Issue #17015: When it has a spec, a Mock object now inspects its signature when matching calls, so that arguments can be matched positionally or by name.

This commit is contained in:
Antoine Pitrou 2013-02-03 00:23:58 +01:00
parent 18b30ee88e
commit 5c64df70b5
6 changed files with 313 additions and 87 deletions

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@ -277,6 +277,20 @@ instantiate the class in those tests.
...
AttributeError: object has no attribute 'old_method'
Using a specification also enables a smarter matching of calls made to the
mock, regardless of whether some parameters were passed as positional or
named arguments::
>>> def f(a, b, c): pass
...
>>> mock = Mock(spec=f)
>>> mock(1, 2, 3)
<Mock name='mock()' id='140161580456576'>
>>> mock.assert_called_with(a=1, b=2, c=3)
If you want this smarter matching to also work with method calls on the mock,
you can use :ref:`auto-speccing <auto-speccing>`.
If you want a stronger form of specification that prevents the setting
of arbitrary attributes as well as the getting of them then you can use
`spec_set` instead of `spec`.

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@ -264,7 +264,6 @@ the `new_callable` argument to `patch`.
<Mock name='mock.method()' id='...'>
>>> mock.method.assert_called_with(1, 2, 3, test='wow')
.. method:: assert_called_once_with(*args, **kwargs)
Assert that the mock was called exactly once and with the specified
@ -685,6 +684,27 @@ have to create a dictionary and unpack it using `**`:
...
KeyError
A callable mock which was created with a *spec* (or a *spec_set*) will
introspect the specification object's signature when matching calls to
the mock. Therefore, it can match the actual call's arguments regardless
of whether they were passed positionally or by name::
>>> def f(a, b, c): pass
...
>>> mock = Mock(spec=f)
>>> mock(1, 2, c=3)
<Mock name='mock()' id='140161580456576'>
>>> mock.assert_called_with(1, 2, 3)
>>> mock.assert_called_with(a=1, b=2, c=3)
This applies to :meth:`~Mock.assert_called_with`,
:meth:`~Mock.assert_called_once_with`, :meth:`~Mock.assert_has_calls` and
:meth:`~Mock.assert_any_call`. When :ref:`auto-speccing`, it will also
apply to method calls on the mock object.
.. versionchanged:: 3.4
Added signature introspection on specced and autospecced mock objects.
.. class:: PropertyMock(*args, **kwargs)

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@ -27,7 +27,7 @@ __version__ = '1.0'
import inspect
import pprint
import sys
from functools import wraps
from functools import wraps, partial
BaseExceptions = (BaseException,)
@ -66,55 +66,45 @@ DescriptorTypes = (
)
def _getsignature(func, skipfirst, instance=False):
if isinstance(func, type) and not instance:
def _get_signature_object(func, as_instance, eat_self):
"""
Given an arbitrary, possibly callable object, try to create a suitable
signature object.
Return a (reduced func, signature) tuple, or None.
"""
if isinstance(func, type) and not as_instance:
# If it's a type and should be modelled as a type, use __init__.
try:
func = func.__init__
except AttributeError:
return
skipfirst = True
return None
# Skip the `self` argument in __init__
eat_self = True
elif not isinstance(func, FunctionTypes):
# for classes where instance is True we end up here too
# 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
return None
if eat_self:
sig_func = partial(func, None)
else:
sig_func = func
try:
argspec = inspect.getfullargspec(func)
except TypeError:
# C function / method, possibly inherited object().__init__
return
regargs, varargs, varkw, defaults, kwonly, kwonlydef, ann = argspec
# 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:]
signature = inspect.formatargspec(
regargs, varargs, varkw, defaults,
kwonly, kwonlydef, ann, formatvalue=lambda value: "")
return signature[1:-1], func
return func, inspect.signature(sig_func)
except ValueError:
# Certain callable types are not supported by inspect.signature()
return None
def _check_signature(func, mock, skipfirst, instance=False):
if not _callable(func):
sig = _get_signature_object(func, instance, skipfirst)
if sig is None:
return
result = _getsignature(func, skipfirst, instance)
if result is None:
return
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, {})
func, sig = sig
def checksig(_mock_self, *args, **kwargs):
sig.bind(*args, **kwargs)
_copy_func_details(func, checksig)
type(mock)._mock_check_sig = checksig
@ -166,15 +156,12 @@ def _set_signature(mock, original, instance=False):
return
skipfirst = isinstance(original, type)
result = _getsignature(original, skipfirst, instance)
result = _get_signature_object(original, instance, skipfirst)
if result is None:
# was a C function (e.g. object().__init__ ) that can't be mocked
return
signature, func = result
src = "lambda %s: None" % signature
checksig = eval(src, {})
func, sig = result
def checksig(*args, **kwargs):
sig.bind(*args, **kwargs)
_copy_func_details(func, checksig)
name = original.__name__
@ -368,7 +355,7 @@ class NonCallableMock(Base):
def __init__(
self, spec=None, wraps=None, name=None, spec_set=None,
parent=None, _spec_state=None, _new_name='', _new_parent=None,
**kwargs
_spec_as_instance=False, _eat_self=None, **kwargs
):
if _new_parent is None:
_new_parent = parent
@ -382,8 +369,10 @@ class NonCallableMock(Base):
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)
self._mock_add_spec(spec, spec_set, _spec_as_instance, _eat_self)
__dict__['_mock_children'] = {}
__dict__['_mock_wraps'] = wraps
@ -428,20 +417,26 @@ class NonCallableMock(Base):
self._mock_add_spec(spec, spec_set)
def _mock_add_spec(self, spec, spec_set):
def _mock_add_spec(self, spec, spec_set, _spec_as_instance=False,
_eat_self=False):
_spec_class = None
_spec_signature = None
if spec is not None and not _is_list(spec):
if isinstance(spec, type):
_spec_class = spec
else:
_spec_class = _get_class(spec)
res = _get_signature_object(spec,
_spec_as_instance, _eat_self)
_spec_signature = res and res[1]
spec = dir(spec)
__dict__ = self.__dict__
__dict__['_spec_class'] = _spec_class
__dict__['_spec_set'] = spec_set
__dict__['_spec_signature'] = _spec_signature
__dict__['_mock_methods'] = spec
@ -695,7 +690,6 @@ class NonCallableMock(Base):
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)
@ -711,6 +705,28 @@ class NonCallableMock(Base):
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:
return e.with_traceback(None)
else:
return _call
def assert_called_with(_mock_self, *args, **kwargs):
"""assert that the mock was called with the specified arguments.
@ -721,9 +737,14 @@ class NonCallableMock(Base):
expected = self._format_mock_call_signature(args, kwargs)
raise AssertionError('Expected call: %s\nNot called' % (expected,))
if self.call_args != (args, kwargs):
def _error_message():
msg = self._format_mock_failure_message(args, kwargs)
raise AssertionError(msg)
return msg
expected = self._call_matcher((args, kwargs))
actual = self._call_matcher(self.call_args)
if expected != actual:
cause = expected if isinstance(expected, Exception) else None
raise AssertionError(_error_message()) from cause
def assert_called_once_with(_mock_self, *args, **kwargs):
@ -747,18 +768,21 @@ class NonCallableMock(Base):
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 calls not in self.mock_calls:
if expected not in all_calls:
raise AssertionError(
'Calls not found.\nExpected: %r\n'
'Actual: %r' % (calls, self.mock_calls)
)
) from cause
return
all_calls = list(self.mock_calls)
all_calls = list(all_calls)
not_found = []
for kall in calls:
for kall in expected:
try:
all_calls.remove(kall)
except ValueError:
@ -766,7 +790,7 @@ class NonCallableMock(Base):
if not_found:
raise AssertionError(
'%r not all found in call list' % (tuple(not_found),)
)
) from cause
def assert_any_call(self, *args, **kwargs):
@ -775,12 +799,14 @@ class NonCallableMock(Base):
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 = self._call_matcher((args, kwargs))
actual = [self._call_matcher(c) for c in self.call_args_list]
if expected not in actual:
cause = expected if isinstance(expected, Exception) else None
expected_string = self._format_mock_call_signature(args, kwargs)
raise AssertionError(
'%s call not found' % expected_string
)
) from cause
def _get_child_mock(self, **kw):
@ -850,11 +876,12 @@ class CallableMixin(Base):
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
_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()
@ -2031,6 +2058,8 @@ def create_autospec(spec, spec_set=False, instance=False, _parent=None,
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)
@ -2097,10 +2126,12 @@ def create_autospec(spec, spec_set=False, instance=False, _parent=None,
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)
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,
@ -2114,6 +2145,10 @@ def create_autospec(spec, spec_set=False, instance=False, _parent=None,
def _must_skip(spec, entry, is_type):
"""
Return whether we should skip the first argument on spec's `entry`
attribute.
"""
if not isinstance(spec, type):
if entry in getattr(spec, '__dict__', {}):
# instance attribute - shouldn't skip
@ -2126,7 +2161,12 @@ def _must_skip(spec, entry, is_type):
continue
if isinstance(result, (staticmethod, classmethod)):
return False
return is_type
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
@ -2160,6 +2200,10 @@ FunctionTypes = (
type(ANY.__eq__),
)
MethodWrapperTypes = (
type(ANY.__eq__.__get__),
)
file_spec = None

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@ -337,9 +337,10 @@ class SpecSignatureTest(unittest.TestCase):
def test_basic(self):
for spec in (SomeClass, SomeClass()):
mock = create_autospec(spec)
self._check_someclass_mock(mock)
mock = create_autospec(SomeClass)
self._check_someclass_mock(mock)
mock = create_autospec(SomeClass())
self._check_someclass_mock(mock)
def test_create_autospec_return_value(self):
@ -576,10 +577,10 @@ class SpecSignatureTest(unittest.TestCase):
def test_spec_inheritance_for_classes(self):
class Foo(object):
def a(self):
def a(self, x):
pass
class Bar(object):
def f(self):
def f(self, y):
pass
class_mock = create_autospec(Foo)
@ -587,26 +588,30 @@ class SpecSignatureTest(unittest.TestCase):
self.assertIsNot(class_mock, class_mock())
for this_mock in class_mock, class_mock():
this_mock.a()
this_mock.a.assert_called_with()
self.assertRaises(TypeError, this_mock.a, 'foo')
this_mock.a(x=5)
this_mock.a.assert_called_with(x=5)
this_mock.a.assert_called_with(5)
self.assertRaises(TypeError, this_mock.a, 'foo', 'bar')
self.assertRaises(AttributeError, getattr, this_mock, 'b')
instance_mock = create_autospec(Foo())
instance_mock.a()
instance_mock.a.assert_called_with()
self.assertRaises(TypeError, instance_mock.a, 'foo')
instance_mock.a(5)
instance_mock.a.assert_called_with(5)
instance_mock.a.assert_called_with(x=5)
self.assertRaises(TypeError, instance_mock.a, 'foo', 'bar')
self.assertRaises(AttributeError, getattr, instance_mock, 'b')
# The return value isn't isn't callable
self.assertRaises(TypeError, instance_mock)
instance_mock.Bar.f()
instance_mock.Bar.f.assert_called_with()
instance_mock.Bar.f(6)
instance_mock.Bar.f.assert_called_with(6)
instance_mock.Bar.f.assert_called_with(y=6)
self.assertRaises(AttributeError, getattr, instance_mock.Bar, 'g')
instance_mock.Bar().f()
instance_mock.Bar().f.assert_called_with()
instance_mock.Bar().f(6)
instance_mock.Bar().f.assert_called_with(6)
instance_mock.Bar().f.assert_called_with(y=6)
self.assertRaises(AttributeError, getattr, instance_mock.Bar(), 'g')
@ -663,12 +668,15 @@ class SpecSignatureTest(unittest.TestCase):
self.assertRaises(TypeError, mock)
mock(1, 2)
mock.assert_called_with(1, 2)
mock.assert_called_with(1, b=2)
mock.assert_called_with(a=1, b=2)
f.f = f
mock = create_autospec(f)
self.assertRaises(TypeError, mock.f)
mock.f(3, 4)
mock.f.assert_called_with(3, 4)
mock.f.assert_called_with(a=3, b=4)
def test_skip_attributeerrors(self):
@ -704,9 +712,13 @@ class SpecSignatureTest(unittest.TestCase):
self.assertRaises(TypeError, mock)
mock(1)
mock.assert_called_once_with(1)
mock.assert_called_once_with(a=1)
self.assertRaises(AssertionError, mock.assert_called_once_with, 2)
mock(4, 5)
mock.assert_called_with(4, 5)
mock.assert_called_with(a=4, b=5)
self.assertRaises(AssertionError, mock.assert_called_with, a=5, b=4)
def test_class_with_no_init(self):
@ -719,24 +731,27 @@ class SpecSignatureTest(unittest.TestCase):
def test_signature_callable(self):
class Callable(object):
def __init__(self):
def __init__(self, x, y):
pass
def __call__(self, a):
pass
mock = create_autospec(Callable)
mock()
mock.assert_called_once_with()
mock(1, 2)
mock.assert_called_once_with(1, 2)
mock.assert_called_once_with(x=1, y=2)
self.assertRaises(TypeError, mock, 'a')
instance = mock()
instance = mock(1, 2)
self.assertRaises(TypeError, instance)
instance(a='a')
instance.assert_called_once_with('a')
instance.assert_called_once_with(a='a')
instance('a')
instance.assert_called_with('a')
instance.assert_called_with(a='a')
mock = create_autospec(Callable())
mock = create_autospec(Callable(1, 2))
mock(a='a')
mock.assert_called_once_with(a='a')
self.assertRaises(TypeError, mock)
@ -779,7 +794,11 @@ class SpecSignatureTest(unittest.TestCase):
pass
a = create_autospec(Foo)
a.f(10)
a.f.assert_called_with(10)
a.f.assert_called_with(self=10)
a.f(self=10)
a.f.assert_called_with(10)
a.f.assert_called_with(self=10)

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@ -25,6 +25,18 @@ class Iter(object):
__next__ = next
class Something(object):
def meth(self, a, b, c, d=None):
pass
@classmethod
def cmeth(cls, a, b, c, d=None):
pass
@staticmethod
def smeth(a, b, c, d=None):
pass
class MockTest(unittest.TestCase):
@ -273,6 +285,43 @@ class MockTest(unittest.TestCase):
mock.assert_called_with(1, 2, 3, a='fish', b='nothing')
def test_assert_called_with_function_spec(self):
def f(a, b, c, d=None):
pass
mock = Mock(spec=f)
mock(1, b=2, c=3)
mock.assert_called_with(1, 2, 3)
mock.assert_called_with(a=1, b=2, c=3)
self.assertRaises(AssertionError, mock.assert_called_with,
1, b=3, c=2)
# Expected call doesn't match the spec's signature
with self.assertRaises(AssertionError) as cm:
mock.assert_called_with(e=8)
self.assertIsInstance(cm.exception.__cause__, TypeError)
def test_assert_called_with_method_spec(self):
def _check(mock):
mock(1, b=2, c=3)
mock.assert_called_with(1, 2, 3)
mock.assert_called_with(a=1, b=2, c=3)
self.assertRaises(AssertionError, mock.assert_called_with,
1, b=3, c=2)
mock = Mock(spec=Something().meth)
_check(mock)
mock = Mock(spec=Something.cmeth)
_check(mock)
mock = Mock(spec=Something().cmeth)
_check(mock)
mock = Mock(spec=Something.smeth)
_check(mock)
mock = Mock(spec=Something().smeth)
_check(mock)
def test_assert_called_once_with(self):
mock = Mock()
mock()
@ -297,6 +346,29 @@ class MockTest(unittest.TestCase):
)
def test_assert_called_once_with_function_spec(self):
def f(a, b, c, d=None):
pass
mock = Mock(spec=f)
mock(1, b=2, c=3)
mock.assert_called_once_with(1, 2, 3)
mock.assert_called_once_with(a=1, b=2, c=3)
self.assertRaises(AssertionError, mock.assert_called_once_with,
1, b=3, c=2)
# Expected call doesn't match the spec's signature
with self.assertRaises(AssertionError) as cm:
mock.assert_called_once_with(e=8)
self.assertIsInstance(cm.exception.__cause__, TypeError)
# Mock called more than once => always fails
mock(4, 5, 6)
self.assertRaises(AssertionError, mock.assert_called_once_with,
1, 2, 3)
self.assertRaises(AssertionError, mock.assert_called_once_with,
4, 5, 6)
def test_attribute_access_returns_mocks(self):
mock = Mock()
something = mock.something
@ -991,6 +1063,39 @@ class MockTest(unittest.TestCase):
)
def test_assert_has_calls_with_function_spec(self):
def f(a, b, c, d=None):
pass
mock = Mock(spec=f)
mock(1, b=2, c=3)
mock(4, 5, c=6, d=7)
mock(10, 11, c=12)
calls = [
('', (1, 2, 3), {}),
('', (4, 5, 6), {'d': 7}),
((10, 11, 12), {}),
]
mock.assert_has_calls(calls)
mock.assert_has_calls(calls, any_order=True)
mock.assert_has_calls(calls[1:])
mock.assert_has_calls(calls[1:], any_order=True)
mock.assert_has_calls(calls[:-1])
mock.assert_has_calls(calls[:-1], any_order=True)
# Reversed order
calls = list(reversed(calls))
with self.assertRaises(AssertionError):
mock.assert_has_calls(calls)
mock.assert_has_calls(calls, any_order=True)
with self.assertRaises(AssertionError):
mock.assert_has_calls(calls[1:])
mock.assert_has_calls(calls[1:], any_order=True)
with self.assertRaises(AssertionError):
mock.assert_has_calls(calls[:-1])
mock.assert_has_calls(calls[:-1], any_order=True)
def test_assert_any_call(self):
mock = Mock()
mock(1, 2)
@ -1017,6 +1122,26 @@ class MockTest(unittest.TestCase):
)
def test_assert_any_call_with_function_spec(self):
def f(a, b, c, d=None):
pass
mock = Mock(spec=f)
mock(1, b=2, c=3)
mock(4, 5, c=6, d=7)
mock.assert_any_call(1, 2, 3)
mock.assert_any_call(a=1, b=2, c=3)
mock.assert_any_call(4, 5, 6, 7)
mock.assert_any_call(a=4, b=5, c=6, d=7)
self.assertRaises(AssertionError, mock.assert_any_call,
1, b=3, c=2)
# Expected call doesn't match the spec's signature
with self.assertRaises(AssertionError) as cm:
mock.assert_any_call(e=8)
self.assertIsInstance(cm.exception.__cause__, TypeError)
def test_mock_calls_create_autospec(self):
def f(a, b):
pass

View File

@ -235,6 +235,10 @@ Core and Builtins
Library
-------
- Issue #17015: When it has a spec, a Mock object now inspects its signature
when matching calls, so that arguments can be matched positionally or
by name.
- Issue #15633: httplib.HTTPResponse is now mark closed when the server
sends less than the advertised Content-Length.