renovate-changeset.yml

# Modelled on https://github.com/backstage/backstage/blob/5083c8024deffbdf454983900f02780d14b55a0b/.github/workflows/sync_renovate-changesets.yml#L6

name: Sync Renovate changeset
on:
  pull_request_target:
    paths:
      - '.github/workflows/renovate-changeset.yml'
      - 'pnpm-lock.yaml'

jobs:
  generate-changeset:
    runs-on: ubuntu-latest
    if: github.actor == 'renovate[bot]' && github.repository == 'seek-oss/skuba'
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 2
          ref: ${{ github.head_ref }}
          token: ${{ secrets.SEEK_OSS_CI_GITHUB_TOKEN }}
      - name: Configure Git
        run: |
          git config --global user.email 34733141+seek-oss-ci@users.noreply.github.com
          git config --global user.name 'Github changeset workflow'
      - name: Generate changeset
        uses: actions/github-script@v7
        env:
          PR_TITLE: ${{ github.event.pull_request.title }}
        with:
          script: |
            const { promises: fs } = require('fs');

            async function getPackagesNames(files) {
              const packageJsons = await Promise.all(
                files.map(async (file) => JSON.parse(await fs.readFile(file, 'utf8'))),
              );

              return packageJsons.flatMap((d) => (d.private ? [] : [d.name]));
            }

            async function createChangeset(fileName, message, packages) {
              const header = packages.map((pkg) => `'${pkg}': patch`).join('\n');
              const body = `---\n${header}\n---\n\n${message.trim()}\n`;
              await fs.writeFile(fileName, body);
            }

            const prTitle = process.env.PR_TITLE;
            if (!prTitle) {
              console.log('No PR title found, skipping');
              return;
            }

            const prefix = prTitle.split(':')[0];
            if (prefix !== 'deps' && prefix !== 'template') {
              console.log('Not a prod/template update PR, skipping');
              return;
            }

            const branch = await exec.getExecOutput('git branch --show-current');
            if (!branch.stdout.startsWith('renovate-')) {
              console.log('Not a renovate branch, skipping');
              return;
            }

            const diffOutput = await exec.getExecOutput('git diff --name-only HEAD~1');
            const diffFiles = diffOutput.stdout.split('\n');
            if (diffFiles.find((f) => f.startsWith('.changeset'))) {
              console.log('Changeset already exists, skipping');
              return;
            }

            const files = diffFiles.filter((file) => file.includes('package.json'));
            const packageNames = await getPackagesNames(files);
            if (!packageNames.length) {
              console.log('No package.json changes to published packages, skipping');
              return;
            }

            const { stdout: shortHash } = await exec.getExecOutput(
              'git rev-parse --short HEAD',
            );
            const fileName = `.changeset/renovate-${shortHash.trim()}.md`;

            await createChangeset(fileName, prTitle, packageNames);
            await exec.exec('git', ['add', fileName]);
            await exec.exec('git commit -C HEAD --amend --no-edit');
            await exec.exec('git push --force');