22

我尝试在我的应用程序上测试一些方法，但在调用 mutablelivedata.postValue 时出现错误。这是一个片段和错误消息：

@Test
public void callStartScreenRepository(){
    Observer<User> userObserver = mock(Observer.class);
    startScreenViewModel.returnUser().observeForever(userObserver);
    maennlich = new User();
    maennlich.setVorname("Christian");
    MutableLiveData<User> userTest = new MutableLiveData<>();
    userTest.postValue(maennlich);
    when(startScreenRepository.userWebService("testUser")).thenReturn(userTest);
    verify(userObserver).onChanged(maennlich);
}

java.lang.RuntimeException：android.os.Looper 中的方法 getMainLooper 未模拟。有关详细信息，请参阅http://g.co/androidstudio/not-mocked。

at android.os.Looper.getMainLooper(Looper.java)
at android.arch.core.executor.DefaultTaskExecutor.postToMainThread(DefaultTaskExecutor.java:48)
at android.arch.core.executor.AppToolkitTaskExecutor.postToMainThread(AppToolkitTaskExecutor.java:100)
at android.arch.lifecycle.LiveData.postValue(LiveData.java:277)
at android.arch.lifecycle.MutableLiveData.postValue(MutableLiveData.java:28)
at com.example.cfrindt.foodtracking.ViewModels.StartScreenViewModelTest.callStartScreenRepository(StartScreenViewModelTest.java:102)
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:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:117)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:42)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:262)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:84)
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 com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)

无论我使用 setValue() 还是 postValue()，都会收到此错误。我怎样才能让它工作？

4

4 回答 4

29

首先，您需要使用 InstantTaskExecutorRule，这意味着：

@Rule public InstantTaskExecutorRule instantExecutorRule = new InstantTaskExecutorRule();

这将允许立即使用 MutableLiveData。请记住在您的应用程序的 build.gradle 中包含导入：

testCompile "android.arch.core:core-testing:$rootProject.ext.arch_version"

然后，您需要使用覆盖 RxScheduler 的规则或在 @Before 中使用 RxAndroidPlugins 覆盖调度程序（如果您使用的是 RxJava）定义 JUnit 规则

RxSchedulersOverrideRule：

public class RxSchedulersOverrideRule implements TestRule {
    @Override public Statement apply(final Statement base, Description description) {
    return new Statement() {
        @Override public void evaluate() throws Throwable {
            RxAndroidPlugins.reset();
            RxAndroidPlugins.setMainThreadSchedulerHandler(scheduler -> Schedulers.trampoline());

        RxJavaPlugins.reset();
        RxJavaPlugins.setIoSchedulerHandler(scheduler -> Schedulers.trampoline());
        RxJavaPlugins.setComputationSchedulerHandler(scheduler -> Schedulers.trampoline());
        RxJavaPlugins.setNewThreadSchedulerHandler(scheduler -> Schedulers.trampoline());

        base.evaluate();

        RxAndroidPlugins.reset();
        RxJavaPlugins.reset();
      }
    };
  }
}

并在测试类中调用它：

@Rule public RxSchedulersOverrideRule rxSchedulersOverrideRule = new RxSchedulersOverrideRule();

另一个选项是在@Before 的 setup() 中调用：

RxAndroidPlugins.setInitMainThreadSchedulerHandler(schedulerCallable -> Schedulers.trampoline());

使用后你需要在@After 的 tearDownClass() 中重置：

RxAndroidPlugins.reset();
于 2017-09-01T02:25:01.320 回答
21

确保观察者不在主线程上

Jeroen Mols概述了 JUnit 4 和 JUnit 5 的每个实现。我使用 Junit 5 方法使用 Kotlin、JUnit 5、MockK 和 AssertJ 库进行 Coinverse Open App 的本地单元测试。

JUnit 4

@Carlos Daniel 的解决方案对于InstantExecutorRuleJUnit 4 是正确的。

ExampleUnitTest.kt

class ExampleUnitTest {

    @get:Rule
    val rule = InstantTaskExecutorRule()

    @Test
    fun `my test`() {
        val mutableLiveData = MutableLiveData<String>()
        mutableLiveData.postValue("test")
        assertEquals("test", mutableLiveData.value)
    }
}

构建.gradle

dependencies {
    testImplementation 'android.arch.core:core-testing:X.X.X'
}

JUnit 5

InstantExecutorExtension.kt

import androidx.arch.core.executor.ArchTaskExecutor
import androidx.arch.core.executor.TaskExecutor
import org.junit.jupiter.api.extension.AfterEachCallback
import org.junit.jupiter.api.extension.BeforeEachCallback
import org.junit.jupiter.api.extension.ExtensionContext

class InstantExecutorExtension : BeforeEachCallback, AfterEachCallback {
    override fun beforeEach(context: ExtensionContext?) {
        ArchTaskExecutor.getInstance().setDelegate(object : TaskExecutor() {
            override fun executeOnDiskIO(runnable: Runnable) = runnable.run()
            override fun postToMainThread(runnable: Runnable) = runnable.run()
            override fun isMainThread(): Boolean = true
        })
    }

    override fun afterEach(context: ExtensionContext?) {
        ArchTaskExecutor.getInstance().setDelegate(null)
    }
}

是通过InstantExecutorExtension本地单元测试类中的注释实现的。

ContentViewModelTest.kt

...
import androidx.paging.PagedList
import com.google.firebase.Timestamp
import io.mockk.*
import org.assertj.core.api.Assertions.assertThat
import org.junit.jupiter.api.AfterAll
import org.junit.jupiter.api.BeforeAll
import org.junit.jupiter.api.BeforeEach
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.ExtendWith

@ExtendWith(InstantExecutorExtension::class)
class ContentViewModelTest {
    val timestamp = getTimeframe(DAY)

    @BeforeAll
    fun beforeAll() {
        mockkObject(ContentRepository)
    }

    @BeforeEach
    fun beforeEach() {
        clearAllMocks()
    }

    @AfterAll
    fun afterAll() {
        unmockkAll()
    }

    @Test
    fun `Feed Load`() {
        val content = Content("85", 0.0, Enums.ContentType.NONE, Timestamp.now(), "",
            "", "", "", "", "", "", MAIN,
            0, 0.0, 0.0, 0.0, 0.0,
            0.0, 0.0, 0.0, 0.0)
        every {
            getMainFeedList(any(), any())
        } returns MutableLiveData<Lce<ContentResult.PagedListResult>>().also { lce ->
            lce.value = Lce.Content(
                ContentResult.PagedListResult(
                    pagedList = MutableLiveData<PagedList<Content>>().apply {
                        this.value = listOf(content).asPagedList(
                            PagedList.Config.Builder().setEnablePlaceholders(false)
                                .setPrefetchDistance(24)
                                .setPageSize(12)
                                .build())
                        }, errorMessage = ""))
        }
        val contentViewModel = ContentViewModel(ContentRepository)
        contentViewModel.processEvent(ContentViewEvent.FeedLoad(MAIN, DAY, timestamp, false))
        assertThat(contentViewModel.feedViewState.getOrAwaitValue().contentList.getOrAwaitValue()[0])
            .isEqualTo(content)
        assertThat(contentViewModel.feedViewState.getOrAwaitValue().toolbar).isEqualTo(
            ToolbarState(
                    visibility = GONE,
                    titleRes = app_name,
                    isSupportActionBarEnabled = false))
        verify {
            getMainFeedList(any(), any())
        }
        confirmVerified(ContentRepository)
    }
}
于 2019-09-08T16:51:01.150 回答
2

@Carlos Daniel的回答对我帮助很大，但遇到了另一个Rule未应用的问题PowerMockRunner。对于那些有同样问题的人，这里是解决方案：

@RunWith(PowerMockRunner::class)
@PowerMockRunnerDelegate(MockitoJUnitRunner::class) //this line allows you to use the powermock runner and mockito runner
@PrepareForTest(UnderTestClass::class)
class UnderTestClassTest {
@get:Rule
var instantExecutorRule = InstantTaskExecutorRule()
于 2018-12-27T16:37:39.020 回答
0

如果没有一个解决方案在我的情况下工作得一样，如果您使用的是 Gradle 的更高版本并且您正在使用 androix，请确保您在构建 gradle 中从androix导入。

  implementation 'androidx.arch.core:core-testing:$version'

代替

 implementation 'android.arch.core:core-testing:$version'
于 2021-09-08T21:14:16.863 回答