js_async_await.md

Using promises in javascript can be a little painful. If you use a recent enough revision of js, you can handle this differently. For example, this code:

function do_stuff(url) {
  return new Promise((resolve) => {
     fetch(url).then(response => {
       response.json().then(data => {
         resolve(data);
       });
     });
  });
}

Can be rewritten like this using async/await:

async function do_stuff(url) {
  const response = await fetch(url);
  const data = await response.json();
  return data;
}

Marking a function async makes it return a promise. Putting await before a promise waits for it to resolve and returns the argument that would have been passed to resolve.

WARNING: this feature is not included in ES6, but can be added with plugins and is part of ES7. This is understood by many browsers.