proxy lichess stream Server Sent Event

package.json

{
  "name": "enhance-lichess",
  "version": "1.0.0",
  "dependencies": {
    "event-stream": "^3.3.0",
    "request": "^2.55.0"
  }
}

server.js

#!/usr/bin/env node

var request = require('request');
var http = require('http');
var fs = require('fs');
var es = require('event-stream');

var port = 9876;

http.createServer(function(req, res) {
  if (req.url === "/") {


    var readStream =
    request('http://lichess.org/network/stream')
      .pipe(es.split())
      .pipe(es.map(function (data, cb) {
        if (data.length > 0 && data.indexOf("data: ")===0) {
          data += "|kiki";
          cb(null, data + "\n\n");
        }
        else
          cb(); // drop
      }));

    res.writeHead(200, {
      "Content-Type": "text/event-stream; charset=utf-8"
    });
    readStream.pipe(res);
    readStream.on('error', function(err) {
      res.end(err);
    });
  }
  else {
    res.writeHead(404);
    res.end();
  }
}).listen(port);
console.log("Listening on: http://127.0.0.1:"+port);