Add Github Actions and derive version from git tags

[lpetre]

Summary

Two changes here:

• I've ported the circleci config to github actions. I propose this as a replacement to circleci
• I've added setuptools_scm and configured it to generate libcst\_version.py

To improve our workflow around libcst releases, I'd like to propose that we publish pre-release versions of the package.

More context about publishing here: https://packaging.python.org/guides/publishing-package-distribution-releases-using-github-actions-ci-cd-workflows/#publishing-the-distribution-to-pypi-and-testpypi

And pre-release versions here: https://packaging.python.org/guides/distributing-packages-using-setuptools/#pre-release-versioning

Relating that to this change:

• setuptools_scm makes the pre-release versioning trivial
• We can add ~10 lines of github action yaml to handle the publishing to PyPi

TODOs:

• I will follow up with a commit that handles the pypi publishing
• I will delete the circleci files
• If this proposal is acceptable, we would need to configure some secrets in Github (ie codecov and pypi tokens)
• Add testing on windows-latest. I discovered that the test suite doesn't pass on windows, which I will fix in another PR.

Test Plan

See https://github.com/lpetre/LibCST/actions/runs/704265869

[zsol]

I like this direction, but let's make sure the CI setup is healthy before changing the release process.

[zsol]

when can this condition trigger?

[lpetre]

I think @thatch's comment is meant to be a reply here.

#471 (comment)

If someone adds it to pythonpath without using setup.py develop or similar.

[codecov-commenter]

Codecov Report

Merging #471 (4798164) into master (a1282f2) will decrease coverage by 0.00%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##           master     #471      +/-   ##
==========================================
- Coverage   94.70%   94.70%   -0.01%     
==========================================
  Files         236      235       -1     
  Lines       23084    23077       -7     
==========================================
- Hits        21861    21854       -7     
  Misses       1223     1223              

Impacted Files	Coverage Δ
libcst/tool.py	33.33% <ø> (ø)
setup.py	100.00% <ø> (+13.33%)	⬆️
libcst/__init__.py	91.30% <50.00%> (-8.70%)	⬇️

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[thatch]

If someone adds it to pythonpath without using setup.py develop or similar. Tim

…

On Mon, Aug 9, 2021, 1:31 PM Zsolt Dollenstein ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In libcst/__init__.py <#471 (comment)>: > +except ImportError: + LIBCST_VERSION = "unknown" when can this condition trigger? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#471 (review)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAMFKUHIM4JJCK63O2ZRKLT4A3HXANCNFSM42EBBNMQ> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&utm_campaign=notification-email> .

[lpetre]

Note: I have a follow up PR w/ windows testing (and a windows fix).

[jimmylai]

Why not 3.9?

Move to GH actions LGTM.

[zsol]

Currently circleci doesn't cover 3.9. I'd prefer adding 3.9 in a separate PR, this is already complex enough

[lpetre]

I'm happy to follow up w/ 3.9 support in a separate PR

[lpetre]

3.9 run here: https://github.com/lpetre/LibCST/actions/runs/1116879480

[zsol]

LGTM. if you resolve the conflict I can merge

[lpetre]

LGTM. if you resolve the conflict I can merge

Resolved!