Unit testing LiveData单元测试在协程和多线程下无法通过，因为返回true而不是预期的false

EnrollmentViewModelTest

@Test
fun getUserProfile() {
    val responseSnapshot = this.javaClass.getResource("/userDetailResponse.json").readText()
    val user = Gson().fromJson<User>(responseSnapshot, User::class.java)
    val response = Response.success(user)
    val deferred = CompletableDeferred<Response<User>>(response)

    coEvery { userService.getUserDetail() } returns deferred

    viewModel.getUserProfile()

    assert(viewModel.loadingStatus.value != null)
    assert(!UITestUtil.getValue(viewModel.loadingStatus)!!)
    assertEquals(false, viewModel.loadingStatus.value!!)
}

当我调试测试用例时，它显示UITestUtil.getValue（viewModel.loadingStatus）！！这是错误的

但奇怪的是，测试用例没有通过，当我打印UITestUtil.getValue（viewModel.loadingStatus）时！！。这是真的

它可能与加载status.postValue（true）

删除后，打印结果为false

但我不知道为什么

object UITestUtil {
    /**
     * Gets the value of a LiveData safely.
     */
    @Throws(InterruptedException::class)
    fun <T> getValue(liveData: LiveData<T>): T? {
        var data: T? = null
        val latch = CountDownLatch(1)
        val observer = object : Observer<T> {
            override fun onChanged(o: T?) {
                data = o
                latch.countDown()
                liveData.removeObserver(this)
            }
        }
        liveData.observeForever(observer)
        latch.await(2, TimeUnit.SECONDS)

        return data
    }

}

更新3: fun loadAllTasksFromRepository\u LoadingLogles和DataLoaded（） 在里面 同样有效，但我尝试在代码中引入，它也失败了

    @ExperimentalCoroutinesApi
    @Test
    fun getUserProfile4Using() {
        // using TestCoroutineScope in kotlinx.coroutines.test
        // Pause dispatcher so we can verify initial values
        mainCoroutineRule.pauseDispatcher()

        val responseSnapshot = this.javaClass.getResource("/userDetailResponse.json").readText()
        val user = Gson().fromJson<User>(responseSnapshot, User::class.java)
        val response = Response.success(user)
        val deferred = CompletableDeferred<Response<User>>(response)

//        coEvery { userService.getUserDetail() } returns deferred

        viewModel.getUserProfile()

        assert(viewModel.loadingStatus.value != null)

//        verify { viewModel.processUserDetails(user) }
        print(viewModel.loadingStatus.value)
        assert(UITestUtil.getValue(viewModel.loadingStatus)!!)
        assertEquals(true, viewModel.loadingStatus.value!!)


        // Execute pending coroutines actions
        mainCoroutineRule.resumeDispatcher()

        print(viewModel.loadingStatus.value!!)
        assert(!UITestUtil.getValue(viewModel.loadingStatus)!!)
        assertEquals(false, viewModel.loadingStatus.value!!)
    }

@experimentalRoutinesAPI
@试验
fun getUserProfile4Using（）{
//在kotlinx.coroutines.test中使用TestCoroutineScope
//暂停调度程序，以便我们可以验证初始值
mainCoroutineRule.pauseDispatcher（）
val responseSnapshot=this.javaClass.getResource（“/userDetailResponse.json”）.readText（）
val user=Gson（）.fromJson（responseSnapshot，user:：class.java）
val response=response.success（用户）
val deferred=CompletableDeferred（响应）
//coEvery{userService.getUserDetail（）}返回延迟的
viewModel.getUserProfile（）
断言（viewModel.loadingStatus.value！=null）
//验证{viewModel.processUserDetails（用户）}
打印（viewModel.loadingStatus.value）
断言（UITestUtil.getValue（viewModel.loadingStatus）！！）
assertEquals（true，viewModel.loadingStatus.value！！）
//执行挂起的协同路由操作
mainCoroutineRule.resumeDispatcher（）文件
打印（viewModel.loadingStatus.value！！）
断言（！UITestUtil.getValue（viewModel.loadingStatus）！！）
assertEquals（false，viewModel.loadingStatus.value！！）
}

我认为您可能应该使用

运行blockingtest来重写您的测试

fun getUserProfile（）=运行blockingtest{
val responseSnapshot=this.javaClass.getResource（“/userDetailResponse.json”）.readText（）
val user=Gson（）.fromJson（responseSnapshot，user:：class.java）
val response=response.success（用户）
val deferred=CompletableDeferred（响应）
coEvery{userService.getUserDetail（）}返回延迟的
viewModel.getUserProfile（）
断言（viewModel.loadingStatus.value！=null）
断言（！UITestUtil.getValue（viewModel.loadingStatus）！！）
assertEquals（false，viewModel.loadingStatus.value！！）
}

您不必使用那些倒计时锁等。这种方法实际上解决了我在测试协同程序时遇到的所有问题，希望它也能帮助您：）！如果没有，请告诉我。
谢谢您的回答。我粘贴了你的代码并进行了测试，但仍然失败。调试时，UITestUtil.getValue（viewModel.loadingStatus）！！仍然返回false。但奇怪的是，它仍然未能通过测试。你需要提供更多的代码-你的callAsync ext函数做什么？更新了它。似乎coEvery正在挂起其余语句：if（user！=null）{processUserDetails（user）}loadingStatus.postValue（false）
import com.google.gson.Gson
import kotlinx.coroutines.Deferred
import retrofit2.Response
import retrofit2.Response.success

data class VPlusResult<T : Any?>(
        val response: Response<T>? = null,
        val exception: Exception? = null
)

inline fun <T : Any> VPlusResult<T>.onSuccess(action: (T?) -> Unit): VPlusResult<T> {
    if (response?.isSuccessful == true)
        action(response.body())

    return this
}

inline fun <T : Any> VPlusResult<T>.onRawSuccess(action: (response: Response<T>) -> Unit): VPlusResult<T> {
    if (response?.isSuccessful == true)
        action(response)

    return this
}

inline fun <T : Any, TR : Any> VPlusResult<T>.map(action: (T?) -> (TR)) =
        if (response?.isSuccessful == true) VPlusResult(success(action(response.body())))
        else this as VPlusResult<TR>

inline fun <T : Any> VPlusResult<T>.onError(action: (String) -> Unit): VPlusResult<T> {
    if (response?.isSuccessful != true) {
        response?.errorBody()?.let {
            action(it.string())
        }
    }

    return this
}

inline fun <T : Any, reified G : Any> VPlusResult<T>.onErrorJson(action: (G) -> Unit): VPlusResult<T> {
    if (response?.isSuccessful != true) {
        response?.errorBody()?.let {
            action(Gson().fromJson(it.string(), G::class.java))
        }
    }

    return this
}

inline fun <T : Any> VPlusResult<T>.onRawError(action: (Response<T>?) -> Unit): VPlusResult<T> {
    if (response?.isSuccessful != true) {
        action(response)
    }

    return this
}

inline fun <T : Any?> VPlusResult<T>.onException(action: (Exception) -> Unit) {
    exception?.let { action(it) }
}

inline fun <T : Any> VPlusResult<T>.onSadness(action: (String?) -> Unit): VPlusResult<T> {
    onError {
        action(it)
    }.onException {
        action(it.message)
    }

    return this
}

suspend fun <T : Any> callAsync(block: () -> Deferred<Response<T>>): VPlusResult<T> {
    return try {
        VPlusResult(block().await())
    } catch (e: Exception) {
        VPlusResult(exception = e)
    }
}

coVerify { userService.getUserDetail() }
coVerify { viewModel.processUserDetails(user) }

    @ExperimentalCoroutinesApi
    @Test
    fun getUserProfile4Using() {
        // using TestCoroutineScope in kotlinx.coroutines.test
        // Pause dispatcher so we can verify initial values
        mainCoroutineRule.pauseDispatcher()

        val responseSnapshot = this.javaClass.getResource("/userDetailResponse.json").readText()
        val user = Gson().fromJson<User>(responseSnapshot, User::class.java)
        val response = Response.success(user)
        val deferred = CompletableDeferred<Response<User>>(response)

//        coEvery { userService.getUserDetail() } returns deferred

        viewModel.getUserProfile()

        assert(viewModel.loadingStatus.value != null)

//        verify { viewModel.processUserDetails(user) }
        print(viewModel.loadingStatus.value)
        assert(UITestUtil.getValue(viewModel.loadingStatus)!!)
        assertEquals(true, viewModel.loadingStatus.value!!)


        // Execute pending coroutines actions
        mainCoroutineRule.resumeDispatcher()

        print(viewModel.loadingStatus.value!!)
        assert(!UITestUtil.getValue(viewModel.loadingStatus)!!)
        assertEquals(false, viewModel.loadingStatus.value!!)
    }

fun getUserProfile() = runBlockingTest{
    val responseSnapshot = this.javaClass.getResource("/userDetailResponse.json").readText()
    val user = Gson().fromJson<User>(responseSnapshot, User::class.java)
    val response = Response.success(user)
    val deferred = CompletableDeferred<Response<User>>(response)

    coEvery { userService.getUserDetail() } returns deferred

    viewModel.getUserProfile()

    assert(viewModel.loadingStatus.value != null)
    assert(!UITestUtil.getValue(viewModel.loadingStatus)!!)
    assertEquals(false, viewModel.loadingStatus.value!!)
}