android - Mockito unit test BaseObserver and static method with context -

i facing unit testing first time , know best approach following scenario. using mockito tests. following test logic(presenter) layer , trying verify behaviors of view.

app classes

the method of presenter need include in test:

public void loadweather() {  citydetailsmodel selectedcity = getdbhelper().getselectedcitymodel();  if (selectedcity != null) {   getcompositedisposablehelper().execute(       getapihelper().weatherapirequest(selectedcity.getlatitude(), selectedcity.getlongitude()),       new weatherobserver(getmvpview())); } else {   getmvpview().showemptyview(); } 

}

weatherobserver:

 public class weatherobserver extends baseviewsubscriber<daymvpview, weatherresponsemodel> {     public weatherobserver(daymvpview view) {       super(view);     }      @override public void onnext(weatherresponsemodel weatherresponsemodel) {       super.onnext(weatherresponsemodel);        if (weatherresponsemodel.getdata().isempty()) {         getmvpview().showemptyview();       } else {         getmvpview().showweather(weatherresponsemodel.getdata());       }     }   } 

baseviewsubscriber (default disposableobserver base class used whenever want default error handling):

 public class baseviewsubscriber<v extends basemvpview, t> extends disposableobserver<t> {    private errorhandlerhelper errorhandlerhelper;   private v view;    public baseviewsubscriber(v view) {     this.view = view;     errorhandlerhelper = weatherapplication.getapplicationcomponent().errorhelper();   }    public v getview() {     return view;   }    public boolean shouldshowerror() {     return true;   }    protected boolean shouldshowloading() {     return true;   }    @override public void onstart() {     if (!apputils.isnetworkavailable(weatherapplication.getapplicationcomponent().context())) {       onerror(new internetconnectionexception());       return;     }      if (shouldshowloading()) {       view.showloading();     }     super.onstart();   }    @override public void onerror(throwable e) {     if (view == null) {       return;     }      if (shouldshowloading()) {       view.hideloading();     }      if (shouldshowerror()) {       view.onerror(errorhandlerhelper.getpropererrormessage(e));     }   }    @override public void oncomplete() {     if (view == null) {       return;     }      if (shouldshowloading()) {       view.hideloading();     }   }    @override public void onnext(t t) {     if (view == null) {       return;     }   } } 

compositedisposablehelper (compositedisposable helper class):

public class compositedisposablehelper {    public compositedisposable disposables;   public testscheduler testscheduler;    @inject public compositedisposablehelper(compositedisposable disposables) {     this.disposables = disposables;     testscheduler = new testscheduler();   }    public <t> void execute(observable<t> observable, disposableobserver<t> observer) {     adddisposable(observable.subscribeon(testscheduler)         .observeon(testscheduler)         .subscribewith(observer));   }    public void dispose() {     if (!disposables.isdisposed()) {       disposables.dispose();     }   }    public testscheduler gettestscheduler() {     return testscheduler;   }    public void adddisposable(disposable disposable) {     disposables.add(disposable);   } } 

my test:

  @test public void loadsuccessfully() {     weatherresponsemodel responsemodel = new weatherresponsemodel();     list<weathermodel> list = new arraylist<>();     list.add(new weathermodel());     responsemodel.setdata(list);      citydetailsmodel citydetailsmodel = new citydetailsmodel();     citydetailsmodel.setlongitude("");     citydetailsmodel.setlatitude("");      when(dbhelper.getselectedcitymodel()).thenreturn(citydetailsmodel);      when(apihelper.weatherapirequest(anystring(), anystring())).thenreturn(         observable.just(responsemodel));      daypresenter.loadweather();      compositedisposablehelper.gettestscheduler().triggeractions();      verify(daymvpview).showweather(list);     verify(daymvpview, never()).showemptyview();     verify(daymvpview, never()).onerror(anystring());   } 

when try run test, nullpointer, because new weatherobserver(getmvpview()) called, , in baseviewsubscriber errorhandlerhelper null because getapplicationcopomnent null. nullpointer thrown in static method apputils.isnetworkavailable() same reason.

when try comment these lines, test ok.

my questions are:

• should use dagger unit test or? if yes please give me example test.
• should use powermockito static method apputils.isnetworkavailable()? if yes, ok because of method use powermockito runner
  @runwith(powermockrunner.class)?

should use dagger unit test or? if yes please give me example test.

you don't have use dagger @ test, that's dependency injection benefit you, strip dependencies out, , tests able replace them.

should use powermockito static method apputils.isnetworkavailable()? if yes, ok because of method use powermockito runner @runwith(powermockrunner.class)?

static methods bad testing, cannot replace them (at least not , without powermock) testing purposes.
better practice use dagger production code inject dependencies, preferably @ constructor, @ tests can provide dependencies according test needs (using mocks or fakes necessary).

in case, can add both errorhandlerhelper , apputils baseviewsubscriber constructor. baseviewsubscriber shouldn't injected, need provide modules outside, in presenter, should use injection objects. again @ constructor.
@ test, replace or provide objects presenter in it's turn hand on baseviewsubscriber.

you can read more tests seams @ android here.

besides that, odd me oo hierarchy of observer , disposable wraps observable getting common behavior, it's breaking functional stream oriented reactive approach, might want consider using patterns compose using transformers , using doonxxx operators apply common behavior @ reactive streams.