// get the top-level comments in a hacker news thread

[].slice.call(document.querySelectorAll('.comment'))
  .filter((el) => {
    var getSiblings = function ( elem ) {
      var siblings = []
      var sibling = elem.parentNode.firstChild
      for (; sibling; sibling = sibling.nextSibling) {
        if (sibling.nodeType === 1 && sibling !== elem) {
          siblings.push(sibling)
        }
      }
      return siblings
    }
    // a transparent 1px gif will have a width of 0 if it is a top-level comment in the comment-tree table
    return getSiblings(el.parentElement)
      .filter((sib) => sib.className.includes('ind') && sib.firstChild.width > 0)
      .length === 0
  })