Angular Services cannot be mocked in Angular TestBed

If I mock an Angular Injectable Service, I get the following as soon as I include it in the module providers list:

TypeError: function is not iterable (cannot read property Symbol(Symbol.iterator))
    at new Set (<anonymous>)

Pseudo code (edited for simplicity)

const issueServiceMock = mock<IssueService>();
TestBed.configureTestingModule({
  imports: [ReactiveFormsModule, RouterTestingModule],
  declarations: [
    IssueDashboardContainerComponent
  ],
  providers: [
    {provide: IssueService, useValue: issueServiceMock},
  ]
});
fixture = TestBed.createComponent(IssueDashboardContainerComponent);  // CRASHES HERE

[myin142]

I fixed this issue by providing the service using factory. But another problem is that the fixture is not updated in jest when async code is finished. Do you also have this problem?

Edit: Nevermind the problem. It happens only inside NX Workspaces.

[dgradwell-ams]

The problem was, in my case, I had a template using an async pipe on an observable that would have been on my mock.

const foo = mock<IFoo>();

   <div *ngFor="let item of foo.someObservable$ | async"> 
       ...

The async pipe is trying to use someObservable$ as an iterable, but it’s really a function. The solution is to override those props after creating the mock:

const foo = Object.assign(mock<IFoo>(), { someObservable$: of(...) });