Discussion on: Gotchas about async/await and Promises

[Jonathan Boudreau]

doSomething().then(data => {
  doStuff(data).then(result => {
    doOtherStuff(data, result).then(outcome => {
      showOutcome(outcome, result, data);
    });
  });
});

Instead of this you can do something like the following:

const concat = _.curry(_.concat, 2)
doSomething()
  .then(data => 
    doStuff(data).then(concat(data))
  .then([data, result] =>
    doOtherStuff(data, result).then(concat([data, result]))
  )
  .then([data, result, outcome] =>
    showOutcome(data, result, outcome)
  )

[K]

Or like this:

doSomething()
  .then(data => Promise.all([data, doStuff(data)]))
  .then(([data, result]) => Promise.all([data, result, doOtherStuff(data, result)]))
  .then(([data, result, outcome]) => showOutcome(data, result, outcome));

Clean and simple approach, but passing around of all the values is quite cumbersome.

[Jonathan Boudreau]

My main point was that you can still get a "flat" result when you have interdependent calls.

You can also pull this off with callbacks.