A Tampermonkey script to default to the rich diff for files in a PR if/when they exist

prefer_rich_diffs.js

// ==UserScript==
// @name         Prefer Rich Diffs
// @namespace    http://deecewan.com/
// @version      0.1
// @description  default to rich diffs when they exist for a given filetype
// @author       You
// @match        https://github.com/*
// ==/UserScript==

(function() {
    'use strict';

    function updatePage() {
        if (!window.location.pathname.match(/ferocia\/up\/pull\/\d+\/files/i)) {
            return;
        }

        let mounted = true;
        const unmount = () => {
            // if we're going to slyly navigate away from this page;
            mounted = false;
        }
        document.addEventListener('pjax:click', unmount);

        Array.from(document.querySelectorAll('[aria-label="Display the rich diff"]')).forEach(el => el.click());
    }

    document.addEventListener('pjax:end', updatePage);
    window.addEventListener('load', updatePage);
})();