[Python-checkins] bpo-37972: unittest.mock._Call now passes on __getitem__ to the __getattr__ chaining so that call() can be subscriptable (GH-15565) (GH-15965)

[Michael Foord]

https://github.com/python/cpython/commit/db0d8a5b2c803d30d9df436e00b6627ec8e09a13
commit: db0d8a5b2c803d30d9df436e00b6627ec8e09a13
branch: 3.8
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: Michael Foord <voidspace at users.noreply.github.com>
date: 2019-09-12T12:52:49+02:00
summary:

bpo-37972: unittest.mock._Call now passes on __getitem__ to the __getattr__ chaining so that call() can be subscriptable (GH-15565) (GH-15965)

* bpo-37972: unittest.mock._Call now passes on __getitem__ to the __getattr__ chaining so that call() can be subscriptable

* 📜🤖 Added by blurb_it.

* Update 2019-08-28-21-40-12.bpo-37972.kP-n4L.rst

added name of the contributor

* bpo-37972: made all dunder methods chainable for _Call

* bpo-37972: delegate only attributes of tuple instead to __getattr__
(cherry picked from commit 72c359912d36705a94fca8b63d80451905a14ae4)

Co-authored-by: blhsing <github at ydooby.com>

files:
A Misc/NEWS.d/next/Library/2019-08-28-21-40-12.bpo-37972.kP-n4L.rst
M Lib/unittest/mock.py
M Lib/unittest/test/testmock/testhelpers.py

diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index 7bfbfc92eef9..cbc4d76b8513 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -2464,6 +2464,12 @@ def __getattr__(self, attr):
         return _Call(name=name, parent=self, from_kall=False)
 
 
+    def __getattribute__(self, attr):
+        if attr in tuple.__dict__:
+            raise AttributeError
+        return tuple.__getattribute__(self, attr)
+
+
     def count(self, /, *args, **kwargs):
         return self.__getattr__('count')(*args, **kwargs)
 
diff --git a/Lib/unittest/test/testmock/testhelpers.py b/Lib/unittest/test/testmock/testhelpers.py
index 301bca430c13..f3c7acb98c21 100644
--- a/Lib/unittest/test/testmock/testhelpers.py
+++ b/Lib/unittest/test/testmock/testhelpers.py
@@ -334,6 +334,26 @@ def test_call_with_name(self):
         self.assertEqual(_Call((('bar', 'barz'),),)[0], '')
         self.assertEqual(_Call((('bar', 'barz'), {'hello': 'world'}),)[0], '')
 
+    def test_dunder_call(self):
+        m = MagicMock()
+        m().foo()['bar']()
+        self.assertEqual(
+            m.mock_calls,
+            [call(), call().foo(), call().foo().__getitem__('bar'), call().foo().__getitem__()()]
+        )
+        m = MagicMock()
+        m().foo()['bar'] = 1
+        self.assertEqual(
+            m.mock_calls,
+            [call(), call().foo(), call().foo().__setitem__('bar', 1)]
+        )
+        m = MagicMock()
+        iter(m().foo())
+        self.assertEqual(
+            m.mock_calls,
+            [call(), call().foo(), call().foo().__iter__()]
+        )
+
 
 class SpecSignatureTest(unittest.TestCase):
 
diff --git a/Misc/NEWS.d/next/Library/2019-08-28-21-40-12.bpo-37972.kP-n4L.rst b/Misc/NEWS.d/next/Library/2019-08-28-21-40-12.bpo-37972.kP-n4L.rst
new file mode 100644
index 000000000000..73d9ef77762b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-08-28-21-40-12.bpo-37972.kP-n4L.rst
@@ -0,0 +1,5 @@
+Subscripts to the `unittest.mock.call` objects now receive the same chaining mechanism as any other custom attributes, so that the following usage no longer raises a `TypeError`:
+
+    call().foo().__getitem__('bar')
+
+Patch by blhsing