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feat(skipUntil): notifier should support ObservableInput (#7091)
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jakovljevic-mladen committed Dec 15, 2022
1 parent 8c4347c commit 60d6c40
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Showing 3 changed files with 54 additions and 14 deletions.
6 changes: 5 additions & 1 deletion spec-dtslint/operators/skipUntil-spec.ts
Expand Up @@ -7,5 +7,9 @@ it('should infer correctly', () => {

it('should enforce types', () => {
const o = of('foo', 'bar', 'baz').pipe(skipUntil()); // $ExpectError
const p = of('foo', 'bar', 'baz').pipe(skipUntil('7')); // $ExpectError
const p = of('foo', 'bar', 'baz').pipe(skipUntil(7)); // $ExpectError
});

it('should support Promises', () => {
of(1, 2, 3).pipe(skipUntil(Promise.resolve('foo'))); // $ExpectType Observable<number>
});
36 changes: 35 additions & 1 deletion spec/operators/skipUntil-spec.ts
@@ -1,5 +1,5 @@
import { expect } from 'chai';
import { concat, defer, of, Subject, Observable } from 'rxjs';
import { concat, defer, of, Subject, Observable, interval } from 'rxjs';
import { skipUntil, mergeMap, take } from 'rxjs/operators';
import { asInteropObservable } from '../helpers/interop-helper';
import { TestScheduler } from 'rxjs/testing';
Expand Down Expand Up @@ -367,4 +367,38 @@ describe('skipUntil', () => {

expect(sideEffects).to.deep.equal([0, 1, 2]);
});

it('should skip until Promise resolves', (done) => {
const e1 = interval(3).pipe(take(5));
const expected = [2, 3, 4];

e1.pipe(skipUntil(new Promise<void>((resolve) => setTimeout(() => resolve(), 8)))).subscribe({
next: (x) => {
expect(x).to.deep.equal(expected.shift());
},
error: () => done(new Error('should not be called')),
complete: () => {
expect(expected.length).to.equal(0);
done();
},
});
});

it('should raise error when Promise rejects', (done) => {
const e1 = interval(1).pipe(take(5));
const error = new Error('err');

e1.pipe(skipUntil(Promise.reject(error))).subscribe({
next: () => {
done(new Error('should not be called'));
},
error: (err: any) => {
expect(err).to.be.an('error');
done();
},
complete: () => {
done(new Error('should not be called'));
},
});
});
});
26 changes: 14 additions & 12 deletions src/internal/operators/skipUntil.ts
@@ -1,5 +1,4 @@
import { Observable } from '../Observable';
import { MonoTypeOperatorFunction } from '../types';
import { MonoTypeOperatorFunction, ObservableInput } from '../types';
import { operate } from '../util/lift';
import { createOperatorSubscriber } from './OperatorSubscriber';
import { innerFrom } from '../observable/innerFrom';
Expand All @@ -8,19 +7,22 @@ import { noop } from '../util/noop';
/**
* Returns an Observable that skips items emitted by the source Observable until a second Observable emits an item.
*
* The `skipUntil` operator causes the observable stream to skip the emission of values until the passed in observable emits the first value.
* This can be particularly useful in combination with user interactions, responses of http requests or waiting for specific times to pass by.
* The `skipUntil` operator causes the observable stream to skip the emission of values until the passed in observable
* emits the first value. This can be particularly useful in combination with user interactions, responses of HTTP
* requests or waiting for specific times to pass by.
*
* ![](skipUntil.png)
*
* Internally the `skipUntil` operator subscribes to the passed in observable (in the following called *notifier*) in order to recognize the emission
* of its first value. When this happens, the operator unsubscribes from the *notifier* and starts emitting the values of the *source*
* observable. It will never let the *source* observable emit any values if the *notifier* completes or throws an error without emitting
* a value before.
* Internally, the `skipUntil` operator subscribes to the passed in `notifier` `ObservableInput` (which gets converted
* to an Observable) in order to recognize the emission of its first value. When `notifier` emits next, the operator
* unsubscribes from it and starts emitting the values of the *source* observable until it completes or errors. It
* will never let the *source* observable emit any values if the `notifier` completes or throws an error without
* emitting a value before.
*
* ## Example
*
* In the following example, all emitted values of the interval observable are skipped until the user clicks anywhere within the page
* In the following example, all emitted values of the interval observable are skipped until the user clicks anywhere
* within the page
*
* ```ts
* import { interval, fromEvent, skipUntil } from 'rxjs';
Expand All @@ -41,13 +43,13 @@ import { noop } from '../util/noop';
* @see {@link skipWhile}
* @see {@link skipLast}
*
* @param {Observable} notifier - The second Observable that has to emit an item before the source Observable's elements begin to
* @param notifier An `ObservableInput` that has to emit an item before the source Observable elements begin to
* be mirrored by the resulting Observable.
* @return A function that returns an Observable that skips items from the
* source Observable until the second Observable emits an item, then emits the
* source Observable until the `notifier` Observable emits an item, then emits the
* remaining items.
*/
export function skipUntil<T>(notifier: Observable<any>): MonoTypeOperatorFunction<T> {
export function skipUntil<T>(notifier: ObservableInput<any>): MonoTypeOperatorFunction<T> {
return operate((source, subscriber) => {
let taking = false;

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