module.exports = {

name: 'Exactly one main heading',

validate: function($, fail) {
  var mainHeadings = $('h1:visible');
  var count = mainHeadings.length;
  if (count == 0) {
    fail('Found 0 h1 elements.');
  } else if (count > 1) {
    fail('Found ' + count + ' h1 elements:', mainHeadings);
  }
}

}