Setting a side_effect on mock from create_autospec doesn't work

[voidspace]

BPO	17826
Nosy	@gpshead, @ezio-melotti, @merwok, @voidspace, @kushaldas
Files	issue17826_v1.patch: Code and test case update issue17826_v2.patch: Code and test case update revision 2 issue17826_v3.patch: New patch with fix in proper place for side_effect for functions (includes test case).

^{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 = 'https://github.com/voidspace'
closed_at = <Date 2014-04-14.20:10:47.946>
created_at = <Date 2013-04-24.10:00:07.992>
labels = ['type-bug', 'library']
title = "Setting a side_effect on mock from create_autospec doesn't work"
updated_at = <Date 2014-04-14.20:10:47.945>
user = 'https://github.com/voidspace'

bugs.python.org fields:

activity = <Date 2014-04-14.20:10:47.945>
actor = 'michael.foord'
assignee = 'michael.foord'
closed = True
closed_date = <Date 2014-04-14.20:10:47.946>
closer = 'michael.foord'
components = ['Library (Lib)']
creation = <Date 2013-04-24.10:00:07.992>
creator = 'michael.foord'
dependencies = []
files = ['30025', '30055', '34838']
hgrepos = []
issue_num = 17826
keywords = ['patch']
message_count = 9.0
messages = ['187692', '187840', '187844', '187845', '188036', '215916', '216098', '216164', '216196']
nosy_count = 6.0
nosy_names = ['gregory.p.smith', 'ezio.melotti', 'eric.araujo', 'michael.foord', 'python-dev', 'kushal.das']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue17826'
versions = ['Python 3.3', 'Python 3.4']

[voidspace]

>>> from unittest.mock import create_autospec
>>> def f(): pass
... 
>>> m = create_autospec(f)
>>> m.side_effect = [1, 2]
>>> m()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 3, in f
  File "/compile/py3k-cpython/Lib/unittest/mock.py", line 872, in __call__
    return _mock_self._mock_call(*args, **kwargs)
  File "/compile/py3k-cpython/Lib/unittest/mock.py", line 931, in _mock_call
    result = next(effect)
TypeError: 'list' object is not an iterator

[voidspace]

This illustrates the difference:

>>> from mock import Mock, create_autospec
>>> some_list = [1, 2, 3]
>>> m = Mock()
>>> m.side_effect = some_list
>>> m.side_effect
<listiterator object at 0x1004ab7d0>
>>> m2 = create_autospec(lambda: None)
>>> m2.side_effect = some_list
>>> m2.side_effect
[1, 2, 3]

When setting a side_effect on a function (created by create_autospec) the side_effect setter is not used - so turning the list into an iterator needs to be done on first use instead.

[kushaldas]

Working on this.

[kushaldas]

Patch along with a test for the same.

[kushaldas]

Version 2 of the patch, with typo fixed also one more addition test to check callable side effect in create_autospec.

[merwok]

Michael, a patch including tests is ready for this issue.

[voidspace]

Can you explain why we need to check for the call_count here? I don't understand why this is needed.

[kushaldas]

New patch with fix in proper place for side_effect for functions (includes test case).

[python-dev]

New changeset 1e3c64470629 by Michael Foord in branch '3.4':
bpo-17826. Setting an iterable side_effect on a mock created by create_autospec now works
http://hg.python.org/cpython/rev/1e3c64470629