Lots of sockets not closed during testing

[gforcada]

Have a look at any 3.6/3.7 jenkins jobs, i.e. https://jenkins.plone.org/job/plone-5.2-python-3.6/ or https://jenkins.plone.org/job/plone-5.2-python-3.7/ and you will see that after this line:

Set up plone.restapi.testing.PloneRestApiDXLayer:Functional in 0.000 seconds.

There are lots, literally lots, of:

zope/testrunner/runner.py:386: ResourceWarning: unclosed <socket.socket fd=8, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=6, laddr=('127.0.0.1', 51612), raddr=('127.0.0.1', 50139)>
  test.__dict__.clear()

On the up side, it feels like all of them come from the very same place, so with one stone all of them might be gone 👍

[davisagli]

My guess is something about the StopableWSGIServer started by plone.testing (which is a thin wrapper around waitress).

[mauritsvanrees]

So this happens during the call to test.__dict__.clear(). In my case it looks like this:

(Pdb) pp test.__dict__
{'_cleanups': [],
 '_outcome': None,
 '_subtest': None,
 '_testMethodDoc': None,
 '_testMethodName': 'test_documentation_users_add',
 '_type_equality_funcs': {<class 'list'>: 'assertListEqual',
                          <class 'dict'>: 'assertDictEqual',
                          <class 'set'>: 'assertSetEqual',
                          <class 'frozenset'>: 'assertSetEqual',
                          <class 'tuple'>: 'assertTupleEqual',
                          <class 'str'>: 'assertMultiLineEqual'},
 'api_session': <plone.restapi.testing.RelativeSession object at 0x108d98ef0>,
 'app': <Application at >,
 'browser': <plone.testing._z2_testbrowser.Browser object at 0x110f71b70>,
 'document': <Document at /plone/front-page>,
 'frozen_time': <freezegun.api.FrozenDateTimeFactory object at 0x11105dda0>,
 'portal': <PloneSite at /plone>,
 'portal_url': 'http://localhost:53215/plone',
 'request': <HTTPRequest, URL=None>,
 'time_freezer': <freezegun.api._freeze_time object at 0x108e1d6a0>}

I can remove several keys from it without problem:

(Pdb) del test.__dict__['_outcome']
(Pdb) del test.__dict__['request']
(Pdb) del test.__dict__['portal']
(Pdb) del test.__dict__['portal_url']
(Pdb) del test.__dict__['app']
(Pdb) del test.__dict__['browser']

But the offending one is api_session:

(Pdb) del test.__dict__['api_session']
.../zope.testrunner-4.9.2-py3.7.egg/zope/testrunner/runner.py:1:
ResourceWarning: unclosed <socket.socket fd=9, family=AddressFamily.AF_INET,
type=SocketKind.SOCK_STREAM, proto=6,
laddr=('127.0.0.1', 53217), raddr=('127.0.0.1', 53215)>

Looks like we need to close the api_session in tearDown. I will prepare a PR.