[Python-checkins] [3.8] bpo-40126: Fix reverting multiple patches in unittest.mock. (GH-19351) (GH-19483)
Serhiy Storchaka
webhook-mailer at python.org
Sun Apr 12 07:53:50 EDT 2020
https://github.com/python/cpython/commit/ee249d798ba08f065efbf4f450880a446c6ca49d
commit: ee249d798ba08f065efbf4f450880a446c6ca49d
branch: 3.8
author: Serhiy Storchaka <storchaka at gmail.com>
committer: GitHub <noreply at github.com>
date: 2020-04-12T14:53:46+03:00
summary:
[3.8] bpo-40126: Fix reverting multiple patches in unittest.mock. (GH-19351) (GH-19483)
Patcher's __exit__() is now never called if its __enter__() is failed.
Returning true from __exit__() silences now the exception.
(cherry picked from commit 4b222c9491d1700e9bdd98e6889b8d0ea1c7321e)
Co-authored-by: Serhiy Storchaka <storchaka at gmail.com>
files:
A Misc/NEWS.d/next/Library/2020-04-04-00-47-40.bpo-40126.Y-bTNP.rst
M Lib/unittest/mock.py
diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index a8f74a95791c1..3629cf61098f6 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -1229,11 +1229,6 @@ def _importer(target):
return thing
-def _is_started(patcher):
- # XXXX horrible
- return hasattr(patcher, 'is_local')
-
-
class _patch(object):
attribute_name = None
@@ -1304,14 +1299,9 @@ def decorate_class(self, klass):
@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:
@@ -1319,19 +1309,6 @@ def decoration_helper(self, patched, args, keywargs):
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):
@@ -1508,25 +1485,26 @@ def __enter__(self):
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:
@@ -1541,9 +1519,9 @@ def __exit__(self, *exc_info):
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):
@@ -1559,9 +1537,9 @@ def stop(self):
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)
diff --git a/Misc/NEWS.d/next/Library/2020-04-04-00-47-40.bpo-40126.Y-bTNP.rst b/Misc/NEWS.d/next/Library/2020-04-04-00-47-40.bpo-40126.Y-bTNP.rst
new file mode 100644
index 0000000000000..8f725cfba86e2
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-04-04-00-47-40.bpo-40126.Y-bTNP.rst
@@ -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.
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