[Python-checkins] [python/cpython] 856cbc: bpo-29403: Fix mock's broken autospec behavior on ...

Wed Jul 19 20:01:15 EDT 2017

 Branch: refs/heads/master
 Home: https://github.com/python/cpython
 Commit: 856cbcc12f2e4cca93af5dc7ed6bcea4dd942f10
 https://github.com/python/cpython/commit/856cbcc12f2e4cca93af5dc7ed6bcea4dd942f10
 Author: Aaron Gallagher <habnabit at users.noreply.github.com>
 Date: 2017年07月20日 (2017年7月20日)
 Changed paths:
 M Lib/unittest/mock.py
 M Lib/unittest/test/testmock/testhelpers.py
 A Misc/NEWS.d/next/Library/2017-07-20-02-29-49.bpo-29403.3RinCV.rst
 Log Message:
 -----------
 bpo-29403: Fix mock's broken autospec behavior on method-bound builtin functions (GH-3)
Cython will, in the right circumstances, offer a MethodType instance
where im_func is a builtin function. Any instance of MethodType is
automatically assumed to be a Python-defined function (more
specifically, a function that has an inspectable signature), but
_set_signature was still conservative in its assumptions. As a result
_set_signature would return early with None instead of a mock since
the im_func had no inspectable signature. This causes problems
deeper inside mock, as _set_signature is assumed to _always_
return a mock, and nothing checked its return value.
In similar corner cases, autospec will simply not check the spec of the
function, so _set_signature is amended to now return early with the
original, not-wrapped mock object.
Patch by Aaron Gallagher.