[Python-checkins] gh-96478: Test `@overload` on C functions (GH-96479)

[miss-islington]

https://github.com/python/cpython/commit/2a5e3337367b4636802697f8e5c78bc5382ec8cb
commit: 2a5e3337367b4636802697f8e5c78bc5382ec8cb
branch: 3.11
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2022-09-20T18:36:23-07:00
summary:

gh-96478: Test `@overload` on C functions (GH-96479)


Co-authored-by: Alex Waygood <Alex.Waygood at Gmail.com>
(cherry picked from commit f177f6f29b069f522a0b3ba44eaae19852b6d2b0)

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

files:
M Lib/test/test_typing.py

diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index 776a6f003c0..7df7e3ceb68 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -4379,6 +4379,20 @@ def blah():
 
         blah()
 
+    @patch("typing._overload_registry",
+        defaultdict(lambda: defaultdict(dict)))
+    def test_overload_on_compiled_functions(self):
+        # The registry starts out empty:
+        self.assertEqual(typing._overload_registry, {})
+
+        # This should just not fail:
+        overload(sum)
+        overload(print)
+
+        # No overloads are recorded (but, it still has a side-effect):
+        self.assertEqual(typing.get_overloads(sum), [])
+        self.assertEqual(typing.get_overloads(print), [])
+
     def set_up_overloads(self):
         def blah():
             pass