name: Check subtree split
on:
  pull_request_target:
jobs:
  close-pull-request:
    runs-on: ubuntu-latest
    steps:
    - name: Close pull request
      uses: actions/github-script@v6
      with:
        script: |
          if (context.repo.owner === "symfony") {
            github.rest.issues.createComment({
              owner: "symfony",
              repo: context.repo.repo,
              issue_number: context.issue.number,
              body: `
          Thanks for your Pull Request! We love contributions.

          However, you should instead open your PR on the main repository:
          https://github.com/symfony/polyfill

          This repository is what we call a "subtree split": a read-only subset of that main repository.
          We're looking forward to your PR there!
          `
            });
            github.rest.pulls.update({
              owner: "symfony",
              repo: context.repo.repo,
              pull_number: context.issue.number,
              state: "closed"
            });
          }