Haskell-language-server: Should we lint, -wall and format our code base?

[alanz]

I have recently spent some time in the code base again.

I can't help noticing that I have several hlint and other warnings, as well as a variety of formatting styles. Format differences naturally occur with multiple contributors of course.

Given the growing size and number of contributors, I think it would be good to enforce an hlint config, as well as require compiles to pass -wall, or some agreed set of warnings. This could initially be done via a separate "allow-fail" CI build which we aim to bring into compliance overtime.

And perhaps we should agree to use a specific formatter, and format all the code with it.

[konn]

I can't help noticing that I have several hlint and other warnings, as well as a variety of formatting styles. Format differences naturally occur with multiple contributors of course.

And perhaps we should agree to use a specific formatter, and format all the code with it.

Even though I'm not a maintainer, but as a spare-time contributor, I strongly agree with this point!
While I tried to make some contributions to HLS, I have already broken the indent styles by accident for some times.
The changes are trivial in some cases so that one can manually re-order import list or adjusting indentation, but sometimes it becomes rather tedious to maintain formatting coherency in per-module manner.

As a contributor, I feel more comfortable if there is project-wide formatter configuration and we can just let HLS to invoke them automatically. That saves essentially unnecessary works both for contributors and reviewers, reducing noise from reviwing process, IMHO.

[alanz]

Contentious question: which formatter?

To my mind it should be one without requiring much config, or used with the default config.

[jneira]

Contentious question: which formatter?

What about making a poll? 😄
I am personally fine with any of them, and even i am not too disturbed with the actual situation (although agree in it can save time for all of us). I've found more useful the more semantic oriented -Wall and hlint.

[Ailrun]

I think in terms of reducing config, ormolu would be a good choice.

[peterwicksstringfield]

Reformat the entire code base with whatever format is chosen, then re-run it on each PR before the unit tests. If there are changes they can be automatically committed and the build restarted. So any successful build is a fixed point of the formatter. I don't think it matters which format is chosen, just so long as the computer is the only one who has to actually think about it.

Wall and hlint sound good too.