Starter code 2

app/build.gradle

@@ -21,10 +21,20 @@ android {
         }
     }
 
+    testOptions.unitTests {
+        includeAndroidResources = true
+    }
+
     dataBinding {
         enabled = true
         enabledForTests = true
     }
+    android {
+        compileOptions {
+            sourceCompatibility JavaVersion.VERSION_1_8
+            targetCompatibility JavaVersion.VERSION_1_8
+        }
+    }
 }
 
 dependencies {
@@ -41,6 +51,7 @@ dependencies {
 
     // Architecture Components
     implementation "androidx.room:room-runtime:$roomVersion"
+    implementation 'androidx.test:core-ktx:1.4.0'
     kapt "androidx.room:room-compiler:$roomVersion"
     implementation "androidx.room:room-ktx:$roomVersion"
     implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$archLifecycleVersion"
@@ -58,7 +69,19 @@ dependencies {
     androidTestImplementation "androidx.test.ext:junit:$androidXTestExtKotlinRunnerVersion"
     androidTestImplementation "androidx.test.espresso:espresso-core:$espressoVersion"
 
+    // AndroidX Test - JVM testing
+    testImplementation "androidx.test.ext:junit-ktx:$androidXTestExtKotlinRunnerVersion"
+    testImplementation "androidx.test:core-ktx:$androidXTestCoreVersion"
+    testImplementation "org.robolectric:robolectric:$robolectricVersion"
+
+    testImplementation "androidx.arch.core:core-testing:$archTestingVersion"
+
+
     // Kotlin
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlinVersion"
     implementation "androidx.fragment:fragment-ktx:$fragmentKtxVersion"
+
+    //other
+    testImplementation "org.hamcrest:hamcrest-all:$hamcrestVersion"
+
 }

app/src/main/java/com/example/android/architecture/blueprints/todoapp/statistics/StatisticsUtils.kt

@@ -22,12 +22,17 @@ import com.example.android.architecture.blueprints.todoapp.data.Task
  * Function that does some trivial computation. Used to showcase unit tests.
  */
 internal fun getActiveAndCompletedStats(tasks: List<Task>?): StatsResult {
-    val totalTasks = tasks!!.size
-    val numberOfActiveTasks = tasks.count { it.isActive }
-    return StatsResult(
-        activeTasksPercent = 100f * numberOfActiveTasks / tasks.size,
-        completedTasksPercent = 100f * (totalTasks - numberOfActiveTasks) / tasks.size
-    )
+    return if (tasks.isNullOrEmpty()){
+        StatsResult(0f,0f)
+    }else{
+        val totalTasks = tasks.size
+        val numberOfActiveTasks = tasks.count { it.isActive }
+        StatsResult(
+            activeTasksPercent = 100f * numberOfActiveTasks / tasks.size,
+            completedTasksPercent = 100f * (totalTasks - numberOfActiveTasks) / tasks.size
+        )
+    }
+
 }
 
 data class StatsResult(val activeTasksPercent: Float, val completedTasksPercent: Float)

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

@@ -9,9 +9,15 @@ import org.junit.Assert.*
  *
  * See [testing documentation](http://d.android.com/tools/testing).
  */
+
 class ExampleUnitTest {
     @Test
     fun addition_isCorrect() {
         assertEquals(4, 2 + 2)
     }
+
+    @Test
+    fun multi_isCorrect(){
+        assertEquals(6,2*3)
+    }
 }

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

@@ -0,0 +1,42 @@
+package com.example.android.architecture.blueprints.todoapp
+
+import androidx.annotation.VisibleForTesting
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.Observer
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.TimeUnit
+import java.util.concurrent.TimeoutException
+
+
+@VisibleForTesting(otherwise = VisibleForTesting.NONE)
+fun <T> LiveData<T>.getOrAwaitValue(
+    time: Long = 2,
+    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()
+            [email protected](this)
+        }
+    }
+    this.observeForever(observer)
+
+    try {
+        afterObserve.invoke()
+
+        // Don't wait indefinitely if the LiveData is not set.
+        if (!latch.await(time, timeUnit)) {
+            throw TimeoutException("LiveData value was never set.")
+        }
+
+    } finally {
+        this.removeObserver(observer)
+    }
+
+    @Suppress("UNCHECKED_CAST")
+    return data as T
+}

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

@@ -0,0 +1,81 @@
+package com.example.android.architecture.blueprints.todoapp.statistics
+
+import com.example.android.architecture.blueprints.todoapp.data.Task
+import org.junit.Assert.*
+import org.junit.Test
+
+class StatisticsUtilsTest{
+    @Test
+    fun getActiveAndCompletedStats_empty_returnZeros(){
+        // create active tasks
+
+        //call your function
+        val result= getActiveAndCompletedStats(emptyList())
+
+        //check the result
+        assertEquals(result.activeTasksPercent,0f)
+        assertEquals(result.completedTasksPercent,0f)
+    }
+
+    @Test
+    fun getActiveAndCompletedStats_null_returnZeros(){
+        // create active tasks
+
+        //call your function
+        val result= getActiveAndCompletedStats(null)
+
+        //check the result
+        assertEquals(result.activeTasksPercent,0f)
+        assertEquals(result.completedTasksPercent,0f)
+    }
+
+    @Test
+    fun getActiveAndCompletedStats_both_returnFiftyFifty(){
+        // create active tasks
+        val tasks= listOf<Task>(
+            Task("title","description",true),
+            Task("title2","description2",false)
+        )
+
+        //call your function
+        val result= getActiveAndCompletedStats(tasks)
+
+        //check the result
+        assertEquals(result.activeTasksPercent,50f)
+        assertEquals(result.completedTasksPercent,50f)
+    }
+
+    @Test
+    fun getActiveAndCompletedStats_noComplete_returnZeroHundred(){
+        // create active tasks
+        val tasks= listOf<Task>(
+            Task("title","description",true),
+            Task("title2","description2",true)
+        )
+
+        //call your function
+        val result= getActiveAndCompletedStats(tasks)
+
+        //check the result
+        assertEquals(result.activeTasksPercent,0f)
+        assertEquals(result.completedTasksPercent,100f)
+    }
+
+    @Test
+    fun getActiveAndCompletedStats_noActive_returnHundredZero(){
+        // create active tasks
+        val tasks= listOf<Task>(
+            Task("title","description",false),
+            Task("title2","description2",false)
+        )
+
+        //call your function
+        val result= getActiveAndCompletedStats(tasks)
+
+        //check the result
+        assertEquals(result.activeTasksPercent,100f)
+        assertEquals(result.completedTasksPercent,0f)
+    }
+
+}
+

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

@@ -0,0 +1,48 @@
+package com.example.android.architecture.blueprints.todoapp.tasks
+
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.example.android.architecture.blueprints.todoapp.getOrAwaitValue
+import org.junit.Assert.*
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class TasksViewModelTest{
+    // subject under test
+    private lateinit var taskViewModel: TasksViewModel
+
+    @get:Rule
+    var instantExecutorRule = InstantTaskExecutorRule()
+
+    @Before
+    fun setUpViewModel(){
+        // Given a fresh ViewModel
+         taskViewModel = TasksViewModel(ApplicationProvider.getApplicationContext())
+    }
+
+    @Test
+    fun addNewTask_setsNewTaskEvent(){
+
+        //When adding a new task
+        taskViewModel.addNewTask()
+
+        //then the new task event is triggered
+        val value= taskViewModel.newTaskEvent.getOrAwaitValue()
+        assertNotNull(value.getContentIfNotHandled())
+    }
+
+    @Test
+    fun setFilterAllTasks_tasksAddViewVisible() {
+
+        // When the filter type is ALL_TASKS
+        taskViewModel.setFiltering(TasksFilterType.ALL_TASKS)
+
+        // Then the "Add task" action is visible
+        assertEquals(taskViewModel.tasksAddViewVisible.getOrAwaitValue(),true)
+
+    }
+}

build.gradle

@@ -6,7 +6,7 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:4.2.1'
+        classpath 'com.android.tools.build:gradle:4.1.3'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlinVersion"
         classpath "androidx.navigation:navigation-safe-args-gradle-plugin:$navigationVersion"