name: CI

on:
  push:
    branches: [main]
  pull_request:
  workflow_dispatch: # allow manual runs from the GitHub UI

# Cancel an in-progress run when a newer commit is pushed to the same ref.
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

permissions:
  contents: read

jobs:
  ci:
    name: Format, lint & build
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Set up Node.js
        uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: npm

      # `npm ci` does a clean, reproducible install from package-lock.json
      # and fails on lockfile drift.
      - name: Install dependencies
        run: npm ci

      - name: Format check
        run: npm run format:check

      - name: Lint
        run: npm run lint

      - name: Build
        run: npm run build