我正在尝试使用 savedStateHandle 测试这个 ViewModel
class PostListViewModel @ViewModelInject constructor(
private val coroutineScope: CoroutineScope,
private val getPostsUseCase: GetPostListUseCaseFlow,
@Assisted savedStateHandle: SavedStateHandle
) : AbstractPostListVM() {
private val _goToDetailScreen =
savedStateHandle.getLiveData<Event<Post>>(POST_DETAIL)
// MutableLiveData<Event<Post>>()
override val goToDetailScreen: LiveData<Event<Post>>
get() = _goToDetailScreen
private val _postViewState =
savedStateHandle.getLiveData<ViewState<List<Post>>>(POST_LIST)
// MutableLiveData<ViewState<List<Post>>>()
override val postViewState: LiveData<ViewState<List<Post>>>
get() = _postViewState
override fun getPosts() {
getPostsUseCase.getPostFlowOfflineFirst()
.convertToFlowViewState()
.onStart {
_postViewState.value = ViewState(status = Status.LOADING)
}
.onEach {
_postViewState.value = it
}
.launchIn(coroutineScope)
}
override fun refreshPosts() {
getPostsUseCase.getPostFlowOfflineLast()
.convertToFlowViewState()
.onStart {
_postViewState.value = ViewState(status = Status.LOADING)
}
.onEach {
_postViewState.value = it
}
.launchIn(coroutineScope)
}
override fun onClick(post: Post) {
_goToDetailScreen.value = Event(post)
}
}
测试是@Test
fun `given exception returned from useCase, should have ViewState ERROR offlineFirst`() =
testCoroutineRule.runBlockingTest {
// GIVEN
every {
savedStateHandle.getLiveData<ViewState<List<Post>>>(AbstractPostListVM.POST_LIST)
} returns MutableLiveData()
every {
savedStateHandle.getLiveData<Event<Post>>(AbstractPostListVM.POST_DETAIL)
} returns MutableLiveData()
every {
useCase.getPostFlowOfflineFirst()
} returns flow<List<Post>> {
emit(throw Exception("Network Exception"))
}
val testObserver = viewModel.postViewState.test()
// WHEN
viewModel.getPosts()
// THEN
testObserver
.assertValue { states ->
(states[0].status == Status.LOADING &&
states[1].status == Status.ERROR)
}
.dispose()
val finalState = testObserver.values()[1]
Truth.assertThat(finalState.error?.message).isEqualTo("Network Exception")
Truth.assertThat(finalState.error).isInstanceOf(Exception::class.java)
verify(atMost = 1) { useCase.getPostFlowOfflineFirst() }
}
当我使用 MutableLiveData
时,此测试有效而不是 SavedStateHandle.getLiveData()
通过这个和其他测试。将 savedStateHandle mock 为
private val savedStateHandle: SavedStateHandle = mockk()
返回io.mockk.MockKException: no answer found for: SavedStateHandle(#2).getLiveData(POST_LIST)
我将模拟的 savedStateHandle 更改为 relaxed = true
private val savedStateHandle: SavedStateHandle = mockk(relaxed = true)
基于此question .现在 postViewState 的值不会改变并且测试失败
java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
使用 SavedStateHandle
模拟和获取 LiveData 的正确方法是什么? ?
最佳答案
我找到了 MockK 的解决方案图书馆,它工作正常,
我已经通过以下方式完成
val savedStateHandle = mockk<SavedStateHandle>(relaxed = true)
通过上面的行,我创建了我在 ViewModel 中使用过的 savedStateHandle@Test
fun `test something simple`() {
val savedStateHandle = mockk<SavedStateHandle>(relaxed = true)
val viewModel = MyViewModel(savedStateHandle)
verify { savedStateHandle.set(MyViewModel.KEY, "Something") }
}
关于android - MockK 模拟 ViewModel 的 savedStateHandle.getLiveData(),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/63620562/