tcp-websocket-tunnel.js

const net = require('net')
const WebSocket = require('ws')

exports.toWebSocket = (fromPort, toAddr) => {
  const server = net.createServer(c => {
    const ws = new WebSocket(toAddr)

    ws.on('close', () => c.destroy())

    ws.on('error', () => c.destroy())

    c.on('end', () => ws.close(1000))

    c.on('error', () => ws.close(1000))

    ws.on('open', () => c.on('data', data => ws.send(data)))

    ws.on('message', data => {
      if (!c.destroyed)
        c.write(data)
    })
  })

  server.on('error', (err) => {
    throw err
  })
  server.listen(fromPort)

  return server
}

exports.toTCP = (fromPort, toPort, toHost) => {
  const wss = new WebSocket.WebSocketServer({ port: fromPort })

  wss.on('connection', ws => this.toTCPOnConnection(ws, toPort, toHost))

  return wss
}

exports.toTCPOnConnection = (ws, toPort, toHost) => {
  const client = net.connect(toPort, toHost)

  client.on('end', () => ws.close(1000))

  client.on('error', () => ws.close(1000))

  ws.on('close', () => client.destroy())

  ws.on('error', () => client.destroy())

  ws.on('message', data => client.write(data))

  client.on('data', data => ws.send(data))
}