Copies issue number and title on click

github-issue-title.user.js

// ==UserScript==
// @name         github issue title
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://github.com/*
// @grant        GM_setClipboard
// ==/UserScript==

(function () {
  'use strict'

  document.addEventListener('click', (e) => {
    const target = e.target.closest('.gh-header-title')

    if (target) {
      let title, number

      if (target.classList.contains('gh-header-title')) {
        title = target.querySelector('.js-issue-title').innerText.trim()
      } else if (target.dataset.testId === 'side-panel-title') {
        title = target.querySelector('h2').innerText.trim()
        number = null
      }

      const matches = window.location.href.match(/(issues|pull)\/(\d+)/)
      number = `#${matches[2].split("/").pop()}`

      if (matches[1] === "pull") {
        const author = document.querySelector('.gh-header-meta .author')

        if (author && author.innerText) {
          title += ` (PR by ${author.innerText.trim()})`
        }
      }

      if (title && number) {
        target.style.transition = 'background .15s ease-in-out'
        target.style.background = '#c2e5f9'

        GM_setClipboard(`${number}: ${title}`)

        setTimeout(() => { target.style.background = 'none' }, 250)
      }
    }
  })
})()