Traverse the DOM with cascading predicates

traverseDOMNode.js

function traverseDOMNodes(node, predicates, cb) {
  if (predicates.length === 0) {
    // Base case: If there are no more predicates, invoke the callback.
    return cb(node);
  }

  const [currentPredicate, ...remainingPredicates] = predicates;
  const children = node.childNodes;

  for (let child of children) {
    if (currentPredicate(child)) {
      const result = traverseDOMNodes(child, remainingPredicates, cb);
      if (result) {
        return result;
      }
    }
  }

  return null;
}

// Ex. Only nodes that exact match UL > LI > DIV > SPAN
const predicates = [
  node => node.nodeName === 'UL',
  node => node.nodeName === 'LI',
  node => node.nodeName === 'DIV',
  node => node.nodeName === 'SPAN'
];

traverseDOMNodes(document.body, predicates, (result) => {
  console.log(result);
  // You can map over this. perhaps grab attributes.
  //
  // result.map(x => x.attributes.value.nodeValue);
});