Fails collecting tests if test module level obj has __getattr__()

[Suor]

The issue is in this line. Object returns something arbitrary and then it's required to be int lineno.

Breaks this for example.

[alfredodeza]

This only happens for me on Python 2.6. Python 2.7 is unaffected.

[nicoddemus]

Thanks for the report! 😄

[RonnyPfannschmidt]

Since its only a proble!m on python 2.6 I'm considering leaving it be

[Suor]

So pytest no longer supports Python 2.6?

[RonnyPfannschmidt]

its still supported, but since python 2.6 is eol'd since years we should think about how much code and maintenance burdens we invest in it as volunteer work, in particular with libs that are somehow broken only on it

@hpk42 whats your oppinion on that matter

[RonnyPfannschmidt]

just discussed with @hpk42 on irc

result: since we officially support it we should fix it

[jantman]

FWIW, I can confirm what @alfredodeza said - https://travis-ci.org/jantman/awslimitchecker/builds/82210772 tests against 26, 27, 32, 33, 34, pypy and pypy3; only 2.6 breaks.

[RonnyPfannschmidt]

at unit-test level all python packages seem to be required

[RonnyPfannschmidt]

i finished a first attempt to solving it, resulting in the python interpreter oom-ing my machine,

[The-Compiler]

It seems this is caused by 3497aa0 / #921

/cc @tomviner

[qwcode]

to be clear, this started with 2.8.0, correct?

[The-Compiler]

Yes, it seems to work fine with 2.7.3 which is before that commit.

[tomviner]

The difference in Python versions seems to be with inspect.isclass:

$ python2.7
Python 2.7.9 (default, Apr  2 2015, 15:33:21)
[GCC 4.9.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from inspect import isclass
>>> from whatever import _
>>> isclass(_)
False

which is the correct answer btw - _ is <whatever.Whatever object at 0x7ff296b57210>, which is an instance not a class. But in Python 2.6:

$ python2.6
Python 2.6.9 (default, Apr 16 2015, 18:31:03)
[GCC 4.9.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from inspect import isclass
>>> from whatever import _
>>> isclass(_)
True

My commit, mentioned above, amends the collector.istestclass line below, but as you can see it's the isclass line above it that's, in the first instance, behaving erroneously in Py2.6:

def pytest_pycollect_makeitem(collector, name, obj):
    ...
    if isclass(obj):
        if collector.istestclass(obj, name):
            Class = collector._getcustomclass("Class")
            outcome.force_result(Class(name, parent=collector))

See pytest_pycollect_makeitem.

So I propose the priority fix, is for us to provide a fixed isclass function when Python version == 2.6. I'd be happy to write a patch for that.

There's a second, and more questionable issue raised here. In my patch, I added support to respect nose's Test.__test__ attribute to mark a class as a test despite not matching any naming rule. But is a class that responds True to getattr(cls, anything) really signalling anything about tests?

The good news is that if we fix the first issue, we're not forced to answer the second (in this ticket).

[nicoddemus]

Thanks for the investigation work @tomviner! It seems your solution of using a fixed isclass function for Python 2.6 would work just fine and would not break anything for Python versions > 2.6, so I'm 👍 on it.

[The-Compiler]

The probably related CPython commit: https://hg.python.org/cpython/rev/35bf8f7a8edc?revcount=1920

[tomviner]

Comments on this patch please #1121

[nicoddemus]

@Suor, could you please try #1121 in your test suite to ensure it works and does not break anything else by accident?

[The-Compiler]

@alfredodeza @jantman @Renstrom @Daikiri @jmoldow @trhoden any chance some of you could test that PR as well? 😉

[jantman]

@The-Compiler This looks good to me - https://travis-ci.org/jantman/awslimitchecker/builds/84219885 and https://github.com/jantman/awslimitchecker/tree/pytest-pr-1121

[dairiki]

PR #1121 works for me. Thank you all!

[nicoddemus]

Fixed in #1121