Node.js - CPU bound operations with Rx

cpu-bound.js

const RxNode = require('rx-node');
const Rx = require('rx');
const spawn = require('child_process').spawn;

RxNode.fromStream(spawn('find', ['/','-type','f','-exec', 'cat', '{}', '\+']).stdout)
	.map(x => x.toString())
	.map(x => RxNode.fromStream(spawn('./word-count.js', [x]).stdout))
	.mergeAll()
	.map(x => x.toString())
	.do(x => console.log(x))
	.subscribe();

word-count.js

#!/usr/bin/env node

const index = {};

process.argv[2]
  .replace(/[.,?!;()"'-]/g, ' ')
  .replace(/\s+/g, ' ')
  .toLowerCase()
  .split(' ')
  .forEach(function (word) {
    if (!(index.hasOwnProperty(word))) index[word] = 0;
    index[word]++;
  });

console.log(index)