Function isURL

client/scripts/ui.js:3–3

const $ = query => document.getElementById(query);
const $$ = query => document.body.querySelector(query);
const isURL = text => /^((https?:\/\/|www)[^\s]+)/g.test(text.toLowerCase());
window.isDownloadSupported = (typeof document.createElement('a').download !== 'undefined');
window.isProductionEnvironment = !window.location.host.startsWith('localhost');
window.iOS = /iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream;