Multiple invocations of class-scoped fixture change called finalizer order

[rmfitzpatrick]

I'm running into some undesired teardown ordering in pytest 3.1.2.

import pytest

order_called = []

@pytest.fixture(scope='class')
def uses_request(request):
    def _uses_request(x):
        request.addfinalizer(lambda: order_called.append(x))

    for name in ('first', 'second'):
         _uses_request('uses_request: {}'.format(name))


@pytest.fixture(scope='class')
def subrequest(request):
    return request


class TestClassOne(object):

    def test_one(self, uses_request, subrequest):
        def uses_subrequest(name):
            subrequest.addfinalizer(lambda: order_called.append('uses_subrequest: {}'.format(name)))

        for name in ('first', 'second'):
            uses_subrequest(name)

    def test_two(self, uses_request, request):
        def in_test_uses_request(x):
            request.addfinalizer(lambda: order_called.append(x))

        for name in ('third', 'fourth'):
            in_test_uses_request('uses_request: {}'.format(name))


def test_order():
    assert order_called == ['uses_request: fourth',
                            'uses_request: third',
                            'uses_subrequest: second',
                            'uses_subrequest: first',
                            'uses_request: second',
                            'uses_request: first']

    def test_order():
>       assert order_called == ['uses_request: fourth',
                                'uses_request: third',
                                'uses_subrequest: second',
                                'uses_subrequest: first',
                                'uses_request: second',
                                'uses_request: first']
E       AssertionError: assert ['uses_reques...quest: first'] == ['uses_request...quest: first']
E         At index 2 diff: 'uses_request: second' != 'uses_subrequest: second'
E         Use -v to get the full diff

tmp.py:36: AssertionError
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> entering PDB >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> /tmp/tmp.py(36)test_order()
-> assert order_called == ['uses_request: fourth',
(Pdb) pp order_called
['uses_request: fourth',
 'uses_request: third',
 'uses_request: second',
 'uses_request: first',
 'uses_subrequest: second',
 'uses_subrequest: first']

If I remove the uses_request parameter from test_two then the tests pass, but this prevents me being able to run test_two on its own (mark.usefixtures('uses_request') also triggers the unwanted behavior). Is my expectation that finalizer calls should always be lifo correct? I'd think that the presence of multiple uses_request should behave no differently than it appearing once.

By having the teardown functions not occur in the order of finalizer registration my tests error in product-specific ways I cannot account for without losing desired coverage.

[nicoddemus]

Is my expectation that finalizer calls should always be lifo correct?

I'm not sure out of my head, I would have to take a look at the code. @RonnyPfannschmidt do you know this promptly and can answer perhaps?

[RonnyPfannschmidt]

Nope

[TheDesertKing]

I believe this issue was addressed on issue #3678, might wanna close it.

[RonnyPfannschmidt]

returning to this now

finalisers belong to requests

requests clean up in fixture order (each request is per fixture)

the expectation of @rmfitzpatrick was wrong and pytest indeed correctly tears down the requests in order,

starting with the function scoped one

then following the class scoped ones in reverse creation order

#3674 is completely unrelated

[RonnyPfannschmidt]

closing as not a bug