How can I ignore leading and trailing linebreaks within an html “code” block using css, javascript or jquery?

Question

In my HTML source code, I have a code block like the following (I use showdown and highlight.js on this page):

double myNum         


        

Answer 1

I just remove them manually before the highlighter starts.

const trimLine = node => 
  node.firstChild.nodeValue = node.firstChild.nodeValue.replace(/^\n+|\n+$/g, "");



window.onload = function () {

  Array.prototype.slice
      .call(document.getElementsByTagName("code"), 0)
      .map(trimLine);

  hljs.initHighlightingOnLoad();

}