sophiebits

const {useCallback, useEffect, useReducer, useRef} = require('react');

let effectCapture = null;

exports.useReducerWithEmitEffect = function(reducer, initialArg, init) {
  let updateCounter = useRef(0);
  let wrappedReducer = useCallback(function(oldWrappedState, action) {
    effectCapture = [];
    try {
      let newState = reducer(oldWrappedState.state, action.action);

aweary

import React from "react";
import useMutableReducer from "./useMutableReducer";

const reducer = (draft, action, state) => {
  switch (action) {
    case "increment":
      draft.count++;
      break;
    case "decrement":
      draft.count--;

charlie-collard

import requests
import praw
import logging
import time
import random
import schedule
import pickle
import sys
from datetime import datetime, timedelta

samthor

// UPDATE: In 2023, you should probably stop using this! The narrow version of Safari that
// does not support `nomodule` is probably not being used anywhere. The code below is left
// for posterity.

/**
 * Safari 10.1 supports modules, but does not support the `nomodule` attribute - it will
 * load <script nomodule> anyway. This snippet solve this problem, but only for script
 * tags that load external code, e.g.: <script nomodule src="nomodule.js"></script>
 *
 * Again: this will **not** prevent inline script, e.g.:

ilfroloff

const ABORTABLE_ERROR_KEY = '__abortablePromise';

/**
 * @typedef {Promise.<*>} AbortablePromise
 *
 * @property {function} abort       Additional method for abort original promise
 */

/**
 *

timoxley

JS Pop Quiz: How well do you know your functions?

Given an Array of Functions fns, what argument(s) can you pass to fns.forEach such that each function in fns will execute, in order, without creating any anonymous (or named) functions or invoking the Function constructor?

Conditions

• Do not use the function keyword, or arrow functions () => .
• Do not invoke the Function constructor.
• Do not use method definitions.
• Function#bind & friends on the Function.prototype are ok.

jawb

<?php

/*
Demos:
https://jsbin.com/gakudi/1/edit?output
https://jsbin.com/xunifo/edit?output

Usage:
php cssImage.php scale image output
*/

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

simmo

function throttle(type, name, obj) {
  var running = false;
  
  obj = obj || window;

  var func = function() {
    if (running) return;

    running = true;

paulirish

/* bling.js */
window.$ = document.querySelector.bind(document);
window.$$ = document.querySelectorAll.bind(document);
Node.prototype.on = window.on = function(name, fn) { this.addEventListener(name, fn); };
NodeList.prototype.__proto__ = Array.prototype;
NodeList.prototype.on = function(name, fn) { this.forEach((elem) => elem.on(name, fn)); };