import { BehaviorSubject, merge, of, Subject } from 'rxjs';
import {
  shareReplay,
  take,
  takeUntil,
  materialize,
  filter,
} from 'rxjs/operators';

const shared$ = new BehaviorSubject('7.5.1').pipe(
  shareReplay({ refCount: true, bufferSize: 1 })
);

const isCompleted$ = shared$.pipe(
  materialize(),
  filter((n) => n.kind === 'C'),
  take(1)
);

const work = new Subject().pipe(takeUntil(isCompleted$));

merge(work, shared$)
  .pipe(take(1))
  .subscribe((value) => console.log('first: ', value));

shared$.subscribe((value) => console.log('second:', value));