MDN js code examples fix

mdn-fix-js-code-examples.js

// ==UserScript==
// @name         MDN js code examples fix
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Fixes MDN code examples formatting glitch on javascript function's pages loading in background by automatically reloading the frame
// @author       schockocraft
// @match        https://developer.mozilla.org/*
// @icon         data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==
// @grant        none
// ==/UserScript==

const stopListening = () => {
    // blur happens before focus, we already had focus
    console.log("page loaded in foreground -> removing event listener")
    window.removeEventListener('focus', fixIFrame)
}
const fixIFrame = () => {
    // focus happens before blur, we had no focus before
    console.log("page loaded in background -> reloading potentially glitched iframes")
    document.querySelector('h2#try_it + div > iframe[src*="/pages/js/"]').src += ''
    window.removeEventListener('blur', stopListening)
}

window.addEventListener('blur', stopListening, { once: true })
window.addEventListener('focus', fixIFrame, { once: true })