const IAB = require('iab');

// VAST 2/3
const parser = new IAB.VAST3Parser(vastXMLContent);
// Or VMAP
const parser = new IAB.VMAPParser(vastXMLContent);

parser.parse()
    .then((document) => {
      // document is now a VAST/VMAP parsed document object.
      // Eg : document.ads[1].adTitle => 'Ad's title'
    })
    .catch((err) => {
      if (err.parsingError) {
        console.err(`Could not parse document : ${err}`);
      } else if (err.parsingError) {
        console.err(`Could not validate document : ${err}`);
      }
    });