userscript.js

// ==UserScript==
// @name         YouTube Sign Out Confirm
// @namespace    http://tampermonkey.net/
// @version      2024-05-29
// @description  Asks for confirmation before signing out of YouTube (when you click the "Sign out" button)
// @author       Wis (wis.am)
// @match        https://www.youtube.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @grant        none
// ==/UserScript==

(function () {
    function mouseDownHandler(event) {
        if (!window.confirm("Do you really want to sign out?")) {
            event.preventDefault();
            event.stopPropagation();
            return;
        } else {
            location.replace("/logout");
        }
    }


    function onLoad(event) {
        if (!signoutEl) {
            signoutEl = document.querySelector('[href="/logout"]');
            addClickListener(signoutEl, event.type);
        }
    }

    document.addEventListener("DOMContentLoaded", onLoad);
    document.addEventListener("load", onLoad);

    // Function to add the event listener to the sign out element
    function addClickListener(signoutEl, eventType) {
        if (signoutEl) {
            signoutEl.addEventListener('mousedown', mouseDownHandler, true);
            console.info("Sign out click event listener added successfully.");
        } else {
            console.warn('Could not find the "Sign out" button element on', eventType);
        }
    }

    // Create a MutationObserver to watch for creation of the sign out element
    const observer = new MutationObserver((mutations) => {
        for (let mutation of mutations) {
            if (mutation.type === 'childList' && mutation.addedNodes.length > 0) {
                for (let node of mutation.addedNodes) {
                    if (node.nodeType === Node.ELEMENT_NODE &&
                        node.hasAttribute('href') && node.getAttribute('href') === '/logout') {
                        addClickListener(node, "mutation observe match");
                        observer.disconnect(); // Stop observing once the element is found
                        return;
                    }
                }
            }
        }
    });

    // Start observing the document for changes
    observer.observe(document.body, { childList: true, subtree: true });

    // Try to add the event listener immediately in case the element is already in the DOM
    var signoutEl = document.querySelector('[href="/logout"]');
    if (signoutEl) {
        addClickListener(signoutEl, "script run");
        observer.disconnect(); // Stop observing if the element is already found
    }
})();