Incorrect type signatures for concatAll and mergeAll operators

[kevgrasso]

RxJS version:
5.4.2

Code to reproduce:

const fromEvent = Rx.Observable.fromEvent;
const mouseEvents = Rx.Observable.of([fromEvent(document, "click"), fromEvent(document, "mouseenter"), fromEvent(document, "mouseleave")]); 

mouseEvents.concatAll().mapTo(null);
mouseEvents.mergeAll().mapTo(null);

Expected behavior:
Code compiles without error.

Actual behavior:
Type error: "[ts] Property 'mapTo' does not exist on type 'Observable<{}>[]'.

Additional information:
Incorrect type signatures are-

function concatAll<T>(this: Observable<T>): T;
function concatAll<T, R>(this: Observable<T>): Subscribable<R>;

function mergeAll<T>(this: Observable<T>, concurrent?: number): T;
function mergeAll<T, R>(this: Observable<T>, concurrent?: number): Subscribable<R>;

They should be (I believe):

function concatAll<T extends ObservableInput<R>, R>(this: Observable<T>): Observable<R>;

function mergeAll<T extends ObservableInput<R>, R>(this: Observable<T>, concurrent?: number): Observable<R>;

[aboyton]

I ran into a similar problem myself today with similar code, trying

Observable.of([[1, 2, 3], [4, 5]]).mergeAll().subscribe(x => console.log(x));

This prints (see jsbin)

[1, 2, 3]
[4, 5]

The current definitions give me the compilation error [ts] Property 'subscribe' does not exist on type 'number[][]'. which seems wrong, but these new proposed definitions give me the final type of x to be (parameter) x: {} which also seems incorrect according to the values emitted on the console.

So the proposed definitions are definitely better and fix other uses of mergeAll in my code, I suspect that we need the following definition as well (before the one above to it's a higher preference).

function concatAll<T>(this: Observable<T[]>): Observable<T>;
function mergeAll<T>(this: Observable<T[]>, concurrent?: number): Observable<T>

[kwonoj]

I'm feeling this is dupe to #2690 (and related issues) which we had fixes in next major.

[tvald]

Can we please fix this without waiting for a major release? This is an active issue, with two separate PRs to (partially) fix it on master in the last month: #2779, #2760

The existing typings for mergeAll() are wrong and unusable. It should be trivial to drop in the correct typing from #2779: https://github.com/ReactiveX/rxjs/pull/2690/files#diff-287d1762ff7b138d92ddcb79627353f7

[aboyton]

Or at least do we have any timeframe on when the next major version is expected to be released? I agree, the current typings are pretty well unusable for me.

[kwonoj]

@aboyton Next major is already published as rxjs@6 alpha version, though it need to be published with latest changes. It won't be released as public soon enough cause we do expect to pick up some more breaking changes.

[simeyla]

Any reason why this was ever there in the first place. I don't see how 6 months later this wasn't ever fixed.
Was it an actual 'typo' or was there a reason it was wrong? And how do I even use concatAll() in my code?

It's confusing the heck out of me even after having found this thread.

[jdevng]

To @simeyla 's post, is verification assistance needed? Is there a write up on how to get started - I've never worked on github before, but I've designed asynchronous semiconductors and verified them. RxJS is cool, but github is a new concept to me.

[benlesh]

Closed by #3321

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.