enforce-develop-base.yml

name: Enforce develop as PR base

# Contributors must open pull requests against `develop`, never `main`.
# Any PR into `main` from someone who is not an owner, org member or
# collaborator is commented on and closed automatically.
#
# Uses pull_request_target so it can comment/close on PRs from forks.
# It never checks out or runs the PR's code.

on:
  pull_request_target:
    types: [opened, reopened, edited, synchronize]
    branches: [main]

permissions:
  pull-requests: write
  issues: write

jobs:
  redirect-to-develop:
    if: >-
      github.event.pull_request.author_association != 'OWNER' &&
      github.event.pull_request.author_association != 'MEMBER' &&
      github.event.pull_request.author_association != 'COLLABORATOR'
    runs-on: ubuntu-latest
    steps:
      - name: Comment and close PR targeting main
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          PR: ${{ github.event.pull_request.number }}
          REPO: ${{ github.repository }}
        run: |
          gh pr comment "$PR" --repo "$REPO" --body "👋 Thanks for the contribution! This repository only accepts contributor pull requests into the **\`develop\`** branch. PRs raised against \`main\` cannot be merged, so this one has been closed automatically.

          Please re-open your PR with **base: \`develop\`** (rebase your branch onto \`develop\` first if needed). See the note at the bottom of the issue you're working on."
          gh pr close "$PR" --repo "$REPO"