How are fixtures closed?

[Stefanhg]

Hello,

I am working on fixing a bug in some internal tools we use to handle working with targets in test.
The tool itself interacts with different targets across multiple Python packages and helps user interact with the targets. The tool is a Pytest plugin that between each tests closes the target
Closing the targets works fine with pytest_runtest_teardown unless people use the targets in the teardown (which they do).
I resolved my issue initially by closing my targets in the pytest_runtest_setup but this looks confusing when reading the output of a test so that's not acceptable.

So my question is. How does PyTest "close"/exit fixtures and is there a more nicer way for me to do something after fixtures are closed?
I have been reading a bit in _pytest/fixtures.py but I could not find anything that could answer my questions.

[RonnyPfannschmidt]

its not clear what you are asking for but it seems like you should use a fixture for your targets or outline the use case enough to avoid the XY-problem

[Stefanhg]

@RonnyPfannschmidt I updated the question. Unsure if this helps tho.
The simplified version. Need to do something after the fixtures are closed before next test starts. Where can i "hook onto" in PyTest?

I cannot use a fixture since we have a plugin that interacts with the targets. Ideally we should switch away from this structure we currently have and use a fixture for spawning the targets and then just have a yield + close routine in the fixture but it would be a MAJOR rewrite of everything and people at my company are not ready for this.

[Stefanhg]

After some more digging in fixtures.py i found the class FixtureDef which included the function finish that closes the fixtures. After all the fixtures has been closed it executes pytest_fixture_post_finalizer which resolves my issue!

[Stefanhg]

More testing later, still not working as intended for my needs!
If anyone looks into this at some point and finds my answer and gives pytest_fixture_post_finalizer a try, it is NOT foolproof!
pytest_fixture_post_finalizer is called with each fixture that is used doing testing. This means in my case i can still end up closing my targets before reaching the fixture i need to close. Works very well on paper and with simple testcases but in practical testing it did not work.
At this point i am clueless how to properly implement a way to do this. The order where pytest_fixture_post_finalizer is called does not match the order that request.fixturenames has so cannot just wait until fixturedef.argname == request.fixturenames[-1] is reached.