static/js/util/cookie.js

var cookieUtils = {

  isCookiesEnabled: function () {
    return navigator.cookieEnabled;
  },

  /**
   * @param name
   * @returns {string|null}
   */
  getCookie: function (name) {
    var regexp = new RegExp('(?:^|; )' + name.replace(/([\.$?*|{}\(\)\[\]\\\/\+^])/g, '\\$1') + '=([^;]*)');
    var matches = document.cookie.match(regexp);
    return matches ? decodeURIComponent(matches[1]) : null;
  },

  /**
   * @param {string} name
   * @returns {boolean}
   */
  hasCookie: function (name) {
    var cookie = this.getCookie(name);
    return cookie !== null;
  },

  /**
   * @param {string} name
   * @param {string} value
   * @param {object} options
   *                 options.expires (number (in seconds), Date, null)
   *                 options.path (string)
   *                 options.domain (string)
   *                 options.secure (boolean)
   * @returns void
   */
  setCookie: function (name, value, options) {
    options = options || {};

    var expires = options.expires;

    if (typeof expires === 'number' && expires) {
      var d = new Date();
      d.setTime(d.getTime() + expires * 1000);
      expires = options.expires = d;
    }
    if (expires && expires.toUTCString) {
      options.expires = expires.toUTCString();
    }

    value = encodeURIComponent(value);

    var updatedCookie = name + '=' + value;

    for (var propName in options) {
      updatedCookie += '; ' + propName;
      var propValue = options[propName];
      if (propValue !== true) {
        updatedCookie += "=" + propValue;
      }
    }

    document.cookie = updatedCookie;
  },

  /**
   * @param {string} name
   * @returns void
   */
  removeCookie: function (name) {
    this.setCookie(name, '', {expires: -1});
  }
};

module.exports = cookieUtils;