bpo-40126: Fix reverting multiple patches in unittest.mock. (GH-19351)

Patcher's __exit__() is now never called if its __enter__() is failed.
Returning true from __exit__() silences now the exception.
This commit is contained in:
Serhiy Storchaka 2020-04-11 10:59:24 +03:00 committed by GitHub
parent cd8295ff75
commit 4b222c9491
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GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 29 additions and 48 deletions

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@ -1241,11 +1241,6 @@ def _importer(target):
return thing
def _is_started(patcher):
# XXXX horrible
return hasattr(patcher, 'is_local')
class _patch(object):
attribute_name = None
@ -1316,14 +1311,9 @@ class _patch(object):
@contextlib.contextmanager
def decoration_helper(self, patched, args, keywargs):
extra_args = []
entered_patchers = []
patching = None
exc_info = tuple()
try:
with contextlib.ExitStack() as exit_stack:
for patching in patched.patchings:
arg = patching.__enter__()
entered_patchers.append(patching)
arg = exit_stack.enter_context(patching)
if patching.attribute_name is not None:
keywargs.update(arg)
elif patching.new is DEFAULT:
@ -1331,19 +1321,6 @@ class _patch(object):
args += tuple(extra_args)
yield (args, keywargs)
except:
if (patching not in entered_patchers and
_is_started(patching)):
# the patcher may have been started, but an exception
# raised whilst entering one of its additional_patchers
entered_patchers.append(patching)
# Pass the exception to __exit__
exc_info = sys.exc_info()
# re-raise the exception
raise
finally:
for patching in reversed(entered_patchers):
patching.__exit__(*exc_info)
def decorate_callable(self, func):
@ -1520,25 +1497,26 @@ class _patch(object):
self.temp_original = original
self.is_local = local
setattr(self.target, self.attribute, new_attr)
if self.attribute_name is not None:
extra_args = {}
if self.new is DEFAULT:
extra_args[self.attribute_name] = new
for patching in self.additional_patchers:
arg = patching.__enter__()
if patching.new is DEFAULT:
extra_args.update(arg)
return extra_args
return new
self._exit_stack = contextlib.ExitStack()
try:
setattr(self.target, self.attribute, new_attr)
if self.attribute_name is not None:
extra_args = {}
if self.new is DEFAULT:
extra_args[self.attribute_name] = new
for patching in self.additional_patchers:
arg = self._exit_stack.enter_context(patching)
if patching.new is DEFAULT:
extra_args.update(arg)
return extra_args
return new
except:
if not self.__exit__(*sys.exc_info()):
raise
def __exit__(self, *exc_info):
"""Undo the patch."""
if not _is_started(self):
return
if self.is_local and self.temp_original is not DEFAULT:
setattr(self.target, self.attribute, self.temp_original)
else:
@ -1553,9 +1531,9 @@ class _patch(object):
del self.temp_original
del self.is_local
del self.target
for patcher in reversed(self.additional_patchers):
if _is_started(patcher):
patcher.__exit__(*exc_info)
exit_stack = self._exit_stack
del self._exit_stack
return exit_stack.__exit__(*exc_info)
def start(self):
@ -1571,9 +1549,9 @@ class _patch(object):
self._active_patches.remove(self)
except ValueError:
# If the patch hasn't been started this will fail
pass
return None
return self.__exit__()
return self.__exit__(None, None, None)
@ -1873,9 +1851,9 @@ class _patch_dict(object):
_patch._active_patches.remove(self)
except ValueError:
# If the patch hasn't been started this will fail
pass
return None
return self.__exit__()
return self.__exit__(None, None, None)
def _clear_dict(in_dict):

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@ -774,7 +774,7 @@ class PatchTest(unittest.TestCase):
d = {'foo': 'bar'}
original = d.copy()
patcher = patch.dict(d, [('spam', 'eggs')], clear=True)
self.assertEqual(patcher.stop(), False)
self.assertFalse(patcher.stop())
self.assertEqual(d, original)

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@ -0,0 +1,3 @@
Fixed reverting multiple patches in unittest.mock. Patcher's ``__exit__()``
is now never called if its ``__enter__()`` is failed. Returning true from
``__exit__()`` silences now the exception.