asynchronous - How to test a Firebase task on Android? -

now trying test using junit4, getting

java.lang.illegalstateexception:     must not called on main application thread  @ com.google.android.gms.common.internal.zzab.zzhj(unknown source) @ com.google.android.gms.common.internal.zzab.zzate(unknown source) @ com.google.android.gms.tasks.tasks.await(unknown source) @ com.example.tasks.getuserprofiletest.then(getuserprofiletest.java:18)     <27 internal calls>  process finished exit code 255 

i've created continuation task performs operation on firebase realtime database.

public class getuserprofile implements continuation<string, task<profile>>,         valueeventlistener {      private taskcompletionsource<profile> mtaskcompletionsource;     private databasereference mdatabase;      public getuserprofile() {         mtaskcompletionsource = new taskcompletionsource();         mdatabase = firebasedatabase.getinstance().getreference();     }      @override     public void oncancelled(databaseerror databaseerror) {         mdatabase.removeeventlistener(this);         mtaskcompletionsource.setexception(databaseerror.toexception());     }      @override     public void ondatachange(datasnapshot datasnapshot) {         mdatabase.removeeventlistener(this);         mtaskcompletionsource.setresult(datasnapshot.getvalue(profile.class));     }      @override     public task<profile> then(task<string> task) {         mdatabase.child(task.getresult()).addvalueeventlistener(this);         return mtaskcompletionsource.gettask();     } } 

and unit test it:

public class getuserprofiletest {     @test     public void then() throws exception {         task<profile> task = tasks.<string>forresult("17354686546")             .continuewithtask(new getuserprofile());          try {             profile profile = tasks.await(task);             assertequals(profile.getemail(), "john.connor@email.com");         } catch (executionexception e) {             fail(e.getmessage());         } catch (interruptedexception e) {             fail(e.getmessage());         }     } } 

is there simple way of testing tasks without using handlers or countdownlatch?

public class getuserprofiletest {     @test     public void then() throws exception {         try {             task<string> previoustask = tasks.forresult("17354686546");             getuserprofile continuation = new getuserprofile();             profile profile = continuation                     .then(previoustask)                     .getresult();              assertequals(profile.getemail(), "john.connor@email.com");         } catch (executionexception e) {             fail(e.getmessage());         } catch (interruptedexception e) {             fail(e.getmessage());         }     } }