class PendingService {
    active = 0;
    isActive = false;

    start() {
        this.active++;
        this.isActive = true;
    }

    stop() {
        this.active--;

        if (this.active === 0) {
            this.isActive = false;
        }
    }
}

pendingService.start();
data.get().subscribe(null, null, () => pendingService.stop());

<spinner [hidden]="!pendingService.isActive"></spinner>

<spinner [hidden]="pendingService.pending | async"></spinner>