main.ts

import http from 'http';
import querystring from 'querystring';
import path from 'path';
import fs from 'fs';

const hostname = '127.0.0.1';
const port = 3000;
const publicPath = path.join(__dirname, './public');

const wait = (time: number) => new Promise(resolve => {
  setTimeout(resolve, time);
});

const makeScript = (jsName: string, needWait: number = 0, url?: string, type?: string) => {
  const waitStr = needWait > 0 ? ` wait: ${needWait}` : '';
  let script = `console.log('${jsName}${waitStr}');`;
  if (url) {
    script += `document.write('<script ${type || ''} src="${url}"></script>');`;
  }
  return script;
}

const server = http.createServer(async (req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  const [reqPath, queryStr] = (req.url || '').split('?');
  const query = querystring.decode(queryStr || '');
  if (reqPath.endsWith('.js')) {
    res.setHeader('Content-Type', 'application/x-javascript');
    const jsName = reqPath.split('/').pop() || '';
    const needWait = (query.wait && +query.wait) || 0;
    const moreUrl = Array.isArray(query.url) ? query.url[0] : query.url;
    const moreType = Array.isArray(query.type) ? query.type[0] : query.type;
    if (needWait > 0) {
      await wait(needWait);
    }
    res.write(makeScript(jsName, needWait, decodeURIComponent(moreUrl || ''), moreType || ''));
  } else {
    let htmlName = 'index.html';
    if (reqPath.endsWith('.html')) {
      htmlName = reqPath.split('/').pop() || '';
    }
    const content = fs.readFileSync(path.join(publicPath, htmlName), 'utf-8');
    res.setHeader('Content-Type', 'text/html; charset=utf-8');
    res.write(content);
  }
  res.end();
});

server.listen(port, hostname, () => {
  const url = `http://${hostname}:${port}/`;
  console.log(`Server running at ${url}`);
});