commit df9f633f94e97fc43e0235cb2be076491ea7f67f
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Tue Jul 10 00:48:57 2018 -0700
committer GitHub <noreply@github.com> Tue Jul 10 00:48:57 2018 -0700
tree 7f9eb16b48e04c3cf717003bdfc4a95b7c17d70b
parent c3bdea4c6ca8861e144802b8e319fe266941790f

bpo-33967: Fix singledispatch raised IndexError when no args (GH-8184)

(cherry picked from commit 445f1b35ce8461268438c8a6b327ddc764287e05)

Co-authored-by: Dong-hee Na <donghee.na92@gmail.com>

Lib/test/test_functools.py

diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index 2245b97..e325480 100644
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -2187,6 +2187,13 @@
         ))
         self.assertTrue(str(exc.exception).endswith(msg_suffix))
 
+    def test_invalid_positional_argument(self):
+        @functools.singledispatch
+        def f(*args):
+            pass
+        msg = 'f requires at least 1 positional argument'
+        with self.assertRaisesRegexp(TypeError, msg):
+            f()
 
 if __name__ == '__main__':
     unittest.main()