xxphantom/frontend-project-lvl3

const propsAllowList = ['title', 'description', 'link', 'guid'];

const domEltoObj = (el) => {
  const obj = propsAllowList.reduce((acc, propName) => {
    if (el.querySelector(`${el.tagName} > ${propName}`) !== null) {
      acc[propName] = el.querySelector(propName).textContent;
    }
    return acc;
  }, {});
  return obj;
};

const parse = (xmlString) => {
  try {
    const xmlParser = new DOMParser();
    const dom = xmlParser.parseFromString(xmlString, 'text/xml');
    const parseErrorEl = dom.querySelector('parsererror');
    if (parseErrorEl) {
      throw new Error(parseErrorEl.textContent);
    }
    const channelEl = dom.querySelector('channel');
    const itemsEls = [...dom.querySelectorAll('item')];
    const { title, link, description = link } = domEltoObj(channelEl);
    const items = itemsEls.map(domEltoObj);
    return { title, description, items };
  } catch (err) {
    err.isParseError = true;
    throw err;
  }
};

export default parse;