remove-twitter-lang-attribute.js

// ==UserScript==
// @name         Remove Twitter Lang Attribute
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Remove Twitter Lang Attribute
// @author       You
// @match        https://twitter.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=twitter.com
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // Ref: https://ryankubik.com/blog/remove-twitter-distractions
    // Ref: https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver

    // Select the node that will be observed for mutations
    const targetNode = document.querySelector('html');

    // Options for the observer (which mutations to observe)
    const config = { attributes: true, childList: true, subtree: true };

    // Callback function to execute when mutations are observed
    const callback = function(mutationsList, observer) {
        mutationsList.forEach(mutation => mutation.target.querySelectorAll("[lang]").forEach(dom => dom.removeAttribute("lang")));
    };

    // Create an observer instance linked to the callback function
    const observer = new MutationObserver(callback);

    // Start observing the target node for configured mutations
    observer.observe(targetNode, config);
    
    // Delete once when load
    document.querySelectorAll("[lang]").forEach(x => x.removeAttribute("lang"))
})();