[wsanchez]

This PR sets up the black linter.

The current branch does not actually run black in the default tox config, or in CI, so that the reviewer can see what changes are made before we reformat the code base.

To run black, use this command: tox -e black. It will fail, since the code is not yet reformatted to comply with black's conventions.

To test out the reformatting, run tox -e black-reformat. At this point, running black (per above) should succeed.

Before merging, we need to (1) reformat the code, (2) add black to the default tox environment list (it's commented out for now) and (3) add the black tox environment to the CI config (4) remove W504 from the flake8 ignore list, as it won't be needed post-reformatting.

[codecov-io]

Codecov Report

Merging #106 into master will not change coverage by %.
The diff coverage is 98.57%.

@@           Coverage Diff           @@
##           master     #106   +/-   ##
=======================================
  Coverage   98.55%   98.55%           
=======================================
  Files          10       10           
  Lines        1595     1595           
  Branches      187      187           
=======================================
  Hits         1572     1572           
  Misses         12       12           
  Partials       11       11           

Impacted Files	Coverage Δ
src/hyperlink/test/common.py	100.00% <ø> (ø)
src/hyperlink/_url.py	96.91% <95.59%> (ø)
src/hyperlink/_socket.py	100.00% <100.00%> (ø)
src/hyperlink/test/test_common.py	100.00% <100.00%> (ø)
src/hyperlink/test/test_decoded_url.py	100.00% <100.00%> (ø)
src/hyperlink/test/test_parse.py	100.00% <100.00%> (ø)
src/hyperlink/test/test_scheme_registration.py	100.00% <100.00%> (ø)
src/hyperlink/test/test_url.py	99.82% <100.00%> (ø)

---

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[wsanchez]

Restarting builds in hopes that codecov wakes up

[wsanchez]

@mahmoud if you get some time for a review, this one would be logistically nice, as this is a difficult branch to merge forward repeatedly due to black touching a lot of code, so there are frequent conflicts.

[mahmoud]

My main concern with Black is how it affects contributor workflow. Maybe we could use a doc on that?

After we merge this, contributors should run tox -e black-reformat before committing?

Also, don't forget to remove that W504.

[mahmoud]

So this works because the lint args are absent?

[wsanchez]

Yeah, {env:BLACK_LINT_ARGS:} evaluates to "" in the black-reformat environment.

[wsanchez]

Thanks for the W504 reminder; I had let that one slip.

And yes, you should run tox -e black-reformat before committing, or at least before pushing. You could also just run black directly if you have it installed; some editors will run black for you, for example.

I do use the Tox environment, because I know that'll work even if I don't have black installed, and it ensured I use the right version in the right way, but YYMV.