update_wrapper() updates __annotate__, not __annotations__

Author: JelleZijlstra

Lib/functools.py

@@ -31,7 +31,7 @@
 # wrapper functions that can handle naive introspection
 
 WRAPPER_ASSIGNMENTS = ('__module__', '__name__', '__qualname__', '__doc__',
-                       '__annotations__', '__type_params__')
+                       '__annotate__', '__type_params__')
 WRAPPER_UPDATES = ('__dict__',)
 def update_wrapper(wrapper,
                    wrapped,

Lib/test/test_functools.py

@@ -718,6 +718,24 @@ def wrapper(*args): pass
         self.assertEqual(wrapper.__annotations__, {})
         self.assertEqual(wrapper.__type_params__, ())
 
+    def test_update_wrapper_annotations(self):
+        def inner(x: int): pass
+        def wrapper(*args): pass
+
+        functools.update_wrapper(wrapper, inner)
+        self.assertEqual(wrapper.__annotations__, {'x': int})
+        self.assertIs(wrapper.__annotate__, inner.__annotate__)
+
+        def with_forward_ref(x: undefined): pass
+        def wrapper(*args): pass
+
+        functools.update_wrapper(wrapper, with_forward_ref)
+
+        self.assertIs(wrapper.__annotate__, with_forward_ref.__annotate__)
+
+        undefined = str
+        self.assertEqual(wrapper.__annotations__, {'x': undefined})
+
 
 class TestWraps(TestUpdateWrapper):