remy

const round(value, decimals) =>Number(Math.round(value+'e'+decimals)+'e-'+decimals);

round(1.005, 2); // 1.01
Math.round(1.005, 2); // 1.00

// via http://www.jacklmoore.com/notes/rounding-in-javascript/

bithavoc

/*
Asymmetric Encryption Sample in Node.js: Encrypt and Decrypt using Password as a key(SECRET_KEY)
Algorithm: des-ede3-cbc (Three key Triple-DES EDE in CBC mode)
johan@firebase.co
@thepumpkin
*/

var assert = require('assert')
var crypto = require('crypto')
var Buffer = require('buffer').Buffer

dperini

/*
 * How to detect which element is the scrolling element in charge of scrolling the viewport:
 *
 * - in Quirks mode the scrolling element is the "body"
 * - in Standard mode the scrolling element is the "documentElement"
 *
 * webkit based browsers always use the "body" element, disrespectful of the specifications:
 *
 *  http://dev.w3.org/csswg/cssom-view/#dom-element-scrolltop
 *

gladchinda

function getValueFromPath(object, path) {
  const OBJECT_TYPE = '[object Object]';
  const $type = Function.prototype.call.bind(Object.prototype.toString);
  
  // Ensure that path is a string, default to an empty string if not provided.
  // Replace bracket notation occurrences on path with dot notation.
  // Split path (to array) using the `.` delimeter, discard empty elements.
  path = (path ? String(path) : String())
    .replace(/\[((?:['"])?)([^[\]]*)\1\]/g, function __replacer__($, $$, key) {
      return `.${Number(key) || String(key)}`;

josemcunha

Project Title

One Paragraph of project description goes here. Don't forget to link back to the tutorial.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. See deployment for notes on how to deploy the project on a live system.

Prerequisites

remy

const webpack = require('webpack');

require('dotenv').config({
  path: process.env.NODE_ENV === 'production' ? '.env.production' : '.env'
});

module.exports = {
  webpack: config => {
    const env = Object.keys(process.env).reduce((acc, curr) => {
      acc[`process.env.${curr}`] = JSON.stringify(process.env[curr]);

gladchinda

JS Data Structures — Maps and Sets

The way, in which data is structured, plays a vital role in being able to efficiently perform certain operations on the data or solve certain problems in relation to the data. For example you can delete any item from a doubly linked list in constant time, whereas that could take linear time if the list is represented as an array. Also, searching for the presence of a key in an array of keys can be done more efficiently (in logarithmic time) when the array is sorted than when not sorted.

Some very popular programming languages like Java and Python provide lots of useful data structure implementations out of the box, as part of their standard library; whereas the ubiquitous "JavaScript" programming language appears to be pretty lean in that regard. However, like most programming languages, JavaScript ships with some very basic data types — such as arrays, strings, objects, sets, maps, etc.

Keyed Collections

Prior to the ECMAScript 2015 specification updates (_

glenjamin

var mysql = require('mysql');

var pool = mysql.createPool('mysql://localhost');

inTransaction(pool, function(db, next) {
    db.query("DELETE * FROM stuff", function(err) {
        if (err) return next(err);

        db.query("INSERT INTO stuff VALUES (1,2,3)", function(err) {
            return next(err);

developit

finally-polyfill

A tiny ~150-byte polyfill for Promise.prototype.finally.

Useful for browsers that support Promise but not the .finally() method.

Usage

npm install finally-polyfill

sspencer

// Two ways to serve transparent GIF

var buf = new Buffer([
    0x47, 0x49, 0x46, 0x38, 0x39, 0x61, 0x01, 0x00, 0x01, 0x00, 
    0x80, 0x00, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x2c, 
    0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x02, 
    0x02, 0x44, 0x01, 0x00, 0x3b]);

res.send(buf, { 'Content-Type': 'image/gif' }, 200);