Exception in thread "main @coroutine#2" java.lang.NullPointerException in ViewModelTest?

0
votes

I have wrote unit testing in ViewModel with coroutines with mockito. class but I am getting following exception

 Exception in thread "main @coroutine#2" java.lang.NullPointerException
    at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModel$getGifsFromText$1.invokeSuspend(GiphyTaskViewModel.kt:24)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
    at kotlinx.coroutines.test.TestCoroutineDispatcher.dispatch(TestCoroutineDispatcher.kt:50)
    at kotlinx.coroutines.test.internal.TestMainDispatcher.dispatch(MainTestDispatcher.kt:35)
    at kotlinx.coroutines.internal.DispatchedContinuationKt.resumeCancellableWith(DispatchedContinuation.kt:305)
    at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:30)
    at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable$default(Cancellable.kt:27)
    at kotlinx.coroutines.CoroutineStart.invoke(CoroutineStart.kt:110)
    at kotlinx.coroutines.AbstractCoroutine.start(AbstractCoroutine.kt:158)
    at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch(Builders.common.kt:56)
    at kotlinx.coroutines.BuildersKt.launch(Unknown Source)
    at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch$default(Builders.common.kt:49)
    at kotlinx.coroutines.BuildersKt.launch$default(Unknown Source)
    at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModel.getGifsFromText(GiphyTaskViewModel.kt:22)
    at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest$onCreation_fetchUserApiCalled_dataSavedToLiveData$1.invokeSuspend(GiphyTaskViewModelTest.kt:61)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
    at kotlinx.coroutines.EventLoopImplBase.processNextEvent(EventLoop.common.kt:274)
    at kotlinx.coroutines.BlockingCoroutine.joinBlocking(Builders.kt:84)
    at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking(Builders.kt:59)
    at kotlinx.coroutines.BuildersKt.runBlocking(Unknown Source)
    at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking$default(Builders.kt:38)
    at kotlinx.coroutines.BuildersKt.runBlocking$default(Unknown Source)
    at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest.onCreation_fetchUserApiCalled_dataSavedToLiveData(GiphyTaskViewModelTest.kt:57)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.mockito.internal.runners.DefaultInternalRunner$1$1.evaluate(DefaultInternalRunner.java:54)
    at com.example.giphyandroidapp.viewmodel.TestCoroutineRule$apply$1.evaluate(TaskCoroutineRule.kt:22)
    at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
    at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
    at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
    at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
    at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
    at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:99)
    at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:105)
    at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:40)
    at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
    at org.junit.vintage.engine.execution.RunnerExecutor.execute(RunnerExecutor.java:42)
    at org.junit.vintage.engine.VintageTestEngine.executeAllChildren(VintageTestEngine.java:80)
    at org.junit.vintage.engine.VintageTestEngine.execute(VintageTestEngine.java:72)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
    at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
    at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)
    at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)


java.lang.RuntimeException: Method getMainLooper in android.os.Looper not mocked. See http://g.co/androidstudio/not-mocked for details.

    at android.os.Looper.getMainLooper(Looper.java)
    at androidx.arch.core.executor.DefaultTaskExecutor.isMainThread(DefaultTaskExecutor.java:77)
    at androidx.arch.core.executor.ArchTaskExecutor.isMainThread(ArchTaskExecutor.java:116)
    at androidx.lifecycle.LiveData.assertMainThread(LiveData.java:486)
    at androidx.lifecycle.LiveData.observeForever(LiveData.java:224)
    at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest$onCreation_fetchUserApiCalled_dataSavedToLiveData$1.invokeSuspend(GiphyTaskViewModelTest.kt:63)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
    at kotlinx.coroutines.EventLoopImplBase.processNextEvent(EventLoop.common.kt:274)
    at kotlinx.coroutines.BlockingCoroutine.joinBlocking(Builders.kt:84)
    at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking(Builders.kt:59)
    at kotlinx.coroutines.BuildersKt.runBlocking(Unknown Source)
    at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking$default(Builders.kt:38)
    at kotlinx.coroutines.BuildersKt.runBlocking$default(Unknown Source)
    at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest.onCreation_fetchUserApiCalled_dataSavedToLiveData(GiphyTaskViewModelTest.kt:57)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.mockito.internal.runners.DefaultInternalRunner$1$1.evaluate(DefaultInternalRunner.java:54)
    at com.example.giphyandroidapp.viewmodel.TestCoroutineRule$apply$1.evaluate(TaskCoroutineRule.kt:22)
    at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
    at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
    at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
    at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
    at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
    at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:99)
    at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:105)
    at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:40)
    at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
    at org.junit.vintage.engine.execution.RunnerExecutor.execute(RunnerExecutor.java:42)
    at org.junit.vintage.engine.VintageTestEngine.executeAllChildren(VintageTestEngine.java:80)
    at org.junit.vintage.engine.VintageTestEngine.execute(VintageTestEngine.java:72)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
    at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
    at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)
    at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)

below my ViewModel class where I have implemented viewmodel logic

 @HiltViewModel
class GiphyTaskViewModel
@Inject
constructor(private val giphyTaskRepository: GiphyTaskRepository):ViewModel()
{
    var giphyresponse = MutableLiveData<Result<List<DataItem>?>>()



    fun getGifsFromText(apikey:String,text:String,limit:Int)= viewModelScope.launch {
        giphyTaskRepository.getGifsFromText(apikey,text,limit).let { response->
            if(response?.isSuccessful){
                var list=response.body()?.data
                giphyresponse.postValue(Success(list))
            }else{
                Error(Exception(response.message()))

            }

        }
    }

}

below Repository class

class GiphyTaskRepository
@Inject
constructor(private val giphyTaskApiService: GiphyTaskApiService)
{

    suspend fun getGifsFromText(apikey:String,text:String,limit:Int)=
        giphyTaskApiService.getGifsFromText(apikey,text,limit)
}

below interface class

interface GiphyTaskApiService {

    @GET("gifs/search")
    suspend fun getGifsFromText(
        @Query("api_key") api_key:String,
        @Query("q") q:String ,
        @Query("limit") limit:Int
    ):Response<GiphyResponse>
}

below my ViewModel test class

 @ExperimentalCoroutinesApi
@RunWith(MockitoJUnitRunner::class)
class GiphyTaskViewModelTest {







    @Mock
    private lateinit var apiUsersObserver: Observer<Result<List<DataItem>?>>


    @RegisterExtension
    @JvmField
    @get:Rule
    val testInstantTaskExecutorRule: TestRule = InstantTaskExecutorRule()

    @get:Rule
   val testCoroutineRule = TestCoroutineRule()
    @Mock
     var giphyTaskViewModel:GiphyTaskViewModel? = null

    @Mock
     lateinit var  giphyTaskRepository:GiphyTaskRepository








    @Before
     fun setUp() {


        /* Create a mock response */;
        /* Create a mock response */;


                giphyTaskViewModel = GiphyTaskViewModel(giphyTaskRepository)
        }

    @Test
    fun onCreation_fetchUserApiCalled_dataSavedToLiveData() {
        runBlockingTest {



            val response: Response<GiphyResponse> = mock()


            giphyTaskViewModel?.getGifsFromText(Constants.Api_Key,"text", Constants.Limit)
           `when`(giphyTaskRepository.getGifsFromText(Constants.Api_Key,"text", Constants.Limit)).thenReturn(response)
            giphyTaskViewModel?.giphyresponse?.observeForever(apiUsersObserver)
            assertNotNull(giphyTaskViewModel?.giphyresponse?.value)




        }
    }



}

What I have tried

1.[I have tried following link][1]

  1. I have rewrite Viewmodel logic but I am getting following exception xception in thread "main @coroutine#2" java.lang.NullPointerException at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModel$getGifsFromText$1.invokeSuspend(GiphyTaskViewModel.kt:26) at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106) at kotlinx.coroutines.test.TestCoroutineDispatcher.dispatch(TestCoroutineDispatcher.kt:50) at kotlinx.coroutines.test.internal.TestMainDispatcher.dispatch(MainTestDispatcher.kt:35) at kotlinx.coroutines.internal.DispatchedContinuationKt.resumeCancellableWith(DispatchedContinuation.kt:305) at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:30) at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable$default(Cancellable.kt:27) at kotlinx.coroutines.CoroutineStart.invoke(CoroutineStart.kt:110) at kotlinx.coroutines.AbstractCoroutine.start(AbstractCoroutine.kt:158) at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch(Builders.common.kt:56) at kotlinx.coroutines.BuildersKt.launch(Unknown Source) at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch$default(Builders.common.kt:49) at kotlinx.coroutines.BuildersKt.launch$default(Unknown Source) at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModel.getGifsFromText(GiphyTaskViewModel.kt:24) at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest$onCreation_fetchUserApiCalled_dataSavedToLiveData$1.invokeSuspend(GiphyTaskViewModelTest.kt:82) at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest$onCreation_fetchUserApiCalled_dataSavedToLiveData$1.invoke(GiphyTaskViewModelTest.kt) at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest$onCreation_fetchUserApiCalled_dataSavedToLiveData$1.invoke(GiphyTaskViewModelTest.kt) at kotlinx.coroutines.test.TestBuildersKt$runBlockingTest$deferred$1.invokeSuspend(TestBuilders.kt:50) at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106) at kotlinx.coroutines.test.TestCoroutineDispatcher.dispatch(TestCoroutineDispatcher.kt:50) at kotlinx.coroutines.internal.DispatchedContinuationKt.resumeCancellableWith(DispatchedContinuation.kt:305) at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:30) at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable$default(Cancellable.kt:27) at kotlinx.coroutines.CoroutineStart.invoke(CoroutineStart.kt:110) at kotlinx.coroutines.AbstractCoroutine.start(AbstractCoroutine.kt:158) at kotlinx.coroutines.BuildersKt__Builders_commonKt.async(Builders.common.kt:91) at kotlinx.coroutines.BuildersKt.async(Unknown Source) at kotlinx.coroutines.BuildersKt__Builders_commonKt.async$default(Builders.common.kt:84) at kotlinx.coroutines.BuildersKt.async$default(Unknown Source) at kotlinx.coroutines.test.TestBuildersKt.runBlockingTest(TestBuilders.kt:49) at kotlinx.coroutines.test.TestBuildersKt.runBlockingTest$default(TestBuilders.kt:45) at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest.onCreation_fetchUserApiCalled_dataSavedToLiveData(GiphyTaskViewModelTest.kt:75) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) at org.mockito.internal.runners.DefaultInternalRunner$1$1.evaluate(DefaultInternalRunner.java:54) at com.example.giphyandroidapp.viewmodel.TestCoroutineRule$apply$1.evaluate(TaskCoroutineRule.kt:22) at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306) at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63) at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329) at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293) at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306) at org.junit.runners.ParentRunner.run(ParentRunner.java:413) at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:99) at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:105) at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:40) at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163) at org.junit.runner.JUnitCore.run(JUnitCore.java:137) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69) at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33) at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220) at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)

java.lang.NullPointerException at androidx.arch.core.executor.DefaultTaskExecutor.isMainThread(DefaultTaskExecutor.java:77) at androidx.arch.core.executor.ArchTaskExecutor.isMainThread(ArchTaskExecutor.java:116) at androidx.lifecycle.LiveData.assertMainThread(LiveData.java:486) at androidx.lifecycle.LiveData.observeForever(LiveData.java:224) at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest$onCreation_fetchUserApiCalled_dataSavedToLiveData$1.invokeSuspend(GiphyTaskViewModelTest.kt:84) at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest$onCreation_fetchUserApiCalled_dataSavedToLiveData$1.invoke(GiphyTaskViewModelTest.kt) at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest$onCreation_fetchUserApiCalled_dataSavedToLiveData$1.invoke(GiphyTaskViewModelTest.kt) at kotlinx.coroutines.test.TestBuildersKt$runBlockingTest$deferred$1.invokeSuspend(TestBuilders.kt:50) at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106) at kotlinx.coroutines.test.TestCoroutineDispatcher.dispatch(TestCoroutineDispatcher.kt:50) at kotlinx.coroutines.internal.DispatchedContinuationKt.resumeCancellableWith(DispatchedContinuation.kt:305) at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:30) at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable$default(Cancellable.kt:27) at kotlinx.coroutines.CoroutineStart.invoke(CoroutineStart.kt:110) at kotlinx.coroutines.AbstractCoroutine.start(AbstractCoroutine.kt:158) at kotlinx.coroutines.BuildersKt__Builders_commonKt.async(Builders.common.kt:91) at kotlinx.coroutines.BuildersKt.async(Unknown Source) at kotlinx.coroutines.BuildersKt__Builders_commonKt.async$default(Builders.common.kt:84) at kotlinx.coroutines.BuildersKt.async$default(Unknown Source) at kotlinx.coroutines.test.TestBuildersKt.runBlockingTest(TestBuilders.kt:49) at kotlinx.coroutines.test.TestBuildersKt.runBlockingTest$default(TestBuilders.kt:45) at com.example.giphyandroidapp.viewmodel.GiphyTaskViewModelTest.onCreation_fetchUserApiCalled_dataSavedToLiveData(GiphyTaskViewModelTest.kt:75) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) at org.mockito.internal.runners.DefaultInternalRunner$1$1.evaluate(DefaultInternalRunner.java:54) at com.example.giphyandroidapp.viewmodel.TestCoroutineRule$apply$1.evaluate(TaskCoroutineRule.kt:22) at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306) at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63) at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329) at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293) at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306) at org.junit.runners.ParentRunner.run(ParentRunner.java:413) at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:99) at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:105) at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:40) at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163) at org.junit.runner.JUnitCore.run(JUnitCore.java:137) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69) at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33) at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220) at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)

I want to know where exactly I am making mistake what I have to inorder to pass the tests successfully

1
androidkotlinjunitkotlin-coroutinesmockito-kotlin
Does this answer your question? What is a NullPointerException, and how do I fix it? - Jeroen Steenbeeke
Doesn't change the fact that you're invoking a method on a null object, giphyTaskRepository if I'm not mistaken. I would guess that MockitoJUnitRunner isn't detecting your lateinit fields. I haven't used Mockito in conjunction with Kotlin before so I can't be sure - Jeroen Steenbeeke
@Jeroen Steenbeeke what is your suggestion then - user16305099
I think that not case if you checkother places I am also lateinit fields - user16305099
Put a breakpoint in your @Before method and check the field values? Might simply be that Mockito doesn't set them until after these are run. Again, I haven't used Mockito with Kotlin before so I'm guessing at this point (hence my commenting rather than posting an answer) - Jeroen Steenbeeke

1 Answers

2
votes

What I believe is happening is that your mocked version of GiphyTaskRepository is exhibiting the default Mockito behavior of returning null for all methods that do not have explicitly specified behavior.

As such, your call giphyTaskRepository.getGifsFromText(apikey,text,limit) in GiphyTaskViewModel returns null, causing the subsequent call to let to throw a NullPointerException.

To avoid this, you need to explicitly specify what this method should return, for instance in your setUp method:

@Before
fun setUp() {
  val response: Response<GiphyResponse> = /* Create a mock response */;
  when(giphyTaskRepository.getGifsFromText(any(),any(),any())).thenReturn(response);

  giphyTaskViewModel = GiphyTaskViewModel(giphyTaskRepository)
}

However, since you are using coroutines, it gets a bit trickier. You should include the mockito-kotlin library:

testImplementation "org.mockito.kotlin:mockito-kotlin:x.x.x"

Next, both the GiphyTaskRepository and the method getGifsFromText need to be declared open for the mocking to work.

Finally, you need to go about stubbing a bit differently:

@Before
fun setUp() = runBlocking { // This bit is important
  val response: Response<GiphyResponse> = /* Create a mock response */;
  given(giphyTaskRepository.getGifsFromText(any(),any(),any())).willSuspendableAnswer {
                response
            }
  giphyTaskViewModel = GiphyTaskViewModel(giphyTaskRepository)

  Unit 
}

I believe your test method will then succeed