toPromise on Observable requires promise constructor argument

[jeffbcross]

https://github.com/ReactiveX/RxJS/blob/master/src/Observable.ts#L247

The constructor should be optional, as it is implemented in the operator itself https://github.com/ReactiveX/RxJS/blob/master/src/operator/toPromise.ts

[kwonoj]

Yes, seems so. I'll update this quickly.

[jeffbcross]

Awesome @kwonoj thanks!

[johnpapa]

thanks!

[robwormald]

Nice one OJ. This sort of thing would be caught with TS running type checks on a TS based test suite, so I'm definitely for that.

[kwonoj]

This sort of thing would be caught with TS running type checks on a TS based test suite, so I'm definitely for that.

: totally agreed. Currently 2 proposals opened for this, #826 and #667. Once it's decided which way to go, test will be added along with updating existing type declarations if necessary.