Collect functools.partial objects

[nicoddemus]

Fix for issue #811.

I feel the current implementation is hackish and might break in some corner-cases.

Perhaps it would be better to don't support tests created by functools.partial objects at all, and issue a warning during collection and add a note to the documentation?

[hpk42]

i think you can just import functools or "partial".

[nicoddemus]

Done.

[hpk42]

Hum, I guess we can try to support functools.partial and besides, your PR does not look too hackish to me although it would be good if we could reduce redundancy (see my code comments).

If it proves to burdensome to support functools.partials we either need to refactor or drop the feature so we probably shouldn't documented it as supported for now.

[RonnyPfannschmidt]

since we consider it "unsupported" we should probably issue a warning as well

[nicoddemus]

@hpk42:

Hum, I guess we can try to support functools.partial and besides, your PR does not look too hackish to me although it would be good if we could reduce redundancy (see my code comments).

Done. I thought it was a little hackish because we have to consider the partial arguments explicitly when extracting the fixture names from the function, but I guess that's OK.

@RonnyPfannschmidt:

since we consider it "unsupported" we should probably issue a warning as well

If we decide to decline this PR for some reason, I agree a warning is appropriate, like we do today when a Test class has an __init__ method.

[RonnyPfannschmidt]

+1

[nicoddemus]

Rebased on pytest-2.7 to get the mock fix to tox.ini.