Userscript to add comment permalinks to Discuit posts

discuit-comment-permalink.user.js

// ==UserScript==
// @name         discuit-comment-permalink
// @namespace    discuit-aw-userscripts
// @version      2024-04-11
// @description  Provide a permalink for comments on post pages
// @author       AuralWanderer
// @match        https://discuit.net/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=discuit.net
// @grant        none
// ==/UserScript==

"use strict";

function nodeSelect(root, selector, handler) {
  // check the node itself for matching the selector
  if (root.matches(selector)) {
    handler(root);
  }
  // check the subtree
  let subMatches = root.querySelectorAll(selector);
  for (let node of subMatches) {
    handler(node);
  }
}

function addPermalink(comment) {
  let commentButtons = comment.querySelector("div.post-comment-buttons");
  if (commentButtons) {
    let permalinkButton = document.createElement("a");
    permalinkButton.style.textDecoration = "none";
    // if the URL already is to a comment, it will have two codes .../post/code1/code2
    let URL = window.location.href.match(/((.+)\/post\/(.+?))(\/|$)/)[1];
    permalinkButton.href = URL + "/" + comment.id;
    permalinkButton.innerHTML = "<button class='button-text' title=''>Permalink</button>";
    // third button is the one after the downvote count--want to insert permalink after that
    let thirdButton = commentButtons.querySelectorAll("button")[2];
    commentButtons.insertBefore(permalinkButton, thirdButton);
  }
}

// for each comment, find the report button, and if found, add another button for the permalink to the comment
function observeComments(mutations) {
  for (let mutation of mutations) {
    for (let node of mutation.addedNodes) {
      if (! (node instanceof HTMLElement)) continue;
      nodeSelect(node, "div.post-comment", addPermalink);
    }
  }
}

let observerInit = new MutationObserver(observeComments);
observerInit.observe(document.querySelector("body"), {childList: true, subtree: true});