From ee3259a1325c8d9c2c746dc2a97e85ca037e3884 Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Thu, 12 Jun 2025 19:35:31 +0200
Subject: [PATCH] Extend dataclass mock_methods

---
 Lib/test/test_unittest/testmock/testhelpers.py |  2 ++
 Lib/unittest/mock.py                           | 15 +++++++++------
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/Lib/test/test_unittest/testmock/testhelpers.py b/Lib/test/test_unittest/testmock/testhelpers.py
index 7dab2e05679ab7..0e82c723ec3eaa 100644
--- a/Lib/test/test_unittest/testmock/testhelpers.py
+++ b/Lib/test/test_unittest/testmock/testhelpers.py
@@ -1125,6 +1125,8 @@ class Description:
                 self.assertIs(mock.__class__, Description)
                 self.assertIsInstance(mock.__dataclass_fields__, MagicMock)
                 self.assertIsInstance(mock.__dataclass_params__, MagicMock)
+                self.assertIsInstance(mock.__match_args__, MagicMock)
+                self.assertIsInstance(mock.__hash__, MagicMock)
 
 class TestCallList(unittest.TestCase):
 
diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index 560ff56815a379..e370aa48b7c703 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -569,6 +569,11 @@ def _mock_add_spec(self, spec, spec_set, _spec_as_instance=False,
         __dict__['_mock_methods'] = spec
         __dict__['_spec_asyncs'] = _spec_asyncs
 
+    def _mock_extend_spec_methods(self, spec_methods):
+        methods = self.__dict__.get('_mock_methods') or []
+        methods.extend(spec_methods)
+        self.__dict__['_mock_methods'] = methods
+
     def __get_return_value(self):
         ret = self._mock_return_value
         if self._mock_delegate is not None:
@@ -2766,17 +2771,15 @@ def create_autospec(spec, spec_set=False, instance=False, _parent=None,
         raise InvalidSpecError(f'Cannot autospec a Mock object. '
                                f'[object={spec!r}]')
     is_async_func = _is_async_func(spec)
+    _kwargs = {'spec': spec}
 
     entries = [(entry, _missing) for entry in dir(spec)]
     if is_type and instance and is_dataclass(spec):
+        is_dataclass_spec = True
         dataclass_fields = fields(spec)
         entries.extend((f.name, f.type) for f in dataclass_fields)
-        spec_list = [f.name for f in dataclass_fields]
-        spec_list.extend(['__dataclass_fields__', '__dataclass_params__'])
-        _kwargs = {'spec': spec_list}  # we set `__class__` further
-        is_dataclass_spec = True
+        dataclass_spec_list = [f.name for f in dataclass_fields]
     else:
-        _kwargs = {'spec': spec}
         is_dataclass_spec = False
 
     if spec_set:
@@ -2815,7 +2818,7 @@ def create_autospec(spec, spec_set=False, instance=False, _parent=None,
     mock = Klass(parent=_parent, _new_parent=_parent, _new_name=_new_name,
                  name=_name, **_kwargs)
     if is_dataclass_spec:
-        mock.__class__ = spec  # we need this for `isinstance` to work
+        mock._mock_extend_spec_methods(dataclass_spec_list)
 
     if isinstance(spec, FunctionTypes):
         # should only happen at the top level because we don't