auto-update-prs.yml

name: Auto-update PRs on base branch push

on:
  push:
    branches: [main]

concurrency:
  group: auto-update-prs
  cancel-in-progress: true

jobs:
  auto-update:
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
    steps:
      - name: Update open PRs targeting main
        uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const owner = context.repo.owner;
            const repo  = context.repo.repo;

            const { data: prs } = await github.rest.pulls.list({
              owner, repo, base: 'main', state: 'open', per_page: 100,
            });

            console.log(`Found ${prs.length} open PR(s) targeting main`);
            let updated = 0;

            for (const pr of prs) {
              if (pr.head.repo?.full_name !== `${owner}/${repo}`) {
                console.log(`Skipping PR #${pr.number} (fork): ${pr.title}`);
                continue;
              }
              try {
                await github.rest.pulls.updateBranch({ owner, repo, pull_number: pr.number });
                console.log(`✓ Updated PR #${pr.number}: ${pr.title}`);
                updated++;
              } catch (e) {
                if (e.status === 422 || e.message?.toLowerCase().includes('already up to date')) {
                  console.log(`  PR #${pr.number} already up to date`);
                } else {
                  console.error(`✗ PR #${pr.number} failed: ${e.message}`);
                }
              }
            }
            console.log(`Done: ${updated} updated.`);