Pytest: markers stains on all related classes

Created on 23 Aug 2014 · 14Comments · Source: pytest-dev/pytest

Originally reported by: Markus Unterwaditzer (BitBucket: untitaker, GitHub: untitaker)

Given this class hierarchy:

import pytest

class Foo(object):
    def test_lol(self):
        pass

@pytest.mark.skipif(False, reason='BECAUSE')
class TestBar(Foo):
    pass

@pytest.mark.skipif(True, reason='BECAUSE')
class TestBaz(Foo):
    pass

py.test will skip the single testcase of both TestBar and TestBaz.

Bitbucket: https://bitbucket.org/pytest-dev/pytest/issue/568

collection marks bug

Source

pytestbot

Most helpful comment

Here's a ugly workaround:


def mark_class(marker):
    '''Workaround for https://github.com/pytest-dev/pytest/issues/568'''
    import types
    def copy_func(f):
        try:
            return types.FunctionType(f.__code__, f.__globals__,
                                      name=f.__name__, argdefs=f.__defaults__,
                                      closure=f.__closure__)
        except AttributeError:
            return types.FunctionType(f.func_code, f.func_globals,
                                      name=f.func_name,
                                      argdefs=f.func_defaults,
                                      closure=f.func_closure)

    def mark(cls):
        for method in dir(cls):
            if method.startswith('test_'):
                f = copy_func(getattr(cls, method))
                setattr(cls, method, marker(f))
        return cls
    return mark


import pytest

class Foo(object):
    def test_lol(self):
        pass

@mark_class(pytest.mark.skipif(False, reason='BECAUSE'))
class TestBar(Foo):
    pass

@mark_class(pytest.mark.skipif(True, reason='BECAUSE'))
class TestBaz(Foo):
    pass

untitaker on 3 May 2016

🎉3

All 14 comments

@untitaker this relates to a recent issue wrt marker transfer, current consent is that class level markers move to inherited methods

RonnyPfannschmidt on 25 Jul 2015

Relates to #535

pfctdayelise on 25 Jul 2015

Yeah I think this is a duplicate.

Ronny, I don't understand what you're saying. Are class markers discouraged? Is this expected behavior?

On 25 July 2015 19:16:40 CEST, Brianna Laugher [email protected] wrote:

Relates to #535

Reply to this email directly or view it on GitHub:
https://github.com/pytest-dev/pytest/issues/568#issuecomment-124863023

Sent from my phone. Please excuse my brevity.

untitaker on 25 Jul 2015

Here's the PR: #848

nicoddemus on 25 Jul 2015

@untitaker py.test has a bug wrt marker transfer, we are on it

RonnyPfannschmidt on 26 Jul 2015

Ok, thanks!

On 26 July 2015 09:00:22 CEST, Ronny Pfannschmidt [email protected] wrote:

@untitaker py.test has a bug wrt marker transfer, we are on it

Reply to this email directly or view it on GitHub:
https://github.com/pytest-dev/pytest/issues/568#issuecomment-124951806

Sent from my phone. Please excuse my brevity.

untitaker on 26 Jul 2015

Any update on this issue?

laserson on 9 Nov 2015

Unfortunately not, a backward compatible resolution is hard and needs time

RonnyPfannschmidt on 10 Nov 2015

Here's a ugly workaround:


def mark_class(marker):
    '''Workaround for https://github.com/pytest-dev/pytest/issues/568'''
    import types
    def copy_func(f):
        try:
            return types.FunctionType(f.__code__, f.__globals__,
                                      name=f.__name__, argdefs=f.__defaults__,
                                      closure=f.__closure__)
        except AttributeError:
            return types.FunctionType(f.func_code, f.func_globals,
                                      name=f.func_name,
                                      argdefs=f.func_defaults,
                                      closure=f.func_closure)

    def mark(cls):
        for method in dir(cls):
            if method.startswith('test_'):
                f = copy_func(getattr(cls, method))
                setattr(cls, method, marker(f))
        return cls
    return mark


import pytest

class Foo(object):
    def test_lol(self):
        pass

@mark_class(pytest.mark.skipif(False, reason='BECAUSE'))
class TestBar(Foo):
    pass

@mark_class(pytest.mark.skipif(True, reason='BECAUSE'))
class TestBaz(Foo):
    pass

untitaker on 3 May 2016

🎉3

Here's how PyKafka works around this issue in its test suite

emmett9001 on 31 May 2016

@emmett9001 there is a pending branch for the initial mark refactor in #1534

after it is merged the base for a backward compatible implementation of non-smearing marker combinations wil lbe in place

RonnyPfannschmidt on 31 May 2016

Since we have #1670 to track all marker staining related issues and the fix for that unfortunately won't make it to 3.0, I'm removing the milestone for now.