Compress a file with gz using node.js zlib module.

create-gz-file.js

const file = process.argv[2];

const {promisify} = require('util');
const zlib = require('zlib');

const gzip = promisify(zlib.gzip);
(async () => {
  const fs = require('fs');
  const data = fs.readFileSync(file, 'utf-8');
  const buf = await gzip(data)
  fs.writeFileSync(`${file}.gz`, buf);
})();