Type definition for extended operator is not published

[kwonoj]

Code snippet below works in JS,

var Rx = require('....Rx.KitchenSink');
Rx.Observable.of(42).isEmpty().subscribe(console.log);

when it comes to TS

import * as Rx from '....Rx.KitchenSink';
Rx.Observable.of(42).isEmpty().subscribe(console.log);

compiler will complain due to Observable.of does not returns extended type of operator instead of core.
error TS2339: Property 'isEmpty' does not exist on type 'Observable<number>'.

[kwonoj]

This issue is related with modularity strategies. Tried some approaches ends up with vain, exploring few other approaches including mixins.

[benlesh]

cc/ @robwormald

[benlesh]

cc/ @jeffbcross

[kwonoj]

Created PR #643 for initial proposal based on mixin, and possibly including ambient declaration merging if it's necessarily required.

[robwormald]

Nice work OJ! I'll try this out later today but at first glance it looks
like it'll solve a bunch of issues for us.

On Wednesday, November 4, 2015, OJ Kwon notifications@github.com wrote:

Created PR #643 #643 for initial
proposal based on mixin, and possibly including ambient declaration merging
if it's necessarily required.

—
Reply to this email directly or view it on GitHub
#642 (comment).

[kwonoj]

Related with #750 .

[benlesh]

@kwonoj @robwormald is this issue resolved? Can we close this?

[kwonoj]

No, it's still there and we don't have decent solution yet.

[benlesh]

@kwonoj @jeffbcross @robwormald ... is it reasonable to say this is a problem with TypeScript and not necessarily with how RxJS is structured?

[kwonoj]

I'm considering half and half. TypeScript can possibly bring better feature resolves this issue, but I would expect it'll eventually requires change structures of RxJS codebase, just matter of how much. Short example would be interfaces are tied to return Observable only as well as implementation of lift does, etcs.

As an issue tracking perspective, I don't think this can be updated in relatively short time frame. I'm seeing couple of discussions are in TypeScript perspective would require some time to something's actually happening. I can suggest close this for now and bring it back once circumstances allowing further discussion.

[kwonoj]

Thinking about this issue, I came to think this also could be resolved via module augmentation as same as #1193, with introducing some organization changes. It might be get rid of interface KitchenSinkOperators and let CoreOperators contains all signatures (maybe renaming required for interface? ) then publish type of each extended operator via module augumentation. By this way, importing Rx.Kitchensink includes extended operator patches as well as type definition belongs Observable, removes type inference issues currently occurring.

Still this is vague idea, might need to come up with solid changes once infrastructure (primarily min version of typescript) is ready.

[david-driscoll]

In theory CoreOperators and KitchenSinkOperators can go away once we have augmentation for all operators in place.