diff --git a/Lib/test/test_unittest/testmock/testmagicmethods.py b/Lib/test/test_unittest/testmock/testmagicmethods.py index a4feae7e9d3b73..a8b52ce48716f7 100644 --- a/Lib/test/test_unittest/testmock/testmagicmethods.py +++ b/Lib/test/test_unittest/testmock/testmagicmethods.py @@ -331,6 +331,45 @@ def test_magic_methods_fspath(self): self.assertEqual(os.fspath(mock), expected_path) mock.__fspath__.assert_called_once() + def test_magic_mock_does_not_reset_magic_returns(self): + # https://github.com/python/cpython/issues/123934 + for reset in (True, False): + with self.subTest(reset=reset): + mm = MagicMock() + self.assertIs(type(mm.__str__()), str) + mm.__str__.assert_called_once() + + self.assertIs(type(mm.__hash__()), int) + mm.__hash__.assert_called_once() + + for _ in range(3): + # Repeat reset several times to be sure: + mm.reset_mock(return_value=reset) + + self.assertIs(type(mm.__str__()), str) + mm.__str__.assert_called_once() + + self.assertIs(type(mm.__hash__()), int) + mm.__hash__.assert_called_once() + + def test_magic_mock_resets_manual_mocks(self): + mm = MagicMock() + mm.__iter__ = MagicMock(return_value=iter([1])) + mm.custom = MagicMock(return_value=2) + self.assertEqual(list(iter(mm)), [1]) + self.assertEqual(mm.custom(), 2) + + mm.reset_mock(return_value=True) + self.assertEqual(list(iter(mm)), []) + self.assertIsInstance(mm.custom(), MagicMock) + + def test_magic_mock_resets_manual_mocks_empty_iter(self): + mm = MagicMock() + mm.__iter__.return_value = [] + self.assertEqual(list(iter(mm)), []) + + mm.reset_mock(return_value=True) + self.assertEqual(list(iter(mm)), []) def test_magic_methods_and_spec(self): class Iterable(object): diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py index f7ab4a5ea22169..da7da87748ffc1 100644 --- a/Lib/unittest/mock.py +++ b/Lib/unittest/mock.py @@ -628,7 +628,7 @@ def __set_side_effect(self, value): side_effect = property(__get_side_effect, __set_side_effect) - def reset_mock(self, visited=None,*, return_value=False, side_effect=False): + def reset_mock(self, visited=None, *, return_value=False, side_effect=False): "Restore the mock object to its initial state." if visited is None: visited = [] @@ -2219,6 +2219,17 @@ def mock_add_spec(self, spec, spec_set=False): self._mock_add_spec(spec, spec_set) self._mock_set_magics() + def reset_mock(self, /, *args, return_value=False, **kwargs): + if ( + return_value + and self._mock_name + and _is_magic(self._mock_name) + ): + # Don't reset return values for magic methods, + # otherwise `m.__str__` will start + # to return `MagicMock` instances, instead of `str` instances. + return_value = False + super().reset_mock(*args, return_value=return_value, **kwargs) class MagicProxy(Base): diff --git a/Misc/NEWS.d/next/Library/2024-09-13-10-34-19.gh-issue-123934.yMe7mL.rst b/Misc/NEWS.d/next/Library/2024-09-13-10-34-19.gh-issue-123934.yMe7mL.rst new file mode 100644 index 00000000000000..cec7741bcabbda --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-09-13-10-34-19.gh-issue-123934.yMe7mL.rst @@ -0,0 +1,2 @@ +Fix :class:`unittest.mock.MagicMock` reseting magic methods return values +after ``.reset_mock(return_value=True)`` was called.