RxJS takeWhile but include the last value

Question

I have a RxJS5 pipeline looks like this

Rx.Observable.from([2, 3, 4, 5, 6])
  .takeWhile((v) => { v !== 4 })

I want to keep the subscrip

Answer 1

You can use endWith(value) which (unlike a lot of RxJS code) is very nicely self documenting.

const example = source.pipe(
                            takeWhile(val => val != 4), 
                            endWith(4));

PS. Also note that takeUntil doesn't take a predicate, so if you were trying to use that operator to solve this problem you can't. It's a whole different method signature.

Official docs: https://rxjs-dev.firebaseapp.com/api/operators/endWith

https://stackblitz.com/edit/typescript-pvuawt