[Cython] cython tests and py3k hash randomization

[Vitja Makarov]

2012/2/24 Stefan Behnel <stefan_ml at behnel.de>:
> Vitja Makarov, 24.02.2012 06:24:
>> 2012/2/24 mark florisson <markflorisson88 at gmail.com>:
>>> On 23 February 2012 20:52, Vitja Makarov <vitja.makarov at gmail.com> wrote:
>>>> Recent py3k version has new feature "hash randomization" it solves
>>>> some security issues.
>>>> But has some drawbacks, for instance, dict.items() order is now
>>>> unknown. So it breaks
>>>> randomly some doctests that rely on exact order of dict items.
>>>>
>>>> vitja at mchome:~/python$ ./py3k/bin/python -c  "print({'a':1, 'b':2})"
>>>> {'b': 2, 'a': 1}
>>>> vitja at mchome:~/python$ ./py3k/bin/python -c  "print({'a':1, 'b':2})"
>>>> {'a': 1, 'b': 2}
>>>>
>>>> As a workaround we can set PYTHONHASHSEED environment variable to zero
>>>> for all cyhon-*-tests targets
>>>>
>>>> This also affects generated code it internally depends on order of
>>>> items returned by dict.items()
>>>
>>> Any code or test that relies on dictionary order is wrong, really. So
>>> I assume any pyregr issues will be fixed by the CPython test suite?
>
> Definitely.
>

Ok, I'll take a look.

>
>>> If there are any such failing tests in Cython we should simply fix them.
>>
>> Yes, you're right but I'm not sure how many tests may be broken. I
>> don't think we want to fix them before release. Now I've added
>>
>> # Disable python hash randomization
>> export PYTHONHASHSEED=0
>>
>> to cython-devel-tests and it worked.
>
> That should only be a work-around until all tests are fixed, though.
>
>
>> It's not that easy to fix, here is simple doctest:
>>
>> def test_foo():
>>     """
>>     >>> test_foo()
>>     {'a': 1, 'b': 2}
>>     """
>>     return {'a': 1, 'b': 2}
>>
>> You can't use dicts in doctests anymore there are few options instead:
>> 1. Compare sorted items(), e.g. sorted(test_foo().items())
>> 2. Inplace compare test_foo() == {...}
>
> I always use 1) because it gives you better test failure output in doctests.
>



-- 
vitja.