From 7f4762ac053f36980604497a850902fce689d124 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Thu, 26 Sep 2024 23:15:28 +0200
Subject: [PATCH 1/2] gh-89683: add tests for `deepcopy` on frozen dataclasses
 (gh-123098)
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Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Co-authored-by: Eric V. Smith <ericvsmith@users.noreply.github.com>
---
 Lib/test/test_dataclasses/__init__.py | 45 ++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_dataclasses/__init__.py b/Lib/test/test_dataclasses/__init__.py
index 260e0d74917181..cdb46a6c9f5846 100644
--- a/Lib/test/test_dataclasses/__init__.py
+++ b/Lib/test/test_dataclasses/__init__.py
@@ -17,7 +17,8 @@
 from typing import ClassVar, Any, List, Union, Tuple, Dict, Generic, TypeVar, Optional, Protocol, DefaultDict
 from typing import get_type_hints
 from collections import deque, OrderedDict, namedtuple, defaultdict
-from functools import total_ordering
+from copy import deepcopy
+from functools import total_ordering, wraps
 
 import typing       # Needed for the string "typing.ClassVar[int]" to work as an annotation.
 import dataclasses  # Needed for the string "dataclasses.InitVar[int]" to work as an annotation.
@@ -3175,6 +3176,48 @@ class C:
         with self.assertRaisesRegex(TypeError, 'unhashable type'):
             hash(C({}))
 
+    def test_frozen_deepcopy_without_slots(self):
+        # see: https://github.com/python/cpython/issues/89683
+        @dataclass(frozen=True, slots=False)
+        class C:
+            s: str
+
+        c = C('hello')
+        self.assertEqual(deepcopy(c), c)
+
+    def test_frozen_deepcopy_with_slots(self):
+        # see: https://github.com/python/cpython/issues/89683
+        with self.subTest('generated __slots__'):
+            @dataclass(frozen=True, slots=True)
+            class C:
+                s: str
+
+            c = C('hello')
+            self.assertEqual(deepcopy(c), c)
+
+        with self.subTest('user-defined __slots__ and no __{get,set}state__'):
+            @dataclass(frozen=True, slots=False)
+            class C:
+                __slots__ = ('s',)
+                s: str
+
+            # with user-defined slots, __getstate__ and __setstate__ are not
+            # automatically added, hence the error
+            err = r"^cannot\ assign\ to\ field\ 's'$"
+            self.assertRaisesRegex(FrozenInstanceError, err, deepcopy, C(''))
+
+        with self.subTest('user-defined __slots__ and __{get,set}state__'):
+            @dataclass(frozen=True, slots=False)
+            class C:
+                __slots__ = ('s',)
+                __getstate__ = dataclasses._dataclass_getstate
+                __setstate__ = dataclasses._dataclass_setstate
+
+                s: str
+
+            c = C('hello')
+            self.assertEqual(deepcopy(c), c)
+
 
 class TestSlots(unittest.TestCase):
     def test_simple(self):

From 6868aa3f6e5304ac8068c9c8facf39346af619f8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Fri, 27 Sep 2024 18:32:32 +0200
Subject: [PATCH 2/2] Update Lib/test/test_dataclasses/__init__.py

---
 Lib/test/test_dataclasses/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/test/test_dataclasses/__init__.py b/Lib/test/test_dataclasses/__init__.py
index cdb46a6c9f5846..54e481132373ba 100644
--- a/Lib/test/test_dataclasses/__init__.py
+++ b/Lib/test/test_dataclasses/__init__.py
@@ -18,7 +18,7 @@
 from typing import get_type_hints
 from collections import deque, OrderedDict, namedtuple, defaultdict
 from copy import deepcopy
-from functools import total_ordering, wraps
+from functools import total_ordering
 
 import typing       # Needed for the string "typing.ClassVar[int]" to work as an annotation.
 import dataclasses  # Needed for the string "dataclasses.InitVar[int]" to work as an annotation.