RxJS 5 merge operator doesn't work for observables created from array

Question

This code logs different result for RxJS 4 and RxJS 5

Rx.Observable.merge( Rx.Observable.from([1,2,3,4]), Rx.Observable.from([5,6,7]) ).subscribe(i => console.log(i))

Result for RxJS 4: 1,5,2,6,3,7,4 - the result is correct according to the docs of merge:

Creates an output Observable which concurrently emits all values from every given input Observable

RxJS5: 1,2,3,4,5,6,7 - result is the same as from concat operator that is not as described in docs

So how to get the values from two array observables concurrently in RxJS5?

You are passing synchronous observables. For an explanation of what's happening, see: staltz.com/primer-on-rxjs-schedulers.html — cartant
And for the v4 and v5 scheduling differences see: github.com/ReactiveX/rxjs/blob/master/… — cartant

Oleh Oleh · Accepted Answer · 2018-01-26T09:18:56

Thanks to cartant.

The proper solution in RxJS 5:

Rx.Observable.merge( Rx.Observable.from([1,2,3,4], Rx.Scheduler.asap), Rx.Observable.from([5,6,7], Rx.Scheduler.asap) ).subscribe(i => console.log(i))

RxJS 5 merge operator doesn't work for observables created from array

1 Answers