How do you yield* with async/await?

[Fishrock123]

Hi there, I was looking to move my CLI tool org-labels over to async/await as an experiment, using node+v8-5.2 & --harmony_async_await.

I've noticed there does not immediately appear to be a replacement for yield*, as with the co library.

That is, it is unclear what you need to do to wait for all awaits to resolve within an async function...

[Fishrock123]

@kittens Given the following: (They deleted their comment...)

async function a() {
  await x; // must wait for this
  await y; // AND this
}

async function b() {
  await a(); // previously `yield* a()`
}

do you mean await Promise.all(a())? Will the async function with multiple awaits return an array?

Always or only when multiple exist/are run?

[ilkkao]

Similar issue: #61

[raymond-h]

Async functions with multiple awaits still only return a single promise, which is resolved once the function has finished. await makes it wait for a given promise to resolve before the function is continued.

With multiple awaits, it'll wait until the first promise is resolved, then the second promise, then the third promise, etc, until the end of the function has been reached. At that point, the promise that the function as a whole returned is resolved.

In your example, when b is called, it'll call a and get a promise that it waits for to get resolved. The function a, in turn, waits for promise x to be resolved, then promise y. Once that's done, a returns, at which point the promise that was gotten by b is resolved.

[raymond-h]

Because an async function that awaits on promises itself returns a promise that is resolved when the async function return, await works for awaiting the result of other async functions too out of the box, so it is a non-issue essentially.

[Fishrock123]

Hmm, ok. Looks/sounds like this is the default behavior. In a bit of hindsight that makes sense.

That being said I am running into problems related to this, but not really this issue.