natasv

import fs from 'fs'

var output = fs.readFileSystem('example.txt', 'utf8')
  .trim()
  .split('\n')
  .map(line => line.split('\t'))
  .reduce((customers, line) => {
    customers[line[0]] =  customers[line[0]] || []
    customers[line[0]].push({
      name: line[1],

natasv

function once(fn, context) { 
    var result;

    return function() { 
        if(fn) {
            result = fn.apply(context || this, arguments);
            fn = null;
        }

        return result;

natasv

function debounce(func, wait, immediate) {
    var timeout;
    return function() {
        var context = this, args = arguments;
        var later = function() {
            timeout = null;
            if (!immediate) func.apply(context, args);
        };
        var callNow = immediate && !timeout;
        clearTimeout(timeout);

natasv

var items = ['one', 'two', 'three', 'four'];
items.splice(items.length / 2, 0, 'hello');

natasv

var Subject = function() {
  this.observers = [];

  return {
    subscribeObserver: function(observer) {
      this.observers.push(observer);
    },
    unsubscribeObserver: function(observer) {
      var index = this.observers.indexOf(observer);
      if(index > -1) {