nuxt-build-monitor.ts

const nuxtBuildMonitor = async (_, nuxt) => {
  const timings = {} as Record<string, number>;

  const os = await import('node:os');
  const fs = await import('node:fs');

  fs.writeFileSync('timings.log', '', 'utf8');

  const log = (message: string) => {
    const timeTag = `[${new Date().toLocaleTimeString()}]`;
    console.log(`${timeTag} ${message}`);
    fs.appendFileSync('timings.log', `${timeTag} ${message}\n`, 'utf8');
  };

  const fmtTime = (ms: number) => `${(ms / 1000).toFixed(2)}s`;
  const fmtPercent = (value: number) => `${(value * 100).toFixed(2)}%`;
  const fmtBytes = (bytes: number) => (bytes / 1024 / 1024).toFixed(2) + 'MB';

  log(`--- System info ---`);
  log(`OS: ${os.platform()} ${os.release()} (${os.arch()})`);
  log(`Node.js: ${process.version}`);

  const stats = () => {
    const { heapUsed, heapTotal, rss } = process.memoryUsage();
    log(`Heap used: ${fmtPercent(heapUsed / heapTotal)} \t RSS: ${fmtBytes(rss)}`);
  };

  nuxt.hooks.hook('build:before', () => {
    timings.beforeBuild = performance.now();
    log(`--- Build started ---`);
    stats();
  });

  nuxt.hooks.hook('vite:compiled', () => {
    log(`Vite compiled in ${fmtTime(performance.now() - timings.beforeBuild)}`);
    stats();
  });

  nuxt.hooks.hook('nitro:build:before', () => {
    timings.nitroBuildBefore = performance.now();
    log(`--- Nitro build started ---`);
    stats();
  });

  nuxt.hooks.hook('nitro:init', (nitro) => {
    nitro.hooks.hook('compiled', () => {
      const afterBuild = performance.now();
      log(`Nitro build completed in ${fmtTime(afterBuild - timings.nitroBuildBefore)}`);
      stats();
    });
  });
};