使用基本的快速设置，我无法到达io.on（'connect '）回调。连接刚刚停止
节点12.14.1快捷方式4.17.1socket.io3.0.1
代码

import express, { ErrorRequestHandler } from 'express';
import path from 'path';
import {Server} from 'socket.io';
import http from 'http';

import cors from 'cors';
import createError from 'http-errors';
import defaultRouter from './routes';

const app = express();

app.use(cors({origin:'*'}));
app.use(express.json());
app.use(express.urlencoded({ extended: true }));
app.use(express.static(path.join(__dirname ,'../public')))

app.get("/",(req,res)=>{return res.sendFile(path.join(__dirname,'public','index.html')) })
app.use(defaultRouter);

app.use((req, res, next) => {
  const { url } = req;
  const message = `Page not found ${url}`;
  next(new createError.NotFound(message));
});

const DefaultErrorHandler: ErrorRequestHandler = (err, req, res, next) => {
  if (err && err.statusCode) {
    return res.status(err.statusCode).send(err);
  }
  res.status(500).send('Yeah...my bad');
};
app.use(DefaultErrorHandler);

app.listen(3000, () => {

  console.log('App listening on port 3000');
});

const server =  require('http').createServer(app);
const io = require('socket.io')(server);

io.on('connection', function (socket:any) {
 console.log("connected")

  io.emit("user connected")
  socket.on('disconnect',()=>{console.log('disconnected')})
});
io.use((socket:any, next: any)=>{console.log(socket.request); next()})
server.listen(3001 )
server.on("listening",()=>{console.log('ws listening on 3001')} )
server.on("error",()=>{console.log('error')} )

WebSocket调用

$ websocat ws://localhost:3001/socket.io/?EIO=3\&transport=websocket
>0{"sid":"Q9Jj3CNtm6MSarmEAAAA","upgrades":[],"pingInterval":25000,"pingTimeout":5000}
>2

除错

engine handshaking client "Q9Jj3CNtm6MSarmEAAAA" +0ms
  engine:socket sending packet "open" ({"sid":"Q9Jj3CNtm6MSarmEAAAA","upgrades":[],"pingInterval":25000,"pingTimeout":5000}) +0ms
  engine:socket flushing buffer to transport +0ms
  engine:ws writing "0{"sid":"Q9Jj3CNtm6MSarmEAAAA","upgrades":[],"pingInterval":25000,"pingTimeout":5000}" +0ms
  engine:transport setting request +0ms
  socket.io:server incoming connection with id Q9Jj3CNtm6MSarmEAAAA +4s
  engine:socket writing ping packet - expecting pong within 5000ms +25s
  engine:socket sending packet "ping" (undefined) +1ms
  engine:socket flushing buffer to transport +0ms
  engine:ws writing "2" +25s
  engine:ws closing +5s
  socket.io:client client close with reason ping timeout +0ms
  socket.io:client no namespace joined yet, close the client +15s

当使用firecamp时，它会连续连接和断开连接，并且不会使用轮询传输进行连接
我不知道发生了什么与这些连接，我打破了它尽可能简单，并得到了相同的结果，侧记，我没有得到pong通知消防营。我打破了它，以最小的，从来没有达到“连接”块