commit 865bb685a67798eb98dcf5f3a852e08c77792998
author Lisa Roach <lisaroach14@gmail.com> Fri Sep 20 23:00:04 2019 -0700
committer Stéphane Wirtel <stephane@wirtel.be> Sat Sep 21 08:00:04 2019 +0200
tree 3540e95408f03228f7b2c9e1ac6f1e281852dc4b
parent f4e0ceb211e65dc080b64477380dfae923eb1306

[3.8] bpo-38093: Correctly returns AsyncMock for async subclasses. (GH-15947) (GH-16299)

(cherry picked from commit 8b03f943c37e07fb2394acdcfacd066647f9b1fd)

Co-authored-by: Lisa Roach <lisaroach14@gmail.com>

Lib/unittest/mock.py

diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index 9fd5c3c..0c7545b 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -988,9 +988,13 @@
         _type = type(self)
         if issubclass(_type, MagicMock) and _new_name in _async_method_magics:
             klass = AsyncMock
-        if issubclass(_type, AsyncMockMixin):
+        elif _new_name  in _sync_async_magics:
+            # Special case these ones b/c users will assume they are async,
+            # but they are actually sync (ie. __aiter__)
             klass = MagicMock
-        if not issubclass(_type, CallableMixin):
+        elif issubclass(_type, AsyncMockMixin):
+            klass = AsyncMock
+        elif not issubclass(_type, CallableMixin):
             if issubclass(_type, NonCallableMagicMock):
                 klass = MagicMock
             elif issubclass(_type, NonCallableMock) :
@@ -1867,7 +1871,7 @@
     '__reduce__', '__reduce_ex__', '__getinitargs__', '__getnewargs__',
     '__getstate__', '__setstate__', '__getformat__', '__setformat__',
     '__repr__', '__dir__', '__subclasses__', '__format__',
-    '__getnewargs_ex__', '__aenter__', '__aexit__', '__anext__', '__aiter__',
+    '__getnewargs_ex__',
 }
 
 
@@ -1886,10 +1890,12 @@
 
 # Magic methods used for async `with` statements
 _async_method_magics = {"__aenter__", "__aexit__", "__anext__"}
-# `__aiter__` is a plain function but used with async calls
-_async_magics = _async_method_magics | {"__aiter__"}
+# Magic methods that are only used with async calls but are synchronous functions themselves
+_sync_async_magics = {"__aiter__"}
+_async_magics = _async_method_magics | _sync_async_magics
 
-_all_magics = _magics | _non_defaults
+_all_sync_magics = _magics | _non_defaults
+_all_magics = _all_sync_magics | _async_magics
 
 _unsupported_magics = {
     '__getattr__', '__setattr__',