bpo-42128: Structural Pattern Matching (PEP 634) (GH-22917)

Co-authored-by: Guido van Rossum <guido@python.org>
Co-authored-by: Talin <viridia@gmail.com>
Co-authored-by: Pablo Galindo <pablogsal@gmail.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/Lib/test/test_dataclasses.py b/Lib/test/test_dataclasses.py
index 8887eb6461b..0bfed41b369 100644
--- a/Lib/test/test_dataclasses.py
+++ b/Lib/test/test_dataclasses.py
@@ -3375,5 +3375,21 @@ class TestAbstract(unittest.TestCase):
         self.assertRaisesRegex(TypeError, msg, Date)
 
 
+class TestMatchArgs(unittest.TestCase):
+    def test_match_args(self):
+        @dataclass
+        class C:
+            a: int
+        self.assertEqual(C(42).__match_args__, ('a',))
+
+    def test_explicit_match_args(self):
+        ma = []
+        @dataclass
+        class C:
+            a: int
+            __match_args__ = ma
+        self.assertIs(C(42).__match_args__, ma)
+
+
 if __name__ == '__main__':
     unittest.main()