android - How correctly test if subscriber is called with correct data in onNext() (RxJava2) -

i test method:

void updateavailablescreens() {         safiecam.availablecameras()                 .flatmap(this::getavailablescreensforcameras)                 // causing failure .observeon(schedulers.mainthread())                 .subscribe(                         screens -> {                             view.setavailablepagesonviewpager(screens);                             view.setavailablepagesonbottomsheet(screens);                         },                         timber::e                 );     } 

with test (so giving known data, expect calling view expected enum list):

@test public void widgetsshouldgetallscreens() {     when(camera.availablecameras()).thenreturn(             observable.just(arrays.aslist(                     safiecam.cameratype.selfie,                     safiecam.cameratype.rear)));     testedvppresenter.updateavailablescreens();      list<viewpagerview.pages> pages = arrays.aslist(             viewpagerview.pages.selfie,             viewpagerview.pages.rear_camera,             viewpagerview.pages.login);     verify(view).setavailablepagesonviewpager(pages);     verify(view).setavailablepagesonbottomsheet(pages); } 

but when observeon uncommented test fail due 0 interactions view, otherwise succed.

needed info: schedulers interface wrapper, , called schedulers mocked on tests testscheduler.

question: doing wrong here? if correct approach?

i misused testscheduler, because didn't call

testscheduler.triggeractions()

after using test scheduler (in case after testedvppresenter.updateavailablescreens())

so events queued, without execution.