docs(sublime): document setup for linting git commit messages

[costajohnt]

Issues

Closes #3781

Follow-up to #3782, which was closed in favor of documenting the configuration instead of widening the languageId match arm.

Description

Sublime Text reports languageId: "git" for commit buffers, and harper-ls routes commit messages by the git-commit languageId, so commit messages go unlinted out of the box. There are two things a user has to do, and neither is currently documented:

1. Add text.git.commit to the selector in the harper-ls client config, so LSP attaches to the buffer at all.
2. Map "text.git.commit": "git-commit" in language-ids.sublime-settings, so the client sends a languageId harper-ls recognizes.

This adds a "Linting Git Commit Messages" section to the Sublime Text integration page covering both.

Demo

Not applicable, documentation only.

How Has This Been Tested?

Documentation only, no code paths touched. The git-commit languageId in the mapping matches the existing match arm in harper-ls/src/backend.rs, and the workaround itself is the one the reporter confirmed working in #3781.

AI Disclosure

• I used an AI agent interactively.

If Your PR Implements or Enhances a Linter

Not applicable.

Checklist

• I have performed a self-review of my own code
• I have considered splitting this into smaller pull requests.

[elijah-potter]

Thanks for submitting this. Can you just double-confirm that you tried this in a real Sublime editor? I want to make sure it covers everything.

[costajohnt]

Yes, tried it now in Sublime Text 4 (build 4200) with LSP from Package Control and harper-ls 2.9.1 on macOS. Opened a COMMIT_EDITMSG with some typos in the subject and body and watched the LSP log panel:

• Without the language-ids mapping, didOpen goes out with languageId: "git" and harper-ls publishes an empty diagnostics list.
• With "text.git.commit": "git-commit" in language-ids.sublime-settings and text.git.commit added to the selector, didOpen goes out with languageId: "git-commit" and harper flags the subject line and the body (spelling, repeated words).

Nothing else was needed. The Git Formats package that ships with Sublime already gives the buffer the text.git.commit scope, so those two settings are the whole setup.

[hippietrail]

Yes, tried it now in Sublime Text 4 (build 4200) with LSP from Package Control and harper-ls 2.9.1 on macOS.

If you could do a little screen recording of it working that would be excellent.

[costajohnt]

Here's a recording. Making it turned up a gap in the docs: harper-ls was publishing the diagnostics fine (that's what I'd been checking in the LSP log panel), but LSP for Sublime Text drops diagnostics for any file matching folder_exclude_patterns, and .git is in the default list, so nothing showed up in the editor for .git/COMMIT_EDITMSG. I pushed a third step that removes .git from that list for the Git Commit syntax only. With all three in place it looks like this:

Screen.Recording.2026-09-18.at.10.55.50.AM.mov