Robolectric 4.4单元测试错误-主活套已将未执行的可运行程序排入队列

Question

此的单元测试错误

Called loadFromPath(/system/framework/framework-res.apk, true); mode=binary sdk=28
java.lang.Exception: Main looper has queued unexecuted runnables. 
This might be the cause of the test failure. You might need a shadowOf(getMainLooper()).idle() call.

我们使用Robolectric 4.4编译到目标29，但在运行单元测试时确保我们的目标是28，因为JDK仍然是8而不是9。这里有一段代码，但我似乎无法在任何地方添加loopers的idle((来实现这个愉快的

@RunWith(AndroidJUnit4::class)
@LooperMode(LooperMode.Mode.PAUSED)
class MyRoomActivityTest {
@get:Rule
val activityRule = ActivityTestRule(MyRoomActivity::class.java, true, false)
@Inject lateinit var mockViewModel: NewMyRoomActivityViewModel
@Inject lateinit var locationManager: LocationManager
private var testViewStateLiveData: MutableLiveData<NewMyRoomActivityViewModel.MyRoomActivityViewState> = MutableLiveData()
@Before
fun setUp() {
RobolectricTestGEComponent.GraphHolder.testGraph.inject(this)
whenever(mockViewModel.viewState).thenReturn(testViewStateLiveData)
shadowOf(getMainLooper()).idle() // doesn't work here
}
@Test
fun `launch activity sets ViewModel room Id`() {
val roomId = "TestMyRoomId"
shadowOf(getMainLooper()).idle() // doesn't work here either 
activityRule.launchActivity(MyRoomActivity.newIntent(ApplicationProvider.getApplicationContext(), roomId))  // fails here all the time
verify(mockViewModel).initialize(roomId)
}
.....
}

Answer 1

添加InstantTaskExecutorRule为我解决了一个问题。

import androidx.arch.core.executor.testing.InstantTaskExecutorRule
import org.junit.Rule
class Test {
@get:Rule
val executorRule = InstantTaskExecutorRule()
}