release.yml

name: Release

on:
  workflow_run:
    workflows:
      - CI
    types:
      - completed

permissions:
  contents: write

concurrency:
  group: release-${{ github.event.workflow_run.head_branch }}
  cancel-in-progress: true

jobs:
  release:
    if: >-
      ${{
        github.event.workflow_run.conclusion == 'success' &&
        (github.event.workflow_run.head_branch == 'main' || github.event.workflow_run.head_branch == 'master')
      }}
    runs-on: ubuntu-latest

    steps:
      - name: Checkout tested commit
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          ref: ${{ github.event.workflow_run.head_sha }}

      - name: Install uv
        uses: astral-sh/setup-uv@v7

      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.12"

      - name: Ensure tested commit is branch tip
        id: tip
        env:
          BRANCH_NAME: ${{ github.event.workflow_run.head_branch }}
          HEAD_SHA: ${{ github.event.workflow_run.head_sha }}
        run: |
          git fetch origin "${BRANCH_NAME}" --tags
          REMOTE_SHA="$(git rev-parse "origin/${BRANCH_NAME}")"

          if [ "${REMOTE_SHA}" != "${HEAD_SHA}" ]; then
            echo "Branch ${BRANCH_NAME} moved from ${HEAD_SHA} to ${REMOTE_SHA}; skipping stale release."
            echo "is_tip=false" >> "${GITHUB_OUTPUT}"
            exit 0
          fi

          echo "is_tip=true" >> "${GITHUB_OUTPUT}"

      - name: Decide release bump
        if: steps.tip.outputs.is_tip == 'true'
        id: bump
        run: |
          python - <<'PY' >> "${GITHUB_OUTPUT}"
          import re
          import subprocess
          import sys

          def git(*args: str) -> str:
              return subprocess.check_output(["git", *args], text=True).strip()

          try:
              last_tag = git("describe", "--tags", "--abbrev=0")
          except subprocess.CalledProcessError:
              last_tag = ""

          rev_range = f"{last_tag}..HEAD" if last_tag else "HEAD"
          raw = git("log", rev_range, "--format=%s%n%b%x00")
          entries = [entry.strip() for entry in raw.split("\x00") if entry.strip()]

          if not entries:
              print("should_release=false")
              print("reason=no_commits")
              sys.exit(0)

          bump = None
          release_notes = []

          for entry in entries:
              lines = entry.splitlines()
              subject = lines[0].strip()
              body = "\n".join(lines[1:])
              text = f"{subject}\n{body}"
              lower = subject.lower()

              if "breaking change" in text.lower() or re.match(r"^[^:]+!:", subject):
                  bump = "major"
                  release_notes.append(subject)
                  break
              if lower.startswith("feat:"):
                  bump = "minor" if bump != "major" else bump
                  release_notes.append(subject)
                  continue
              if lower.startswith("fix:"):
                  if bump not in {"major", "minor"}:
                      bump = "patch"
                  release_notes.append(subject)
                  continue

          print(f"last_tag={last_tag}")
          print(f"should_release={'true' if bump else 'false'}")
          print(f"bump={bump or ''}")
          PY

      - name: Stop when no release is needed
        if: steps.tip.outputs.is_tip == 'true' && steps.bump.outputs.should_release != 'true'
        run: echo "No feat/fix/breaking changes since the last tag."

      - name: Bump version
        if: steps.tip.outputs.is_tip == 'true' && steps.bump.outputs.should_release == 'true'
        run: uv version --bump "${{ steps.bump.outputs.bump }}" --frozen

      - name: Read version
        if: steps.tip.outputs.is_tip == 'true' && steps.bump.outputs.should_release == 'true'
        id: version
        run: echo "value=$(uv version --short)" >> "${GITHUB_OUTPUT}"

      - name: Commit release change
        if: steps.tip.outputs.is_tip == 'true' && steps.bump.outputs.should_release == 'true'
        env:
          VERSION: ${{ steps.version.outputs.value }}
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
          git switch -C "${{ github.event.workflow_run.head_branch }}"
          git add pyproject.toml
          git commit -m "chore: release ${VERSION} [skip ci]"

      - name: Create tag
        if: steps.tip.outputs.is_tip == 'true' && steps.bump.outputs.should_release == 'true'
        env:
          VERSION: ${{ steps.version.outputs.value }}
        run: git tag -a "v${VERSION}" -m "Release v${VERSION}"

      - name: Push release commit and tag
        if: steps.tip.outputs.is_tip == 'true' && steps.bump.outputs.should_release == 'true'
        env:
          BRANCH_NAME: ${{ github.event.workflow_run.head_branch }}
          VERSION: ${{ steps.version.outputs.value }}
        run: |
          git push origin "HEAD:${BRANCH_NAME}"
          git push origin "v${VERSION}"