Promises don't handle a 404 response

The fix shown in other comments is an appalling bodge-up. Students should NOT be encouraged to use this example just to get through the tutorial. Treehouse - you need to address the fact that a 404 is breaking the project during these lessons. The generateHTML function is passed an undefined item in the object array, breaking the app when data.map tries to read the value person.thumbnail.source.

Wrapping the html builder in a conditional stops the app breaking, but then there's the unhandled 404 sitting in the console. We need to know how to deal with situations like that too. This problem meant that it took me three days to complete the Promises tutorials because I spent so much time looking for ways to handle the 404 properly. (I didn't find one because, technically, it's not an error).

function generateHTML(data) {
  data.map( person => {
    if(person.title !== "Not found."){
      const section = document.createElement('section');
      peopleList.appendChild(section);
      section.innerHTML = `
        <img src=${person.thumbnail.source}>
        <span>${person.craft}</span>
        <h2>${person.title}</h2>
        <p>${person.description}</p>
        <p>${person.extract}</p>
      `;
    }
  });
}

I'm a little disillusioned with Treehouse at this point, these tutorials are clearly not covering everything we need to know. The plethora of comments on this issue, none of which have a good professional answer, is proof that nothing has been done to fix the failing. The lack of a supplementary video to address it also tells me Treehouse aren't interested in customer feedback.