toPromise() does not propagate errors properly

[NoxPhoenix]

There are certain situations where the toPromise method will resolve successfully with a highland internal error being thrown.

to recreate...

_([1])
  .map(x => _.nil)
  .toArray(arr => console.log);

Will error Error: Cannot call next after nil

however....

_([1])
  .map(x => _.nil)
  .collect()
  .toPromise(Promise)
  .then(console.log);

Will just log an empty array to the console.

[vqvu]

This is a bug in map, not in toPromise. map shouldn't let you map to nil in the first place. This is pretty easy to fix. But in the meantime, if you're doing this to early-terminate a stream, you should be using filter instead of (or in addition to) map.

…

On Sat, Jun 8, 2019, 3:22 AM NoxPhoenix ***@***.***> wrote: There are certain situations where the toPromise method will resolve successfully with a highland internal error being thrown. to recreate... _([1]) .map(x => _.nil) .toArray(arr => console.log); Will error Error: Cannot call next after nil however.... _([1]) .map(x => _.nil) .collect() .toPromise(Promise) .then(console.log); Will just log an empty array to the console. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#683?email_source=notifications&email_token=ABRDEZKRCJZVOW5TGZODG2TPZK7QBA5CNFSM4HV2BKN2YY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4GYKTCWQ>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABRDEZKD5KYVXCCC64PXBM3PZK7QBANCNFSM4HV2BKNQ> .

[NoxPhoenix]

Oh ok. I was digging through the code for toPromise and collect to try and find it myself. Good to know you think it's an easy fix!

If you let me know the premise of what needs to be added, I will open a PR for it.

[dvisztempacct]

This is a bug in map
This is pretty easy to fix

waiting for a PR?