rxjs

let keydownBufferSubject$: Subject<frontendNote> = new Subject()

        const keydowns$ = fromEvent(document, "keydown").pipe(
            filter((val: any) => val.key !== "Meta")
        )
        this.keydowns$ = keydowns$.subscribe((_) => {
            // console.log(_)
            keydownBufferSubject$.next(this.activeNote)
        })

        const keydownBuffer$ = keydownBufferSubject$.pipe(
            scan<any, Array<frontendNote>>((acc, val) => {
                return [...acc, val]
            }, []),
            debounce((_) => timer(500)),
            take(1),
            mergeAll(),
            distinctUntilKeyChanged("id"),
            repeat()
        )

        keydownBuffer$.subscribe((previouslyActiveNote) => {
            this.requests.notes.save.send(previouslyActiveNote)
        })