Get all text values under a specific node

textNodesUnder.js

function textNodesUnder(node){
  const all = [];
  for (node = node.firstChild; node; node = node.nextSibling){
    if (node.nodeType === 3) all.push(node);
    else all = all.concat(textNodesUnder(node));
  }
  return all;
}

let selector = '';
textNodesUnder(selector)
  .map(n => n.nodeValue)
  .filter(s => s.replace(/\s/g, '').length)
  .join('\n')