youtube_chat_shortener

// ==UserScript==
// @name         youtube_chat_shortener
// @namespace    http://tampermonkey.net/
// @version      1
// @description  this script fires the indians working for google
// @author       Ina
// @match        *.youtube.com/live_chat*
// @grant        none
// ==/UserScript==


(function() {
    'use strict';

    const targetNode = document.querySelector("#item-offset").querySelector("#items");

    targetNode.innerHTML = "";

    const chatOptimizer = function (mutationsList, observer) {
        for(let mutation of mutationsList) {
            if (mutation.addedNodes[0] && (mutation.addedNodes[0].nodeName=="YT-LIVE-CHAT-PAID-MESSAGE-RENDERER" || mutation.addedNodes[0].nodeName=="YT-LIVE-CHAT-TEXT-MESSAGE-RENDERER")){
                //the '17' bellow is how many posts you'll see in the chat. this doesn't include the super chats attached at the top. you can always check those
                //the next two lines are intentionally duplicate
                if (targetNode.childElementCount>17) {
                    targetNode.removeChild(targetNode.firstChild);
                    targetNode.removeChild(targetNode.firstChild);
                }
            }
        }
    };

    const chatObserver = new MutationObserver(chatOptimizer);
    chatObserver.observe(targetNode, { attributes: false, childList: true, subtree: true, characterData: false, characterDataOldValue: false });

})();