Contributing

You want to start contributing? Nice!

We do use Gerrit  for Code Review. It allows a more granular review (per-commit granularity rather than PR granularity), as well as keeping track as how commits change over time. It greatly simplifies the review process, and leads to overall more high-quality contributions.

While it might initially look a bit intimidating, you hopefully will spend less time learning its workflow than writing actual Snix code.

Creating a Gerrit account#

• Navigate to our Gerrit instance  . Hit the “Sign in” button (which allows SSO with some common IdPs)
• In the User settings, paste an SSH public key and hit the “Add New SSH key” button. ¹
• Alternatively, you can also create “HTTP Credentials” (though saving the HTTP password is messy).

Update your git remote URL#

Instead of trying to push to Forgejo, reconfigure your git remote URL to interact with Gerrit directly.

Replace $USER with your Username shown in the Gerrit settings.

If using SSH authentication:#

$ git remote set-url origin "ssh://$USER@cl.snix.dev:29418/snix"

If using HTTP authentication:#

$ git remote set-url origin "https://$USER@cl.snix.dev/a/snix"

Install the commit-msg hook#

Gerrit uses a commit-msg hook to add a Change-Id: … field to each commit message if not present already. This allows Gerrit to identify new revisions / updates of old commits, and track them as new revisions of the same “CL” ².

To install the commit-msg hook, run the following from the repo root:

$ mkdir -p .git/hooks
$ curl -Lo .git/hooks/commit-msg https://cl.snix.dev/tools/hooks/commit-msg
$ chmod +x .git/hooks/commit-msg

Push your changes#

Do some local changes, and push them to Gerrit as follows:

$ git push origin HEAD:refs/for/canon

Gerrit will print links to newly created CLs to your terminal.

If you want to update/edit your CL, simply squash these changes into your local commit and push again.

The Gerrit model#

If do not have experience with the Gerrit, consider reading the Working with Gerrit: An example  or Basic Gerrit Walkthrough — For GitHub Users  .

Some more tips:

• Assign a reviewer to review your changes.
• React on comments and mark them as resolved once you did.
  • Comments are only “Drafts” (stored server-side) until you send them off. This can be done by the Reply button on the top, for example.
• Once CI is green, it’s up to the Author of the CL to submit, not the reviewer. If you want a bot to automatically submit in this case, you can add the Autosubmit+1 label.
• Rebase on origin/canon regularly. You cannot push if you still have an old version of a now-submitted CL in your git log.

$ git push origin HEAD:refs/for/canon%r=alice,cc=bob,l=Autosubmit+1,publish-comments

Commit conventions#

Commit messages#

The following described way of writing commit messages is known as Conventional Commits  and should bring these advantages:

• automatic creation of changelogs from commit messages
• lean commits: one focused change per commit
• filtering of commit history by type

All commit messages should be structured like this:

type(scope): Subject line with at most a 72 character length

Body of the commit message with an empty line between subject and
body. This text should explain what the change does and why it has
been made, *especially* if it introduces a new feature.

Relevant issues should be mentioned if they exist.

Where type can be one of:

• feat: A new feature has been introduced
• fix: An issue of some kind has been fixed
• docs: Documentation or comments have been updated
• style: Formatting changes only
• refactor: Hopefully self-explanatory!
• test: Added missing tests / fixed tests
• chore: Maintenance work

And scope should refer to some kind of logical grouping inside of the project.

It does not make sense to include the full path unless it aids in disambiguating. For example, when changing /snix/eval/src/lib.rs it is enough to write feat(eval): ....

Please take a look at the existing commit history  for examples.

Commit content#

Multiple changes should be divided into multiple git commits whenever possible. Common sense applies.

Code quality#

This one should go without saying - but please ensure that your code quality does not fall below the rest of the project. This is of course very subjective, but as an example if you place code that throws away errors into a block in which errors are handled properly your change might be rejected.