Rxjs: Rx.Observable.catch(args) absent

[crunchie84]

The static Rx.Observable.catch() method present in Rxjs 4.x seems to be absent in RxJs 5.0.2

RxJS version:
5.0.2

Code to reproduce:

Rx.Observable.catch(
  Rx.Observable.throw(new Error()),
  Rx.Observable.of('only i will be emitted'),
  Rx.Observable.of('never subscribed to')
)
.take(1)
.subscribe(
 v => console.log(v), 
 err => console.log(err.message), 
 () => console.log('completed')
)

Expected behavior:

"only i will be emitted"
"completed"

Actual behavior:

"TypeError: Rx.Observable.catch is not a function"

[Dorus]

I don't think this operator is needed, it's trivial to write.

Rx.Observable.of(
  Rx.Observable.throw(new Error()),
  Rx.Observable.of('only i will be emitted'),
  Rx.Observable.of('never subscribed to')
).reduce((ob1, ob2) => ob1.catch(() => ob2), Rx.Observable.throw(''))
.mergeAll()

[crunchie84]

This was not 100% trivial for me to write. Learned something today though! :+1: So it seems that this issue can be resolved in one of the following ways:

1) Document absent catch() overload in MIGRATION.md + point to how to do this yourself?
2) Implement missing overload

[Dorus]

Trivial to write, probably not trivial to come up with :)

[benlesh]

More trivially than that, Observable.catch(a, b, c) is really just a.catch(() => b).catch(() => c):

Observable.throw(new Error())
  .catch(() => Observable.of('only I will be emitted'))
  .catch(() => Observable.of('never subscribed to'))

I hope that helps.

[kwonoj]

Closing as I believe it won't be added in core as it's achievable via existing opeartor chains.

[lock[bot]]

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.