Warnings from conftest.py should show up in warning summary

[drdavella]

Right now if a conftest.py (or a module it imports) issues a warning, it does not show up in the warnings summary. Since conftest.py can be used to load plugins from other packages, it would be useful to be able to issue DeprecationWarnings and other warnings that are actually visible when pytest is run.

[nicoddemus]

Definitely @drdavella, this is on our plans, please see #2452

[drdavella]

@nicoddemus, great, thanks! Just wondering, but is there any temporary workaround in the meantime?

[nicoddemus]

Hooks are the mechanism in which it is possible to extend pytest behavior, but using hooks for capturing warnings from conftest files seems tricky because conftest files will be imported before any hooks are executed.

It should be possible to implement a hookwrapper around pytest_collect_file to capture warnings emitted during import of test modules though.

If the latter is acceptable to you, let me know and I can provide some sample code.

[drdavella]

Thanks, that sounds like a good starting point. Just to be clear, we are talking about the following scenario, right?

# conftest.py
# Importing this causes a DeprecationWarning
from foo import baz

In this case, I'd like to see a warning from pytest, but none currently appears.

You can even do this, and it doesn't work:

# conftest.py
import warnings

warnings.warn("No one will ever see this warning!", DeprecationWarning)

[nicoddemus]

Exactly. The case you describe was my first point, which I don't believe is doable right now without changing the pytest's internals.

The second scenario describes when a test module test_foo.py emits a warning during import (or other module it imports emits it), then I believe it is possible to implement this in a custom plugin (conftest.py file).

[twmr]

related to #3251

[nicoddemus]

Just a heads up: I'm currently working on #2452, but this issue is a little trickier because when we are loading conftest files, the pytest options are not quite ready for use yet, and the warnings plugin needs access to some options from command-line and ini file to do its work. We will probably need some more time to fix this issue in particular, possibly after the internal refactoring to the config system lead by @RonnyPfannschmidt.

[CentralLT]

What's the status on this issue? Is it already fixed?

[The-Compiler]

@CentralLT Doesn't look like it - with the conftest.py from #2891 (comment) above, I still don't see any warning. @nicoddemus might know more, given that 0fffa6b (which was part of #3931) was merged.