skipUntil

通知用 Observable が発行するまで、ソース Observable からのすべての値をスキップします。

Marble Diagram

skipUntil(notifier$)

使用例

//  Timeline:
//
//  num$          1     2     3     start   4     5     6
//  startNotifier                   X
//  skipped$                                4     5     6
//                |------ skipped -------|
//
//  Explanation:
//  - skipUntil ignores all values until the notifier emits
//  - After the notifier emits, all subsequent values are passed through
//  - Opposite of takeUntil (which completes when notifier emits)

const num$ = source<number>();

const [startNotifier, start_] = createEventEmitter();

const skipped$ = num$.pipe(skipUntil(startNotifier));

const valueHistory: number[] = [];

skipped$.subscribe((x) => {
    valueHistory.push(x);
});

num$.next(1); // nothing logged

num$.next(2); // nothing logged

assert.deepStrictEqual(valueHistory, []);

start_();

num$.next(4); // logs: 4

assert.deepStrictEqual(valueHistory, [4]);

num$.next(5); // logs: 5

assert.deepStrictEqual(valueHistory, [4, 5]);

View source on GitHub