Handle Unwritable Path

[ooglek]

Description

If the OS cannot open a file because the path is bad, it does not make sense to repeatedly attempt to open the file as it will continue to fail, indefinitely if the -1 default timeout is used, without any feedback to the user.

This modifies the behavior to raise the OSError/IOError exception received on Windows or Unix so FileLock exits rather than a futile infinite loop that will never succeed.

Tests are written to demonstrate the behavior.

[AdorablePotato]

Thank you!
I merged your pull request and made some changes to SoftFileLock: https://github.com/benediktschmitt/py-filelock/tree/ooglek-handle-unwritable-path

I can only run tests on linux at the moment, so I'd appreciate any feedback for other systems.

[mcsimps2]

@benediktschmitt I don't see these changes in master and it still seems to be a problem in the latest pip release #60. It looks like the changes are only in the branch ooglek-handle-unwritable-path and not in master.

[hmeine]

I am very much interested in this fix. Indeed, we had two situations (after switching from a different lock implementation to filelock) in which SoftFileLock would just hang:

• a read-only filesystem
• a non-existant directory

In both cases, one would expect an exception to be raised that allows to discriminate from an existing lock file.

[gaborbernat]

Can you please rebase it on the latest main? You'll need to add some tests for it too, Thanks!

[ooglek]

I included a test for the change in the original pull request 2+ years ago. Hopefully it should suffice.

[gaborbernat]

Oh missed that, still needs a rebase though 😊

[ooglek]

@mcsimps2 @hmeine My need for this passed 2 years ago. One of you or someone you know will need to carry on this one-line change if you want it in a release.

[codecov]

Codecov Report

Merging #47 (895b353) into main (9191150) will decrease coverage by 6.52%.
The diff coverage is 72.22%.

@@            Coverage Diff             @@
##             main      #47      +/-   ##
==========================================
- Coverage   93.14%   86.61%   -6.53%     
==========================================
  Files           2        2              
  Lines         394      411      +17     
  Branches       25       25              
==========================================
- Hits          367      356      -11     
- Misses         22       49      +27     
- Partials        5        6       +1     

Flag	Coverage Δ
tests	86.61% <72.22%> (-6.28%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/filelock/__init__.py	79.44% <0.00%> (-13.34%)	⬇️
tests/test_filelock.py	92.20% <76.47%> (-1.26%)	⬇️

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[FFY00]

I rebased the PR.

[gaborbernat]

We'll need to fix the tests and linting 👍

[FFY00]

Yes, I had a look and the issues seem to be false positives (unless my english is rusty and there is actually a typo in words flagged).

[gaborbernat]

Superseded by #96