Merge pull request #685 from android/reactive_testfix

Fixes tests in reactive branch

Author: JoseAlcerreca

app/src/androidTest/java/com/example/android/architecture/blueprints/todoapp/tasks/AppNavigationTest.kt renamed to app/src/androidTestMock/java/com/example/android/architecture/blueprints/todoapp/tasks/AppNavigationTest.kt

@@ -51,6 +51,9 @@ import org.junit.runner.RunWith
 /**
  * Tests for the [DrawerLayout] layout component in [TasksActivity] which manages
  * navigation within the app.
+ *
+ * UI tests usually use [ActivityTestRule] but there's no API to perform an action before
+ * each test. The workaround is to use `ActivityScenario.launch()` and `ActivityScenario.close()`.
  */
 @RunWith(AndroidJUnit4::class)
 @LargeTest
@@ -117,6 +120,8 @@ class AppNavigationTest {
 
         // Check that tasks screen was opened.
         onView(withId(R.id.tasks_container_layout)).check(matches(isDisplayed()))
+        // When using ActivityScenario.launch, always call close()
+        activityScenario.close()
     }
 
     @Test
@@ -140,6 +145,8 @@ class AppNavigationTest {
         // Check if drawer is open
         onView(withId(R.id.drawer_layout))
             .check(matches(isOpen(Gravity.START))) // Left drawer is open open.
+        // When using ActivityScenario.launch, always call close()
+        activityScenario.close()
     }
 
     @Test
@@ -168,6 +175,8 @@ class AppNavigationTest {
         // Then check that the drawer is open
         onView(withId(R.id.drawer_layout))
             .check(matches(isOpen(Gravity.START))) // Left drawer is open open.
+        // When using ActivityScenario.launch, always call close()
+        activityScenario.close()
     }
 
     @Test
@@ -201,6 +210,8 @@ class AppNavigationTest {
             )
         ).perform(click())
         onView(withId(R.id.tasks_container_layout)).check(matches(isDisplayed()))
+        // When using ActivityScenario.launch, always call close()
+        activityScenario.close()
     }
 
     @Test
@@ -224,5 +235,7 @@ class AppNavigationTest {
         // Confirm that if we click back a second time, we end up back at the home screen
         pressBack()
         onView(withId(R.id.tasks_container_layout)).check(matches(isDisplayed()))
+        // When using ActivityScenario.launch, always call close()
+        activityScenario.close()
     }
 }

app/src/androidTest/java/com/example/android/architecture/blueprints/todoapp/tasks/TasksActivityTest.kt renamed to app/src/androidTestMock/java/com/example/android/architecture/blueprints/todoapp/tasks/TasksActivityTest.kt

@@ -52,6 +52,9 @@ import org.junit.runner.RunWith
 
 /**
  * Large End-to-End test for the tasks module.
+ *
+ * UI tests usually use [ActivityTestRule] but there's no API to perform an action before
+ * each test. The workaround is to use `ActivityScenario.launch()` and `ActivityScenario.close()`.
  */
 @RunWith(AndroidJUnit4::class)
 @LargeTest
@@ -116,6 +119,8 @@ class TasksActivityTest {
         onView(withText("NEW TITLE")).check(matches(isDisplayed()))
         // Verify previous task is not displayed
         onView(withText("TITLE1")).check(doesNotExist())
+        // Make sure the activity is closed before resetting the db:
+        activityScenario.close()
     }
 
     @Test
@@ -141,6 +146,8 @@ class TasksActivityTest {
         onView(withId(R.id.menu_filter)).perform(click())
         onView(withText(string.nav_all)).perform(click())
         onView(withText("TITLE1")).check(doesNotExist())
+        // Make sure the activity is closed before resetting the db:
+        activityScenario.close()
     }
 
     @Test
@@ -162,6 +169,8 @@ class TasksActivityTest {
         onView(withText(string.nav_all)).perform(click())
         onView(withText("TITLE1")).check(matches(isDisplayed()))
         onView(withText("TITLE2")).check(doesNotExist())
+        // Make sure the activity is closed before resetting the db:
+        activityScenario.close()
     }
 
     @Test
@@ -190,6 +199,8 @@ class TasksActivityTest {
         // Check that the task is marked as completed
         onView(allOf(withId(R.id.complete_checkbox), hasSibling(withText(taskTitle))))
             .check(matches(isChecked()))
+        // Make sure the activity is closed before resetting the db:
+        activityScenario.close()
     }
 
     @Test
@@ -217,6 +228,8 @@ class TasksActivityTest {
         // Check that the task is marked as active
         onView(allOf(withId(R.id.complete_checkbox), hasSibling(withText(taskTitle))))
             .check(matches(not(isChecked())))
+        // Make sure the activity is closed before resetting the db:
+        activityScenario.close()
     }
 
     @Test
@@ -275,6 +288,8 @@ class TasksActivityTest {
         // Check that the task is marked as active
         onView(allOf(withId(R.id.complete_checkbox), hasSibling(withText(taskTitle))))
             .check(matches(isChecked()))
+        // Make sure the activity is closed before resetting the db:
+        activityScenario.close()
     }
 
     @Test
@@ -292,5 +307,7 @@ class TasksActivityTest {
 
         // Then verify task is displayed on screen
         onView(withText("title")).check(matches(isDisplayed()))
+        // Make sure the activity is closed before resetting the db:
+        activityScenario.close()
     }
 }

app/src/androidTest/java/com/example/android/architecture/blueprints/todoapp/tasks/TestUtils.kt renamed to app/src/androidTestMock/java/com/example/android/architecture/blueprints/todoapp/tasks/TestUtils.kt

@@ -45,7 +45,9 @@ object ServiceLocator {
     }
 
     private fun createTasksRepository(context: Context): TasksRepository {
-        return DefaultTasksRepository(FakeTasksRemoteDataSource, createTaskLocalDataSource(context))
+        val newRepo = DefaultTasksRepository(FakeTasksRemoteDataSource, createTaskLocalDataSource(context))
+        tasksRepository = newRepo
+        return newRepo
     }
 
     private fun createTaskLocalDataSource(context: Context): TasksDataSource {

app/src/mock/java/com/example/android/architecture/blueprints/todoapp/ServiceLocator.kt

@@ -46,7 +46,9 @@ object ServiceLocator {
     }
 
     private fun createTasksRepository(context: Context): TasksRepository {
-        return DefaultTasksRepository(TasksRemoteDataSource, createTaskLocalDataSource(context))
+        val newRepo = DefaultTasksRepository(TasksRemoteDataSource, createTaskLocalDataSource(context))
+        tasksRepository = newRepo
+        return newRepo
     }
 
     private fun createTaskLocalDataSource(context: Context): TasksDataSource {

app/src/prod/java/com/example/android/architecture/blueprints/todoapp/ServiceLocator.kt

@@ -13,7 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package com.example.android.architecture.blueprints.todoapp
 
 import androidx.annotation.VisibleForTesting
@@ -23,26 +22,50 @@ import java.util.concurrent.CountDownLatch
 import java.util.concurrent.TimeUnit
 import java.util.concurrent.TimeoutException
 
+/**
+ * Gets the value of a [LiveData] or waits for it to have one, with a timeout.
+ *
+ * Use this extension from host-side (JVM) tests. It's recommended to use it alongside
+ * `InstantTaskExecutorRule` or a similar mechanism to execute tasks synchronously.
+ */
 @VisibleForTesting(otherwise = VisibleForTesting.NONE)
-fun <T> LiveData<T>.awaitNextValue(
+fun <T> LiveData<T>.getOrAwaitValue(
     time: Long = 2,
-    timeUnit: TimeUnit = TimeUnit.SECONDS
+    timeUnit: TimeUnit = TimeUnit.SECONDS,
+    afterObserve: () -> Unit = {}
 ): T {
     var data: T? = null
     val latch = CountDownLatch(1)
     val observer = object : Observer<T> {
         override fun onChanged(o: T?) {
             data = o
             latch.countDown()
-            this@awaitNextValue.removeObserver(this)
+            this@getOrAwaitValue.removeObserver(this)
         }
     }
     this.observeForever(observer)
+
+    afterObserve.invoke()
+
     // Don't wait indefinitely if the LiveData is not set.
     if (!latch.await(time, timeUnit)) {
+        this.removeObserver(observer)
         throw TimeoutException("LiveData value was never set.")
     }
 
     @Suppress("UNCHECKED_CAST")
     return data as T
 }
+
+/**
+ * Observes a [LiveData] until the `block` is done executing.
+ */
+fun <T> LiveData<T>.observeForTesting(block: () -> Unit) {
+    val observer = Observer<T> { }
+    try {
+        observeForever(observer)
+        block()
+    } finally {
+        removeObserver(observer)
+    }
+}

app/src/test/java/com/example/android/architecture/blueprints/todoapp/LiveDataTestUtil.kt

@@ -23,11 +23,11 @@ fun assertLiveDataEventTriggered(
     liveData: LiveData<Event<String>>,
     taskId: String
 ) {
-    val value = liveData.awaitNextValue()
+    val value = liveData.getOrAwaitValue()
     assertEquals(value.getContentIfNotHandled(), taskId)
 }
 
 fun assertSnackbarMessage(snackbarLiveData: LiveData<Event<Int>>, messageId: Int) {
-    val value: Event<Int> = snackbarLiveData.awaitNextValue()
+    val value: Event<Int> = snackbarLiveData.getOrAwaitValue()
     assertEquals(value.getContentIfNotHandled(), messageId)
 }

app/src/test/java/com/example/android/architecture/blueprints/todoapp/TestUtil.kt

@@ -19,9 +19,9 @@ import androidx.arch.core.executor.testing.InstantTaskExecutorRule
 import com.example.android.architecture.blueprints.todoapp.MainCoroutineRule
 import com.example.android.architecture.blueprints.todoapp.R.string
 import com.example.android.architecture.blueprints.todoapp.assertSnackbarMessage
-import com.example.android.architecture.blueprints.todoapp.awaitNextValue
 import com.example.android.architecture.blueprints.todoapp.data.Task
 import com.example.android.architecture.blueprints.todoapp.data.source.FakeRepository
+import com.example.android.architecture.blueprints.todoapp.getOrAwaitValue
 import com.google.common.truth.Truth.assertThat
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import org.junit.Before
@@ -86,13 +86,13 @@ class AddEditTaskViewModelTest {
         addEditTaskViewModel.start(task.id)
 
         // Then progress indicator is shown
-        assertThat(addEditTaskViewModel.dataLoading.awaitNextValue()).isTrue()
+        assertThat(addEditTaskViewModel.dataLoading.getOrAwaitValue()).isTrue()
 
         // Execute pending coroutines actions
         mainCoroutineRule.resumeDispatcher()
 
         // Then progress indicator is hidden
-        assertThat(addEditTaskViewModel.dataLoading.awaitNextValue()).isFalse()
+        assertThat(addEditTaskViewModel.dataLoading.getOrAwaitValue()).isFalse()
     }
 
     @Test
@@ -104,9 +104,9 @@ class AddEditTaskViewModelTest {
         addEditTaskViewModel.start(task.id)
 
         // Verify a task is loaded
-        assertThat(addEditTaskViewModel.title.awaitNextValue()).isEqualTo(task.title)
-        assertThat(addEditTaskViewModel.description.awaitNextValue()).isEqualTo(task.description)
-        assertThat(addEditTaskViewModel.dataLoading.awaitNextValue()).isFalse()
+        assertThat(addEditTaskViewModel.title.getOrAwaitValue()).isEqualTo(task.title)
+        assertThat(addEditTaskViewModel.description.getOrAwaitValue()).isEqualTo(task.description)
+        assertThat(addEditTaskViewModel.dataLoading.getOrAwaitValue()).isFalse()
     }
 
     @Test

app/src/test/java/com/example/android/architecture/blueprints/todoapp/addedittask/AddEditTaskViewModelTest.kt

@@ -15,6 +15,7 @@
  */
 package com.example.android.architecture.blueprints.todoapp.data.source
 
+import com.example.android.architecture.blueprints.todoapp.MainCoroutineRule
 import com.example.android.architecture.blueprints.todoapp.data.Result
 import com.example.android.architecture.blueprints.todoapp.data.Result.Success
 import com.example.android.architecture.blueprints.todoapp.data.Task
@@ -23,6 +24,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.test.runBlockingTest
 import org.junit.Before
+import org.junit.Rule
 import org.junit.Test
 
 /**
@@ -44,14 +46,19 @@ class DefaultTasksRepositoryTest {
     // Class under test
     private lateinit var tasksRepository: DefaultTasksRepository
 
+    // Set the main coroutines dispatcher for unit testing.
+    @ExperimentalCoroutinesApi
+    @get:Rule
+    var mainCoroutineRule = MainCoroutineRule()
+
     @ExperimentalCoroutinesApi
     @Before
     fun createRepository() {
         tasksRemoteDataSource = FakeDataSource(remoteTasks.toMutableList())
         tasksLocalDataSource = FakeDataSource(localTasks.toMutableList())
         // Get a reference to the class under test
         tasksRepository = DefaultTasksRepository(
-            tasksRemoteDataSource, tasksLocalDataSource, Dispatchers.Unconfined
+            tasksRemoteDataSource, tasksLocalDataSource, Dispatchers.Main
         )
     }
 
@@ -60,7 +67,7 @@ class DefaultTasksRepositoryTest {
     fun getTasks_emptyRepositoryAndUninitializedCache() = runBlockingTest {
         val emptySource = FakeDataSource()
         val tasksRepository = DefaultTasksRepository(
-            emptySource, emptySource, Dispatchers.Unconfined
+            emptySource, emptySource, Dispatchers.Main
         )
 
         assertThat(tasksRepository.getTasks() is Success).isTrue()

app/src/test/java/com/example/android/architecture/blueprints/todoapp/data/source/DefaultTasksRepositoryTest.kt

@@ -18,10 +18,10 @@ package com.example.android.architecture.blueprints.todoapp.statistics
 import androidx.arch.core.executor.testing.InstantTaskExecutorRule
 import com.example.android.architecture.blueprints.todoapp.FakeFailingTasksRemoteDataSource
 import com.example.android.architecture.blueprints.todoapp.MainCoroutineRule
-import com.example.android.architecture.blueprints.todoapp.awaitNextValue
 import com.example.android.architecture.blueprints.todoapp.data.Task
 import com.example.android.architecture.blueprints.todoapp.data.source.DefaultTasksRepository
 import com.example.android.architecture.blueprints.todoapp.data.source.FakeRepository
+import com.example.android.architecture.blueprints.todoapp.getOrAwaitValue
 import com.google.common.truth.Truth.assertThat
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.ExperimentalCoroutinesApi
@@ -61,7 +61,7 @@ class StatisticsViewModelTest {
         // Given an initialized StatisticsViewModel with no tasks
 
         // Then the results are empty
-        assertThat(statisticsViewModel.empty.awaitNextValue()).isTrue()
+        assertThat(statisticsViewModel.empty.getOrAwaitValue()).isTrue()
     }
 
     @Test
@@ -74,29 +74,28 @@ class StatisticsViewModelTest {
         tasksRepository.addTasks(task1, task2, task3, task4)
 
         // Then the results are not empty
-        assertThat(statisticsViewModel.empty.awaitNextValue())
+        assertThat(statisticsViewModel.empty.getOrAwaitValue())
             .isFalse()
-        assertThat(statisticsViewModel.activeTasksPercent.awaitNextValue())
+        assertThat(statisticsViewModel.activeTasksPercent.getOrAwaitValue())
             .isEqualTo(25f)
-        assertThat(statisticsViewModel.completedTasksPercent.awaitNextValue())
+        assertThat(statisticsViewModel.completedTasksPercent.getOrAwaitValue())
             .isEqualTo(75f)
     }
 
     @Test
-    fun loadStatisticsWhenTasksAreUnavailable_CallErrorToDisplay() =
-        mainCoroutineRule.runBlockingTest {
-            val errorViewModel = StatisticsViewModel(
-                DefaultTasksRepository(
-                    FakeFailingTasksRemoteDataSource,
-                    FakeFailingTasksRemoteDataSource,
-                    Dispatchers.Main  // Main is set in MainCoroutineRule
-                )
+    fun loadStatisticsWhenTasksAreUnavailable_CallErrorToDisplay(){
+        val errorViewModel = StatisticsViewModel(
+            DefaultTasksRepository(
+                FakeFailingTasksRemoteDataSource,
+                FakeFailingTasksRemoteDataSource,
+                Dispatchers.Main  // Main is set in MainCoroutineRule
             )
+        )
 
-            // Then an error message is shown
-            assertThat(errorViewModel.empty.awaitNextValue()).isTrue()
-            assertThat(errorViewModel.error.awaitNextValue()).isTrue()
-        }
+        // Then an error message is shown
+        assertThat(errorViewModel.empty.getOrAwaitValue()).isTrue()
+        assertThat(errorViewModel.error.getOrAwaitValue()).isTrue()
+    }
 
     @Test
     fun loadTasks_loading() {
@@ -107,12 +106,12 @@ class StatisticsViewModelTest {
         statisticsViewModel.refresh()
 
         // Then progress indicator is shown
-        assertThat(statisticsViewModel.dataLoading.awaitNextValue()).isTrue()
+        assertThat(statisticsViewModel.dataLoading.getOrAwaitValue()).isTrue()
 
         // Execute pending coroutines actions
         mainCoroutineRule.resumeDispatcher()
 
         // Then progress indicator is hidden
-        assertThat(statisticsViewModel.dataLoading.awaitNextValue()).isFalse()
+        assertThat(statisticsViewModel.dataLoading.getOrAwaitValue()).isFalse()
     }
 }