block-pr-to-master.yml

name: Block PR to master

on:
  pull_request:
    types:
      - opened
      - reopened
      - synchronize
      - edited
    branches:
      - master

permissions:
  pull-requests: write
  issues: write

jobs:
  close-pr-to-master:
    name: Close PR to master
    runs-on: ubuntu-latest

    steps:
      - name: Close pull request targeting master
        uses: actions/github-script@v7
        with:
          script: |
            const pullRequest = context.payload.pull_request;

            await github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: pullRequest.number,
              body: 'Pull requests directly to `master` are not allowed. Please open your PR against `develop` or the correct target branch.'
            });

            await github.rest.pulls.update({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: pullRequest.number,
              state: 'closed'
            });