Start of setup of w3cjs for automated markup validation service.

w3cjs.js

// npm install --save-dev w3cjs
var w3cjs = require('w3cjs');

var timer = 0;
var takeTime = setInterval(function() {
  timer = timer + 1;
}, 1);

const validationService = (target) => {
  return new Promise((resolve, reject) => {
    var results = w3cjs.validate({
      file: target,
      output: 'json',
      callback: function (err, res) {
        if(err){
          reject(err);
        }

        if (res && res.messages.length > 0 ) {
          resolve(res);
        } else {
          resolve("No errors found on page " + target);
        }
      }
    });
  });
}

(function validateMarkup() {
  var promises = [];
  var validationTargets = ['http://vg.no', 'http://www.vg.no/sport/'];

  validationTargets.map(target => {
    promises.push(validationService(target));
  });

  Promise.all(promises)
    .then(success => {
      var totalMessageCount = totalErrorCount = 0;
      var message = {};

      success.map((error, key) => {
        totalMessageCount += success[key].messages.length;

        var errors = success[key].messages.filter(item => item.type === 'error');
        totalErrorCount += errors.length;

        var url = success[key].url;
        message[url] = success[key].messages;
      });

      clearInterval(takeTime);
      console.log(totalMessageCount + " messages in total after " + timer + " ms.");
      console.log("Errors: " + totalErrorCount);
      console.log("Warnings: " + (totalMessageCount - totalErrorCount));
      // uncomment to get all messages displayed
      // console.log(message);
    })
    .catch(err => {
      clearInterval(takeTime);
      console.log("Obs! Error occured in the excecution of the script: Promise was rejected. More detailed error: \n");
      console.log(err);
    })
})();