mock.ANY doesn't match mock.MagicMock() object

[felixonmars]

BPO	25195
Nosy	@voidspace, @berkerpeksag, @serhiy-storchaka, @felixonmars
Files	fix_mock_call_ne.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2016-03-27.21:29:41.270>
created_at = <Date 2015-09-20.10:27:20.336>
labels = ['type-bug', 'library']
title = "mock.ANY doesn't match mock.MagicMock() object"
updated_at = <Date 2016-03-27.21:30:10.932>
user = 'https://github.com/felixonmars'

bugs.python.org fields:

activity = <Date 2016-03-27.21:30:10.932>
actor = 'berker.peksag'
assignee = 'none'
closed = True
closed_date = <Date 2016-03-27.21:29:41.270>
closer = 'berker.peksag'
components = ['Library (Lib)']
creation = <Date 2015-09-20.10:27:20.336>
creator = 'felixonmars'
dependencies = []
files = ['41848']
hgrepos = []
issue_num = 25195
keywords = ['patch', '3.5regression']
message_count = 7.0
messages = ['251162', '259811', '259814', '259822', '259835', '262538', '262539']
nosy_count = 6.0
nosy_names = ['michael.foord', 'python-dev', 'berker.peksag', 'serhiy.storchaka', 'felixonmars', 'aplummer']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue25195'
versions = ['Python 3.5', 'Python 3.6']

[felixonmars]

Since Python 3.5.0 mock.MagicMock() object seems not matched by mock.ANY. This behavior looks weird and breaks tests of boto.

Minimized example:

In Python 3.4.3:
>>> from unittest import mock
>>> m = mock.MagicMock()
>>> m(mock.MagicMock())
<MagicMock name='mock()' id='139728217270704'>
>>> m.assert_called_with(mock.ANY)
>>>

In Python 3.5.0:
>>> from unittest import mock
>>> m = mock.MagicMock()
>>> m(mock.MagicMock())
<MagicMock name='mock()' id='140093484276536'>
>>> m.assert_called_with(mock.ANY)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.5/unittest/mock.py", line 792, in assert_called_with
    raise AssertionError(_error_message()) from cause
AssertionError: Expected call: mock(<ANY>)
Actual call: mock(<MagicMock id='140093520206872'>)

[aplummer]

I've had a look and I think this could be because the class _Call (also in unittest.mock) has lost its __ne__ method between 3.4 and 3.5.

Compare
https://hg.python.org/cpython/file/v3.4.4/Lib/unittest/mock.py#l2010
with
https://hg.python.org/cpython/file/v3.5.1/Lib/unittest/mock.py#l2028

This leads me to this changeset:
https://hg.python.org/cpython/rev/3603bae63c13

My failing test:

from unittest import mock

call1 = mock.call(mock.MagicMock())
call2 = mock.call(mock.ANY)

assert call1 == call2
assert not (call1 != call2)

This passes in 3.4 but fails in 3.5, but fails on the second assert, not the first. So they are equal, but they're not not-equal. I've added this as a test and reinstated __ne__ in my patch.

[berkerpeksag]

Looks like _Call is a subclass of tuple. Checks in the test could be written as "self.assertIs(a == b, True)".

[serhiy-storchaka]

It would be better to use just default implementation:

    __ne__ = object.__ne__

Interesting that while call1 == call2 is True, call2 == call1 is False. But this is different issue.

[aplummer]

Have added a new diff to just use the default __ne__ implementation rather than tuple's.

Have also added a test that targets exactly the reported issue.

[python-dev]

New changeset dcd3b078ab84 by Berker Peksag in branch '3.5':
Issue bpo-25195: Fix a regression in mock.MagicMock
https://hg.python.org/cpython/rev/dcd3b078ab84

New changeset 880d609b6664 by Berker Peksag in branch 'default':
Issue bpo-25195: Fix a regression in mock.MagicMock
https://hg.python.org/cpython/rev/880d609b6664

[berkerpeksag]

Thanks!