Блог

Я пытаюсь внедрить область сопрограммы в viewmodel, чтобы ее можно было соответствующим образом использовать в тесте ViewModel.

Я получаю ошибку исключение NullPointerException в тесте ViewModel

 java.lang.NullPointerException
    at kotlinx.coroutines.CoroutineContextKt.newCoroutineContext(CoroutineContext.kt:33)
    at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch(Builders.common.kt:52)
    at kotlinx.coroutines.BuildersKt.launch(Unknown Source)
    at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch$default(Builders.common.kt:47)
    at kotlinx.coroutines.BuildersKt.launch$default(Unknown Source)
    at com.example.breakingbad.MainActivityViewModelTest.fetchCharacters(MainActivityViewModelTest.kt:60)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    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.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$1.run(DefaultInternalRunner.java:79)
    at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:85)
    at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39)
    at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)
 

mainactivityviewмодельтест

 @RunWith(MockitoJUnitRunner::class)
class MainActivityViewModelTest {


    @Mock
    private lateinit var dataRepository: DataRepository

    @Mock
    private lateinit var applicationScope: CoroutineScope

    @Mock
    private lateinit var dataObserver: Observer<Result<List<Character>>>

    @InjectMocks
    private lateinit var mainActivityViewModel: MainActivityViewModel

    @Test
    fun fetchCharacters() {
        applicationScope.launch(Dispatchers.IO) {
            Mockito.`when`(dataRepository.getCharacters())
                    .thenReturn(Result.success(arrayListOf(Character(
                            name = "myName",
                            img = "image",
                            occupation = arrayListOf(),
                            status = "status",
                            nickname = "nickName",
                            appearance = arrayListOf()
                    ))))
            mainActivityViewModel.fetchCharacters()
            verify(dataRepository).getCharacters()

            Mockito.verify(dataObserver).onChanged(Result.success(listOf(Character (
                    name = "myName",
                    img = "image",
                    occupation = arrayListOf(),
                    status = "status",
                    nickname = "nickName",
                    appearance = arrayListOf()
            ))))
            mainActivityViewModel.charactersLiveData.removeObserver(dataObserver)
        }
    }
}
 

ViewModel

 class MainActivityViewModel @Inject constructor(
        @ApplicationScope private val applicationScope: CoroutineScope,
        private val dataRepository: DataRepository
): ViewModel() {
    val _charactersLiveData = MutableLiveData<Result<ArrayList<Character>>>()
    val charactersLiveData: LiveData<Result<ArrayList<Character>>> = _charactersLiveData


    fun fetchCharacters() {


        applicationScope.launch(Dispatchers.IO) {
            //_charactersLiveData.value = dataRepository.getCharacters()
            _charactersLiveData.postValue(dataRepository.getCharacters())
        }
    }
}
 

AppModule for reference

 @Retention(AnnotationRetention.BINARY)
@Qualifier
annotation class ApplicationScope

@Module
class AppModule {

    @ApplicationScope
    @Provides
    @Singleton
    fun providesApplicationScope() = CoroutineScope(SupervisorJob())
}
 

пожалуйста, подскажите, как пройти правильный сопрограммный прицел в модульном тесте

Спасибо Р