multitwitch-bigger-chat.user.js

// ==UserScript==
// @name         MultiTwitch Bigger Chat
// @namespace    http://tampermonkey.net/
// @version      2024-02-20
// @description  Easily make chat window bigger in MultiTwitch
// @author       Jacob Allen Morris
// @match        https://www.multitwitch.tv/**
// @icon         https://www.google.com/s2/favicons?sz=64&domain=multitwitch.tv
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    let chat = document.getElementById("chatbox");
    const splitAt = (index, xs) => [xs.slice(0, index), xs.slice(index)];
    let size = prompt("Width in pixels for chat", "500");
    if (parseInt(size) === NaN) {
        alert("Invalid size value");
    } else {
        setInterval(() => {
            let attr = chat.getAttribute("style");
            let width_index = attr.search(/width: \d*px;/);
            let pixel_value = splitAt(width_index + 7, attr)[1];
            let semi_index = pixel_value.search(/px;/);
            let pixels = splitAt(semi_index, pixel_value)[0];
            if (pixels != 500) {
                chat.setAttribute("style", `width: ${parseInt(size)}px;`);
            }
        }, 100);
    }
})();