node js gzip

const fs = require('fs');
const zlib = require('zlib');

const gzip = zlib.createGzip();
const input = fs.createReadStream('input.txt');
const output = fs.createWriteStream('input.txt.gz');

input.pipe(gzip).pipe(output);

const fs = require('fs');
const zlib = require('zlib');

const gunzip = zlib.createGunzip();
const input = fs.createReadStream('input.txt.gz');
const output = fs.createWriteStream('input.txt');

input.pipe(gunzip).pipe(output);

const http = require('http');
const zlib = require('zlib');

http.createServer((req, res) => {
  const acceptEncoding = req.headers['accept-encoding'];
  if (acceptEncoding && acceptEncoding.includes('gzip')) {
    res.writeHead(200, {
      'Content-Encoding': 'gzip',
      'Content-Type': 'text/plain'
    });
    const gzip = zlib.createGzip();
    const data = 'Hello, World!';
    gzip.write(data);
    gzip.end();
    gzip.pipe(res);
  } else {
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.end('Hello, World!');
  }
}).listen(3000);