Automatically redirects any page on the old fandom.com Isaac wiki to the new wiki.gg domain while preserving the path and anchor

isaac-wiki-redirect.user.js

// ==UserScript==
// @name         Isaac Wiki Redirector
// @version      1.0
// @description  Redirects from fandom.com Isaac wiki to wiki.gg
// @match        https://bindingofisaacrebirth.fandom.com/*
// @run-at       document-start
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    const currentUrl = window.location.href;

    // Replace domain
    const newUrl = currentUrl.replace(
        /^https:\/\/bindingofisaacrebirth\.fandom\.com/,
        'https://bindingofisaacrebirth.wiki.gg'
    );

    // Redirect only if different
    if (currentUrl !== newUrl) {
        window.location.replace(newUrl);
    }
})();