Demystifying Async Programming in Javascript - fetchJson promise closurized

fetchJson-promise-closurized.js

// We declare these variables we want to save ahead of time.
var user, recommendations;
fetchJson('/api/user/self')
    .then(function (fetchedUser) {
      user = fetchedUser;
      return fetchJson('/api/user/interests?userId=' + self.id);
    })
    .then(function (fetchedInterests) {
      interests = fetchedInterests;
      return Promise.all(interests.map(i => fetchJson('/api/recommendations?topic=' + i)));
    })
    .then(function (recomendations) {
      render(user, interests, recommendations);
    })
    .then(function () {
      console.log('We are done!');
    });