即使在添加 RxImmediateSchedulerRule 之后，android.os.Looper 中的方法 getMainLooper 未被模拟仍然发生

Question

趋势视图模型测试

@RunWith(JUnit4::class)
class TrendingViewModelTest {
    private lateinit var trendingRepository: TrendingRepository
    private lateinit var trendingViewModel: TrendingViewModel

    @get:Rule
    val schedulers = RxImmediateSchedulerRule()

    @Before
    fun setUp() {
        trendingRepository = mock(TrendingRepository::class.java)
        trendingViewModel = TrendingViewModel(trendingRepository)
    }

    @Test
    fun testWithNetwork() {
        trendingViewModel.isConnected = true
        trendingViewModel.fetchTrendingRepos()
        verify(trendingRepository, times(1)).getTrendingRepos()
    }

    //...
}

趋势视图模型

fun fetchTrendingRepos() {
if (isConnected) {
    loadingProgress.value = true
    compositeDisposable.add(
        trendingRepository.getTrendingRepos().subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe({ response ->
                run {
                    loadingProgress.value = false
            },
                { error ->
                    loadingProgress.value = false
                }
            )
    )
} 

RxImmediateSchedulerRule：

class RxImmediateSchedulerRule : TestRule {
    override fun apply(base: Statement?, description: Description?): Statement {
        return object : Statement() {
            @Throws(Throwable::class)
            override fun evaluate() {
                RxJavaPlugins.setIoSchedulerHandler { Schedulers.trampoline() }
                RxJavaPlugins.setComputationSchedulerHandler { Schedulers.trampoline() }
                RxJavaPlugins.setNewThreadSchedulerHandler { Schedulers.trampoline() }
                RxAndroidPlugins.setInitMainThreadSchedulerHandler { Schedulers.trampoline() }

                try {
                    base?.evaluate()
                } finally {
                    RxJavaPlugins.reset()
                    RxAndroidPlugins.reset()
                }
            }
        }
    }
}

TrendingRepositoryImpl：

class TrendingRepositoryImpl @Inject constructor(
    val apiService: GitHubApi,
    val trendingDao: AppDao
) : TrendingRepository {

    override fun getTrendingRepos(): Single<List<TrendingRepo>> {
        return apiService.getTrendingGits()
    }
}

趋势库：

interface TrendingRepository {
    fun getTrendingRepos(): Single<List<TrendingRepo>>
}

在fetchTrendingRepos()启动 Rxjava 调用时，它还挂钩到可能是导致它的原因的“AndroidSchedulers.mainThread()”。

java.lang.RuntimeException：未模拟 android.os.Looper 中的方法 getMainLooper。在 android.os.Looper.getMainLooper(Looper.java) 在 androidx.arch.core.executor.DefaultTaskExecutor.isMainThread(DefaultTaskExecutor.java:77) 在 androidx.arch.core.executor.ArchTaskExecutor.isMainThread(ArchTaskExecutor.java:116) ) 在 androidx.lifecycle.LiveData.assertMainThread(LiveData.java:461) 在 androidx.lifecycle.LiveData.setValue(LiveData.java:304) 在 androidx.lifecycle.MutableLiveData.setValue(MutableLiveData.java:50) 在 com.manoj .trendgitz.mvvm.ui.TrendingViewModel.fetchTrendingRepos(TrendingViewModel.kt:32) at com.manoj.trendgitz.TrendingViewModelTest.testWithNetwork(TrendingViewModelTest.kt:52) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.ref .NativeMethodAccessorImpl。

Answer 1

当您更新LiveData值时，您还应该添加@get:Rule var rule: TestRule = InstantTaskExecutorRule()。

不要忘记在build.gradle文件中添加以下内容：

dependencies {
    // ...
    testImplementation "androidx.arch.core:core-testing:2.1.0"
}

此外，相应地更改您的测试代码以避免NullPointerException：

@Test
fun testWithNetwork() {
    trendingViewModel.isConnected = true
    Mockito.`when`(trendingRepository.fetchTrendingRepos()).thenReturn(Single.just(listOf<TrendingRepo>()))
    trendingViewModel.fetchTrendingRepos()
    verify(trendingRepository, times(1)).getTrendingRepos()
}

Mockito.when()每次调用模拟方法时，您都可以执行不同的操作。如果您不使用它，NullPointerException根据您的测试功能，您可能会看到可能。

Answer 2

在应用程序的 build.gradle 中的 android {} 下添加以下行

testOptions {
            // Used for Unit testing Android dependent elements in /test folder
            unitTests.includeAndroidResources  = true
            unitTests.returnDefaultValues = true
        }

Answer 3

首先testImplementation添加core-testing.

testImplementation 'androidx.arch.core:core-testing:2.1.0'

然后在您的单元测试类中添加一个InstantTaskExecutorRuleat 变量rule。

import androidx.arch.core.executor.testing.InstantTaskExecutorRule

class TrendingViewModelTest {

     @get:Rule
     val rule = InstantTaskExecutorRule()

}