python_classes: match class names on word boundaries

[theY4Kman]

The python_classes setting instructs pytest to include or ignore certain classes for test discovery based on their classname. I've been using some BDD/declarative-style test context names like ForCurrentUser, which I want tests to be discovered under. However, I also use mixin classes like ForbidsAnonymousUsers to include common tests in other test contexts.

To support my case, I've been using a custom plugin to allow dashes in python_classes to represent CamelCase word boundaries: https://gist.github.com/25861e8acd564fe3a0e4a9f45b54a316

I wondered if it might be useful to anyone else before I write up a PR.

[RonnyPfannschmidt]

@theY4Kman this sound slike something that should be explored in a external plugin first - just like pytest-bdd and similar toolkits do their specialties without forcing core pytest to adapt those structures

[RonnyPfannschmidt]

oh, and just fyi - the mechanism you used in your script is deprecated and will be removed

[theY4Kman]

Sounds good!

re: deprecation — Are you referring to using Class and family to customize collection, like the Deprecations page warns of? I'm not sure if it's a typo, or I'm not searching deep enough, or maybe it ain't released, yet, but that page suggests using the pytest_collect_make_item, which I can't find. I figure it might mean pytest_pycollect_makeitem.

Thanks for the heads-up, in any case!

[RonnyPfannschmidt]

@theY4Kman i meant using Class&co do customize it

[theY4Kman]

I finally packaged up the plugin: https://pypi.org/project/pytest-camel-collect/

---

I'm still kinda fuzzy on the proper way to have my custom PyCollector classes used. I thought I could use a hookwrapper on pytest_pycollect_makeitem to augment the regularly-scheduled return value with my base class — which did seem to work with trylast=True, but failed in a different environment? _(or I can't remember what happened there...)

Though, when the hookwrapper was working alright, pytest_pycollect_makeitem didn't seem to get passed any Modules — whose collection I wanted to augment to change how class names were filtered. I added a similar pytest_pycollect_makemodule hookwrapper to patch them Moddies, and collection seemed as expected.

But I noticed child context classes weren't being collected. For example:

class TestMyStuff:
	def test_my_stuff(self):
		pass

    class TestMyStuff:
		def test_my_stuff_also(self):
			pass

My plugin was only collecting test_my_stuff, but not test_my_stuff_also. It seemed pytest_pycollect_makeitem was being passed Classes, but not Instances, which were apparently responsible for collection of inner test classes.

I'm sure I missed something obvious along the way (or took so many left turns I thought I was right), but I couldn't find a way to achieve my desired results with something mostly purely hook-centric. I landed on a simple strategy: inject my base class into Modules with pytest_pycollect_makemodule, and override _getcustomclass in my PyCollector subclasses.

[RonnyPfannschmidt]

@theY4Kman _getcustomclass was removed in pytest 4.0 and the supporting code will be removed in 4.1

[theY4Kman]

That removal must not've made it to 4.0.

Cheers for the heads-up! I'll find another way to hack me plugin together when the time comes :P

[RonnyPfannschmidt]

@theY4Kman the code paths that use it trigger an error in 4.0, its removed in 4.1

[theY4Kman]

To be clear, I'm not requesting anything from ya. It would be nice if my sooper-dooper important use case /s was tendered to, but I ain't demanding it. For a ginormous OSS project like pytest, not for a second would I think I could somehow squeeze dev effort out of ya. Same would apply for the smallest of OSS projects. Plus, I know my way around a code or two; I'll be fine when things change — and I'm happy when they do, 'cause things have gotten nicer and nicer as time goes on.

I say that 'cause I'm not sure what makes ya so certain _getcustomclass isn't in 4.0.x. I built the thing with 4.0.2 installed; my red/green tests pass. Here's a REPL with a basic example using the plugin. I see that it's gone in the features branch — maybe something slipped past the packaging/release process?