auto-merge.yml

name: Auto-merge pull requests

on:
  pull_request:

permissions:
  contents: write
  pull-requests: write

jobs:
  auto-merge:
    name: Enable auto-merge
    runs-on: ubuntu-latest
    if: >
      contains(fromJSON('["dependabot[bot]", "pre-commit-ci[bot]"]'), github.event.pull_request.user.login)
      && github.event.pull_request.head.repo.full_name == github.repository
      && github.event.pull_request.commits == 1
    steps:
      - name: Check changed files
        if: github.event.pull_request.user.login == 'pre-commit-ci[bot]'
        uses: actions/github-script@v7
        with:
          script: |
            const response = await github.rest.pulls.listFiles({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: context.payload.pull_request.number,
            });

            const changedFiles = response.data.map(file => file.filename);

            if (changedFiles.length !== 1 || changedFiles[0] !== '.pre-commit-config.yaml') {
              core.setFailed(
                `Unexpected files modified:\n${changedFiles.join('\n')}`
              );
            }
      - name: Enable auto-merge
        run: gh pr merge --auto --merge "$PR_URL"
        env:
          PR_URL: ${{github.event.pull_request.html_url}}
          GH_TOKEN: ${{secrets.GITHUB_TOKEN}}