name: Close invalid PRs

on:
  pull_request_target:
    types: [ opened ]

jobs:
  run:
    if: ${{ github.repository != github.event.pull_request.head.repo.full_name && github.head_ref == 'master' }}
    runs-on: ubuntu-latest
    steps:
      - uses: superbrothers/close-pull-request@v3
        with:
          comment: "Please do not open pull requests from the `master` branch, create a new branch instead."