rtk/.github/workflows/pr-target-check.yml

name: PR Target Branch Check

on:
  pull_request_target:
    types: [opened, edited]

jobs:
  check-target:
    runs-on: ubuntu-latest
    # Skip develop→master PRs (maintainer releases)
    if: >-
      github.event.pull_request.base.ref == 'master' &&
      github.event.pull_request.head.ref != 'develop'
    steps:
      - name: Add wrong-base label
        uses: actions/github-script@v7
        with:
          script: |
            const pr = context.payload.pull_request;

            // Add label
            await github.rest.issues.addLabels({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: pr.number,
              labels: ['wrong-base']
            });

            // Post comment
            const body = `👋 Thanks for the PR! It looks like this targets \`master\`, but all PRs should target the **\`develop\`** branch.

            Please update the base branch:
            1. Click **Edit** at the top right of this PR
            2. Change the base branch from \`master\` to \`develop\`

            See [CONTRIBUTING.md](https://github.com/${context.repo.owner}/${context.repo.repo}/blob/master/CONTRIBUTING.md) for details.`;

            await github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: pr.number,
              body: body
            });