throwIfEmpty

If the source observable completes without emitting a value, it will emit an error. The error will be created at that time by the optional errorFactory argument, otherwise, the error will be EmptyError.

const throwIfEmpty: any;

Description

Example

import { fromEvent, timer } from 'rxjs'; import { throwIfEmpty, takeUntil } from 'rxjs/operators'; const click$ = fromEvent(button, 'click'); clicks$.pipe( takeUntil(timer(1000)), throwIfEmpty( () => new Error('the button was not clicked within 1 second') ), ) .subscribe({ next() { console.log('The button was clicked'); }, error(err) { console.error(err); }, });