android - Verify interactions in rxjava subscribers -

picture situation in mvp pattern presenter subscribes service returning observer:

public void gatherdata(){    service.dosomemagic()       .observeon(schedulers.io())       .subscribeon(androidschedulers.mainthread())       .subscribe(new thesubscriber()); } 

now class thesubscriber calls onnext method view, say:

@override public void onnext(returnvalue value) {   view.displaywhatever(value); } 

now, in unit test verify when method gatherdata() called on non-erroneous situation, view's method displaywhatever(value) called.

the question:

is there clean way this?

background:

• i'm using mockito verify interactions , lot more of course
• dagger injecting entire presenter except thesubscriber

what have tried:

• inject subscriber , mock in tests. looks bit dirty me, because if want change way presenter interacts service (say not rx) need change lot of tests , code.
• mock entire service. not bad, requires me mock lot of methods , didn't quite reach wanted.
• looked around internet, no 1 seems have clean straight way of doing this

thanks help

assuming using interfaces service , view in similar manner:

class presenter{   service service;   view view;    presenter(service service){     this.service = service;   }    void bindview(view view){     this.view = view;   }    void gatherdata(){     service.dosomemagic()       .observeon(schedulers.io())       .subscribeon(androidschedulers.mainthread())       .subscribe(view::displayvalue);   } } 

it possible provide mock control , verify behaviour:

@test void assert_that_displayvalue_is_called(){   service service = mock(service.class);   view view = mock(view.class);   when(service.dosomemagic()).thenreturn(observable.just("myvalue"));   presenter presenter = new presenter(service);   presenter.bindview(view);    presenter.gatherdata();    verify(view).displayvalue("myvalue"); }