Scheduler.asap doesn't use `nextTick`?

RxJS version:

5.4.0

Code to reproduce:

process.nextTick(() => { console.log('nextTick 1'); });
setImmediate(() => { console.log('setImmediate 1'); });
Observable.of('now!', Scheduler.asap).subscribe(x => console.log(x));
setImmediate(() => { console.log('setImmediate 2'); });
process.nextTick(() => { console.log('nextTick 2'); });

Expected behavior:

"nextTick 1"
"now!"
"nextTick 2"
"setImmediate 1"
"setImmediate 2"

Actual behavior:

"nextTick 1"
"nextTick 2"
"setImmediate 1"
"now!"
"setImmediate 2"

Additional information:

Am I misunderstanding something? I reached for the asap scheduler because the docs say it’s supposed to schedule using nextTick (when available), but it doesn’t appear to be doing so.

[trxcllnt]

@benlesh I think what @matthewwithanm is pointing out is that setImmediate isn’t the microtask scheduling method (see here). Furthermore, setImmediate docs on MDN seem to indicate setImmediate is dead, so we should probably find an alternative.

[trxcllnt]

@matthewwithanm hey Matt, sorry for the confusion. The asap scheduler attempts to use setImmediate, and falls back to nextTick if it isn’t available (you can see how it’s resolved here). Let me know if you have any suggestions on a better approach.