espresso 测试时房间数据库错误 "Cannot access database on the main thread"

Question

我正在使用浓缩咖啡进行测试，但在执行以下方法时出现错误。

viewModel.getData().observe(viewLifecycleOwner, Observer { options ->
            Log.d(TAG, "onViewCreated: $options")
            val data = options.filter { option -> option.type!! == OptionType.DATA}

            updateData.updateUIComponent(data)
        })

获取数据方法return 一个 LiveData 对象。这在 Fragments 中运行良好，但在 espresso 测试中不起作用 class

Cannot access database on the main thread since it may potentially lock the UI for a long period of time.

这是我的测试class

@LargeTest
@RunWith(AndroidJUnit4::class)
open class BaseIntegrationTest {

    @get:Rule
    val instantTestExecutorRule = InstantTaskExecutorRule()

    lateinit var navController: TestNavHostController

    lateinit var fragmentScenario: FragmentScenario<DetailsFragment>


    @Before
    fun initTest() {

        navController = TestNavHostController(
            ApplicationProvider.getApplicationContext()
        )

    }

    @Test
    fun launchFragment() {

        val bundle = Bundle()

        fragmentScenario =
            launchFragmentInContainer(bundle, themeResId = R.style.Theme_mainTheme)

        fragmentScenario.moveToState(Lifecycle.State.STARTED)

        UiThreadStatement.runOnUiThread {
            navController.setGraph(R.navigation.app_navigation_graph)
        }
        fragmentScenario.onFragment { fragment ->

            //CollectFeedbackFragment()
            Navigation.setViewNavController(fragment.requireView(), navController)
        }

        onView(withId(R.id.progressBar)).isVisible()
    }

}

Answer 1

我设法通过使用 Dispatchers.IO 和 Dispatchers.Main

解决了这个问题

class SampleViewModel : ViewModel() {

    fun getData():DataLiveData {
        viewModelScope.launch {

            withContext(Dispatchers.IO) {

                 // here I am seding the Room db call
                
                withContext(Dispatchers.Main) {
               // I am updating the MutableLiveData object here
                }
            }
        }
        return mutableLiveData
    }
}

并且不要忘记注入调度程序而不是硬编码。点击 here!

espresso 测试时房间数据库错误 "Cannot access database on the main thread"

Room Database Error when espresso test "Cannot access database on the main thread"

android

android-room

android-espresso

android-livedata