auth.effect.ts

@Effect()
  authenticateUser$ = this.actions$
    .pipe(
      ofType(authActions.AUTHENTICATE_USER),
      switchMap(() => {
        return this.angularFireAuth.authState.pipe(
          map((identity: fromFirebase.User) => {
            return identity
              ? new authActions.AuthenticateUserSuccess(ConvertingHelper.extractFirebaseUserInfo(identity))
              : new authActions.AuthenticateUserFail('User Not logged In.');
          }),
          catchError(error => of(new authActions.AuthenticateUserFail(error)))
        );
      })
    );