textarcana

/*jslint sloppy:true, white:true, vars:true, plusplus:true */

var permutation = function (collection){
    var current,
        subarray,
        result = [],
        currentArray = [],
        newResultArray = [];

    if (collection.length){

Chaser324

Whether you're trying to give back to the open source community or collaborating on your own projects, knowing how to properly fork and generate pull requests is essential. Unfortunately, it's quite easy to make mistakes or not know what you should do when you're initially learning the process. I know that I certainly had considerable initial trouble with it, and I found a lot of the information on GitHub and around the internet to be rather piecemeal and incomplete - part of the process described here, another there, common hangups in a different place, and so on.

In an attempt to coallate this information for myself and others, this short tutorial is what I've found to be fairly standard procedure for creating a fork, doing your work, issuing a pull request, and merging that pull request back into the original project.

Creating a Fork

Just head over to the GitHub page and click the "Fork" button. It's just that simple. Once you've done that, you can use your favorite git client to clone your repo or j

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

scmx

Make React PropType warnings throw errors with enzyme.js + sinon.js + mocha.js

A simple stateless functional component that we want to test that it renders without propType warnings.

import React, { PropTypes } from 'react'

let VersionListItem = function ({ active, version }) {
  return (

markerikson

import React from "react";
import ReactDOM from "react-dom";

import configureStore from "./store/configureStore";


const store = configureStore();


const rootEl = document.getElementById("root");

karlhorky

[alias]
  fetch-pr  = "!f() { git fetch origin refs/pull/$1/head:pr/$1; } ; f"
  delete-prs = "!git for-each-ref refs/heads/pr/* --format='%(refname)' | while read ref ; do branch=${ref#refs/heads/} ; git branch -D $branch ; done"

bvaughn

React lifecycle cheatsheet

Method	Side effects1	State updates2	Example uses
Mounting
componentWillMount		✓	Constructor equivalent for createClass
render			Create and return element(s)
componentDidMount	✓	✓	DOM manipulations, network requests, etc.
Updating
componentWillReceiveProps		✓	Update state based on changed props

sebmarkbage

The Rules of React

All libraries have subtle rules that you have to follow for them to work well. Often these are implied and undocumented rules that you have to learn as you go. This is an attempt to document the rules of React renders. Ideally a type system could enforce it.

What Functions Are "Pure"?

A number of methods in React are assumed to be "pure".

On classes that's the constructor, getDerivedStateFromProps, shouldComponentUpdate and render.

eps1lon

// jonschlinkert/is-object
type IsObjectObject<T> = T extends
  | AnyArray
  | AnyFunction
  | boolean
  | null
  | number
  | string
  | symbol
  | undefined