Ar5iv Hash Attacher: Attach a hash to the URL to create a permanent link when elements like sections and figures are clicked

ar5iv-hash-attacher.user.js

// ==UserScript==
// @name         Ar5iv Hash Attacher
// @namespace    http://mooz.github.io/
// @version      0.1
// @description  When elements like sections and figures are clicked, attach a hash to the URL to create a permanent link
// @author       Masafumi Oyamada
// @match        https://ar5iv.labs.arxiv.org/html/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=arxiv.org
// @grant        none
// ==/UserScript==

(() => {
  document.addEventListener("click", (ev) => {
    if (ev.button !== 0) return;
    const target = /^h[0-9]$/.exec(ev.target.localName) ? ev.target.parentElement : ev.target;
    const id = target.getAttribute("id");
    if (id) {
        history.replaceState(null, null, "#" + id);
    }
  });
})();