Open the overview panel in GitHub code review

open-the-overview-panel-in-github-code-review.user.js

// ==UserScript==
// @name         Open the overview panel in GitHub code review
// @namespace    http://tampermonkey.net/
// @version      2026-09-03
// @description  Open the overview panel in GitHub code review
// @author       Warren Seine
// @match        https://github.com/*/*/pull/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=github.com
// @run-at       document-idle
// @grant        none
// ==/UserScript==

(function() {
  'use strict';

  // The diff tab, where the overview panel lives.
  const DIFF_TAB = /^\/[^/]+\/[^/]+\/pull\/\d+\/(?:changes|files)\b/;

  // The toolbar toggle, labelled Open overview panel / Close overview panel.
  const TOGGLE = /overview panel/i;

  // Closing the side panel, either from the toolbar or from the panel header.
  const CLOSE = /^close (?:side|overview) panel$/i;

  // The panel header, present for whichever view is on screen — Overview,
  // Comments, Alerts, Merge status, any of them.
  const PANEL = '[class*="Panel-module__Header__"], [class*="PanelNavigationDropdown"]';

  // The header's close button, whose label is the same signal without leaning
  // on a hashed class name.
  const CLOSE_SIDE = /^close side panel$/i;

  // GitHub can re-render the toolbar with the panel shut, so opening is retried
  // rather than done once. The cap per visit stops the retry from becoming a loop.
  const MAX_OPENS = 5;

  let tab = null;
  let opens = 0;
  let dismissed = false;

  function label(button) {
    const direct = button.getAttribute('aria-label');
    if (direct) return direct;
    // Most of these buttons carry their text in a tooltip instead.
    const tooltip = document.getElementById(button.getAttribute('aria-labelledby') || '');
    return tooltip ? tooltip.textContent : '';
  }

  function buttons() {
    return [...document.querySelectorAll('button')];
  }

  function panelIsOpen() {
    return !!document.querySelector(PANEL) || buttons().some(b => CLOSE_SIDE.test(label(b).trim()));
  }

  function openOverview() {
    if (!DIFF_TAB.test(document.location.pathname)) {
      tab = null;
      return;
    }

    if (tab !== document.location.pathname) {
      tab = document.location.pathname;
      opens = 0;
      dismissed = false;
    }

    if (dismissed || opens >= MAX_OPENS) return;

    // A panel showing another view still reads as an unexpanded overview
    // toggle. Opening it there would drag the reader back to Overview, so the
    // panel being shut at all is the condition, not the overview toggle alone.
    if (panelIsOpen()) return;

    const button = buttons().find(b => TOGGLE.test(label(b)));
    if (!button) return;

    opens += 1;
    button.click();
  }

  // Closing the panel by hand settles it for this visit.
  document.addEventListener('click', event => {
    if (!event.isTrusted || !event.target.closest) return;
    const button = event.target.closest('button');
    if (button && CLOSE.test(label(button).trim())) dismissed = true;
  }, true);

  // The toolbar renders late, and the diff tab can be reached by client-side
  // navigation, so keep watching instead of running once.
  let scheduled = false;
  const observer = new MutationObserver(() => {
    if (scheduled) return;
    scheduled = true;
    // A timer rather than requestAnimationFrame, which never fires while the
    // tab sits in the background.
    setTimeout(() => {
      scheduled = false;
      openOverview();
    }, 50);
  });

  observer.observe(document.body, {childList: true, subtree: true});
  openOverview();
})();