RxJS waitLatestForm

wait-latest-from.ts

import { switchMap } from 'rxjs/operators';

action$;
state$; // facade.country$ etc...
repository$;

fetch$.pipe(withLatestFrom(facade.country$));

waitLatestFrom = (action$) =>
  action$.pipe(
    switchMap((action) =>
      combineLatest(of(action), facade.country$.pipe(take(1)))
    )
  );

waitLatestFrom = (action$) =>
  action$.pipe(concatLatestFrom(() => facade.country$.pipe(take(1))));

fetch$.pipe(
  switchMap(
    (action) => country$.pipe(take(1)),
    map((country) => ({ ...action, country }))
  )
);