gh-96478: Test @overload on C functions

sobolevn · sobolevn · commit 189797f3c7d1 · 2022-09-01T17:07:24.000+03:00
diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
@@ -4391,6 +4391,21 @@ 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), [])
+        self.assertNotEqual(typing._overload_registry, {})
+
     def set_up_overloads(self):
         def blah():
             pass
