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Reviewed:  https://review.openstack.org/539954
Committed: https://git.openstack.org/cgit/openstack/compute-hyperv/commit/?id=d19606a82809f2a909d20b102166880b65d74b1f
Submitter: Zuul
Branch:    master

commit d19606a82809f2a909d20b102166880b65d74b1f
Author: Claudiu Belu <cbelu@xxxxxxxxxxxxxxxxxxxxxx>
Date:   Tue Jan 30 06:06:47 2018 -0800

    autospecs os-win utils classes
    
    Most of the os-win utils are created through
    os_win.utilsfactory, which all rely on its function
    '_get_class' to load and initialize the proper Utils
    based on the OS version.
    
    This commit patches the mention method, returning
    an autospeced mock for the desired Utils instead.
    
    Closes-Bug: #1735588
    
    Change-Id: If0002b2c711aaeaf13273bed9b912fdd9c639a64


** Changed in: compute-hyperv
       Status: New => Fix Released

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https://bugs.launchpad.net/bugs/1735588

Title:
  Mock autospec not used, or not used properly

Status in compute-hyperv:
  Fix Released
Status in networking-hyperv:
  Fix Released
Status in OpenStack Compute (nova):
  In Progress
Status in os-win:
  Fix Released
Status in oslotest:
  Fix Released

Bug description:
  Description
  ===========

  In typical unit tests, almost all of the dependencies are mocked or
  patched (mock.patch), without any guarantee that the mocked methods
  actually exist, or if their signatures are respected (see below).
  Because of this, actual issues can easily be overlooked and missed, as
  the unit tests are wrongfully passing. [0]

  The mock.Mock class accepts a spec as an argument, which only solves
  half the problem: it only checks if an attribute exists, based on the
  given spec. It does not guarantee that the given attribute is actually
  a method, or if its signature is respected [1][2]. Some unit tests may
  pass the autospec argument, but mock doesn't support it at the moment.

  mock.patch, mock.patch.object, mock.patch.multiple accept an autospec
  argument, but because of a bug [3][4], it cannot be used properly.

  
  Steps to reproduce
  ==================

  import mock
  from mock.tests import testmock

  m = mock.Mock(spec=testmock.Something)

  # meth has the following signature:
  # def meth(self, a, b, c, d=None):
  m.meth()

  
  Expected result
  ===============

  TypeError should be raised.

  
  Actual result
  =============

  A mock object is returned.

  
  Proposal
  ========

  Bug reports have been issues for the bugs mentioned above, see
  [1][2][3][4], but until then, the mock library can be patched to
  include the following changes:

  - add autospec argument to mock.Mock and mock.MagicMock. Unit test should then pass the autospec argument whenever possible.
  - fix the mock.patch autospec issue.
  - enable mock.patch autospec by default, unless otherwise specified.

  
  Links
  =====

  [0] https://review.openstack.org/#/c/461689/
  [1] https://github.com/testing-cabal/mock/issues/393
  [2] https://bugs.python.org/issue30587
  [3] https://github.com/testing-cabal/mock/issues/396
  [4] https://bugs.python.org/issue32092

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