From 02b84cb1b4f5407309c81c8b1ae0397355d6e568 Mon Sep 17 00:00:00 2001 From: Xtreak Date: Fri, 29 Mar 2019 02:38:43 +0530 Subject: [PATCH] bpo-36366: Return None on stopping unstarted patch object (GH-12472) Return None after calling unittest.mock.patch.object.stop() regardless of whether the object was started. This makes the method idempotent. https://bugs.python.org/issue36366 --- Lib/unittest/mock.py | 2 +- Lib/unittest/test/testmock/testpatch.py | 12 ++++++++++-- .../Library/2019-03-20-15-13-18.bpo-36366.n0eav_.rst | 4 ++++ 3 files changed, 15 insertions(+), 3 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2019-03-20-15-13-18.bpo-36366.n0eav_.rst diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py index fdde16be03..8684f1dfa5 100644 --- a/Lib/unittest/mock.py +++ b/Lib/unittest/mock.py @@ -1398,7 +1398,7 @@ class _patch(object): def __exit__(self, *exc_info): """Undo the patch.""" if not _is_started(self): - raise RuntimeError('stop called on unstarted patcher') + return if self.is_local and self.temp_original is not DEFAULT: setattr(self.target, self.attribute, self.temp_original) diff --git a/Lib/unittest/test/testmock/testpatch.py b/Lib/unittest/test/testmock/testpatch.py index c484adb605..2c14360b2d 100644 --- a/Lib/unittest/test/testmock/testpatch.py +++ b/Lib/unittest/test/testmock/testpatch.py @@ -772,10 +772,18 @@ class PatchTest(unittest.TestCase): def test_stop_without_start(self): + # bpo-36366: calling stop without start will return None. patcher = patch(foo_name, 'bar', 3) + self.assertIsNone(patcher.stop()) - # calling stop without start used to produce a very obscure error - self.assertRaises(RuntimeError, patcher.stop) + + def test_stop_idempotent(self): + # bpo-36366: calling stop on an already stopped patch will return None. + patcher = patch(foo_name, 'bar', 3) + + patcher.start() + patcher.stop() + self.assertIsNone(patcher.stop()) def test_patchobject_start_stop(self): diff --git a/Misc/NEWS.d/next/Library/2019-03-20-15-13-18.bpo-36366.n0eav_.rst b/Misc/NEWS.d/next/Library/2019-03-20-15-13-18.bpo-36366.n0eav_.rst new file mode 100644 index 0000000000..a43504839c --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-03-20-15-13-18.bpo-36366.n0eav_.rst @@ -0,0 +1,4 @@ +Calling ``stop()`` on an unstarted or stopped :func:`unittest.mock.patch` +object will now return `None` instead of raising :exc:`RuntimeError`, +making the method idempotent. +Patch byKarthikeyan Singaravelan. -- 2.50.1