release.yml

name: Release

on:
  push:
    branches:
      - main
      - "release/**"

concurrency: ${{ github.workflow }}-${{ github.ref }}

permissions:
  contents: write
  pull-requests: write

jobs:
  release:
    name: Release
    runs-on: ubuntu-latest
    steps:
      - name: Generate App Token
        id: app-token
        uses: actions/create-github-app-token@v3
        with:
          client-id: ${{ secrets.CHANGESETS_BOT_CLIENT_ID }}
          private-key: ${{ secrets.CHANGESETS_BOT_PRIVATE_KEY }}

      - name: Checkout
        uses: actions/checkout@v6
        with:
          fetch-depth: 0
          token: ${{ steps.app-token.outputs.token }}

      - name: Setup Node.js
        uses: actions/setup-node@v6
        with:
          node-version: 24

      - name: Install dependencies
        run: npm ci

      - name: Create Release Pull Request or Publish
        id: changesets
        uses: changesets/action@v1
        with:
          version: node scripts/sync-versions.js
          publish: npx changeset publish
          title: "chore: version packages"
          commit: "chore: version packages"
        env:
          GITHUB_TOKEN: ${{ steps.app-token.outputs.token }}

      - name: Create release branch on major version bump
        if: steps.changesets.outputs.published == 'true' && github.ref == 'refs/heads/main'
        uses: actions/github-script@v8
        with:
          script: |
            const published = JSON.parse('${{ steps.changesets.outputs.publishedPackages }}');
            if (!published.length) return;

            const newVersion = published[0].version;
            const newMajor = parseInt(newVersion.split('.')[0], 10);

            // Only act on stable major bumps (not prereleases)
            if (newVersion.includes('-') || newMajor < 1) return;

            const prevMajor = newMajor - 1;
            const branchName = `release/v${prevMajor}.x`;

            try {
                await github.rest.repos.getBranch({
                    owner: context.repo.owner,
                    repo: context.repo.repo,
                    branch: branchName,
                });
                console.log(`Branch ${branchName} already exists, skipping.`);
                return;
            } catch (e) {
                if (e.status !== 404) throw e;
            }

            const tags = await github.paginate(github.rest.repos.listTags, {
                owner: context.repo.owner,
                repo: context.repo.repo,
                per_page: 100,
            });

            const prevTag = tags.find(t => {
                const match = t.name.match(/(?:^v?|@)(\d+)\.\d+\.\d+$/);
                return match && parseInt(match[1], 10) === prevMajor;
            });

            if (!prevTag) {
                console.log(`No tag found for v${prevMajor}, skipping branch creation.`);
                return;
            }

            await github.rest.git.createRef({
                owner: context.repo.owner,
                repo: context.repo.repo,
                ref: `refs/heads/${branchName}`,
                sha: prevTag.commit.sha,
            });

            console.log(`Created ${branchName} from tag ${prevTag.name} (${prevTag.commit.sha}).`);