1 files changed, 21 insertions, 0 deletions
diff --git a/Lib/test/test_unittest/testmock/testhelpers.py b/Lib/test/test_unittest/testmock/testhelpers.py
index d1e48bde982..0e82c723ec3 100644
--- a/Lib/test/test_unittest/testmock/testhelpers.py
+++ b/Lib/test/test_unittest/testmock/testhelpers.py
@@ -1050,6 +1050,7 @@ class SpecSignatureTest(unittest.TestCase):
             create_autospec(WithPostInit()),
         ]:
             with self.subTest(mock=mock):
+                self.assertIsInstance(mock, WithPostInit)
                 self.assertIsInstance(mock.a, int)
                 self.assertIsInstance(mock.b, int)
 
@@ -1072,6 +1073,7 @@ class SpecSignatureTest(unittest.TestCase):
             create_autospec(WithDefault(1)),
         ]:
             with self.subTest(mock=mock):
+                self.assertIsInstance(mock, WithDefault)
                 self.assertIsInstance(mock.a, int)
                 self.assertIsInstance(mock.b, int)
 
@@ -1087,6 +1089,7 @@ class SpecSignatureTest(unittest.TestCase):
             create_autospec(WithMethod(1)),
         ]:
             with self.subTest(mock=mock):
+                self.assertIsInstance(mock, WithMethod)
                 self.assertIsInstance(mock.a, int)
                 mock.b.assert_not_called()
 
@@ -1102,11 +1105,29 @@ class SpecSignatureTest(unittest.TestCase):
             create_autospec(WithNonFields(1)),
         ]:
             with self.subTest(mock=mock):
+                self.assertIsInstance(mock, WithNonFields)
                 with self.assertRaisesRegex(AttributeError, msg):
                     mock.a
                 with self.assertRaisesRegex(AttributeError, msg):
                     mock.b
 
+    def test_dataclass_special_attrs(self):
+        @dataclass
+        class Description:
+            name: str
+
+        for mock in [
+            create_autospec(Description, instance=True),
+            create_autospec(Description(1)),
+        ]:
+            with self.subTest(mock=mock):
+                self.assertIsInstance(mock, 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):
 
     def test_args_list_contains_call_list(self):