[Python-checkins] gh-98086: Now ``patch.dict`` can decorate async functions (#98095)

[cjw296]

https://github.com/python/cpython/commit/67b4d2772c5124b908f8ed9b13166a79bbeb88d2
commit: 67b4d2772c5124b908f8ed9b13166a79bbeb88d2
branch: main
author: Nikita Sobolev <mail at sobolevn.me>
committer: cjw296 <chris at withers.org>
date: 2022-11-11T08:04:30Z
summary:

gh-98086: Now ``patch.dict`` can decorate async functions (#98095)

files:
A Misc/NEWS.d/next/Library/2022-10-08-19-39-27.gh-issue-98086.y---WC.rst
M Lib/test/test_unittest/testmock/testasync.py
M Lib/unittest/mock.py

diff --git a/Lib/test/test_unittest/testmock/testasync.py b/Lib/test/test_unittest/testmock/testasync.py
index 1bab671acdef..e05a22861d47 100644
--- a/Lib/test/test_unittest/testmock/testasync.py
+++ b/Lib/test/test_unittest/testmock/testasync.py
@@ -149,6 +149,23 @@ async def test_async():
 
         run(test_async())
 
+    def test_patch_dict_async_def(self):
+        foo = {'a': 'a'}
+        @patch.dict(foo, {'a': 'b'})
+        async def test_async():
+            self.assertEqual(foo['a'], 'b')
+
+        self.assertTrue(iscoroutinefunction(test_async))
+        run(test_async())
+
+    def test_patch_dict_async_def_context(self):
+        foo = {'a': 'a'}
+        async def test_async():
+            with patch.dict(foo, {'a': 'b'}):
+                self.assertEqual(foo['a'], 'b')
+
+        run(test_async())
+
 
 class AsyncMockTest(unittest.TestCase):
     def test_iscoroutinefunction_default(self):
diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index 096b1a571473..a273753d6a0a 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -1809,6 +1809,12 @@ def __init__(self, in_dict, values=(), clear=False, **kwargs):
     def __call__(self, f):
         if isinstance(f, type):
             return self.decorate_class(f)
+        if inspect.iscoroutinefunction(f):
+            return self.decorate_async_callable(f)
+        return self.decorate_callable(f)
+
+
+    def decorate_callable(self, f):
         @wraps(f)
         def _inner(*args, **kw):
             self._patch_dict()
@@ -1820,6 +1826,18 @@ def _inner(*args, **kw):
         return _inner
 
 
+    def decorate_async_callable(self, f):
+        @wraps(f)
+        async def _inner(*args, **kw):
+            self._patch_dict()
+            try:
+                return await f(*args, **kw)
+            finally:
+                self._unpatch_dict()
+
+        return _inner
+
+
     def decorate_class(self, klass):
         for attr in dir(klass):
             attr_value = getattr(klass, attr)
diff --git a/Misc/NEWS.d/next/Library/2022-10-08-19-39-27.gh-issue-98086.y---WC.rst b/Misc/NEWS.d/next/Library/2022-10-08-19-39-27.gh-issue-98086.y---WC.rst
new file mode 100644
index 000000000000..f4a1d272e13b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-10-08-19-39-27.gh-issue-98086.y---WC.rst
@@ -0,0 +1 @@
+Make sure ``patch.dict()`` can be applied on async functions.