dnm.yml

name: Do Not Merge

on:
  pull_request:
    types: [synchronize, opened, reopened, labeled, unlabeled]

permissions:
  contents: read
  pull-requests: read

jobs:
  do-not-merge:
    name: Prevent Merging
    runs-on: ubuntu-24.04
    steps:
      - name: Check for DNM label
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          labels=$(gh pr view "${{ github.event.pull_request.number }}" \
            --repo "${{ github.repository }}" \
            --json labels -q '.labels[].name')

          if echo "$labels" | grep -qx 'DNM'; then
            echo "Pull request is labeled as 'DNM'"
            echo "This workflow fails so that the pull request cannot be merged"
            exit 1
          fi

          echo "No DNM label on PR #${{ github.event.pull_request.number }}"