Angular directive to check consecutive characters

consecutive.js

var app = angular.module('myApp', []);

app.directive('consecutive', function () {
  return {
    require: 'ngModel',
    restrict: 'A',
    priority: 50,
    link: function(scope, elem, attrs, ctrl) {
      if (!ctrl) return;
      
      // four identical consecutive characters
      var CONSECUTIVE_REGEX = new RegExp('(.)\\1\\1\\1+');
      
      function checkConsecutive(value) {
        if (ctrl.$isEmpty(value)) {
          ctrl.$setValidity('consecutive', true);
        } else {
          var valid = !(CONSECUTIVE_REGEX.test(value));
          ctrl.$setValidity('consecutive', valid);
        }
      }
      
      ctrl.$parsers.push(checkConsecutive);
    }
  };
});