android - 当您必须使用父 Activity 引用时，如何使用 `FragmentScenario` 单独测试 Fragment

Question

我计划使用 FragmentScenario 来单独测试 fragment 。在此 fragment 中，我正在访问父 Activity 以调用一些方法。为此，我使用 CommonActivityOperations 接口(interface)。我在此应用程序中使用导航架构组件。

interface CommonActivityOperations {
    fun closeSearchBar()
    fun navigateBackWithResult(resultFor: String, result: Bundle)
}

当我尝试在 AttractionDestinationFragment 上运行测试时，出现以下错误。

java.lang.ClassCastException:androidx.fragment.app.testing.FragmentScenario$EmptyFragmentActivity 无法转换为 .interfaces.CommonActivityOperations

AttractionDestinationFragment

const val DESTINATION_DATA_EXTRA = "destination_data_result"

class AttractionDestinationFragment : BaseFragment(), ItemClickListener, ToolbarSearchChangeListener{

    private lateinit var navigationController: NavController
    private lateinit var defaultAttractionList: MutableList<AttractionDestinations>
    private lateinit var attractionDestinationRecyclerViewAdapter: AttractionDestinationRecyclerViewAdapter

    private val viewModel by lazy { getViewModel<AttractionDestinationViewModel>() }

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.fragment_attraction_destination, container, false)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {

        initialization(view)
        observeAttractionDestinations()
    }

    private fun initialization(view: View) {

        navigationController = Navigation.findNavController(view)

        defaultAttractionList = mutableListOf(...)

        attractionDestinationRecyclerViewAdapter =
                AttractionDestinationRecyclerViewAdapter(defaultAttractionList)
        attractionDestinationRecyclerViewAdapter.itemClickListener = this
        attractionDestinationRecyclerView.addItemDecoration(SimpleLineDividerItemDecoration(context))
        attractionDestinationRecyclerView.adapter = attractionDestinationRecyclerViewAdapter

        activity?.invalidateOptionsMenu()

    }

    private fun observeAttractionDestinations() {

        viewModel.attractionDestinationsLiveData.observe(viewLifecycleOwner, Observer {

            it.getContentIfNotHandled()?.also { resource ->

                when (resource.status) {

                    DataRetrieveStatus.SUCCESS -> {
                        // apply new data
                    }

                    DataRetrieveStatus.RESPONSE_ERROR -> {
                        //Show error
                    }

                    DataRetrieveStatus.CONNECTION_ERROR,
                    DataRetrieveStatus.PROCESSING_ERROR -> {
                        //error handling
                    }
                }
            }
        })
    }

    override fun onItemClick(position: Int) {

        val bundle = Bundle()
        bundle.putParcelable(DESTINATION_DATA_EXTRA, attractionDestinationRecyclerViewAdapter.data[position])

        activity?.invalidateOptionsMenu()

        commonActivityOperations.navigateBackWithResult(DESTINATION_DATA_RESULT, bundle)
        commonActivityOperations.closeSearchBar()
    }

    override fun onQueryChange(text: String) {

        if(networkConnectivity.isOnline){

            viewModel.getAttractionDestinations(text)

        }else{
            // Error handling
        }
    }

    override fun onSearchBarClose() {
        // Reset List
    }

基础 fragment

abstract class BaseFragment : Fragment() {

    private lateinit var windowFocusChangeReceiver: BroadcastReceiver

    protected var dialogToDisplayOnWindowIsFocus: MaterialDialog.Builder? = null

    lateinit var commonActivityOperations: CommonActivityOperations

    val networkConnectivity: NetworkStatus by lazy { NetworkStatus(context) }

    override fun onAttach(context: Context) {
        commonActivityOperations = activity as CommonActivityOperations
        super.onAttach(context)
    }
}

AttractionDestinationFragmentTest

class AttractionDestinationFragmentTest {

    private val mockNavController by lazy {
        Mockito.mock(NavController::class.java)
    }

    @Before
    fun setUp() {

        MockitoAnnotations.initMocks(this)

        val fragment = AttractionDestinationFragment()

        launchFragmentInContainer(themeResId = R.style.AppTheme){
            fragment.also { fragment ->
                fragment.viewLifecycleOwnerLiveData.observeForever { viewLifecycleOwner ->
                    if (viewLifecycleOwner != null) {
                        Navigation.setViewNavController(fragment.requireView(), mockNavController)
                    }
                }
            }
        }

    }

    @Test
    fun destinationRecyclerViewLoadTest(){

        onView(withId(R.id.attractionDestinationRecyclerView))
                .check(RecyclerViewItemCountAssertion(15))
                .perform(actionOnItemAtPosition<AttractionDestinationRecyclerViewAdapter.ViewHolder>(0, click()))
    }

    @After
    fun tearDown() {
    }

如您所见，我已经在 onAttach(context: Context) 内设置了 CommonActivityOperations 接口(interface)在BaseFragment中。我收到此错误是因为 FragmentScenario 创建了 EmptyFragmentActivity ，它没有实现 CommonActivityOperations 并且我正在尝试启动它。

是否有其他方法来启动此界面？如何使这个 fragment 可测试？

谢谢。

编辑:我经历过以下类似的question 。

这个问题没有解决我遇到的问题，因为我正在使用导航架构组件。当使用导航架构组件时，我不会手动创建 fragment 来将接口(interface)传递给 fragment ，如本问题所示。

AttractionFlowActivity

private fun initialization() {

        navigationController = Navigation.findNavController(this, R.id.hostFragment)
        setSupportActionBar(toolbar)

        val appBarConfiguration = AppBarConfiguration
                .Builder()
                .setFallbackOnNavigateUpListener(this)
                .build()

        NavigationUI.setupActionBarWithNavController(this, navigationController, appBarConfiguration)

    }

上面的代码显示了父 Activity 内部的初始化函数，该函数负责设置导航架构组件并使用工具栏进行设置。

Answer 1

如果不引用导航架构组件的 Activity ，我找不到使用此界面的方法。我最终做的是使用 ReactiveX 。我创建了一个类，使用 PublishSubject 通知 Activity 关于值(value)变化。

CommonActivityTrigger

class CommonActivityTrigger private constructor() {

    val navigateBackResultPublishSubject: PublishSubject<Pair<String,Bundle>>
            = PublishSubject.create()
    val closeSearchBarPublishSubject: PublishSubject<Boolean>
            = PublishSubject.create()

    private object HOLDER {
        val INSTANCE = CommonActivityTrigger()
    }

    companion object {
        val INSTANCE: CommonActivityTrigger by lazy { HOLDER.INSTANCE }
    }

    fun navigateBackWithResult(resultFor: String, result: Bundle){
        navigateBackResultPublishSubject.onNext(Pair(resultFor,result))
    }

    fun closeSearchBar(){
        closeSearchBarPublishSubject.onNext(true)
    }
}

AttractionDestinationFragment

class AttractionDestinationFragment : BaseFragment(), ItemClickListener, ToolbarSearchChangeListener{

    private lateinit var defaultAttractionList: MutableList<AttractionDestinations>
    private lateinit var attractionDestinationRecyclerViewAdapter: AttractionDestinationRecyclerViewAdapter

    private val viewModel by lazy { getViewModel<AttractionDestinationViewModel>() }
    private val commonActivityTrigger by lazy { CommonActivityTrigger.INSTANCE }

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.fragment_attraction_destination, container, false)
    }

    override fun onItemClick(position: Int) {

        val bundle = Bundle()
        bundle.putParcelable(DESTINATION_DATA_EXTRA, attractionDestinationRecyclerViewAdapter.data[position])

        activity?.invalidateOptionsMenu()

        commonActivityTrigger.navigateBackWithResult(DESTINATION_DATA_RESULT, bundle)
        commonActivityTrigger.closeSearchBar()
    }
}

AttractionFlow1Activity

class AttractionFlow1Activity : AppCompatActivity(), AppBarConfiguration.OnNavigateUpListener {

    private lateinit var navigationController: NavController

    private val navHostFragment by lazy { supportFragmentManager.findFragmentById(R.id.hostFragment) }
    private val commonActivityTrigger by lazy { CommonActivityTrigger.INSTANCE }

    private val compositeDisposable = CompositeDisposable()

    private fun navigateBackWithResult() {

        val navigationBlackResultPublishDisposable = commonActivityTrigger
                .navigateBackResultPublishSubject
                .subscribe {

                    val (resultFor, result) = it

                    val childFragmentManager = supportFragmentManager
                            .findFragmentById(R.id.hostFragment)?.childFragmentManager
                    var backStackListener: FragmentManager.OnBackStackChangedListener by Delegates.notNull()
                    backStackListener = FragmentManager.OnBackStackChangedListener {
                        (childFragmentManager?.fragments?.get(0) as NavigationResult).onNavigationResult(resultFor, result)
                        childFragmentManager.removeOnBackStackChangedListener(backStackListener)
                    }
                    childFragmentManager?.addOnBackStackChangedListener(backStackListener)
                    navigationController.popBackStack()
                }

        compositeDisposable.add(navigationBlackResultPublishDisposable)

    }

    override fun onDestroy() {
        compositeDisposable.dispose()
        super.onDestroy()
    }
}