Handling 404 Status from Wikipedia

function getJSON(url, allow404 = false) {
  //when allow404 == true, http 404 errors won't reject Promise
  return new Promise((resolve, reject) => {
    const xhr = new XMLHttpRequest();
    xhr.open('GET', url);
    xhr.onload = () => {
      if (xhr.status === 200 || (xhr.status === 404 && allow404)) {
        let data = JSON.parse(xhr.responseText);
        resolve(data);
      } else {
        reject(Error(xhr.statusText));
      }
    }
    xhr.onerror = () => reject(Error('A network error occured.'));
    xhr.send();
  });
}

function getProfiles(json) {
  const profiles = json.people.map(person => {
    return getJSON(wikiUrl + person.name, true);
  });
  return Promise.all(profiles);
}

function generateHTML(data) {
  data.map(person => {
    const section = document.createElement('section');
    peopleList.appendChild(section);
    if (person.title === 'Not found.') {
      /*If Bio page wasn't found, pull person's name out of URL and format a 
      section with defaults
      */
      let uriToTokens = person.uri.split('/');
      let name = decodeURI(uriToTokens[uriToTokens.length - 1]);
      section.innerHTML = `
     <img src="img/profile.jpg" alt="ocean clouds seen from space">
     <h2>${name}</h2>
     <p>Wikipedia results unavailable for ${name}</p>
     <p>But this person is really in space! Try searching 
     <a href="https://www.google.com/search?q=${encodeURIComponent(name)}" target="_blank">Google for them</a></p>
   `;
    } else if (person.type === 'standard') {
      // Check if request returns a 'standard' page from Wiki
      section.innerHTML = `
        <img src=${person.thumbnail.source}>
        <h2>${person.title}</h2>
        <p>${person.description}</p>
        <p>${person.extract}</p>
      `;
    } else {
      section.innerHTML = `
        <img src="img/profile.jpg" alt="ocean clouds seen from space">
        <h2>${person.title}</h2>
        <p>Results unavailable for ${person.title}</p>
        ${person.extract_html}
      `;
    }
  });
}