Userscript to add a direct link to the latest version of a gist

latest-gist.user.js

// ==UserScript==
// @name         Latest Gist
// @namespace    nickslash
// @version      1.1
// @description  Shift clicking "Raw" link will take you to the latest version
// @author       nickslash
// @match        https://gist.github.com/*/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    function processLink(link) {
        if (link.getAttribute("latest-href")) return
        let href = link.getAttribute("href")
        if (!href) return
        let match = href.match(/^\/([^\/]+)\/([^\/]+)\/raw\/[^\/]+\/(.+)$/)
        if (match) {
            link.setAttribute("latest-href", `/${match[1]}/${match[2]}/raw/${match[3]}`)    
            let buttonLabel = link.querySelector(".Button-label")
            if (buttonLabel) buttonLabel.innerText += "+"
            link.addEventListener("click", event => {
                if (event.shiftKey) {
                    event.preventDefault()
                    window.location.href = link.getAttribute("latest-href") // Use `link` directly
                }
            })
        }
    }
    function processLinks() {
        document.querySelectorAll("a:not([latest-href])").forEach(link => processLink(link))
    }

    processLinks()
    
    const observer = new MutationObserver(mutations => {
        for (let mutation of mutations) {
            if (mutation.type === "childList") {
                if (mutation.addedNodes.length > 0) { 
                    processLinks() 
                }
            }
        }
    })
    
    observer.observe(document.body, { childList: true, subtree: true })
    
})();