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Reviewed:  https://review.openstack.org/532619
Committed: https://git.openstack.org/cgit/openstack/os-win/commit/?id=823b162c6a02083f6ae6f6ce27150c039687993d
Submitter: Zuul
Branch:    master

commit 823b162c6a02083f6ae6f6ce27150c039687993d
Author: Claudiu Belu <cbelu@xxxxxxxxxxxxxxxxxxxxxx>
Date:   Wed Jan 10 21:47:21 2018 +0200

    tests: Use mock autospec in unit tests
    
    Autospecing will ensure that the method signatures are respected
    during calls.
    
    oslotest.mock_fixture contains 2 components, one of them adds the autospec
    argument to mock.Mock and mock.MagicMock, while the other one fixes the
    autospec behaviour for mock.patch functions, and sets autospec to True by
    default, unless otherwise specified.
    
    Closes-Bug: #1735588
    
    Change-Id: I5a1dd8571988859b4a14a505fd5e016079582363


** Changed in: os-win
       Status: In Progress => Fix Released

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

Title:
  Mock autospec not used, or not used properly

Status in networking-hyperv:
  In Progress
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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