[Python-checkins] cpython: Issue #17015: When it has a spec, a Mock object now inspects its signature when
antoine.pitrou
python-checkins at python.org
Sun Feb 3 00:28:27 CET 2013
http://hg.python.org/cpython/rev/b888c9043566
changeset: 81960:b888c9043566
user: Antoine Pitrou <solipsis at pitrou.net>
date: Sun Feb 03 00:23:58 2013 +0100
summary:
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.
files:
Doc/library/unittest.mock-examples.rst | 14 +
Doc/library/unittest.mock.rst | 22 +-
Lib/unittest/mock.py | 182 ++++++---
Lib/unittest/test/testmock/testhelpers.py | 59 ++-
Lib/unittest/test/testmock/testmock.py | 125 ++++++
Misc/NEWS | 4 +
6 files changed, 316 insertions(+), 90 deletions(-)
diff --git a/Doc/library/unittest.mock-examples.rst b/Doc/library/unittest.mock-examples.rst
--- a/Doc/library/unittest.mock-examples.rst
+++ b/Doc/library/unittest.mock-examples.rst
@@ -277,6 +277,20 @@
...
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`.
diff --git a/Doc/library/unittest.mock.rst b/Doc/library/unittest.mock.rst
--- a/Doc/library/unittest.mock.rst
+++ b/Doc/library/unittest.mock.rst
@@ -264,7 +264,6 @@
<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 @@
...
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)
diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -27,7 +27,7 @@
import inspect
import pprint
import sys
-from functools import wraps
+from functools import wraps, partial
BaseExceptions = (BaseException,)
@@ -66,55 +66,45 @@
)
-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 func, inspect.signature(sig_func)
+ except ValueError:
+ # Certain callable types are not supported by inspect.signature()
+ return None
+
+
+def _check_signature(func, mock, skipfirst, instance=False):
+ sig = _get_signature_object(func, instance, skipfirst)
+ if sig is None:
return
-
- 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
-
-
-def _check_signature(func, mock, skipfirst, instance=False):
- if not _callable(func):
- 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 @@
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 @@
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 @@
if spec_set is not None:
spec = spec_set
spec_set = True
-
- self._mock_add_spec(spec, spec_set)
+ 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
@@ -428,20 +417,26 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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)
+ _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,
@@ -2114,6 +2145,10 @@
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 @@
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 @@
type(ANY.__eq__),
)
+MethodWrapperTypes = (
+ type(ANY.__eq__.__get__),
+)
+
file_spec = None
diff --git a/Lib/unittest/test/testmock/testhelpers.py b/Lib/unittest/test/testmock/testhelpers.py
--- a/Lib/unittest/test/testmock/testhelpers.py
+++ b/Lib/unittest/test/testmock/testhelpers.py
@@ -337,9 +337,10 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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)
diff --git a/Lib/unittest/test/testmock/testmock.py b/Lib/unittest/test/testmock/testmock.py
--- a/Lib/unittest/test/testmock/testmock.py
+++ b/Lib/unittest/test/testmock/testmock.py
@@ -25,6 +25,18 @@
__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 @@
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 @@
)
+ 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 @@
)
+ 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 @@
)
+ 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
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -235,6 +235,10 @@
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.
--
Repository URL: http://hg.python.org/cpython
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