Fix get_decorator_name with callable in between

[Llandy3d]

Description

get_decorator_name would fail with an AttributeError on decorators on the style of the prometheus_client where you actually have a call in between instead of just at the end of it. Ex. @hist.labels('label').time()

This pr changes the method to loop so that we will catch all the ast.Call and can build the full name.

Related Issue

https://github.com/jendrikseipp/vulture/issues/283

Checklist:

• [x] I have updated the documentation in the README.md file or my changes don't require an update.
• [x] I have added an entry in CHANGELOG.md.
• [x] I have added or adapted tests to cover my changes.
• [x] I have run tox -e fix-style to format my code and checked the result with tox -e style.

[codecov-commenter]

Codecov Report

Merging #285 (5417b4a) into main (fb126c7) will increase coverage by 0.00%. The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #285   +/-   ##
=======================================
  Coverage   99.38%   99.38%           
=======================================
  Files          19       19           
  Lines         647      650    +3     
=======================================
+ Hits          643      646    +3     
  Misses          4        4           

Impacted Files	Coverage Δ
vulture/utils.py	98.66% <100.00%> (+0.05%)	:arrow_up:

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[jendrikseipp]

Thanks for making these additional changes @Llandy3d ! I'll have a look at the PR when @RJ722 is happy :-)

[Llandy3d]

@jendrikseipp just pinging as I'm not sure if github gives notifications for emoji responses, but seems like a positive one? 😁

[RJ722]

Hi @Llandy3d! I appreciate the reminder -- It comes at just the right time, when I have found some time to work on open source. I'll give another round of review in a few hours. ^>^. Thanks for the patience!

[Llandy3d]

Hi @RJ722 , I probably misunderstood the hooray icon response as a positive review 😅 No rush at all, and thank you!

[jendrikseipp]

First off, thanks for looking into this, @Llandy3d and @RJ722 ! The code fixes the issue you were seeing, but I think we need a more general solution to cover the flexible decorators that Python 3.9 allows: a decorator can be any expression now (https://peps.python.org/pep-0614/). For example @foo[2] is valid, but not accepted by the code in this PR.

Since we cannot hope to cover all possible decorator names, I suggest we use the following basic solution:

• utils.get_decorator_name() preserves its old behaviour but returns the empty string for decorator names that it cannot parse (caught in an except AttributeError block)
• we update the readme file to briefly reflect that we only support decorators of the form @foo.bar(x, y, z)

@Llandy3d do you want to incorporate these changes into this PR?

[jendrikseipp]

@Llandy3d If you don't have the time to continue the PR that's completely fine of course. If so, maybe @RJ722 or I can pick up where you left off.

[Llandy3d]

sorry I missed the first message. TIL about that on decorators :) it makes sense, I don't know if/when I would be able to pick this back up so please feel free to work on it! 🙇‍♂️

[jendrikseipp]

I'm making the fix discussed above in #284.