Android 从未设置实时数据值

我对Kotlin Android还是个新手.我正在try 学习测试，但收到一个错误，显示从未设置实时数据值，即使我使用AdvanceUntilIdle也是如此.

这是我的储存库

class UserRepository private constructor(
    private val userPreference: UserPreference,
    private val apiService: ApiService
) {
  
    private val _loginResponse = MutableLiveData<LoginResponse?>()
    val loginResponse: LiveData<LoginResponse?> = _loginResponse

    private val _errorLoginMessage = MutableLiveData<String?>()
    val errorLoginMessage: LiveData<String?> = _errorLoginMessage

    fun login(email: String, password: String) {
        _showLoading.value = true
        val client = apiService.login(email, password)

        client.enqueue(object : Callback<LoginResponse> {
            override fun onResponse(
                call: Call<LoginResponse>, response: Response<LoginResponse>
            ) {
                _showLoading.value = false
                Log.d(TAG, "Register Response : ${response.body()}")
                if (response.isSuccessful && response.body() != null) {
                    _loginResponse.value = response.body()
                } else {
                    _errorLoginMessage.value = response.message()
                    Log.e(TAG, "onFailure: ${response.message()}")
                }
            }

            override fun onFailure(call: Call<LoginResponse>, t: Throwable) {
                _showLoading.value = false
                _errorLoginMessage.value = t.message
                Log.e(TAG, "onFailure: ${t.message}")
            }
        })
    }
}

这是我的取景模型

class LoginViewModel(private val repository: UserRepository) : ViewModel() {

    val loginResponse: LiveData<LoginResponse?> = repository.loginResponse
    val errorMessage = repository.errorLoginMessage

    fun login(email: String, password: String) {
        repository.login(email, password)
    }
}

这是我的测试

@RunWith(RobolectricTestRunner::class)
class LoginViewModelTest {

    private lateinit var viewModel: LoginViewModel
    private val context = RuntimeEnvironment.getApplication().applicationContext

    @get:Rule
    val instantTaskExecutorRule = InstantTaskExecutorRule()

    @Before
    fun setup() {
        val userRepository = UserRepository.getInstance(
            UserPreference.getInstance(context.dataStore)
        )

        viewModel = LoginViewModel(
            userRepository
        )

        Dispatchers.setMain(StandardTestDispatcher())
    }

    @After
    fun tearDown() {
        Dispatchers.resetMain()
    }

    @Test
    fun `Test Login Failed`() = runTest {
        viewModel.login("testWrongEmail@gmail.com", "testWrongPassword")
        advanceUntilIdle()
        val result = viewModel.loginResponse.getOrAwaitValue()
        Assert.assertEquals(true, result?.error)
        Assert.assertEquals("failed", result?.message)
    }
}

它在运行时运行得很好，但在测试时就不行了.为什么会这样呢？

我正在try 添加InstantRuleExecutor，设置主调度程序，并添加runTest.我也试着把排队改为执行，但仍然没有结果.