name: PR Checks

on:
  pull_request:
    branches: [main]
  # Also run on every push to main so post-merge regressions surface
  # immediately instead of being discovered on the next PR.
  push:
    branches: [main]

concurrency:
  group: pr-checks-${{ github.ref }}
  cancel-in-progress: true

# FN-4863: Opt JavaScript actions into Node 24 ahead of GitHub's forced cutover on 2026-06-02.
env:
  FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"

jobs:
  lint:
    name: Lint
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Node.js and pnpm
        uses: ./.github/actions/setup-node-pnpm

      - name: Lint
        run: pnpm lint

  typecheck:
    name: Typecheck
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Node.js and pnpm
        uses: ./.github/actions/setup-node-pnpm

      - name: Typecheck
        run: pnpm typecheck

  build:
    name: Build
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Node.js and pnpm
        uses: ./.github/actions/setup-node-pnpm

      - name: Install Bun
        uses: oven-sh/setup-bun@v2

      - name: Build
        run: pnpm build

  test-shards:
    name: Test shard ${{ matrix.shard }}/4
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        shard: [1, 2, 3, 4]

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          # Engine tests run real git operations (merge-base against main,
          # case-variant ref checks) that require full history. Shallow
          # clones silently break tests like worktree-acquisition's resume
          # misbinding path.
          fetch-depth: 0

      - name: Setup Node.js and pnpm
        uses: ./.github/actions/setup-node-pnpm

      - name: Test (deterministic shard)
        run: pnpm test:ci:shard --shard ${{ matrix.shard }} --total 4