From: sobolevn <mail@sobolevn.me>
Date: Tue, 5 May 2026 14:58:49 +0000 (+0300)
Subject: gh-149410: Test that `typing.NoDefault` is final (#149411)
X-Git-Tag: v3.15.0b1~36
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bad9296fb0424bc480fa0ecfd2d60f73c33358f5;p=thirdparty%2FPython%2Fcpython.git

gh-149410: Test that `typing.NoDefault` is final (#149411)
---

diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index 5d19e3706802..ad644bb31288 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -11131,6 +11131,10 @@ class NoDefaultTests(BaseTestCase):
         with self.assertRaises(AttributeError):
             type(NoDefault).foo
 
+    def test_no_subclassing(self):
+        with self.assertRaises(TypeError):
+            class Test(type(NoDefault)): ...
+
 
 class AllTests(BaseTestCase):
     """Tests for __all__."""