Check if comment authors in PRs are Node.js collaborators

node-check-collaborators.js

javascript: {
  getCollaboratorsUsernames();

  function getCollaboratorsUsernames() {
    const xhr = new XMLHttpRequest();
    xhr.open('GET', 'https://github.com/nodejs/node/blob/master/README.md', true);
    xhr.responseType = 'document';
    xhr.withCredentials = true;
    xhr.onload = markAuthorsLinks;
    xhr.ontimeout = xhr.onerror = (evt) => { console.log(evt); };
    xhr.send(null);
  }

  function markAuthorsLinks(evt) {
    const xhrDoc = evt.target.response;
    const collaboratorsUsernames = Array.from(
      xhrDoc.body.querySelectorAll('h3 + ul > li > a[href^="https://github.com/"]'),
      link => link.textContent.trim()
    );

    const authorsLinks = [...document.body.querySelectorAll('a[href].author')];
    authorsLinks.forEach((link) => {
      link.style.backgroundColor =
        collaboratorsUsernames.includes(link.textContent.trim()) ?
          'LightGreen' : 'LightGray';
    });
  }
}

Tampermonkey header example:

/******************************************************************************/
// ==UserScript==
// @name         Check Authors
// @namespace    vsemozhetbyt
// @description  Check if comment authors in PRs are Node.js collaborators
// @version      1.0.0
// @include      https://github.com/nodejs/node/pull/*
// @exclude      https://github.com/nodejs/node/pull/*/files*
// @exclude      https://github.com/nodejs/node/pull/*/commits*
// @noframes
// @grant        none
// @nocompat     Chrome
// ==/UserScript==
/******************************************************************************/

See nodejs/node#12284