update.yaml

# this workflow merges requests from Dependabot if tests are passing
# ref https://docs.github.com/en/code-security/dependabot/working-with-dependabot/automating-dependabot-with-github-actions
# and https://github.com/dependabot/fetch-metadata
name: Auto-merge

# `pull_request_target` means this uses code in the base branch, not the PR.
on: pull_request_target

# Dependabot PRs' tokens have read permissions by default and thus we must enable write permissions.
permissions:
  contents: write
  pull-requests: write

jobs:
  dependencies:
    runs-on: ubuntu-latest
    if: github.actor == 'dependabot[bot]'

    steps:
      - name: Fetch PR metadata
        id: metadata
        uses: dependabot/fetch-metadata@v2.1.0
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}

      - name: Wait for PR CI
        # Don't merge updates to GitHub Actions versions automatically.
        # (Some repos may wish to limit by version range (major/minor/patch), or scope (dep vs dev-dep), too.)
        if: contains(steps.metadata.outputs.package-ecosystem, 'npm')
        uses: lewagon/wait-on-check-action@v1.3.4
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          repo-token: ${{ secrets.GITHUB_TOKEN }}
          wait-interval: 30 # seconds
          running-workflow-name: dependencies # wait for all checks except this one
          allowed-conclusions: success # all other checks must pass, being skipped or cancelled is not sufficient

      - name: Auto-merge dependabot PRs
        # Don't merge updates to GitHub Actions versions automatically.
        # (Some repos may wish to limit by version range (major/minor/patch), or scope (dep vs dev-dep), too.)
        if: contains(steps.metadata.outputs.package-ecosystem, 'npm')
        env:
          PR_URL: ${{ github.event.pull_request.html_url }}
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        # The "auto" flag will only merge once all of the target branch's required checks
        # are met. Configure those in the "branch protection" settings for each repo.
        run: gh pr merge --auto --squash "$PR_URL"