在應用程式中實作分頁程式庫時,應搭配完善的測試策略。建議您測試 PagingSource
和 RemoteMediator
等資料載入元件,確保元件運作正常。此外,您也應撰寫端對端測試,確認 Paging 實作項目中的所有元件都能正常運作,而不會產生意外的副作用。
本指南說明如何在應用程式的不同架構層測試 Paging 程式庫,以及如何為整個 Paging 實作項目撰寫端對端測試。
UI 層測試
透過 Paging 程式庫擷取的資料會在 UI 中用做 Flow<PagingData<Value>>
。如要撰寫測試,驗證 UI 中的資料是否符合預期,請納入 paging-testing
依附元件。這個依附元件包含 Flow<PagingData<Value>>
的 asSnapshot()
擴充功能,其中的 lambda 接收器提供 API,可模擬捲動互動。此方法會傳回由模擬的捲動互動產生的標準 List<Value>
,您就能透過包含這些互動所產生的預期元素,宣告資料已分頁。如以下程式碼片段所示:
fun test_items_contain_one_to_ten() = runTest {
// Get the Flow of PagingData from the ViewModel under test
val items: Flow<PagingData<String>> = viewModel.items
val itemsSnapshot: List<String> = items.asSnapshot {
// Scroll to the 50th item in the list. This will also suspend till
// the prefetch requirement is met if there's one.
// It also suspends until all loading is complete.
scrollTo(index = 50)
}
// With the asSnapshot complete, you can now verify that the snapshot
// has the expected values
assertEquals(
expected = (0..50).map(Int::toString),
actual = itemsSnapshot
)
}
您也可以捲動畫面,直到符合特定述詞為止,如以下程式碼片段所示:
fun test_footer_is_visible() = runTest {
// Get the Flow of PagingData from the ViewModel under test
val items: Flow<PagingData<String>> = viewModel.items
val itemsSnapshot: List<String> = items.asSnapshot {
// Scroll till the footer is visible
appendScrollWhile { item: String -> item != "Footer" }
}
測試轉換作業
您也應該撰寫單元測試,涵蓋套用至 PagingData
串流的所有轉換作業。請使用 asPagingSourceFactory
擴充功能。這項擴充功能支援下列資料類型:
List<Value>
。Flow<List<Value>>
。
請根據要測試的項目,選擇使用適合的擴充功能。您可以使用下列功能:
List<Value>.asPagingSourceFactory()
:測試資料上的靜態轉換作業,例如map()
和insertSeparators()
。Flow<List<Value>>.asPagingSourceFactory()
:測試寫入備份資料來源等資料更新方式會如何影響分頁管道。
如要使用上述任一擴充功能,請按照下列模式操作:
- 使用符合需求的擴充功能建立
PagingSourceFactory
。 - 在
Repository
的假例項中,使用傳回的PagingSourceFactory
。 - 將該
Repository
傳遞至ViewModel
。
接著,您就可以依據上一節的說明測試 ViewModel
。請考量以下 ViewModel
:
class MyViewModel(
myRepository: myRepository
) {
val items = Pager(
config: PagingConfig,
initialKey = null,
pagingSourceFactory = { myRepository.pagingSource() }
)
.flow
.map { pagingData ->
pagingData.insertSeparators<String, String> { before, _ ->
when {
// Add a dashed String separator if the prior item is a multiple of 10
before.last() == '0' -> "---------"
// Return null to avoid adding a separator between two items.
else -> null
}
}
}
如要在 MyViewModel
中測試轉換作業,請提供 MyRepository
的假例項,此例項會委派至用來代表所要轉換資料的靜態 List
,如以下程式碼片段所示:
class FakeMyRepository(): MyRepository {
private val items = (0..100).map(Any::toString)
private val pagingSourceFactory = items.asPagingSourceFactory()
val pagingSource = pagingSourceFactory()
}
接著,您就能為分隔符邏輯撰寫測試,如下列程式碼片段所示:
fun test_separators_are_added_every_10_items() = runTest {
// Create your ViewModel
val viewModel = MyViewModel(
myRepository = FakeMyRepository()
)
// Get the Flow of PagingData from the ViewModel with the separator transformations applied
val items: Flow<PagingData<String>> = viewModel.items
val snapshot: List<String> = items.asSnapshot()
// With the asSnapshot complete, you can now verify that the snapshot
// has the expected separators.
}
資料層測試
請針對資料層的元件撰寫單元測試,確保這些元件能妥善從資料來源載入資料。請提供假版本的依附元件,驗證受測元件能正常獨立運作。您需要測試的存放區層主要元件為 PagingSource
和 RemoteMediator
。後續章節中的範例是以搭配使用 Paging 與網路的範例為基礎。
PagingSource 測試
PagingSource
實作項目的單元測試涉及設定 PagingSource
例項,以及使用 TestPager
載入該例項的資料。
如要設定用於測試的 PagingSource
例項,請將假資料提供給建構函式。這麼做可以控管測試中的資料。在以下範例中,RedditApi
參數是 Retrofit
介面,定義伺服器要求和回應類別。
假版本可以實作介面、覆寫任何必要函式,並提供便利的方法,設定假物件在測試中的預期回應方式。
假物件設定完畢後,請設定依附元件,並初始化測試中的 PagingSource
物件。以下範例說明如何透過測試貼文清單來初始化 FakeRedditApi
物件,並測試 RedditPagingSource
例項:
class SubredditPagingSourceTest {
private val mockPosts = listOf(
postFactory.createRedditPost(DEFAULT_SUBREDDIT),
postFactory.createRedditPost(DEFAULT_SUBREDDIT),
postFactory.createRedditPost(DEFAULT_SUBREDDIT)
)
private val fakeApi = FakeRedditApi().apply {
mockPosts.forEach { post -> addPost(post) }
}
@Test
fun loadReturnsPageWhenOnSuccessfulLoadOfItemKeyedData() = runTest {
val pagingSource = RedditPagingSource(
fakeApi,
DEFAULT_SUBREDDIT
)
val pager = TestPager(CONFIG, pagingSource)
val result = pager.refresh() as LoadResult.Page
// Write assertions against the loaded data
assertThat(result.data)
.containsExactlyElementsIn(mockPosts)
.inOrder()
}
}
您也可以使用 TestPager
執行下列操作:
- 測試
PagingSource
的連續載入作業:
@Test
fun test_consecutive_loads() = runTest {
val page = with(pager) {
refresh()
append()
append()
} as LoadResult.Page
assertThat(page.data)
.containsExactlyElementsIn(testPosts)
.inOrder()
}
- 測試
PagingSource
中的錯誤情境:
@Test
fun refresh_returnError() {
val pagingSource = RedditPagingSource(
fakeApi,
DEFAULT_SUBREDDIT
)
// Configure your fake to return errors
fakeApi.setReturnsError()
val pager = TestPager(CONFIG, source)
runTest {
source.errorNextLoad = true
val result = pager.refresh()
assertTrue(result is LoadResult.Error)
val page = pager.getLastLoadedPage()
assertThat(page).isNull()
}
}
RemoteMediator 測試
RemoteMediator
單元測試的目標是驗證 load()
函式會傳回正確的 MediatorResult
。
針對副作用 (例如插入資料庫的資料) 的測試較適用於整合測試。
首先,您必須決定 RemoteMediator
實作所需要的依附元件。以下範例說明需要 Room 資料庫、Retrofit 介面和搜尋字串的 RemoteMediator
實作:
Kotlin
@OptIn(ExperimentalPagingApi::class) class PageKeyedRemoteMediator( private val db: RedditDb, private val redditApi: RedditApi, private val subredditName: String ) : RemoteMediator<Int, RedditPost>() { ... }
Java
public class PageKeyedRemoteMediator extends RxRemoteMediator<Integer, RedditPost> { @NonNull private RedditDb db; @NonNull private RedditPostDao postDao; @NonNull private SubredditRemoteKeyDao remoteKeyDao; @NonNull private RedditApi redditApi; @NonNull private String subredditName; public PageKeyedRemoteMediator( @NonNull RedditDb db, @NonNull RedditApi redditApi, @NonNull String subredditName ) { this.db = db; this.postDao = db.posts(); this.remoteKeyDao = db.remoteKeys(); this.redditApi = redditApi; this.subredditName = subredditName; ... } }
Java
public class PageKeyedRemoteMediator extends ListenableFutureRemoteMediator<Integer, RedditPost> { @NonNull private RedditDb db; @NonNull private RedditPostDao postDao; @NonNull private SubredditRemoteKeyDao remoteKeyDao; @NonNull private RedditApi redditApi; @NonNull private String subredditName; @NonNull private Executor bgExecutor; public PageKeyedRemoteMediator( @NonNull RedditDb db, @NonNull RedditApi redditApi, @NonNull String subredditName, @NonNull Executor bgExecutor ) { this.db = db; this.postDao = db.posts(); this.remoteKeyDao = db.remoteKeys(); this.redditApi = redditApi; this.subredditName = subredditName; this.bgExecutor = bgExecutor; ... } }
您可以按照 PagingSource 測試一節的說明,來提供 Retrofit 介面和搜尋字串。提供 Room 資料庫的模擬版本十分複雜,因此較簡單的做法是提供資料庫的記憶體內實作,而不是完整的模擬版本。由於建立 Room 資料庫需要 Context
物件,因此您必須將此 RemoteMediator
測試放在 androidTest
目錄中,並使用 AndroidJUnit4 測試執行工具,以便存取測試應用程式的內容。如要進一步瞭解檢測設備測試,請參閱建構檢測設備單元測試。
定義拆除函式,確保狀態在測試函式之間不會外洩。這樣可確保測試執行結果維持一致。
Kotlin
@ExperimentalPagingApi @OptIn(ExperimentalCoroutinesApi::class) @RunWith(AndroidJUnit4::class) class PageKeyedRemoteMediatorTest { private val postFactory = PostFactory() private val mockPosts = listOf( postFactory.createRedditPost(SubRedditViewModel.DEFAULT_SUBREDDIT), postFactory.createRedditPost(SubRedditViewModel.DEFAULT_SUBREDDIT), postFactory.createRedditPost(SubRedditViewModel.DEFAULT_SUBREDDIT) ) private val mockApi = mockRedditApi() private val mockDb = RedditDb.create( ApplicationProvider.getApplicationContext(), useInMemory = true ) @After fun tearDown() { mockDb.clearAllTables() // Clear out failure message to default to the successful response. mockApi.failureMsg = null // Clear out posts after each test run. mockApi.clearPosts() } }
Java
@RunWith(AndroidJUnit4.class) public class PageKeyedRemoteMediatorTest { static PostFactory postFactory = new PostFactory(); static List<RedditPost> mockPosts = new ArrayList<>(); static MockRedditApi mockApi = new MockRedditApi(); private RedditDb mockDb = RedditDb.Companion.create( ApplicationProvider.getApplicationContext(), true ); static { for (int i=0; i<3; i++) { RedditPost post = postFactory.createRedditPost(DEFAULT_SUBREDDIT); mockPosts.add(post); } } @After public void tearDown() { mockDb.clearAllTables(); // Clear the failure message after each test run. mockApi.setFailureMsg(null); // Clear out posts after each test run. mockApi.clearPosts(); } }
Java
@RunWith(AndroidJUnit4.class) public class PageKeyedRemoteMediatorTest { static PostFactory postFactory = new PostFactory(); static List<RedditPost> mockPosts = new ArrayList<>(); static MockRedditApi mockApi = new MockRedditApi(); private RedditDb mockDb = RedditDb.Companion.create( ApplicationProvider.getApplicationContext(), true ); static { for (int i=0; i<3; i++) { RedditPost post = postFactory.createRedditPost(DEFAULT_SUBREDDIT); mockPosts.add(post); } } @After public void tearDown() { mockDb.clearAllTables(); // Clear the failure message after each test run. mockApi.setFailureMsg(null); // Clear out posts after each test run. mockApi.clearPosts(); } }
下一步是測試 load()
函式。在這個範例中,有三個案例可以進行測試:
- 第一個案例是
mockApi
傳回有效的資料。load()
函式應傳回MediatorResult.Success
,而endOfPaginationReached
屬性應為false
。 - 第二個案例是
mockApi
傳回成功的回應,但傳回的資料是空的。load()
函式應傳回MediatorResult.Success
,而endOfPaginationReached
屬性應為true
。 - 第三個案例是
mockApi
在擷取資料時擲回例外狀況。load()
函式應會傳回MediatorResult.Error
。
請按照下列步驟測試第一個案例:
- 使用要傳回的訊息資料設定
mockApi
。 - 將
RemoteMediator
物件初始化。 - 測試
load()
函式。
Kotlin
@Test fun refreshLoadReturnsSuccessResultWhenMoreDataIsPresent() = runTest { // Add mock results for the API to return. mockPosts.forEach { post -> mockApi.addPost(post) } val remoteMediator = PageKeyedRemoteMediator( mockDb, mockApi, SubRedditViewModel.DEFAULT_SUBREDDIT ) val pagingState = PagingState<Int, RedditPost>( listOf(), null, PagingConfig(10), 10 ) val result = remoteMediator.load(LoadType.REFRESH, pagingState) assertTrue { result is MediatorResult.Success } assertFalse { (result as MediatorResult.Success).endOfPaginationReached } }
Java
@Test public void refreshLoadReturnsSuccessResultWhenMoreDataIsPresent() throws InterruptedException { // Add mock results for the API to return. for (RedditPost post: mockPosts) { mockApi.addPost(post); } PageKeyedRemoteMediator remoteMediator = new PageKeyedRemoteMediator( mockDb, mockApi, SubRedditViewModel.DEFAULT_SUBREDDIT ); PagingState<Integer, RedditPost> pagingState = new PagingState<>( new ArrayList(), null, new PagingConfig(10), 10 ); remoteMediator.loadSingle(LoadType.REFRESH, pagingState) .test() .await() .assertValueCount(1) .assertValue(value -> value instanceof RemoteMediator.MediatorResult.Success && ((RemoteMediator.MediatorResult.Success) value).endOfPaginationReached() == false); }
Java
@Test public void refreshLoadReturnsSuccessResultWhenMoreDataIsPresent() throws InterruptedException, ExecutionException { // Add mock results for the API to return. for (RedditPost post: mockPosts) { mockApi.addPost(post); } PageKeyedRemoteMediator remoteMediator = new PageKeyedRemoteMediator( mockDb, mockApi, SubRedditViewModel.DEFAULT_SUBREDDIT, new CurrentThreadExecutor() ); PagingState<Integer, RedditPost> pagingState = new PagingState<>( new ArrayList(), null, new PagingConfig(10), 10 ); RemoteMediator.MediatorResult result = remoteMediator.loadFuture(LoadType.REFRESH, pagingState).get(); assertThat(result, instanceOf(RemoteMediator.MediatorResult.Success.class)); assertFalse(((RemoteMediator.MediatorResult.Success) result).endOfPaginationReached()); }
如要進行第二個測試,mockApi
必須傳回空白結果。由於每次執行測試後都會清除 mockApi
中的資料,因此根據預設將會傳回空白結果。
Kotlin
@Test fun refreshLoadSuccessAndEndOfPaginationWhenNoMoreData() = runTest { // To test endOfPaginationReached, don't set up the mockApi to return post // data here. val remoteMediator = PageKeyedRemoteMediator( mockDb, mockApi, SubRedditViewModel.DEFAULT_SUBREDDIT ) val pagingState = PagingState<Int, RedditPost>( listOf(), null, PagingConfig(10), 10 ) val result = remoteMediator.load(LoadType.REFRESH, pagingState) assertTrue { result is MediatorResult.Success } assertTrue { (result as MediatorResult.Success).endOfPaginationReached } }
Java
@Test public void refreshLoadSuccessAndEndOfPaginationWhenNoMoreData() throws InterruptedException() { // To test endOfPaginationReached, don't set up the mockApi to return post // data here. PageKeyedRemoteMediator remoteMediator = new PageKeyedRemoteMediator( mockDb, mockApi, SubRedditViewModel.DEFAULT_SUBREDDIT ); PagingState<Integer, RedditPost> pagingState = new PagingState<>( new ArrayList(), null, new PagingConfig(10), 10 ); remoteMediator.loadSingle(LoadType.REFRESH, pagingState) .test() .await() .assertValueCount(1) .assertValue(value -> value instanceof RemoteMediator.MediatorResult.Success && ((RemoteMediator.MediatorResult.Success) value).endOfPaginationReached() == true); }
Java
@Test public void refreshLoadSuccessAndEndOfPaginationWhenNoMoreData() throws InterruptedException, ExecutionException { // To test endOfPaginationReached, don't set up the mockApi to return post // data here. PageKeyedRemoteMediator remoteMediator = new PageKeyedRemoteMediator( mockDb, mockApi, SubRedditViewModel.DEFAULT_SUBREDDIT, new CurrentThreadExecutor() ); PagingState<Integer, RedditPost> pagingState = new PagingState<>( new ArrayList(), null, new PagingConfig(10), 10 ); RemoteMediator.MediatorResult result = remoteMediator.loadFuture(LoadType.REFRESH, pagingState).get(); assertThat(result, instanceOf(RemoteMediator.MediatorResult.Success.class)); assertTrue(((RemoteMediator.MediatorResult.Success) result).endOfPaginationReached()); }
如要進行最後一個測試,mockApi
必須擲回例外狀況,以便驗證 load()
函式是否正確傳回 MediatorResult.Error
。
Kotlin
@Test fun refreshLoadReturnsErrorResultWhenErrorOccurs() = runTest { // Set up failure message to throw exception from the mock API. mockApi.failureMsg = "Throw test failure" val remoteMediator = PageKeyedRemoteMediator( mockDb, mockApi, SubRedditViewModel.DEFAULT_SUBREDDIT ) val pagingState = PagingState<Int, RedditPost>( listOf(), null, PagingConfig(10), 10 ) val result = remoteMediator.load(LoadType.REFRESH, pagingState) assertTrue {result is MediatorResult.Error } }
Java
@Test public void refreshLoadReturnsErrorResultWhenErrorOccurs() throws InterruptedException { // Set up failure message to throw exception from the mock API. mockApi.setFailureMsg("Throw test failure"); PageKeyedRemoteMediator remoteMediator = new PageKeyedRemoteMediator( mockDb, mockApi, SubRedditViewModel.DEFAULT_SUBREDDIT ); PagingState<Integer, RedditPost> pagingState = new PagingState<>( new ArrayList(), null, new PagingConfig(10), 10 ); remoteMediator.loadSingle(LoadType.REFRESH, pagingState) .test() .await() .assertValueCount(1) .assertValue(value -> value instanceof RemoteMediator.MediatorResult.Error); }
Java
@Test public void refreshLoadReturnsErrorResultWhenErrorOccurs() throws InterruptedException, ExecutionException { // Set up failure message to throw exception from the mock API. mockApi.setFailureMsg("Throw test failure"); PageKeyedRemoteMediator remoteMediator = new PageKeyedRemoteMediator( mockDb, mockApi, SubRedditViewModel.DEFAULT_SUBREDDIT, new CurrentThreadExecutor() ); PagingState<Integer, RedditPost> pagingState = new PagingState<>( new ArrayList(), null, new PagingConfig(10), 10 ); RemoteMediator.MediatorResult result = remoteMediator.loadFuture(LoadType.REFRESH, pagingState).get(); assertThat(result, instanceOf(RemoteMediator.MediatorResult.Error.class)); }
端對端測試
單元測試可保證個別分頁元件能夠獨立運作,但端對端測試更能確保應用程式整體都能正常運作。這些測試仍需要一些模擬依附元件,但通常已涵蓋大部分的應用程式程式碼。
本節中的範例使用模擬 API 依附元件,避免在測試中使用網路。模擬 API 已設為傳回一組一致的測試資料,進而產生可重複的測試。根據依附元件的作用、輸出內容的一致性,以及測試所需的擬真度,決定要針對模擬實作替換的依附元件。
編寫程式碼時,請採取可讓您輕鬆替換依附元件模擬版本的方式。以下範例使用基本的服務定位器實作,並視需要提供及變更依附元件。在大型應用程式中,使用依附元件插入程式庫 (例如 Hilt) 有助管理更複雜的依附元件圖表。
Kotlin
class RedditActivityTest { companion object { private const val TEST_SUBREDDIT = "test" } private val postFactory = PostFactory() private val mockApi = MockRedditApi().apply { addPost(postFactory.createRedditPost(DEFAULT_SUBREDDIT)) addPost(postFactory.createRedditPost(TEST_SUBREDDIT)) addPost(postFactory.createRedditPost(TEST_SUBREDDIT)) } @Before fun init() { val app = ApplicationProvider.getApplicationContext<Application>() // Use a controlled service locator with a mock API. ServiceLocator.swap( object : DefaultServiceLocator(app = app, useInMemoryDb = true) { override fun getRedditApi(): RedditApi = mockApi } ) } }
Java
public class RedditActivityTest { public static final String TEST_SUBREDDIT = "test"; private static PostFactory postFactory = new PostFactory(); private static MockRedditApi mockApi = new MockRedditApi(); static { mockApi.addPost(postFactory.createRedditPost(DEFAULT_SUBREDDIT)); mockApi.addPost(postFactory.createRedditPost(TEST_SUBREDDIT)); mockApi.addPost(postFactory.createRedditPost(TEST_SUBREDDIT)); } @Before public void setup() { Application app = ApplicationProvider.getApplicationContext(); // Use a controlled service locator with a mock API. ServiceLocator.Companion.swap( new DefaultServiceLocator(app, true) { @NotNull @Override public RedditApi getRedditApi() { return mockApi; } } ); } }
Java
public class RedditActivityTest { public static final String TEST_SUBREDDIT = "test"; private static PostFactory postFactory = new PostFactory(); private static MockRedditApi mockApi = new MockRedditApi(); static { mockApi.addPost(postFactory.createRedditPost(DEFAULT_SUBREDDIT)); mockApi.addPost(postFactory.createRedditPost(TEST_SUBREDDIT)); mockApi.addPost(postFactory.createRedditPost(TEST_SUBREDDIT)); } @Before public void setup() { Application app = ApplicationProvider.getApplicationContext(); // Use a controlled service locator with a mock API. ServiceLocator.Companion.swap( new DefaultServiceLocator(app, true) { @NotNull @Override public RedditApi getRedditApi() { return mockApi; } } ); } }
設定測試結構後,下一步就是驗證 Pager
實作傳回的資料是否正確。一項測試應確保 Pager
物件在網頁初次載入時載入預設資料,而另一項測試應驗證 Pager
物件是否可根據使用者輸入內容正確載入額外資料。在以下範例中,測試會驗證當使用者輸入不同的子版 (subreddit) 進行搜尋時,Pager
物件是否可根據 API 傳回的正確項目數量更新 RecyclerView.Adapter
。
Kotlin
@Test fun loadsTheDefaultResults() { ActivityScenario.launch(RedditActivity::class.java) onView(withId(R.id.list)).check { view, noViewFoundException -> if (noViewFoundException != null) { throw noViewFoundException } val recyclerView = view as RecyclerView assertEquals(1, recyclerView.adapter?.itemCount) } } @Test // Verify that the default data is swapped out when the user searches for a // different subreddit. fun loadsTheTestResultsWhenSearchingForSubreddit() { ActivityScenario.launch(RedditActivity::class.java ) onView(withId(R.id.list)).check { view, noViewFoundException -> if (noViewFoundException != null) { throw noViewFoundException } val recyclerView = view as RecyclerView // Verify that it loads the default data first. assertEquals(1, recyclerView.adapter?.itemCount) } // Search for test subreddit instead of default to trigger new data load. onView(withId(R.id.input)).perform( replaceText(TEST_SUBREDDIT), pressKey(KeyEvent.KEYCODE_ENTER) ) onView(withId(R.id.list)).check { view, noViewFoundException -> if (noViewFoundException != null) { throw noViewFoundException } val recyclerView = view as RecyclerView assertEquals(2, recyclerView.adapter?.itemCount) } }
Java
@Test public void loadsTheDefaultResults() { ActivityScenario.launch(RedditActivity.class); onView(withId(R.id.list)).check((view, noViewFoundException) -> { if (noViewFoundException != null) { throw noViewFoundException; } RecyclerView recyclerView = (RecyclerView) view; assertEquals(1, recyclerView.getAdapter().getItemCount()); }); } @Test // Verify that the default data is swapped out when the user searches for a // different subreddit. public void loadsTheTestResultsWhenSearchingForSubreddit() { ActivityScenario.launch(RedditActivity.class); onView(withId(R.id.list)).check((view, noViewFoundException) -> { if (noViewFoundException != null) { throw noViewFoundException; } RecyclerView recyclerView = (RecyclerView) view; // Verify that it loads the default data first. assertEquals(1, recyclerView.getAdapter().getItemCount()); }); // Search for test subreddit instead of default to trigger new data load. onView(withId(R.id.input)).perform( replaceText(TEST_SUBREDDIT), pressKey(KeyEvent.KEYCODE_ENTER) ); onView(withId(R.id.list)).check((view, noViewFoundException) -> { if (noViewFoundException != null) { throw noViewFoundException; } RecyclerView recyclerView = (RecyclerView) view; assertEquals(2, recyclerView.getAdapter().getItemCount()); }); }
Java
@Test public void loadsTheDefaultResults() { ActivityScenario.launch(RedditActivity.class); onView(withId(R.id.list)).check((view, noViewFoundException) -> { if (noViewFoundException != null) { throw noViewFoundException; } RecyclerView recyclerView = (RecyclerView) view; assertEquals(1, recyclerView.getAdapter().getItemCount()); }); } @Test // Verify that the default data is swapped out when the user searches for a // different subreddit. public void loadsTheTestResultsWhenSearchingForSubreddit() { ActivityScenario.launch(RedditActivity.class); onView(withId(R.id.list)).check((view, noViewFoundException) -> { if (noViewFoundException != null) { throw noViewFoundException; } RecyclerView recyclerView = (RecyclerView) view; // Verify that it loads the default data first. assertEquals(1, recyclerView.getAdapter().getItemCount()); }); // Search for test subreddit instead of default to trigger new data load. onView(withId(R.id.input)).perform( replaceText(TEST_SUBREDDIT), pressKey(KeyEvent.KEYCODE_ENTER) ); onView(withId(R.id.list)).check((view, noViewFoundException) -> { if (noViewFoundException != null) { throw noViewFoundException; } RecyclerView recyclerView = (RecyclerView) view; assertEquals(2, recyclerView.getAdapter().getItemCount()); }); }
檢測設備測試應確認資料可正確顯示在使用者介面中。方法是驗證 RecyclerView.Adapter
中的項目數量正確,或反覆檢視個別的資料列檢視畫面,並確認資料格式正確。
為您推薦
- 注意:系統會在 JavaScript 關閉時顯示連結文字
- 從網路和資料庫進行分頁
- 遷移至 Paging 3
- 載入並顯示分頁資料