A tampermonkey script which adds a review checklist to GitHub PRs.

github-code-review-checklist.js

// ==UserScript==
// @name         GitHub Code Review Checklist
// @namespace    https://ricekot.com/
// @version      0.1
// @description  Adds a code review checklist to GitHub PRs.
// @author       ricekot
// @match        https://github.com/*/*/pull/*/files
// @icon         data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    let checklist = `
<div class="diffbar-item dropdown js-review-checklist-container mr-3">
  <details class="details-reset details-overlay js-dropdown-details position-relative" id="review-checklist-modal">
    <summary data-view-component="true" class="js-review-checklist-toggle btn-sm btn"> Review Checklist
      <span class="dropdown-caret"></span>
    </summary>
    <div class="SelectMenu left-0">
      <div class="pull-request-suggested-changes-menu SelectMenu-modal top-0 p-0 mt-sm-2" style="max-width: 300px;"
        id="review-checklist">
        <header class="SelectMenu-header p-2">
          <span class="SelectMenu-title">Review Checklist</span>
          <button class="SelectMenu-closeButton" type="button" data-toggle-for="review-checklist-modal">
            <svg aria-label="Review Checklist dialog" role="img" height="16" viewBox="0 0 16 16" version="1.1"
              width="16" data-view-component="true" class="octicon octicon-x">
              <path fill-rule="evenodd"
                d="M3.72 3.72a.75.75 0 011.06 0L8 6.94l3.22-3.22a.75.75 0 111.06 1.06L9.06 8l3.22 3.22a.75.75 0 11-1.06 1.06L8 9.06l-3.22 3.22a.75.75 0 01-1.06-1.06L6.94 8 3.72 4.78a.75.75 0 010-1.06z">
              </path>
            </svg>
          </button>
        </header>

        <div class="comment-body markdown-body js-preview-body" data-skip-sizing="" style="max-height:50vh;">
          <ul class="contains-task-list">
            <li class="task-list-item"><input type="checkbox" class="task-list-item-checkbox"> Requirement 1</li>
            <li class="task-list-item"><input type="checkbox" class="task-list-item-checkbox"> Requirement 2</li>
          </ul>
        </div>
  </details>
</div>
`;
    document.querySelector('div.pr-review-tools').insertAdjacentHTML("afterbegin", checklist);
})();