError:
for key in original:
in_dict[key] = original[key]
def __exit__(self, *args):
"""Unpatch the dict."""
return False
start = __enter__
stop = __exit__
def _clear_dict(in_dict):
except AttributeError:
keys = list(in_dict)
for key in keys:
del in_dict[key]
def _patch_stopall():
"""Stop all active patches."""
for patch in list(_patch._active_patches):
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 "
"divmod neg pos abs invert "
"complex int float index "
"trunc floor ceil "
numerics = "add sub mul div floordiv mod lshift rshift and xor or pow "
inplace = ' '.join('i%s' % n for n in numerics.split())
right = ' '.join('r%s' % n for n in numerics.split())
extra = ''
if inPy3k:
extra = 'bool next '
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('__%s__' % method for method in [
'cmp', 'getslice', 'setslice', 'coerce', 'subclasses',
'format', 'get', 'set', 'delete', 'reversed',
'missing', 'reduce', 'reduce_ex', 'getinitargs',
'getnewargs', 'getstate', 'setstate', 'getformat',
'setformat', 'repr', 'dir'
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__',
_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_calulator = _calculate_return_value.get(name)
if return_calulator is not None:
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
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):
_super(MagicMixin, self).__init__(*args, **kw)
def _mock_set_magics(self):
these_magics = _magics
if self._mock_methods 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)
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)
class MagicProxy(object):
def __init__(self, name, parent): = name
self.parent = parent
def __call__(self, *args, **kwargs):
m = self.create_mock()
return m(*args, **kwargs)
def create_mock(self):
entry =
parent = self.parent
m = parent._get_child_mock(name=entry, _new_name=entry,
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 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})) ==, 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,
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
kwargs = second
args, kwargs = first, second
elif _len == 1:
value, = value
if isinstance(value, basestring):
name = value
elif isinstance(value, tuple):
args = value
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): = name
self.parent = parent
self.from_kall = from_kall
def __eq__(self, other):
if other is ANY:
return True
len_other = len(other)
except TypeError:
return False
self_name = ''
if len(self) == 2:
self_args, self_kwargs = self
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 = (), {}
other_args = ()
other_kwargs = value
# len 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, {}
other_args, other_kwargs = (), second
other_args, other_kwargs = first, second
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 is None:
return _Call(('', args, kwargs), name='()')
name = + '()'
return _Call((, args, kwargs), name=name, parent=self)
def __getattr__(self, attr):
if is None:
return _Call(name=attr, from_kall=False)
name = '%s.%s' % (, attr)
return _Call(name=name, parent=self, from_kall=False)
def __repr__(self):
if not self.from_kall:
name = or 'call'
if name.startswith('()'):
name = 'call%s' % name
return name
if len(self) == 2:
name = 'call'
args, kwargs = self
name, args, kwargs = self
if not name:
name = 'call'
elif not name.startswith('()'):
name = 'call.%s' % name
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:
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
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 = {}
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
_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)
_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
if isinstance(spec, FunctionTypes) and entry in FunctionAttributes:
# allow a mock to actually be a function
# 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
original = getattr(spec, entry)
except AttributeError:
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
parent = mock
if isinstance(spec, FunctionTypes):
parent = mock.mock
new = MagicMock(parent=parent, name=entry, _new_name=entry,
_new_parent=parent, **kwargs)
mock._mock_children[entry] = new
skipfirst = _must_skip(spec, entry, is_type)
_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):
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:
if isinstance(result, (staticmethod, classmethod)):
return False
return is_type
# shouldn't get here unless function is a dynamically provided attribute
# XXXX untested behaviour
return is_type
def _get_class(obj):
return obj.__class__
except AttributeError:
# in Python 2, _sre.SRE_Pattern objects 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 = name
FunctionTypes = (
# python function
# instance method
# unbound method
FunctionAttributes = set([
file_spec = None
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` method of the file handle to return.
This is an empty string by default.
global file_spec
if file_spec is None:
# set on first use
if inPy3k:
import _io
file_spec = list(set(dir(_io.TextIOWrapper)).union(set(dir(_io.BytesIO))))
file_spec = file
if mock is None:
mock = MagicMock(name='open', spec=open)
handle = MagicMock(spec=file_spec)
handle.write.return_value = None
handle.__enter__.return_value = handle = read_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):