bpo-32299: Return patched dict when using patch.dict as a context manager (GH-11062)
diff --git a/Doc/library/unittest.mock.rst b/Doc/library/unittest.mock.rst
index 36ac24a..da6cdfe 100644
--- a/Doc/library/unittest.mock.rst
+++ b/Doc/library/unittest.mock.rst
@@ -1556,15 +1556,24 @@
decorator. When used as a class decorator :func:`patch.dict` honours
``patch.TEST_PREFIX`` for choosing which methods to wrap.
+ .. versionchanged:: 3.8
+
+ :func:`patch.dict` now returns the patched dictionary when used as a context
+ manager.
+
:func:`patch.dict` can be used to add members to a dictionary, or simply let a test
change a dictionary, and ensure the dictionary is restored when the test
ends.
>>> foo = {}
- >>> with patch.dict(foo, {'newkey': 'newvalue'}):
+ >>> with patch.dict(foo, {'newkey': 'newvalue'}) as patched_foo:
... assert foo == {'newkey': 'newvalue'}
+ ... assert patched_foo == {'newkey': 'newvalue'}
+ ... # You can add, update or delete keys of foo (or patched_foo, it's the same dict)
+ ... patched_foo['spam'] = 'eggs'
...
>>> assert foo == {}
+ >>> assert patched_foo == {}
>>> import os
>>> with patch.dict('os.environ', {'newkey': 'newvalue'}):
diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index fac4535..055fbb3 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -1730,6 +1730,7 @@
def __enter__(self):
"""Patch the dict."""
self._patch_dict()
+ return self.in_dict
def _patch_dict(self):
diff --git a/Lib/unittest/test/testmock/testpatch.py b/Lib/unittest/test/testmock/testpatch.py
index 3295c5b..27914a9 100644
--- a/Lib/unittest/test/testmock/testpatch.py
+++ b/Lib/unittest/test/testmock/testpatch.py
@@ -619,6 +619,13 @@
self.assertEqual(foo.values, original)
+ def test_patch_dict_as_context_manager(self):
+ foo = {'a': 'b'}
+ with patch.dict(foo, a='c') as patched:
+ self.assertEqual(patched, {'a': 'c'})
+ self.assertEqual(foo, {'a': 'b'})
+
+
def test_name_preserved(self):
foo = {}
diff --git a/Misc/NEWS.d/next/Library/2017-12-13-17-49-56.bpo-32299.eqAPWs.rst b/Misc/NEWS.d/next/Library/2017-12-13-17-49-56.bpo-32299.eqAPWs.rst
new file mode 100644
index 0000000..4e1afa9
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2017-12-13-17-49-56.bpo-32299.eqAPWs.rst
@@ -0,0 +1,2 @@
+Changed :func:`unittest.mock.patch.dict` to return the patched
+dictionary when used as context manager. Patch by Vadim Tsander.