bpo-45280: Add test for empty `NamedTuple` in `test_typing` (GH-28559) (GH-28571)

Co-authored-by: Dong-hee Na <donghee.na92@gmail.com>
(cherry picked from commit f56268a2cd38b3fe2be1e4361d3d8b581e73559b)

Co-authored-by: Nikita Sobolev <mail@sobolevn.me>

1 files changed, 13 insertions, 0 deletions

diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index 4f250f2..762c0cc 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -4081,6 +4081,19 @@ class NamedTupleTests(BaseTestCase):
         self.assertEqual(a.typename, 'foo')
         self.assertEqual(a.fields, [('bar', tuple)])
 
+    def test_empty_namedtuple(self):
+        NT = NamedTuple('NT')
+
+        class CNT(NamedTuple):
+            pass  # empty body
+
+        for struct in [NT, CNT]:
+            with self.subTest(struct=struct):
+                self.assertEqual(struct._fields, ())
+                self.assertEqual(struct._field_defaults, {})
+                self.assertEqual(struct.__annotations__, {})
+                self.assertIsInstance(struct(), struct)
+
     def test_namedtuple_errors(self):
         with self.assertRaises(TypeError):
             NamedTuple.__new__()