Real-life: forkJoin() with a per-field fallback

One request fails. Catch the error inside the profile$ field so forkJoin still completes.

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const { of, throwError, forkJoin, catchError, map } = Rx;

const user$ = of('profile');
const profile$ = throwError(() => new Error('missing')).pipe(
  catchError(() => of('guest'))
);

const result$ = forkJoin({ user: user$, profile: profile$ }).pipe(
  map(({ user, profile }) => user + ':' + profile)
);

result$.subscribe(value => console.log(value));

script.ts // TypeScript

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