server.js

import express from "express";
import { createServer } from "http";
import fetch from "node-fetch";

function connect(conn, PORT, opts) {
  const app = express(),
    server = createServer(app);
  let _qr = "invalid";
  conn.ev.on("connection.update", ({ qr }) => qr && (_qr = qr)),
    app.use(async (req, res) => {
      res.setHeader("content-type", "image/png"), res.end(await toBuffer(_qr));
    }),
    server.listen(PORT, () => {
      console.log("App listened on port", PORT), opts.keepalive && keepAlive();
    });
}

function pipeEmit(event, event2, prefix = "") {
  const oldEmit = event.emit;
  return (
    (event.emit = (event, ...args) => {
      oldEmit(event, ...args), event2.emit(prefix + event, ...args);
    }),
    {
      unpipeEmit() {
        event.emit = oldEmit;
      },
    }
  );
}

function keepAlive() {
  const url = `https://${process.env.REPL_SLUG}.${process.env.REPL_OWNER}.repl.co`;
  /(\/\/|\.)undefined\./.test(url) ||
    setInterval(() => fetch(url).catch(console.error), 3e5);
}
export default connect;