Asynchronous

[ForbesLindesay]

We've had the discussion and accepted that Promises/A+ promises are always asynchronous for then but what about for calls to resolve

let {promise, resolve} = defer();
console.log(1);
promise.then(() => console.log(4));
console.log(2);
resolve(null);
console.log(3);

If resolve is allowed to be synchronous, this could result in:

1
2
4
3

But if it must be asynchronous then it must result in

1
2
3
4

Because of the restrictions of Promises/A+ it can never result in

1
4
2
3

So what's it to be? Do we force asynchronous behavior?

[domenic]

Very interesting, thanks for bringing this up! My first instinct is that synchronicity would be bizarre. But, not based on anything concerete yet.

Let's try this similar scenario:

let {promise, resolve} = defer();
console.log(1);
resolve(null);
promise.then(() => console.log(4));
console.log(2);
console.log(3);

The only thing this can be, by Promises/A+, is

1
2
3
4

To me it seems weird that the output would change depending on whether you hooked up the then before or after the resolve.

[ForbesLindesay]

Another question is how that plays with 'synchronous inspection'.