name: Dependabot Pull Request Approve and Merge
on: pull_request_target
permissions:
  contents: read
jobs:
  dependabot:
    permissions:
      pull-requests: write
      contents: write
    runs-on: ubuntu-latest
    # Checking the actor will prevent your Action run failing on non-Dependabot
    # PRs but also ensures that it only does work for Dependabot PRs.
    if: github.actor == 'dependabot[bot]' && github.event.pull_request.user.login == 'dependabot[bot]'
    steps:
      - uses: step-security/harden-runner@f808768d1510423e83855289c910610ca9b43176 # v2.17.0
        with:
          egress-policy: audit
      - uses: actions/create-github-app-token@1b10c78c7865c340bc4f6099eb2f838309f1e8c3 # v3.1.1
        id: app-token
        env:
          APP_ID: ${{ secrets.APP_ID }}
        with:
          app-id: ${{ env.APP_ID }}
          private-key: ${{ secrets.PRIVATE_KEY }}
      # This first step will fail if there's no metadata and so the approval
      # will not occur.
      - name: Dependabot metadata
        id: dependabot-metadata
        uses: dependabot/fetch-metadata@ffa630c65fa7e0ecfa0625b5ceda64399aea1b36 # v3.0.0
        with:
          github-token: "${{ steps.app-token.outputs.token }}"
      # Here the PR gets approved.
      - name: Approve a PR
        run: gh pr review --approve "$PR_URL"
        env:
          PR_URL: ${{ github.event.pull_request.html_url }}
          GITHUB_TOKEN: "${{ steps.app-token.outputs.token }}"
      # Finally, this sets the PR to allow auto-merging for patch and minor
      # updates if all checks pass
      - name: Enable auto-merge for Dependabot PRs
        if: ${{ steps.dependabot-metadata.outputs.update-type == 'version-update:semver-patch' }}
        run: gh pr merge --auto --squash "$PR_URL"
        env:
          PR_URL: ${{ github.event.pull_request.html_url }}
          GITHUB_TOKEN: "${{ steps.app-token.outputs.token }}"