staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

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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.

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DavidKuennen

(function (context, trackingId, options) {
    const history = context.history;
    const doc = document;
    const nav = navigator || {};
    const storage = localStorage;
    const encode = encodeURIComponent;
    const pushState = history.pushState;
    const typeException = 'exception';
    const generateId = () => Math.random().toString(36);
    const getId = () => {

paulirish

/* bling.js */

window.$ = document.querySelectorAll.bind(document);

Node.prototype.on = window.on = function (name, fn) {
  this.addEventListener(name, fn);
}

NodeList.prototype.__proto__ = Array.prototype;

jesstelford

Regular Event Loop

This shows the execution order given JavaScript's Call Stack, Event Loop, and any asynchronous APIs provided in the JS execution environment (in this example; Web APIs in a Browser environment)

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Given the code

tdreyno

[
  {
    "code": "AAA",
    "lat": "-17.3595",
    "lon": "-145.494",
    "name": "Anaa Airport",
    "city": "Anaa",
    "state": "Tuamotu-Gambier",
    "country": "French Polynesia",
    "woeid": "12512819",

mmocny

// max-INP:
(()=>{let o=globalThis;return void 0===o.winp&&(o.winp=0,new PerformanceObserver(n=>{for(let e of n.getEntries()){if(!e.interactionId)continue;o.winp=Math.max(e.duration,o.winp);let r=o=>o<=200?"color: green":o<=500?"color: yellow":"color: red";console.log(`%c[Interaction: ${e.name.padEnd(12)}] %cDuration: %c${e.duration}`,"color: grey; font-family: Consolas,monospace","",r(e.duration))}}).observe({type:"event",durationThreshold:0,buffered:!0})),o.winp})();

// interactionCount
performance.interactionCount;

lucasfais

Sublime Text 2 – Useful Shortcuts (Mac OS X)

General

⌘T	go to file
⌘⌃P	go to project
⌘R	go to methods
⌃G	go to line
⌘KB	toggle side bar
⌘⇧P	command prompt

malchata

// Cribbed this from:
// https://web.dev/debug-web-vitals-in-the-field/#usage-with-the-web-vitals-javascript-library
export function getSelector(node, maxLen = 100) {
  let sel = '';

  try {
    while (node && node.nodeType !== 9) {
      const part = node.id ? '#' + node.id : node.nodeName.toLowerCase() + (
        (node.className && node.className.length) ?
        '.' + Array.from(node.classList.values()).join('.') : '');

paulirish

A few conversations have circled around user-side structural profiling. For context, see React PR #7549: Show React events in the timeline when ReactPerf is active

One particular concern is the measurement overhead. This gist has a benchmarking script (measure.js) for evaluating overhead and initial results.

Results: performance.mark()

Runs about 0.65µs per mark() call. Naturally, that's ~= an overhead of 1ms for 1500 mark()s.

domenic

This article has been given a more permanent home on my blog. Also, since it was first written, the development of the Promises/A+ specification has made the original emphasis on Promises/A seem somewhat outdated.

You're Missing the Point of Promises

Promises are a software abstraction that makes working with asynchronous operations much more pleasant. In the most basic definition, your code will move from continuation-passing style:

getTweetsFor("domenic", function (err, results) {
 // the rest of your code goes here.