dependabot-auto-merge.yaml

# see https://docs.github.com/en/code-security/dependabot/working-with-dependabot/automating-dependabot-with-github-actions#enable-auto-merge-on-a-pull-request

name: Dependabot auto-merge
on: pull_request

permissions:
  contents: write
  pull-requests: write

jobs:
  dependabot:
    runs-on: ubuntu-latest
    if: github.actor == 'dependabot[bot]'
    steps:
      - name: Dependabot metadata
        id: metadata
        uses: dependabot/fetch-metadata@c9c4182bf1b97f5224aee3906fd373f6b61b4526 # v1.6.0
        with:
          github-token: "${{ secrets.GITHUB_TOKEN }}"
      - name: Check whether anyone besides dependabot has pushed
        id: pr_author
        run: |
          EXTRA_AUTHORS=$(gh pr view "$PR_URL" --json commits --jq '.commits[] | .authors[] | .login' | sort | uniq | grep -v dependabot || echo -n '')
          if [ -n "$EXTRA_AUTHORS" ]; then
            echo "PR has authors in addition to dependabot: $EXTRA_AUTHORS"
            echo "human_pushed=true" >> "$GITHUB_OUTPUT"
          else
            echo "human_pushed=false" >> "$GITHUB_OUTPUT"
          fi
        env:
          PR_URL: ${{github.event.pull_request.html_url}}
          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}
      - name: Enable auto-merge for Dependabot PRs
        if: >
            ( steps.pr_author.human_pushed != 'true' ) &&
            ( steps.metadata.outputs.update-type == 'version-update:semver-patch' || steps.metadata.outputs.update-type == 'version-update:semver-minor' )
        run: gh pr merge --auto --squash "$PR_URL" && gh pr review --approve "$PR_URL"
        env:
          PR_URL: ${{github.event.pull_request.html_url}}
          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}
      - name: Disable auto-merge if human modified PR
        if: steps.pr_author.human_pushed == 'true'
        run: |
          echo "disabling auto-merge due to non-dependabot push"
          gh pr merge --disable-auto "$PR_URL"
        env:
          PR_URL: ${{github.event.pull_request.html_url}}
          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}