http-proxy with cookies and gzip responses(Solved CORS limit)

http-proxy-cookies.js

var http = require("http"),
  httpProxy = require("http-proxy");
var url = require("url");
var zlib = require("zlib");

var proxy = httpProxy.createProxyServer({});
proxy.on("proxyRes", function(proxyRes, req, res) {
  console.log("Proxy response");
  // res.headers = proxyRes.headers;

  let allowedOrigin = false;
  if (req.headers.origin) {
    const originHostName = url.parse(req.headers.origin).hostname;
    if (originHostName) {
      res.setHeader("access-control-allow-origin", req.headers.origin);
      res.setHeader("access-control-allow-credentials", "true");
      allowedOrigin = true;
    }
  }

  if (req.headers["access-control-request-method"]) {
    res.setHeader(
      "access-control-allow-methods",
      req.headers["access-control-request-method"]
    );
  }

  if (req.headers["access-control-request-headers"]) {
    res.setHeader(
      "access-control-allow-headers",
      req.headers["access-control-request-headers"]
    );
  }

  if (allowedOrigin) {
    res.setHeader("access-control-max-age", 60 * 60 * 24 * 30);
    if (req.method === "OPTIONS") {
      res.end();
    }
  }

  // http://nickfishman.com/post/49533681471/nodejs-http-requests-with-gzip-deflate-compression
  var encoding = proxyRes.headers["content-encoding"];
  var onPipeError = function(e) {
    console.log(`Gunzip ${req.url} error: ${e}`);
    res.end();
  };

  console.log(req.url, "encoding", encoding);

  if (encoding == "gzip") {
    proxyRes.pipe(zlib.createGunzip()).on("error", onPipeError).pipe(res);
  } else if (encoding == "deflate") {
    proxyRes.pipe(zlib.createInflate()).on("error", onPipeError).pipe(res);
  } else {
    proxyRes.pipe(res);
  }
});

var server = http.createServer(function(req, res) {
  console.log("req cookies", req.headers.cookie);
  proxy.web(req, res, {
    target: "https://refundhunter.cn",
    changeOrigin: true,
    selfHandleResponse: true,
    headers: {
      cookie: req.headers.cookie || ""
    }
  });
});

console.log("Listening on 8090");
server.listen(8090); // See (†)