RemovedInPytest4Warning via _pytest\compat.py:321

[blueyed]

There are many RemovedInPytest4Warnings with pytest's own tests, e.g.:

c:\projects\pytest\.tox\py36\lib\site-packages\_pytest\compat.py:321: RemovedInPytest4Warning: usage of Session.Class is deprecated, please use pytest.Class instead
360  return getattr(object, name, default)
361

(via https://ci.appveyor.com/project/pytestbot/pytest/builds/19474342/job/c83h5n8ne3snvf8o#L359)

Are those expected?

I would assume pytest should not causes warnings itself.

[nicoddemus]

In most cases it is inevitable because we still need to test deprecated features.

[blueyed]

I see.. there are more than 130 of them though.
Maybe pytest's tests should be configured to ignore those warnings then maybe?

[nicoddemus]

Maybe pytest's tests should be configured to ignore those warnings then maybe?

Hmmm yep, makes sense.

[RonnyPfannschmidt]

@nicoddemus this is a bug in plugin factory parsing - we souldnt parse elements that are CompatProperties, or remove those things already

[nicoddemus]

We shouldn't remove it now, those are scheduled to be removed in 4.1.

But I'm OK with just ignoring that for now, TBH. They will go away soon anyway.

[blueyed]

Cool, closing then.

[blueyed]

After all I think it is worth not having a bunch of warnings (that are expected).
I will look into it, but any pointers are appreciated of course - the one from Ronny seems good already.

[nicoddemus]

I think it is fine to ignore them by configuring filterwarnings in pytest.ini.

[Zac-HD]

Ignoring internal warnings in our own tests seems very risky to me - at some point we'll deprecate something without removing an internal use, and then all downstream test suites using -Werror will fail 😭

In Hypothesis we get around this with an explicit decorator for all tests that should raise deprecation warnings - it even errors if no warning is emitted.

IMO we should also test Pytest with all warnings as errors, except for jobs deliberately testing older versions of dependencies, to make this practical for downstream users.

[edmorley]

I'm seeing these warnings in our project's own pytest runs. I presume this is not expected?
https://travis-ci.org/mozilla/treeherder/jobs/442405171#L777

Our pytest config is here:
https://github.com/mozilla/treeherder/blob/97480c66c9700b77dae581205207802848bdea6c/setup.cfg#L32-L61

[nicoddemus]

Ignoring internal warnings in our own tests seems very risky to me

Oh I meant to ignore the warnings mentioned in this thread explicitly, not all internal warnings, which I agree would be very risky. 👍

IMO we should also test Pytest with all warnings as errors

We do that already 😉

pytest/tox.ini

Lines 206 to 220 in e4871f7

	filterwarnings =
	error
	ignore:yield tests are deprecated, and scheduled to be removed in pytest 4.0:pytest.RemovedInPytest4Warning
	ignore:Metafunc.addcall is deprecated and scheduled to be removed in pytest 4.0:pytest.RemovedInPytest4Warning
	ignore:Module already imported so cannot be rewritten:pytest.PytestWarning
	# produced by path.local
	ignore:bad escape.*:DeprecationWarning:re
	# produced by path.readlines
	ignore:.*U.*mode is deprecated:DeprecationWarning
	# produced by pytest-xdist
	ignore:.*type argument to addoption.*:DeprecationWarning
	# produced by python >=3.5 on execnet (pytest-xdist)
	ignore:.*inspect.getargspec.*deprecated, use inspect.signature.*:DeprecationWarning
	# pytest's own futurewarnings
	ignore::pytest.PytestExperimentalApiWarning