TypeError: You provided an invalid object where a stream was expected. You can provide an Observable, Promise, Array, or Iterable

Question

I am trying to map from a service call but getting an error. Looked at subscribe is not defined in angular 2? and it said that in order to subscribe we need to

Answer 1

In my case the error occurred only during e2e tests. It was caused by throwError in my AuthenticationInterceptor.

I imported it from a wrong source because I used WebStorm's import feature. I am using RxJS 6.2.

Wrong:

import { throwError } from 'rxjs/internal/observable/throwError';

Correct:

import { throwError } from 'rxjs';

Here the full code of the interceptor:

import { Injectable } from '@angular/core';
import { HttpErrorResponse, HttpEvent, HttpHandler, HttpInterceptor, HttpRequest } from '@angular/common/http';
import { Observable, throwError } from 'rxjs';
import { catchError } from 'rxjs/operators';

@Injectable()
export class AuthenticationInterceptor implements HttpInterceptor {

  intercept(req: HttpRequest, next: HttpHandler): Observable> {
    const reqWithCredentials = req.clone({withCredentials: true});
    return next.handle(reqWithCredentials)
     .pipe(
        catchError(error => {
          if (error.status === 401 || error.status === 403) {
            // handle error
          }
          return throwError(error);
        })
     );
  }
}