Rich-Harris

Edit — February 2019

This gist had a far larger impact than I imagined it would, and apparently people are still finding it, so a quick update:

• TC39 is currently moving forward with a slightly different version of TLA, referred to as 'variant B', in which a module with TLA doesn't block sibling execution. This vastly reduces the danger of parallelizable work happening in serial and thereby delaying startup, which was the concern that motivated me to write this gist
• In the wild, we're seeing (async main(){...}()) as a substitute for TLA. This completely eliminates the blocking problem (yay!) but it's less powerful, and harder to statically analyse (boo). In other words the lack of TLA is causing real problems
• Therefore, a version of TLA that solves the original issue is a valuable addition to the language, and I'm in full support of the current proposal, which you can read here.

I'll leave the rest of this document unedited, for archaeological

gaearon

function mapValues(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    result[key] = fn(obj[key], key);
    return result;
  }, {});
}

function pick(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    if (fn(obj[key])) {

somebody32

You can convert js-code like this:

var a = '1',
    b,
    c = '2';

into

spiralx

if (!Object.assign) {
  Object.defineProperty(Object, 'assign', {
    enumerable: false,
    configurable: true,
    writable: true,
    value: function(target) {
      'use strict';
      if (target === undefined || target === null) {
        throw new TypeError('Cannot convert first argument to object');
      }

sebmarkbage

import { Component } from "React";

export var Enhance = ComposedComponent => class extends Component {
  constructor() {
    this.state = { data: null };
  }
  componentDidMount() {
    this.setState({ data: 'Hello' });
  }
  render() {

bradfrost

Answering the Front-end developer JavaScript interview questions to the best of my ability.

• Explain event delegation

Sometimes you need to delegate events to things.

• Explain how this works in JavaScript

This references the object or "thing" defined elsewhere. It's like "hey, thing I defined elsewhere, I'm talkin' to you."

• Explain how prototypal inheritance works.

pongstr

Javascript Shorthand Coding Techniques

My (@pongstr) opinion about shorthand coding techniques

Shorthand code is not really a replacement for normal coding but it is very handy and useful in some cases. There are tons of opinions and debates around this but, again it all comes down what is necessary for your codebase and using it responsibly.

learncodeacademy

##what are generators##

• They're pausable functions, pausable iterable functions, to be more precise
• They're defined with the *
• every time you yield a value, the function pauses until .next(modifiedYieldValue) is called

var myGen = function*() {
  var one = yield 1;
  var two = yield 2;
  var three = yield 3;
 console.log(one, two, three);

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.

---

wikimatze

I heard from GitHub Two-Factor Authentication](https://github.com/blog/1614-two-factor-authentication) nearly a couple of days ago when I was reading my RSS feed. I enabled it and couldn' push to any of my repositories anymore. Learn in this blog post how to fix it.

Two-Factor Authentication

"Is a process involving two stages to verify the identity of an entity trying to access services in a computer or in a network". Github solves this authentication with sending an SMS to a device which wants to push to their platform.

Enabling Two-Factor Authentication