How to mock abstract service?

[jfpicard123]

I'm testing a component that has dependency on abstract class

constructor(private service: IService) { }

The providers are configured as such

{ provide: IService, useClass: Service}

How can I mock the dependency? Using mockProvider(IService), I always get nulls on all service methods

service = spectator.inject(IService); service.method.andReturn ...

Cannot call andReturn of null ...