#1174 Introduce Unit Testing - example of unit testing of a viewmodel

app/build.gradle

@@ -136,6 +136,14 @@ dependencies {
   implementation "android.arch.lifecycle:extensions:1.1.1"
   implementation "io.objectbox:objectbox-kotlin:$objectboxVersion"
   implementation "io.objectbox:objectbox-rxjava:$objectboxVersion"
+
+  testImplementation "org.junit.jupiter:junit-jupiter:5.4.2"
+  testImplementation "io.mockk:mockk:1.9"
+  testImplementation "org.assertj:assertj-core:3.11.1"
+  //update this with androidx
+  testImplementation 'com.jraska.livedata:testing-ktx:0.2.1'
+  testImplementation 'android.arch.core:core-testing:1.1.1'
+
 }
 
 // Set custom app import directory
@@ -364,6 +372,9 @@ android {
   androidExtensions {
     experimental = true
   }
+  testOptions {
+    unitTests.returnDefaultValues = true
+  }
 }
 
 // Testdroid deployment configuration

app/src/main/java/org/kiwix/kiwixmobile/di/modules/ApplicationModule.java

@@ -25,6 +25,7 @@ import dagger.Module;
 import dagger.Provides;
 import dagger.android.AndroidInjectionModule;
 import javax.inject.Singleton;
+import org.kiwix.kiwixmobile.downloader.model.UriToFileConverter;
 import org.kiwix.kiwixmobile.utils.BookUtils;
 
 @Module(includes = {
@@ -52,4 +53,9 @@ public class ApplicationModule {
   BookUtils provideBookUtils() {
     return new BookUtils();
   }
+
+  @Provides @Singleton
+  UriToFileConverter provideUriToFIleCOnverter() {
+    return new UriToFileConverter.Impl();
+  }
 }

app/src/main/java/org/kiwix/kiwixmobile/downloader/model/BookOnDisk.kt

@@ -6,8 +6,8 @@ import java.io.File
 
 data class BookOnDisk(
   val databaseId: Long? = null,
-  val book: Book,
+  val book: Book = Book().apply { id = "" },
-  val file: File
+  val file: File = File("")
 ) {
   constructor(bookOnDiskEntity: BookOnDiskEntity) : this(
       bookOnDiskEntity.id,

app/src/main/java/org/kiwix/kiwixmobile/downloader/model/DownloadModel.kt

@@ -17,12 +17,11 @@
  */
 package org.kiwix.kiwixmobile.downloader.model
 
-import android.view.WindowId
-import org.kiwix.kiwixmobile.database.newdb.entities.DownloadEntity
 import org.kiwix.kiwixmobile.library.entity.LibraryNetworkEntity
+import org.kiwix.kiwixmobile.library.entity.LibraryNetworkEntity.Book
 
 data class DownloadModel(
   val databaseId: Long? = null,
-  val downloadId: Long,
+  val downloadId: Long = 0,
-  val book: LibraryNetworkEntity.Book
+  val book: LibraryNetworkEntity.Book = Book().apply { id = "" }
 )

app/src/main/java/org/kiwix/kiwixmobile/downloader/model/DownloadStatus.kt

@@ -55,21 +55,22 @@ import org.kiwix.kiwixmobile.library.entity.LibraryNetworkEntity.Book
 import java.io.File
 
 class DownloadStatus(
-  val downloadId: Long,
+  val downloadId: Long = 0L,
-  val title: String,
+  val title: String = "",
-  val description: String,
+  val description: String = "",
-  val state: DownloadState,
+  val state: DownloadState = DownloadState.Pending,
-  val bytesDownloadedSoFar: Long,
+  val bytesDownloadedSoFar: Long = 0,
-  val totalSizeBytes: Long,
+  val totalSizeBytes: Long = 0,
-  val lastModified: String,
+  val lastModified: String = "",
-  val localUri: String?,
+  val localUri: String? = null,
-  val mediaProviderUri: String?,
+  val mediaProviderUri: String? = null,
-  val mediaType: String?,
+  val mediaType: String? = null,
-  val uri: String?,
+  val uri: String? = null,
-  val book: Book
+  val book: Book = Book().apply { id = "" }
 ) {
 
-  fun toBookOnDisk() = BookOnDisk(book = book, file = File(Uri.parse(localUri).path))
+  fun toBookOnDisk(uriToFileConverter:UriToFileConverter) =
+    BookOnDisk(book = book, file = uriToFileConverter.convert(localUri))
 
   constructor(
     cursor: Cursor,
@@ -90,6 +91,11 @@ class DownloadStatus(
   )
 }
 
+interface UriToFileConverter {
+  fun convert(uriString: String?) = File(Uri.parse(uriString).path)
+  class Impl:UriToFileConverter{}
+}
+
 sealed class DownloadState(val stringId: Int) {
   companion object {
     fun from(

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/ConnectivityBroadcastReceiver.kt

@@ -3,8 +3,8 @@ package org.kiwix.kiwixmobile.zim_manager
 import android.content.Context
 import android.content.Intent
 import android.net.ConnectivityManager
+import io.reactivex.Flowable
 import io.reactivex.processors.BehaviorProcessor
-import io.reactivex.processors.PublishProcessor
 import org.kiwix.kiwixmobile.extensions.networkState
 import javax.inject.Inject
 
@@ -13,14 +13,14 @@ class ConnectivityBroadcastReceiver @Inject constructor(private val connectivity
 
   override val action: String = ConnectivityManager.CONNECTIVITY_ACTION
 
-  val networkStates =
+  private val _networkStates = BehaviorProcessor.createDefault(connectivityManager.networkState)
-    BehaviorProcessor.createDefault(connectivityManager.networkState)
+  val networkStates: Flowable<NetworkState> = _networkStates
 
   override fun onIntentWithActionReceived(
     context: Context,
     intent: Intent
   ) {
-    networkStates.onNext(connectivityManager.networkState)
+    _networkStates.onNext(connectivityManager.networkState)
   }
 
 }

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/ZimManageViewModel.kt

@@ -21,6 +21,7 @@ package org.kiwix.kiwixmobile.zim_manager
 import android.app.Application
 import android.arch.lifecycle.MutableLiveData
 import android.arch.lifecycle.ViewModel
+import android.support.annotation.VisibleForTesting
 import io.reactivex.Flowable
 import io.reactivex.disposables.CompositeDisposable
 import io.reactivex.disposables.Disposable
@@ -39,6 +40,7 @@ import org.kiwix.kiwixmobile.downloader.model.DownloadItem
 import org.kiwix.kiwixmobile.downloader.model.DownloadModel
 import org.kiwix.kiwixmobile.downloader.model.DownloadState.Successful
 import org.kiwix.kiwixmobile.downloader.model.DownloadStatus
+import org.kiwix.kiwixmobile.downloader.model.UriToFileConverter
 import org.kiwix.kiwixmobile.extensions.calculateSearchMatches
 import org.kiwix.kiwixmobile.extensions.registerReceiver
 import org.kiwix.kiwixmobile.library.entity.LibraryNetworkEntity
@@ -71,7 +73,8 @@ class ZimManageViewModel @Inject constructor(
   private val context: Application,
   private val connectivityBroadcastReceiver: ConnectivityBroadcastReceiver,
   private val bookUtils: BookUtils,
-  private val fat32Checker: Fat32Checker
+  private val fat32Checker: Fat32Checker,
+  private val uriToFileConverter: UriToFileConverter
 ) : ViewModel() {
 
   val libraryItems: MutableLiveData<List<LibraryListItem>> = MutableLiveData()
@@ -94,6 +97,11 @@ class ZimManageViewModel @Inject constructor(
     context.registerReceiver(connectivityBroadcastReceiver)
   }
 
+  @VisibleForTesting
+  fun onClearedExposed() {
+    onCleared()
+  }
+
   override fun onCleared() {
     compositeDisposable.clear()
     context.unregisterReceiver(connectivityBroadcastReceiver)
@@ -155,6 +163,7 @@ class ZimManageViewModel @Inject constructor(
       )
       .buffer(3, SECONDS)
       .map(this::downloadIdsWithNoStatusesOverBufferPeriod)
+      .filter { it.isNotEmpty() }
       .subscribe(
           {
             downloadDao.delete(*it.toLongArray())
@@ -411,7 +420,7 @@ class ZimManageViewModel @Inject constructor(
         .filter { it.isNotEmpty() }
         .subscribe(
             {
-              bookDao.insert(it.map { downloadStatus -> downloadStatus.toBookOnDisk() })
+              bookDao.insert(it.map { downloadStatus -> downloadStatus.toBookOnDisk(uriToFileConverter) })
               downloadDao.delete(
                   *it.map { status -> status.downloadId }.toLongArray()
               )

app/src/test/java/org/kiwix/kiwixmobile/InstantExecutorExtension.kt

@@ -0,0 +1,44 @@
+/*
+ * Kiwix Android
+ * Copyright (C) 2018  Kiwix <android.kiwix.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.kiwix.kiwixmobile
+
+import android.arch.core.executor.ArchTaskExecutor
+import android.arch.core.executor.TaskExecutor
+import org.junit.jupiter.api.extension.AfterEachCallback
+import org.junit.jupiter.api.extension.BeforeEachCallback
+import org.junit.jupiter.api.extension.ExtensionContext
+
+class InstantExecutorExtension : BeforeEachCallback, AfterEachCallback {
+
+  override fun beforeEach(context: ExtensionContext?) {
+    ArchTaskExecutor.getInstance()
+        .setDelegate(object : TaskExecutor() {
+          override fun executeOnDiskIO(runnable: Runnable) = runnable.run()
+
+          override fun postToMainThread(runnable: Runnable) = runnable.run()
+
+          override fun isMainThread(): Boolean = true
+        })
+  }
+
+  override fun afterEach(context: ExtensionContext?) {
+    ArchTaskExecutor.getInstance().setDelegate(null)
+  }
+
+}

app/src/test/java/org/kiwix/kiwixmobile/zim_manager/ZimManageViewModelTest.kt

@@ -0,0 +1,208 @@
+/*
+ * Kiwix Android
+ * Copyright (C) 2018  Kiwix <android.kiwix.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.kiwix.kiwixmobile.zim_manager
+
+import android.app.Application
+import com.jraska.livedata.test
+import io.mockk.clearMocks
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.verify
+import io.reactivex.Scheduler
+import io.reactivex.android.plugins.RxAndroidPlugins
+import io.reactivex.plugins.RxJavaPlugins
+import io.reactivex.processors.PublishProcessor
+import io.reactivex.schedulers.Schedulers
+import io.reactivex.schedulers.TestScheduler
+import org.junit.jupiter.api.AfterAll
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Nested
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.extension.ExtendWith
+import org.kiwix.kiwixmobile.InstantExecutorExtension
+import org.kiwix.kiwixmobile.database.newdb.dao.NewBookDao
+import org.kiwix.kiwixmobile.database.newdb.dao.NewDownloadDao
+import org.kiwix.kiwixmobile.database.newdb.dao.NewLanguagesDao
+import org.kiwix.kiwixmobile.downloader.Downloader
+import org.kiwix.kiwixmobile.downloader.model.BookOnDisk
+import org.kiwix.kiwixmobile.downloader.model.DownloadItem
+import org.kiwix.kiwixmobile.downloader.model.DownloadModel
+import org.kiwix.kiwixmobile.downloader.model.DownloadState
+import org.kiwix.kiwixmobile.downloader.model.DownloadStatus
+import org.kiwix.kiwixmobile.downloader.model.UriToFileConverter
+import org.kiwix.kiwixmobile.network.KiwixService
+import org.kiwix.kiwixmobile.utils.BookUtils
+import org.kiwix.kiwixmobile.zim_manager.Fat32Checker.FileSystemState
+import org.kiwix.kiwixmobile.zim_manager.NetworkState.NOT_CONNECTED
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.StorageObserver
+import org.kiwix.kiwixmobile.zim_manager.library_view.adapter.Language
+import java.io.File
+import java.util.concurrent.TimeUnit.SECONDS
+
+@ExtendWith(InstantExecutorExtension::class)
+class ZimManageViewModelTest {
+
+  private val newDownloadDao: NewDownloadDao = mockk()
+  private val newBookDao: NewBookDao = mockk()
+  private val newLanguagesDao: NewLanguagesDao = mockk()
+  private val downloader: Downloader = mockk()
+  private val storageObserver: StorageObserver = mockk()
+  private val kiwixService: KiwixService = mockk()
+  private val application: Application = mockk()
+  private val connectivityBroadcastReceiver: ConnectivityBroadcastReceiver = mockk()
+  private val bookUtils: BookUtils = mockk()
+  private val fat32Checker: Fat32Checker = mockk()
+  private val uriToFileConverter: UriToFileConverter = mockk()
+  lateinit var viewModel: ZimManageViewModel
+
+  private val downloads: PublishProcessor<List<DownloadModel>> = PublishProcessor.create()
+  private val books: PublishProcessor<List<BookOnDisk>> = PublishProcessor.create()
+  private val languages: PublishProcessor<List<Language>> = PublishProcessor.create()
+  private val fileSystemStates: PublishProcessor<FileSystemState> = PublishProcessor.create()
+  private val networkStates: PublishProcessor<NetworkState> = PublishProcessor.create()
+
+  private val testScheduler = TestScheduler()
+
+  init {
+    setScheduler(testScheduler)
+  }
+
+  private fun setScheduler(replacementScheduler: Scheduler) {
+    RxJavaPlugins.setIoSchedulerHandler { scheduler -> replacementScheduler }
+    RxJavaPlugins.setComputationSchedulerHandler { scheduler -> replacementScheduler }
+    RxJavaPlugins.setNewThreadSchedulerHandler { scheduler -> replacementScheduler }
+    RxAndroidPlugins.setInitMainThreadSchedulerHandler { scheduler -> Schedulers.trampoline() }
+  }
+
+  @AfterAll
+  fun teardown() {
+    RxJavaPlugins.reset()
+    RxAndroidPlugins.reset();
+  }
+
+  @BeforeEach
+  fun init() {
+    clearMocks(
+        newDownloadDao, newBookDao, newLanguagesDao, downloader,
+        storageObserver, kiwixService, application, connectivityBroadcastReceiver, bookUtils,
+        fat32Checker, uriToFileConverter
+    )
+    every { connectivityBroadcastReceiver.action } returns "test"
+    every { newDownloadDao.downloads() } returns downloads
+    every { newBookDao.books() } returns books
+    every { newLanguagesDao.languages() } returns languages
+    every { fat32Checker.fileSystemStates } returns fileSystemStates
+    every { connectivityBroadcastReceiver.networkStates } returns networkStates
+    every { application.registerReceiver(any(), any()) } returns mockk()
+    viewModel = ZimManageViewModel(
+        newDownloadDao, newBookDao, newLanguagesDao, downloader,
+        storageObserver, kiwixService, application, connectivityBroadcastReceiver, bookUtils,
+        fat32Checker, uriToFileConverter
+    )
+    testScheduler.triggerActions()
+  }
+
+  @Nested
+  inner class Context {
+    @Test
+    fun `registers broadcastReceiver in init`() {
+      verify {
+        application.registerReceiver(connectivityBroadcastReceiver, any())
+      }
+    }
+
+    @Test
+    fun `unregisters broadcastReceiver in onCleared`() {
+      every { application.unregisterReceiver(any()) } returns mockk()
+      viewModel.onClearedExposed()
+      verify {
+        application.unregisterReceiver(connectivityBroadcastReceiver)
+      }
+    }
+  }
+
+  @Nested
+  inner class Downloads {
+    @Test
+    fun `on emission from database query and render downloads`() {
+      val expectedStatus = DownloadStatus()
+      expectStatus(expectedStatus)
+      viewModel.downloadItems
+          .test()
+          .assertValue(listOf(DownloadItem(expectedStatus)))
+          .dispose()
+    }
+
+    @Test
+    fun `on emission of successful status create a book and delete the download`() {
+      every { newBookDao.insert(any()) } returns Unit
+      every { newDownloadDao.delete(any()) } returns Unit
+      every { uriToFileConverter.convert(any()) } returns File("test")
+      val expectedStatus = DownloadStatus(
+          downloadId = 10L,
+          state = DownloadState.Successful
+      )
+      expectStatus(expectedStatus)
+      val element = expectedStatus.toBookOnDisk(uriToFileConverter)
+      verify {
+        newBookDao.insert(listOf(element))
+        newDownloadDao.delete(10L)
+      }
+    }
+
+    private fun expectStatus(expectedStatus: DownloadStatus) {
+      val downloadList = listOf(DownloadModel())
+      every { downloader.queryStatus(downloadList) } returns listOf(expectedStatus)
+      downloads.offer(downloadList)
+      testScheduler.triggerActions()
+      testScheduler.advanceTimeBy(1, SECONDS)
+      testScheduler.triggerActions()
+    }
+  }
+
+  @Nested
+  inner class Books {
+    @Test
+    fun `emissions from DB sorted by title and observed`() {
+      books.onNext(
+          listOf(
+              BookOnDisk().apply { book.title = "z" },
+              BookOnDisk().apply { book.title = "a" }
+          )
+      )
+      testScheduler.triggerActions()
+      viewModel.bookItems.test()
+          .assertValue(
+              listOf(
+                  BookOnDisk().apply { book.title = "a" },
+                  BookOnDisk().apply { book.title = "z" }
+              )
+          )
+          .dispose()
+    }
+  }
+
+  @Test
+  fun `network states observed`() {
+    networkStates.offer(NOT_CONNECTED)
+    viewModel.networkStates.test()
+        .assertValue(NOT_CONNECTED)
+        .dispose()
+  }
+}

app/src/test/resources/junit-platform.properties

@@ -0,0 +1 @@
+junit.jupiter.testinstance.lifecycle.default = per_class