Tampermonkey Script: Button that will allow you to collape right sitebar in Jira issue view

Jira Collapse Sidebar Button.user.js

// ==UserScript==
// @name         Jira Collapse Sidebar Button
// @namespace    https://gist.github.com/KristianP26/da54152268e26b73893fa7792f04196f
// @version      1.0
// @description  Button that will allow you to collape right sitebar in Jira issue view
// @author       Kristian Partl
// @homepage     https://github.com/KristianP26
// @match        https://*/browse/*
// @match        https://*/projects/*/issues/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    function addCollapseButton() {
        const toolsDiv = document.getElementById('opsbar-jira.issue.tools');
        if (!toolsDiv) {
            setTimeout(addCollapseButton, 300);
            return;
        }

        const collapseButton = document.createElement('button');
        collapseButton.textContent = 'Collapse';
        collapseButton.classList.add('aui-button');

        toolsDiv.appendChild(collapseButton);

        const sidebarDiv = document.getElementById('viewissuesidebar');

        collapseButton.addEventListener('click', () => {
            if (sidebarDiv) {
                if (sidebarDiv.classList.contains('aui-item')) {
                    sidebarDiv.style.display = 'none';
                    sidebarDiv.classList.remove('aui-item', 'issue-side-column');
                    collapseButton.textContent = 'Expand';
                } else {
                    sidebarDiv.classList.add('aui-item', 'issue-side-column');
                    sidebarDiv.style.display = '';
                    collapseButton.textContent = 'Collapse';
                }
            }
        });
    }

    addCollapseButton();
})();