How to compress a response

compressAgainAgian.js

const http = require("http");
const fs = require("fs");
const zlib = require("zlib");

const server = http.createServer();

server.on("request", (req, res) => {
  const data = "random string";

  const encodingHeader = req.headers["accept-encoding"];
  let compressedDataStream;
  // for deflate
  if (/\bdeflate\b/.test(encodingHeader)) {
    compressedDataStream = zlib.createDeflate();
    res.writeHead(200, { "Content-Encoding": "deflate" });
    compressedDataStream.pipe(res);
    compressedDataStream.write(data);
    compressedDataStream.end();
    // for gzip
  } else if (/\bgzip\b/.test(encodingHeader)) {
    compressedDataStream = zlib.createGzip();
    res.writeHead(200, { "Content-Encoding": "gzip" });
    compressedDataStream.pipe(res);
    compressedDataStream.write(data);
    compressedDataStream.end();
    // if does understand encoding
  } else {
    res.writeHead(200);
    res.write(data);
    res.end();
  }
});

server.listen(3001);