release-on-merge.yml

name: Release on merge

# When a release/* PR merges into main, create a GitHub release (tag v-<version>).
# Events from GITHUB_TOKEN do not start other workflows; publish.yml is triggered via
# workflow_run when this workflow completes (see publish.yml).

on:
  pull_request:
    types: [closed]
    branches:
      - main

concurrency:
  group: release-on-merge-${{ github.event.pull_request.number }}
  cancel-in-progress: false

permissions:
  contents: write

jobs:
  github-release:
    if: >-
      github.event.pull_request.merged == true &&
      startsWith(github.head_ref, 'release/') &&
      github.event.pull_request.head.repo.full_name == github.repository
    runs-on: ubuntu-latest
    steps:
      - name: Checkout merge commit
        uses: actions/checkout@v6
        with:
          ref: ${{ github.event.pull_request.merge_commit_sha }}

      - name: Read version
        id: ver
        run: |
          VERSION="$(node -p "require('./package.json').version")"
          echo "version=${VERSION}" >> "${GITHUB_OUTPUT}"

      - name: Create GitHub release
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          set -euo pipefail
          VERSION="${{ steps.ver.outputs.version }}"
          TAG="v-${VERSION}"
          if gh release view "${TAG}" --repo "${{ github.repository }}" >/dev/null 2>&1; then
            echo "Release ${TAG} already exists; skipping."
            exit 0
          fi
          gh release create "${TAG}" \
            --repo "${{ github.repository }}" \
            --title "${VERSION}" \
            --generate-notes