RXJS合并:在需要流的地方提供了“未定义”

我出错了 You provided 'undefined' where a stream was expected. 当我试图合并可观察到的东西时。

我在这里创建了我的可观察刷新:

refresh$: Observable<Funnel[]>; 

然后我有一个计时器…

TimerObservable.create(0, (this.storageService.refRate * 1000))
    .takeWhile(() => this.interval)
    .subscribe(() => {
        this.refresh$ = this.funnelService.getStoryFunnels({}).map(response => [...response]);
    });

然后,当我尝试合并可观察到的数据时,会产生错误:

this.funnels$ = this.funnelService.getStoryFunnels({}).pipe(
    merge(this.refresh$, funnelCreation$.pipe(
            filter(funnel => !!funnel),
            map(funnel => [funnel])
        )
    )
);

根据Cozzy的回答更新:

this.refresh$ = TimerObservable.create(0, (this.storageService.refRate * 500))
    .takeWhile(() => this.interval)
    .switchMap(() =>  this.funnelService.getStoryFunnels({}).map(response => [...response]));

this.funnels$ = this.funnelService.getStoryFunnels({}).pipe(
        merge(this.refresh$, funnelCreation$.pipe(
                filter(funnel => !!funnel),
                map(funnel => [funnel])
            )
        )
    );