ES6 version of the mozilla lib

cookies.js

/*
 * https://developer.mozilla.org/en-US/docs/Web/API/document.cookie
 * https://developer.mozilla.org/User:fusionchess
 */

const getItem = (sKey) => {
  if (!sKey) { return null; }
  return decodeURIComponent(document.cookie.replace(new RegExp('(?:(?:^|.*;)\\s*' + encodeURIComponent(sKey).replace(/[\-\.\+\*]/g, '\\$&') + '\\s*\\=\\s*([^;]*).*$)|^.*$'), '$1')) || null;
};

const setItem = (sKey, sValue, vEnd, sPath, sDomain, bSecure) => {
  let sExpires = '';
  if (!sKey || /^(?:expires|max\-age|path|domain|secure)$/i.test(sKey)) { return false; }
  if (vEnd) {
    switch (vEnd.constructor) {
      case Number:
        sExpires = vEnd === Infinity ? '; expires=Fri, 31 Dec 9999 23:59:59 GMT' : '; max-age=' + vEnd;
        break;
      case String:
        sExpires = '; expires=' + vEnd;
        break;
      case Date:
        sExpires = '; expires=' + vEnd.toUTCString();
        break;
      default:
        break;
    }
  }
  document.cookie = encodeURIComponent(sKey) + '=' + encodeURIComponent(sValue) + sExpires + (sDomain ? '; domain=' + sDomain : '') + (sPath ? '; path=' + sPath : '') + (bSecure ? '; secure' : '');
  return true;
};

const removeItem = (sKey, sPath, sDomain) => {
  if (!this.hasItem(sKey)) { return false; }
  document.cookie = encodeURIComponent(sKey) + '=; expires=Thu, 01 Jan 1970 00:00:00 GMT' + (sDomain ? '; domain=' + sDomain : '') + (sPath ? '; path=' + sPath : '');
  return true;
};

const hasItem = (sKey) => {
  if (!sKey) { return false; }
  return (new RegExp('(?:^|;\\s*)' + encodeURIComponent(sKey).replace(/[\-\.\+\*]/g, '\\$&') + '\\s*\\=')).test(document.cookie);
};

const keys = () => {
  const aKeys = document.cookie.replace(/((?:^|\s*;)[^\=]+)(?=;|$)|^\s*|\s*(?:\=[^;]*)?(?:\1|$)/g, '').split(/\s*(?:\=[^;]*)?;\s*/);
  const nLen = aKeys.length;
  for (nLen, nIdx = 0; nIdx < nLen; nIdx++) { aKeys[nIdx] = decodeURIComponent(aKeys[nIdx]); }
  return aKeys;
};

export default { getItem, setItem, removeItem, hasItem, keys };