父模拟类测试失败

Question

我有DetailViewModel和CoreDetailViewModel`，DetailViewModel扩展了CoreDetailViewModel

class DetailViewModel @Inject constructor(xxxapp: XXXApp) : CoreDetailViewModel(xxxapp), Injectable


abstract class CoreDetailViewModel(val context: Application) : AndroidViewModel(context){

  private val liveEventActionTitleMutableData = MutableLiveData<String>()
  val liveEventActionTitleData: LiveData<String>
    get() = liveEventActionTitleMutableData
}

在测试类中，我模拟DetailViewModel和

viewModel = Mockito.mock(DetailViewModel::class.java)
 Mockito.`when`(viewModel.liveEventActionTitleData).thenReturn(data)````

and my test fails saying

org.mockito.exceptions.misusing.MissingMethodInvocationException：     when（）需要一个参数，该参数必须是“模拟的方法调用”。     例如：         when（mock.getArticles（））。thenReturn（articles）;

Also, this error might show up because:
1. you stub either of: final/private/equals()/hashCode() methods.
   Those methods *cannot* be stubbed/verified.
   Mocking methods declared on non-public parent classes is not supported.
2. inside when() you don't call method on mock but on some other object.```

当我将liveEventActionTitleData移到DetailViewModel时，它就会起作用 我想知道为什么CoreDetailViewModel是抽象的？