strict to run for the console to speedup and smarten up exporting github issues to PDF

print-github-issues.js

const style = document.createElement('style')
style.innerHTML = '@media print {.no-print, .no-print *{display: none !important;}}'
document.querySelector('head').appendChild(style)

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

async function pending_images() {
  const pending_images = Array.from(document.images).filter(img => !img.complete)
  if (pending_images.length) {
    console.log(`${issue_id} - waiting for ${pending_images.length} to load`)
    await Promise.all(
      pending_images
        .map(img => new Promise(resolve => {
          img.onload = img.onerror = resolve
        }))
    )
  }
}

async function wait_for_element(selector, page) {
  console.log(`waiting for "${selector}" on ${page}`)
  while (true) {
    const element = document.getElementById(selector)
    if (element) {
      return element
    }
    await sleep(100)
  }
}

async function save(issue_id) {
  const side_bar = await wait_for_element('partial-discussion-sidebar', issue_id)
  side_bar.classList.add('no-print')
  await pending_images()

  document.querySelector('.js-repo-nav').classList.add('no-print')
  document.querySelector('.gh-header-actions').classList.add('no-print')

  document.title = location.pathname.substr(1).replace('/issues/', '#')
  console.log('printing issue', document.title)
  window.print()
}

const issue_ids = Array.from(document.querySelectorAll('a[id^="issue_"]')).map(el => el.id)
console.log('getting issues:', issue_ids)
for (const issue_id of issue_ids) {
  const issue = await wait_for_element(issue_id, 'issue list')
  issue.click()
  await save(issue_id)
  history.back()
}