update-pr-leaderboard.yml

name: Update PR leaderboard

on:
  pull_request_target:
    types:
      - opened

permissions:
  contents: write
  pull-requests: read

concurrency:
  group: leaderboard-json-update
  cancel-in-progress: false

jobs:
  update-leaderboard:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout default branch (trusted code only)
        uses: actions/checkout@v4
        with:
          ref: ${{ github.event.repository.default_branch }}
          fetch-depth: 0
          persist-credentials: false

      - name: Increment PR count in leaderboard.json
        env:
          GH_TOKEN: ${{ github.token }}
          DEFAULT_BRANCH: ${{ github.event.repository.default_branch }}
          PR_USER: ${{ github.event.pull_request.user.login }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
        run: |
          set -euo pipefail

          git config user.name "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
          git remote set-url origin "https://x-access-token:${GH_TOKEN}@github.com/${GITHUB_REPOSITORY}.git"

          git checkout "${DEFAULT_BRANCH}"
          git pull --ff-only origin "${DEFAULT_BRANCH}"

          if git --no-pager log --format=%s --grep="^chore: update leaderboard for PR #${PR_NUMBER}$" -n 1 | grep -q .; then
            echo "PR #${PR_NUMBER} already counted."
            exit 0
          fi

          if [ ! -f leaderboard.json ]; then
            printf '{}\n' > leaderboard.json
          fi

          tmp_file="$(mktemp)"
          jq --arg user "${PR_USER}" '.[$user] = ((.[$user] // 0) + 1)' leaderboard.json > "${tmp_file}"
          mv "${tmp_file}" leaderboard.json

          git add leaderboard.json

          if git diff --cached --quiet -- leaderboard.json; then
            echo "No leaderboard changes to commit."
            exit 0
          fi

          git commit -m "chore: update leaderboard for PR #${PR_NUMBER}"
          git pull --rebase origin "${DEFAULT_BRANCH}"
          git push origin "HEAD:${DEFAULT_BRANCH}"