HTTP server returning an error code specified by the client

server-with-error.mjs

import * as http from "node:http";

const PORT = 8000;

// source: https://developer.mozilla.org/en-US/docs/Learn/Server-side/Node_server_without_framework
http
  .createServer(async (req, res) => {
    const statusCode = parseInt(req.url.slice(1));
    res.writeHead(statusCode, { "Content-Type": "application/json" });
    res.end("{}");
    console.log(`${req.method} ${req.url} ${statusCode}`);
  })
  .listen(PORT);

console.log(`Server running at http://127.0.0.1:${PORT}/`);