Android Automated Testing

A talk a gave on the Israeli Android Academy. Sept 2019.

Transcript

1. Android Automated Testing
2. Definition The use of software separate from the software being tested to control the execution of tests and the comparison of actual outcomes with predicted outcomes https://en.wikipedia.org/wiki/Test_automation
3. App adb install app
4. App Instrumentation Tests Local Tests adb install app adb install tests
5. About Me https://github.com/roisagiv https://www.linkedin.com/in/roisagiv/
6. About You
7. • Experienced in developing Android apps • Familiar with: • LiveData • ViewModel • Coroutines • Room • Heard about / Some experience with testing About You
8. Agenda • Android testing tools landscape • Benefits and challenges of automated testing • Tips & Tricks
9. Android Testing Landscape
10. Android Testing Landscape Two types of runtimes: • "Unit Tests" - local machine • Instrumentation - Device / Emulator Powered by JUnit
11. The build process
12. Local Tests Fast - Runs on the JVM (Local machine) • No DEX • No APK Installation Limited - No access to Android SDK / components • Views, Context, SharedPreferences, res... • *Can be simulated (Robolectrics & others) or mocked.
13. Local Tests app src androidTest main test
14. Example
15. My Weight Tracker API https://github.com/roisagiv/WeightTracker-Android
16. Architecture Activity / Fragment
17. Architecture Activity / Fragment ViewModel
18. Architecture Activity / Fragment ViewModel Repository
19. Architecture Activity / Fragment ViewModel Repository Network (Retrofit)
20. Architecture Activity / Fragment ViewModel Repository Network (Retrofit) Local (Room)
21. Architecture Activity / Fragment ViewModel Repository Network (Retrofit) Local (Room)
22. interface AirtableAPI { @GET("./") suspend fun records(): Response<RecordsApiResponse> @POST("./") suspend fun create(@Body fields: CreateRecordBody): Response<AirtableRecord> companion object { fun build(baseUrl: String, apiKey: String): AirtableAPI { ... } } } data class RecordsApiResponse(val records: List<AirtableRecord>) data class AirtableRecord(val id: String, val fields: Map<String, String>) data class CreateRecordBody(val fields: Map<String, Any>)
23. interface AirtableAPI { @GET("./") suspend fun records(): Response<RecordsApiResponse> @POST("./") suspend fun create(@Body fields: CreateRecordBody): Response<AirtableRecord> companion object { fun build(baseUrl: String, apiKey: String): AirtableAPI { ... } } } data class RecordsApiResponse(val records: List<AirtableRecord>) data class AirtableRecord(val id: String, val fields: Map<String, String>) data class CreateRecordBody(val fields: Map<String, Any>)
24. class AirtableAPITest { @get:Rule var mockWebServer = MockWebServer() @Test fun recordsShouldReturnListOfWeightRecords() = runBlocking { // Arrange ... // Act ... // Assert ... } }
25. class AirtableAPITest { @get:Rule var mockWebServer = MockWebServer() @Test fun recordsShouldReturnListOfWeightRecords() = runBlocking { // Arrange ... // Act ... // Assert ... } }
26. class AirtableAPITest { @get:Rule var mockWebServer = MockWebServer() @Test fun recordsShouldReturnListOfWeightRecords() = runBlocking { // Arrange ... // Act ... // Assert ... } }
27. class AirtableAPITest { @get:Rule var mockWebServer = MockWebServer() @Test fun recordsShouldReturnListOfWeightRecords() = runBlocking { // Arrange ... // Act ... // Assert ... } }
28. @Test fun recordsShouldReturnListOfWeightRecords() = runBlocking { // Arrange val client = AirtableAPI.build( mockWebServer.url("/").toString(), API_KEY ) mockWebServer.enqueue( MockResponse() .setResponseCode(200) .setBody(Resources.read("records_success.json")) ) // Act ... // Assert ... }
29. @Test fun recordsShouldReturnListOfWeightRecords() = runBlocking { // Arrange ... // Act val clientResponse = client.records() // Assert ... }
30. @Test fun recordsShouldReturnListOfWeightRecords() = runBlocking { ... // Assert assertThat(mockWebServer.requestCount).isEqualTo(1) val request = mockWebServer.takeRequest() assertThat(request.path).isEqualTo("/") assertThat(request.headers["Authorization"]) .isEqualTo("Bearer $API_KEY") assertThat(clientResponse.isSuccessful).isTrue() val records = clientResponse.body()?.records ?: listOf() assertThat(records).hasSize(3) val record = records[0] assertThat(record.fields).hasSize(6) assertThat(record.fields["Weight"]).isEqualTo("80") assertThat(record.fields["Date"]).isEqualTo("2019-06-03T21:03:00.000Z }
31. Tada!
32. MockWebServer class AirtableAPITest { @get:Rule var mockWebServer = MockWebServer() @Test fun recordsShouldReturnListOfWeightRecords() = runBlocking { ... } } testImplementation "com.squareup.okhttp3:mockwebserver:$rootProject.okhttpVersion"
33. @Test fun recordsShouldReturnListOfWeightRecords() = runBlocking { // Arrange ... mockWebServer.enqueue( MockResponse() .setResponseCode(200) .setBody(Resources.read("records_success.json")) ) // Act ... // Assert assertThat(mockWebServer.requestCount).isEqualTo(1) val request = mockWebServer.takeRequest() assertThat(request.path).isEqualTo("/") assertThat(request.headers["Authorization"]).isEqualTo("Bearer $API_KEY") ... }
34. @Test fun recordsShouldReturnListOfWeightRecords() = runBlocking { // Arrange ... mockWebServer.enqueue( MockResponse() .setResponseCode(200) .setBody(Resources.read("records_success.json")) ) // Act ... // Assert assertThat(mockWebServer.requestCount).isEqualTo(1) val request = mockWebServer.takeRequest() assertThat(request.path).isEqualTo("/") assertThat(request.headers["Authorization"]).isEqualTo("Bearer $API_KEY") ... }
35. { "records": [ { "id": "recx6FjYsKNY5R5sF", "fields": { "UserName": "fsdfsdf", "Date": "2019-06-03T21:03:00.000Z", "Weight": 80, "Week Avg": 81.5, "Created time": "2019-06-29T20:58:53.000Z", "Last modified time": "2019-07-06T11:02:34.000Z" }, "createdTime": "2019-06-29T20:58:53.000Z" }, { "id": "recVzvGP6aXci0Lly", "fields": { "UserName": "Aenean.euismod.mauris@rutrum.net", "Date": "2020-01-10T00:48:24.000Z", "Weight": 101, "Week Avg": 82.5, "Notes": "hymenaeos. Mauris ut quam vel", "Created time": "2019-07-06T11:05:54.000Z", "Last modified time": "2019-07-06T11:05:54.000Z" }, "createdTime": "2019-07-06T11:05:54.000Z" }, { "id": "rec8hgWP8HFByqnSz", "fields": { app src test resources records_success.json
36. @Test fun recordsShouldReturnFailureResponseInCaseOfServerError() = runBlocking { // Arrange mockWebServer.enqueue(MockResponse().setResponseCode(500)) ... // Act ... // Assert ... }
37. FIRST - Principles of Unit Tests • Fast • Isolated • Repeatable • Self-Validating • Thorough / Timely
38. Recap / Questions? • "Unit Tests" / Local Tests • Test a single class (AirtableAPI) • The structure of a test (AAA) • FIRST principals • MockWebServer
39. Architecture Activity / Fragment ViewModel Repository Network (Retrofit) Local (Room)
40. @Database(entities = [WeightItem::class], version = 1) @TypeConverters(DateConverters::class) abstract class WeightsDatabase : RoomDatabase() { abstract fun weightItemsDao(): WeightItemsDao } @Entity(tableName = "WeightItems") data class WeightItem( @PrimaryKey val id: String, val date: OffsetDateTime, val weight: Double, val notes: String? ) @Dao interface WeightItemsDao { @Insert(onConflict = REPLACE) suspend fun save(item: WeightItem) @Query("SELECT * from WeightItems") suspend fun all(): List<WeightItem> }
41. @Database(entities = [WeightItem::class], version = 1) @TypeConverters(DateConverters::class) abstract class WeightsDatabase : RoomDatabase() { abstract fun weightItemsDao(): WeightItemsDao } @Entity(tableName = "WeightItems") data class WeightItem( @PrimaryKey val id: String, val date: OffsetDateTime, val weight: Double, val notes: String? ) @Dao interface WeightItemsDao { @Insert(onConflict = REPLACE) suspend fun save(item: WeightItem) @Query("SELECT * from WeightItems") suspend fun all(): List<WeightItem> }
42. @Database(entities = [WeightItem::class], version = 1) @TypeConverters(DateConverters::class) abstract class WeightsDatabase : RoomDatabase() { abstract fun weightItemsDao(): WeightItemsDao } @Entity(tableName = "WeightItems") data class WeightItem( @PrimaryKey val id: String, val date: OffsetDateTime, val weight: Double, val notes: String? ) @Dao interface WeightItemsDao { @Insert(onConflict = REPLACE) suspend fun save(item: WeightItem) @Query("SELECT * from WeightItems") suspend fun all(): List<WeightItem> }
43. Instrumentation Tests Easy(ish) - Access to android SDK / components • Context, SharedPreferences, etc. • UI & Resources Slow(er) - Android toolchain • DEX • APK install every run
44. Instrumentation Tests app src androidTest main test
45. @RunWith(AndroidJUnit4::class) class WeightsDatabaseTest { @get:Rule var weightsDatabaseRule = WeightsDatabaseRule() @Test fun newSavedItemShouldBeReturnInAllQuery() = runBlocking { // Arrange ... // Act ... // Assert ... } }
46. @Test fun newSavedItemShouldBeReturnInAllQuery() = runBlocking { // Arrange val dao = weightsDatabaseRule.weightItemsDao val newEntry = WeightItem( id = Random.nextInt().toString(), date = OffsetDateTime.now(), weight = Random.nextDouble(), notes = "" ) // Act dao.save(newEntry) // Assert val items = dao.all() assertThat(items).hasSize(1) assertThat(items[0].weight).isEqualTo(newEntry.weight) }
47. @Test fun newSavedItemShouldBeReturnInAllQuery() = runBlocking { // Arrange val dao = weightsDatabaseRule.weightItemsDao val newEntry = WeightItem( id = Random.nextInt().toString(), date = OffsetDateTime.now(), weight = Random.nextDouble(), notes = "" ) // Act dao.save(newEntry) // Assert val items = dao.all() assertThat(items).hasSize(1) assertThat(items[0].weight).isEqualTo(newEntry.weight) }
48. @Test fun newSavedItemShouldBeReturnInAllQuery() = runBlocking { // Arrange val dao = weightsDatabaseRule.weightItemsDao val newEntry = WeightItem( id = Random.nextInt().toString(), date = OffsetDateTime.now(), weight = Random.nextDouble(), notes = "" ) // Act dao.save(newEntry) // Assert val items = dao.all() assertThat(items).hasSize(1) assertThat(items[0].weight).isEqualTo(newEntry.weight) }
49. class WeightsDatabaseRule : TestRule { internal lateinit var weightItemsDao: WeightItemsDao private lateinit var db: WeightsDatabase override fun apply(base: Statement?, description: Description?): Statement { return object : Statement() { override fun evaluate() { ... try { base?.evaluate() } finally { ... } ... } } } }
50. class WeightsDatabaseRule : TestRule { internal lateinit var weightItemsDao: WeightItemsDao private lateinit var db: WeightsDatabase override fun apply(base: Statement?, description: Description?): Statement { return object : Statement() { override fun evaluate() { db = Room.inMemoryDatabaseBuilder( InstrumentationRegistry.getInstrumentation().targetContext, WeightsDatabase::class.java ).build() weightItemsDao = db.weightItemsDao() try { base?.evaluate() } finally { db.close() } } } }
51. Recap / Questions? • Instrumentation Tests • Test a single component (Room) • InMemory database • JUnit rule Tip • Skip local tests, focus on instrumentation tests
52. The Test Pyramid
53. Architecture Activity / Fragment ViewModel Repository Network (Retrofit) Local (Room)
54. interface WeightsRepository { suspend fun allItems(): LiveData<Resource<List<WeightItem>>> suspend fun save(item: NewWeightItem): LiveData<Resource<WeightItem?>> }
55. class LiveWeightsRepository( private val airtableAPI: AirtableAPI, private val weightItemsDao: WeightItemsDao ) : WeightsRepository { override suspend fun allItems(): LiveData<Resource<List<WeightItem>>> { return object : NetworkBoundResource<List<WeightItem>, RecordsApiResponse>() { ... }.build().asLiveData() } override suspend fun save(item: NewWeightItem): LiveData<Resource<WeightItem?>> { return object : NetworkBoundResource<WeightItem?, AirtableRecord>() { ... }.build().asLiveData() } }
56. @RunWith(AndroidJUnit4::class) class LiveWeightsRepositoryTest { @get:Rule var mockWebServer = MockWebServer() @get:Rule var weightsDatabase = WeightsDatabaseRule() @get:Rule var instantTaskExecutorRule = InstantTaskExecutorRule() @Test fun givenCleanStateAllShouldCallNetworkAndSaveInDB() { } }
57. @RunWith(AndroidJUnit4::class) class LiveWeightsRepositoryTest { @get:Rule var mockWebServer = MockWebServer() @get:Rule var weightsDatabase = WeightsDatabaseRule() @get:Rule var instantTaskExecutorRule = InstantTaskExecutorRule() @Test fun givenCleanStateAllShouldCallNetworkAndSaveInDB() { } }
58. @Test fun givenCleanStateAllShouldCallNetworkAndSaveInDB() { // Arrange val body = Assets.read( "records_success.json", InstrumentationRegistry.getInstrumentation().context ) mockWebServer.enqueue( MockResponse().setResponseCode(200).setBody(body) ) val client = AirtableAPI.build( mockWebServer.url("").toString(), API_KEY ) val weightItemsDao = weightsDatabase.weightItemsDao var observer: TestObserver<Resource<List<WeightItem>>>? = null val repository = LiveWeightsRepository(client, weightItemsDao) // Act ... // Assert ... }
59. @Test fun givenCleanStateAllShouldCallNetworkAndSaveInDB() { // Arrange ... var observer: TestObserver<Resource<List<WeightItem>>>? = null val repository = LiveWeightsRepository(client, weightItemsDao) // Act runBlocking { observer = repository.allItems().test(2) } // Assert ... }
60. @Test fun givenCleanStateAllShouldCallNetworkAndSaveInDB() { // Arrange ... // Act runBlocking { observer = repository.allItems().test(2) } // Assert assertThat(mockWebServer.takeRequest()).isNotNull() assertThat(mockWebServer.requestCount).isEqualTo(1) observer?.await() observer?.assertValues { assertThat(it[0].status).isEqualTo(Status.LOADING) assertThat(it[0].data).hasSize(0) assertThat(it[1].status).isEqualTo(Status.SUCCESS) assertThat(it[1].data).hasSize(3) } }
61. class TestObserver<T>(expectedCount: Int) : Observer<T> { private val values = mutableListOf<T>() private val latch: CountDownLatch = CountDownLatch(expectedCount) override fun onChanged(value: T) { values.add(value) latch.countDown() } fun assertValues(function: (List<T>) -> Unit) { function.invoke(values) } fun await(timeout: Long = 5, unit: TimeUnit = TimeUnit.SECONDS) { if (!latch.await(timeout, unit)) { throw TimeoutException() } } }
62. class TestObserver<T>(expectedCount: Int) : Observer<T> { ... } fun <T> LiveData<T>.test(expectedCount: Int = 1) = TestObserver<T>(expectedCount).also { observeForever(it) }
63. @RunWith(AndroidJUnit4::class) class LiveWeightsRepositoryTest { @get:Rule var mockWebServer = MockWebServer() @get:Rule var weightsDatabase = WeightsDatabaseRule() @get:Rule var instantTaskExecutorRule = InstantTaskExecutorRule() @Test fun givenCleanStateAllShouldCallNetworkAndSaveInDB() { } }
64. @RunWith(AndroidJUnit4::class) class LiveWeightsRepositoryTest { @get:Rule var mockWebServer = MockWebServer() @get:Rule var weightsDatabase = WeightsDatabaseRule() @get:Rule var instantTaskExecutorRule = InstantTaskExecutorRule() @Test fun givenCleanStateAllShouldCallNetworkAndSaveInDB() { } @Test fun givenSavedItemsAllShouldUpdateDB() { } }
65. @Test fun givenSavedItemsAllShouldUpdateDB() { // Arrange ... val weightItemsDao = weightsDatabase.weightItemsDao runBlocking { weightItemsDao.save( WeightItem( id = "recVzvGP6aXci0Lly", date = OffsetDateTime.parse("2019-06-12T21:00:00.000Z"), weight = 172.42, notes = "" ) ) } // Act ... // Assert ... }
66. @Test fun givenSavedItemsAllShouldUpdateDB() { // Arrange ... // Act ... // Assert assertThat(mockWebServer.takeRequest()).isNotNull() assertThat(mockWebServer.requestCount).isEqualTo(1) observer?.await() observer?.assertValues { assertThat(it[0].status).isEqualTo(Status.LOADING) assertThat(it[0].data).hasSize(1) assertThat(it[1].status).isEqualTo(Status.SUCCESS) assertThat(it[1].data).hasSize(3) } }
67. @RunWith(AndroidJUnit4::class) class LiveWeightsRepositoryTest { ... @Test fun givenCleanStateAllShouldCallNetworkAndSaveInDB() { } @Test fun givenSavedItemsAllShouldUpdateDB() { } @Test fun saveShouldPerformNetworkAndSaveInDB() { } }
68. @Test fun saveShouldPerformNetworkAndSaveInDB() { // Arrange ... val repository = LiveWeightsRepository(client, weightItemsDao) // Act runBlocking { observer = repository .save(NewWeightItem(OffsetDateTime.now(), 10.0, null)) .test(2) } // Assert ... runBlocking { assertThat(historyDataItemDao.all()).hasSize(1) } }
69. Architecture Activity / Fragment ViewModel Repository Network (Retrofit) Local (Room)
70. abstract class HistoryViewModel : ViewModel() { abstract val state: LiveData<ViewState> abstract fun refresh() sealed class ViewState { object Loading : ViewState() data class Error(val error: Throwable? = null) : ViewState() data class Success(val list: List<WeightItem>) : ViewState() } }
71. class LiveHistoryViewModel(private val repository: WeightsRepository) : HistoryViewModel() { private val refreshAction: MutableLiveData<Unit> = MutableLiveData() override val state: LiveData<ViewState> = refreshAction.switchMap { ... } override fun refresh() { refreshAction.postValue(Unit) } }
72. class LiveHistoryViewModel(private val repository: WeightsRepository) : HistoryViewModel() { private val refreshAction: MutableLiveData<Unit> = MutableLiveData() override val state: LiveData<ViewState> = refreshAction.switchMap { liveData<ViewState>( context = viewModelScope.coroutineContext + Dispatchers.IO ) { emitSource(repository.allItems().map { when (it.status) { Status.LOADING -> ViewState.Loading Status.SUCCESS -> ViewState.Success(it.data!!) Status.ERROR -> ViewState.Error() } }) } } override fun refresh() { ... } }
73. @RunWith(AndroidJUnit4::class) class HistoryViewModelTest { @get:Rule var instantTaskExecutorRule = InstantTaskExecutorRule() @get:Rule var mockWebServer = MockWebServer() @get:Rule var weightsDatabase = WeightsDatabaseRule() @Test fun refreshShouldFetchFromServer() { ... } @Test fun givenServerErrorShouldReturnError() { ... } }
74. @Test fun refreshShouldFetchFromServer() { // Arrange val body = Assets.read( "records_success.json", InstrumentationRegistry.getInstrumentation().context ) mockWebServer.enqueue(MockResponse().setResponseCode(200).setBody(body)) val client = AirtableAPI.build(mockWebServer.url("").toString(), API_KEY) val repository = LiveWeightsRepository(client, weightsDatabase.weightItemsDao) val viewModel = LiveHistoryViewModel(repository) // Act ... // Assert ... }
75. @Test fun refreshShouldFetchFromServer() { // Arrange ... val viewModel = LiveHistoryViewModel(repository) // Act val observer = viewModel.state.test(expectedCount = 2) viewModel.refresh() observer.await() // Assert ... }
76. @Test fun refreshShouldFetchFromServer() { ... // Assert assertThat(mockWebServer.requestCount).isEqualTo(1) observer.assertValues { assertThat(it).hasSize(2) assertThat(it[0]).isSameInstanceAs(HistoryViewModel.ViewState.Loading) val items = it[1] as? HistoryViewModel.ViewState.Success assertThat(items?.list).hasSize(3) assertThat(items?.list?.get(0)?.id).isEqualTo("recx6FjYsKNY5R5sF") assertThat(items?.list?.get(0)?.date).isEqualTo( OffsetDateTime.parse( "2019-06-03T21:03:00.000Z", DateTimeFormatter.ISO_OFFSET_DATE_TIME ) ) } }
77. @Test fun givenServerErrorShouldReturnError() { // Arrange mockWebServer.enqueue(MockResponse().setResponseCode(400)) val client = AirtableAPI.build(mockWebServer.url("").toString(), API_KEY) val repository = LiveWeightsRepository(client, weightsDatabase.weightItemsDao) val viewModel = LiveHistoryViewModel(repository) // Act val observer = viewModel.state.test(expectedCount = 2) viewModel.refresh() // Assert observer.await() assertThat(mockWebServer.requestCount).isEqualTo(1) observer.assertValues { assertThat(it).hasSize(2) assertThat(it[0]).isSameInstanceAs(HistoryViewModel.ViewState.Loading) val error = it[1] as? HistoryViewModel.ViewState.Error assertThat(error).isNotNull() } }
78. The Test Pyramid
79. The Test Pyramid
80. The Test Pyramid
82. The Modern Test Pyramid (Trophy)
83. Recap / Questions? • Integration Tests • Test couple of components together • TestObserver & InstantTaskExecutorRule • Modern test pyramid Tips • Integration tests increase confidence • Unit tests are disposable
84. Architecture Activity / Fragment ViewModel Repository Network (Retrofit) Local (Room)
85. class HistoryActivity : AppCompatActivity() { private var linearLayoutManager: LinearLayoutManager? = null private var adapter: HistoryRecyclerAdapter? = null private val viewModel by viewModel<HistoryViewModel>() override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) ... } override fun onStart() { super.onStart() viewModel.refresh() } }
86. class HistoryActivity : AppCompatActivity() { private var linearLayoutManager: LinearLayoutManager? = null private var adapter: HistoryRecyclerAdapter? = null private val viewModel by viewModel<HistoryViewModel>() override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) ... } override fun onStart() { super.onStart() viewModel.refresh() } }
87. class HistoryActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) ... viewModel.state.observe(this, Observer { state -> when (state) { is HistoryViewModel.ViewState.Error -> { } is HistoryViewModel.ViewState.Loading -> { progressBar.visibility = View.VISIBLE } is HistoryViewModel.ViewState.Success -> { progressBar.visibility = View.GONE adapter?.submitList(state.list) } } }) } }
88. @RunWith(AndroidJUnit4::class) class HistoryActivityTest { @get:Rule val activityRule = ActivityTestRule( HistoryActivity::class.java, false, false ) @get:Rule val animationsRule = DisableAnimationsRule() @get:Rule val permissionRule: GrantPermissionRule = GrantPermissionRule.grant(WRITE_EXTERNAL_STORAGE) @get:Rule val screenshotRule = ScreenshotRule() private var viewModel: MockHistoryViewModel = MockHistoryViewModel() @Before fun before() { ... } }
89. @RunWith(AndroidJUnit4::class) class HistoryActivityTest { ... private var viewModel: MockHistoryViewModel = MockHistoryViewModel() @Before fun before() { viewModel = MockHistoryViewModel() loadKoinModules(module { viewModel<HistoryViewModel> { viewModel } }) } @Test fun successStateShouldDisplayListOfItems() { ... } ... }
90. class MockHistoryViewModel : HistoryViewModel() { private val internalState: MutableLiveData<ViewState> = MutableLiveData() override val state: LiveData<ViewState> = internalState override fun refresh() = Unit fun postViewState(viewState: ViewState) { internalState.postValue(viewState) } }
91. @Test fun successStateShouldDisplayListOfItems() { // Arrange activityRule.launchActivity(Intent()) // Act viewModel.postViewState(createSuccessState()) // Assert InstrumentationRegistry.getInstrumentation().waitForIdleSync() onView(withId(R.id.recycler_history_items)).perform( RecyclerHelpers.waitUntil( RecyclerHelpers.hasItemCount(greaterThan(0)) ) ) assertRecyclerViewItemCount(R.id.recycler_history_items, 5) screenshotRule.takeScreenshot() }
92. private fun createSuccessState(): HistoryViewModel.ViewState.Success { val items: List<WeightItem> = listOf( WeightItem( ... ), WeightItem( ... ), WeightItem( ... ), WeightItem( ... ), WeightItem( ... ) ) return HistoryViewModel.ViewState.Success(items) }
93. api27-1080x1920x2.625-en/HistoryActivityTest-successStateShouldDisplayListOfItems.png
94. @Test fun loadingStateShouldDisplayProgressBar() { // Arrange activityRule.launchActivity(Intent()) // Act viewModel.postViewState(HistoryViewModel.ViewState.Loading) // Assert assertDisplayed(R.id.progressBar) screenshotRule.takeScreenshot() }
95. api27-1080x1920x2.625-en/HistoryActivityTest-loadingStateShouldDisplayProgressBar.png
96. Recap / Questions? • Unit test for the UI • Mock the ViewModel • Screenshots Tip • Helps verifying different UI states - loading, error, empty, etc.
97. End to End tests Automated the user experience • Multiple screens • Minimal to none mocks / stubs / etc. • Real server* • FIRST principals
98. My Weight Tracker
99. My Weight Tracker Production E2E
100. @RunWith(AndroidJUnit4::class) class AddWeightE2ETest { @Before fun before() = runBlocking { ... } @Test fun addNewWeight() { val uiDevice = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation()) ApplicationRobot.launchApp() val historyRobot = HistoryRobot(uiDevice) historyRobot.assertPageDisplayed() historyRobot.assertNumberOfItemsInList(5) historyRobot.navigateToAddWeight() val addWeightRobot = AddWeightRobot(uiDevice) addWeightRobot.assertPageDisplayed()
101. @Test fun addNewWeight() { val uiDevice = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation()) ApplicationRobot.launchApp() val historyRobot = HistoryRobot(uiDevice) historyRobot.assertPageDisplayed() historyRobot.assertNumberOfItemsInList(5) historyRobot.navigateToAddWeight() val addWeightRobot = AddWeightRobot(uiDevice) addWeightRobot.assertPageDisplayed() addWeightRobot.typeWeight("12.34") addWeightRobot.save() historyRobot.assertPageDisplayed() historyRobot.assertNumberOfItemsInList(6) } }
102. class HistoryRobot(private val uiDevice: UiDevice) { fun assertPageDisplayed() { assertDisplayed(R.string.app_name) } fun assertNumberOfItemsInList(expected: Int) { uiDevice.findObject(UiSelector().textContains("Test Node 1")) .waitForExists(500) onView(withContentDescription(R.string.content_description_history_list)) .check(RecyclerViewItemCountAssertion(expected)) } fun navigateToAddWeight() { onView(withContentDescription(R.string.content_description_add_weight)) .perform(click()) } }
103. class AddWeightRobot(private val uiDevice: UiDevice) { fun assertPageDisplayed() { uiDevice.findObject(UiSelector().textContains("SAVE")) .waitForExists(5000) assertDisplayed("SAVE") } fun typeWeight(weight: String) { onView(withContentDescription(R.string.content_description_weight)) .perform(typeText(weight)) closeSoftKeyboard() } fun save() { onView(withContentDescription(R.string.content_description_save_button)) .perform(click()) } }
104. @Before fun before() = runBlocking { val airtable = AirtableBatchAPI.build(BuildConfig.AIRTABLE_E2E_URL, BuildConfig.AIRTABLE_E2E_KEY) val records = airtable.records() assertThat(records.isSuccessful).isTrue() records.body()?.records?.map { it.id }?.let { if (it.isNotEmpty()) { assertThat(airtable.delete(it).isSuccessful).isTrue() } } val body = Assets.read( "create_records_e2e_body.json", InstrumentationRegistry.getInstrumentation().context ) val response = airtable.create( Gson().fromJson(body, JsonObject::class.java) ) assertThat(response.isSuccessful).isTrue() }
105. interface AirtableBatchAPI { @GET("./") suspend fun records(): Response<RecordsApiResponse> @POST("./") suspend fun create(@Body body: JsonObject): Response<Unit> @DELETE("./") suspend fun delete(@Query("records[]") records: List<String>): Response<Unit> companion object { fun build(baseUrl: String, apiKey: String): AirtableBatchAPI { ... } } }
106. Recap / Questions? • End to End tests simulate the user • Separated environment • Server state Tip • Existing app without tests? start with E2E tests.
107. The Test Pyramid
108. The Test Pyramid Development Quality
109. Thank You! • https://martinfowler.com/articles/practical-test-pyramid.html • https://kentcdodds.com/blog/write-tests • https://dhh.dk/2014/tdd-is-dead-long-live-testing.html • https://medium.com/@copyconstruct/testing-in-production-the-safe- way-18ca102d0ef1 • https://twitter.com/thepracticaldev/status/733908215021199360 • https://github.com/goldbergyoni/javascript-testing-best-practices https://github.com/roisagiv https://www.linkedin.com/in/roisagiv/