validator.js

import $ from 'jquery';

export const isEmpty = value => !value.length;

export default function getValidator(rule, inputSelector, valueGetter) {
  return {
    validate() {
      const $input = $(inputSelector);
      const value = valueGetter();

      if (isEmpty(value)) {
        $input.addClass('error');
        return false;
      }
      else {
        $input.removeClass('error');
        return true;
      }
    }
  }
}