NodeJS - CRYPTO : How to calculate a hash from file or string

nodeJs.crypto.calculatingHash.js

var crypto = require('crypto')
  , fs = require('fs')

// Algorithm depends on availability of OpenSSL on platform
// Another algorithms: 'sha1', 'md5', 'sha256', 'sha512' ...
var algorithm = 'sha1'
  , shasum = crypto.createHash(algorithm)

// Updating shasum with file content
var filename = __dirname + "/anything.txt"
  , s = fs.ReadStream(filename)
s.on('data', function(data) {
  shasum.update(data)
})

// making digest
s.on('end', function() {
  var hash = shasum.digest('hex')
  console.log(hash + '  ' + filename)
})

// Calculating hash from string
var textToHash = "Hello, I want a hash from it"
  , shasum2 = crypto.createHash(algorithm)
shasum2.update(textToHash)
var hash2 = shasum2.digest('hex')
console.log(hash2 + '  ' + textToHash)

promiseToSmokeHash.js

//by funnyzak from the original repo's comments

function fileHash(filename, algorithm = 'md5') {
  return new Promise((resolve, reject) => {
    // Algorithm depends on availability of OpenSSL on platform
    // Another algorithms: 'sha1', 'md5', 'sha256', 'sha512' ...
    let shasum = crypto.createHash(algorithm);
    try {
      let s = fs.ReadStream(filename)
      s.on('data', function (data) {
        shasum.update(data)
      })
      // making digest
      s.on('end', function () {
        const hash = shasum.digest('hex')
        return resolve(hash);
      })
    } catch (error) {
      return reject('calc fail');
    }
  });
}

sha-cli.js

// sha-cli.js by styfle from the original repo's comments
// Hash file from CLI with node script.
// example use : node sha-cli.js example-input-file.zip
const filename = process.argv[2];
const crypto = require('crypto');
const fs = require('fs');
const hash = crypto.createHash('sha256');
const input = fs.createReadStream(filename);
input.on('readable', () => {
  const data = input.read();
  if (data)
    hash.update(data);
  else {
    console.log(`${hash.digest('hex')} ${filename}`);
  }
});