+++ /dev/null
-import { EmptyError } from '../util/EmptyError';
-import { Observable } from '../Observable';
-import { Operator } from '../Operator';
-import { Subscriber } from '../Subscriber';
-import { TeardownLogic, MonoTypeOperatorFunction } from '../types';
-
-/**
- * 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 {@link EmptyError}.
- *
- * ![](throwIfEmpty.png)
- *
- * ## Example
- * ```ts
- * import { fromEvent, timer } from 'rxjs';
- * import { throwIfEmpty, takeUntil } from 'rxjs/operators';
- *
- * const click$ = fromEvent(document, 'click');
- *
- * click$.pipe(
- * takeUntil(timer(1000)),
- * throwIfEmpty(
- * () => new Error('the document was not clicked within 1 second')
- * ),
- * )
- * .subscribe({
- * next() { console.log('The button was clicked'); },
- * error(err) { console.error(err); }
- * });
- * ```
- *
- * @param errorFactory A factory function called to produce the
- * error to be thrown when the source observable completes without emitting a
- * value.
- */
-export function throwIfEmpty <T>(errorFactory: (() => any) = defaultErrorFactory): MonoTypeOperatorFunction<T> {
- return (source: Observable<T>) => {
- return source.lift(new ThrowIfEmptyOperator(errorFactory));
- };
-}
-
-class ThrowIfEmptyOperator<T> implements Operator<T, T> {
- constructor(private errorFactory: () => any) {
- }
-
- call(subscriber: Subscriber<T>, source: any): TeardownLogic {
- return source.subscribe(new ThrowIfEmptySubscriber(subscriber, this.errorFactory));
- }
-}
-
-class ThrowIfEmptySubscriber<T> extends Subscriber<T> {
- private hasValue: boolean = false;
-
- constructor(destination: Subscriber<T>, private errorFactory: () => any) {
- super(destination);
- }
-
- protected _next(value: T): void {
- this.hasValue = true;
- this.destination.next(value);
- }
-
- protected _complete() {
- if (!this.hasValue) {
- let err: any;
- try {
- err = this.errorFactory();
- } catch (e) {
- err = e;
- }
- this.destination.error(err);
- } else {
- return this.destination.complete();
- }
- }
-}
-
-function defaultErrorFactory() {
- return new EmptyError();
-}