dependabot-automerge.yml

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: Fetch Dependabot metadata
        id: metadata
        uses: dependabot/fetch-metadata@v3
        with:
          github-token: "${{ secrets.GITHUB_TOKEN }}"

      # Security-sensitive packages are excluded from auto-merge so a
      # compromised upstream release cannot ship to consumers without a
      # human eyeballing the diff. These are the packages whose code
      # directly renders or sanitizes user-controlled content (links,
      # markdown, block payloads) — a malicious minor release here is
      # the worst case for our supply-chain posture.
      - name: Check exclusion list
        id: excluded
        env:
          PACKAGE_NAMES: ${{ steps.metadata.outputs.dependency-names }}
        run: |
          set -euo pipefail
          excluded=false
          IFS=', ' read -r -a names <<< "$PACKAGE_NAMES"
          for pkg in "${names[@]}"; do
            case "$pkg" in
              slack-blocks-to-jsx|react-markdown|remark-gfm|@tiptap/extension-link|@tiptap/starter-kit|@tiptap/core|@tiptap/react|@tiptap/pm|@tightknitai/slack-block-kit-validator|ajv|ajv-formats|slack-web-api-client)
                excluded=true
                ;;
            esac
          done
          echo "excluded=$excluded" >> "$GITHUB_OUTPUT"

      - name: Enable auto-merge for minor/patch updates
        if: |
          steps.metadata.outputs.update-type != 'version-update:semver-major' &&
          steps.excluded.outputs.excluded != 'true'
        run: gh pr merge --auto --squash "$PR_URL"
        env:
          PR_URL: ${{ github.event.pull_request.html_url }}
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Approve PR
        if: |
          steps.metadata.outputs.update-type != 'version-update:semver-major' &&
          steps.excluded.outputs.excluded != 'true'
        run: gh pr review --approve "$PR_URL"
        env:
          PR_URL: ${{ github.event.pull_request.html_url }}
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Comment when held for manual review
        if: |
          steps.metadata.outputs.update-type != 'version-update:semver-major' &&
          steps.excluded.outputs.excluded == 'true'
        run: |
          gh pr comment "$PR_URL" --body "Held for manual review: \`${{ steps.metadata.outputs.dependency-names }}\` is on the security-sensitive auto-merge exclusion list. Verify the changelog and source diff before merging."
        env:
          PR_URL: ${{ github.event.pull_request.html_url }}
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}