[kammce]

Adds a reusable workflow that releases each version line of a repository independently. A version line is one major version living in its own directory, e.g. v4/ and v5/ in libhal, or v5/ and v6/ in libhal-util.

Usage

concurrency:
  group: semantic-release
  cancel-in-progress: false
jobs:
  release:
    uses: libhal/ci/.github/workflows/[email protected]
    with:
      lines: '[{"major": 4, "dir": "v4"}, {"major": 5, "dir": "v5"}]'
    secrets:
      release_token: ${{ secrets.SEMANTIC_RELEASE }}

A single-directory repository uses one line with "dir": ".".

Rules

The version logic is in .github/scripts/semantic_release.py:

• Scope: a line only sees its own tags (<major>.*) and only counts commits that change its directory since its last release. A commit that changes several directories counts for each of their lines.
• Keywords: (minor) or (patch) in a commit subject asks for a release. The highest keyword since the last release wins, so several (patch) commits make one patch release. Commit bodies are ignored, so a squash merge's list of commits, or a message describing these rules (like this PR's own commit), doesn't count. Every intentional keyword in libhal, libhal-util, libhal-arm-mcu and ci history is in a subject line.
• No (major): it fails the run. Major versions are started by hand: publish the line's first tag yourself and add the line to lines.
• Pre-releases: a line whose only tags are <major>.0.0-alpha.K cuts <major>.0.0-alpha.K+1 on either keyword. Publishing <major>.0.0 by hand switches it to normal releases.

Because releases are computed from the last tag rather than from the commits in one push, a skipped or failed run is picked up by the next push.

Testing

• test_semantic_release.py: 20 unit tests that build throwaway git repositories. Run them locally with python3 -m unittest discover -s .github/scripts -p "test_*.py".
• Run against the real histories of libhal (4.x, 5.x), libhal-util (5.x, 6.x) and ci (5.x). Each reports nothing pending, and util's 6.x line reports that it isn't started yet.
• Self Check runs the unit tests and a dry run against this repository.

Follow-ups

• Move libhal and libhal-util to this workflow once 5.x.y includes it.
• util's 6.x line needs its first tag, 6.0.0-alpha.1, published by hand.