kerimdzhanov

const array = []; // array to iterate

const promise = array.reduce((p, entry) => {
  p.then(() => {
    return new Promise((resolve, reject) => {...});
  });
}, Promise.resolve());

promise
  .then(() => console.log('done!'))

kerimdzhanov

// instead of using `expect(object).to.exist`, assert things
// through `.to.be.a(type)` which make failures more informative
expect(result).to.be.an('object')
  .that.includes({
    foo: 'bar',
    baz: 'quux'
  });

// to assert property value types i.e. date:
expect(result)

kerimdzhanov

'use strict';

module.exports = function CustomError(message, extra) {
  Error.captureStackTrace(this, this.constructor);
  this.name = this.constructor.name;
  this.message = message;
  this.extra = extra;
};

require('util').inherits(module.exports, Error);

kerimdzhanov

/**
 * Sum two big numbers given as strings.
 * 
 * @param {string} a
 * @param {string} b
 * @return {string}
 */
function sumStrings(a, b) {
  var zrx = /^0+/; // remove leading zeros
  a = a.replace(zrx, '').split('').reverse();

kerimdzhanov

// The polling function
function poll(fn, callback, timeout, interval) {
  var endTime = Number(new Date()) + (timeout || 2000);
  interval = interval || 100;

  (function p() {
    // If the condition is met, we're done!
    if (fn()) {
      callback();
    }

kerimdzhanov

// http://paulirish.com/2011/requestanimationframe-for-smart-animating/
// http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating

// requestAnimationFrame polyfill by Erik Möller. fixes from Paul Irish and Tino Zijdel

// MIT license

(function() {
    var lastTime = 0;
    var vendors = ['ms', 'moz', 'webkit', 'o'];

kerimdzhanov

Textual types

      Type | Maximum length | Size (bytes)
-----------+----------------+------------------
  TINYTEXT |            255 | (2^8−1)
      TEXT |         65,535 | (2^16−1) = 64 KiB
MEDIUMTEXT |     16,777,215 | (2^24−1) = 16 MiB
  LONGTEXT |  4,294,967,295 | (2^32−1) =  4 GiB

kerimdzhanov

/**
 * Get a random floating point number between `min` and `max`.
 * 
 * @param {number} min - min number
 * @param {number} max - max number
 * @return {number} a random floating point number
 */
function getRandomFloat(min, max) {
  return Math.random() * (max - min) + min;
}