Added Unit testing with Mockito

KotlinMVVM/app/build.gradle

@@ -33,9 +33,14 @@ dependencies {
     implementation "androidx.constraintlayout:constraintlayout:$constraintLayoutVersion"
     implementation "androidx.recyclerview:recyclerview:$recyclerViewVersion"
     implementation "androidx.cardview:cardview:$cardViewVersion"
+
     testImplementation "junit:junit:$junitVersion"
+    testImplementation "org.mockito:mockito-core:$mockitoVersion"
+    testImplementation "android.arch.core:core-testing:$archTestingVersion"
+
     androidTestImplementation "androidx.test:runner:$runnerVersion"
     androidTestImplementation "androidx.test.espresso:espresso-core:$espressoVersion"
+    androidTestImplementation "org.mockito:mockito-core:$mockitoVersion"
 
     implementation "androidx.lifecycle:lifecycle-extensions:$archLifecycleVersion"
     kapt "androidx.lifecycle:lifecycle-compiler:$archLifecycleVersion"
@@ -44,6 +49,5 @@ dependencies {
     implementation "com.google.code.gson:gson:$rootProject.gsonVersion"
     implementation "com.squareup.retrofit2:converter-gson:$rootProject.gson"
     implementation "com.squareup.okhttp3:logging-interceptor:$rootProject.okhttp3"
-
-    implementation 'com.github.bumptech.glide:glide:4.9.0'
+    implementation "com.github.bumptech.glide:glide:$rootProject.glideVersion"
 }

KotlinMVVM/app/src/main/java/com/emedinaa/kotlinmvvm/data/Entity.kt

@@ -2,4 +2,6 @@ package com.emedinaa.kotlinmvvm.data
 
 import com.emedinaa.kotlinmvvm.model.Museum
 
-data class MuseumResponse(val status:Int?,val msg:String?,val data:List<Museum>?)
+data class MuseumResponse(val status:Int?,val msg:String?,val data:List<Museum>?){
+    fun isSuccess():Boolean= (status==200)
+}

KotlinMVVM/app/src/main/java/com/emedinaa/kotlinmvvm/data/OperationCallback.kt

@@ -1,7 +1,6 @@
 package com.emedinaa.kotlinmvvm.data
 
 interface OperationCallback {
-
     fun onSuccess(obj:Any?)
     fun onError(obj:Any?)
 }

KotlinMVVM/app/src/main/java/com/emedinaa/kotlinmvvm/di/Injection.kt

@@ -5,7 +5,8 @@ import com.emedinaa.kotlinmvvm.model.MuseumRepository
 
 object Injection {
 
+    //MuseumRepository could be a singleton
     fun providerRepository():MuseumDataSource{
-        return MuseumRepository()//could be a singleton
+        return MuseumRepository()
     }
 }

KotlinMVVM/app/src/main/java/com/emedinaa/kotlinmvvm/model/MuseumDataSource.kt

@@ -5,6 +5,5 @@ import com.emedinaa.kotlinmvvm.data.OperationCallback
 interface MuseumDataSource {
 
     fun retrieveMuseums(callback: OperationCallback)
-
     fun cancel()
 }

KotlinMVVM/app/src/main/java/com/emedinaa/kotlinmvvm/model/MuseumRepository.kt

@@ -8,6 +8,8 @@ import retrofit2.Call
 import retrofit2.Callback
 import retrofit2.Response
 
+const val TAG="CONSOLE"
+
 class MuseumRepository:MuseumDataSource {
 
     private var call:Call<MuseumResponse>?=null
@@ -21,8 +23,8 @@ class MuseumRepository:MuseumDataSource {
 
             override fun onResponse(call: Call<MuseumResponse>, response: Response<MuseumResponse>) {
                 response?.body()?.let {
-                    if(response.isSuccessful && (it.status==200)){ //200
-                        Log.v("CONSOLE", "data ${it.data}")
+                    if(response.isSuccessful && (it.isSuccess())){
+                        Log.v(TAG, "data ${it.data}")
                         callback.onSuccess(it.data)
                     }else{
                         callback.onError(it.msg)

KotlinMVVM/app/src/main/java/com/emedinaa/kotlinmvvm/view/MuseumActivity.kt

@@ -24,36 +24,44 @@ class MuseumActivity : AppCompatActivity() {
         const val TAG= "CONSOLE"
     }
 
+    /**
+     //Consider this, if you need to call the service once when activity was created.
+        Log.v(TAG,"savedInstanceState $savedInstanceState")
+        if(savedInstanceState==null){
+            viewModel.loadMuseums()
+        }
+     */
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_museum)
 
-        //viewmodel
-        setUpViewModel()
+        setupViewModel()
+        setupUI()
+    }
 
-        //ui
+    //ui
+    private fun setupUI(){
         adapter= MuseumAdapter(viewModel.museums.value?: emptyList())
         recyclerView.layoutManager= LinearLayoutManager(this)
         recyclerView.adapter= adapter
-
-        Log.v(TAG,"savedInstanceState $savedInstanceState")
-
-        //Consider this, if you need to call the service once when activity was created.
-        /*if(savedInstanceState==null){
-            viewModel.loadMuseums()
-        }*/
     }
 
-    private fun setUpViewModel(){
-        //viewModel = ViewModelProviders.of(this).get(MuseumViewModel::class.java)
+    //viewmodel
+    /**
+        //Consider this if ViewModel class don't require parameters.
+        viewModel = ViewModelProviders.of(this).get(MuseumViewModel::class.java)
 
         //if you require any parameters to  the ViewModel consider use a ViewModel Factory
         viewModel = ViewModelProviders.of(this,ViewModelFactory(Injection.providerRepository())).get(MuseumViewModel::class.java)
-        /*viewModel.museums.observe(this,
-            Observer<List<Museum>> {
-                Log.v("CONSOLE", "data updated $it")
-                adapter.update(it)
-            })*/
+
+        //Anonymous observer implementation
+        viewModel.museums.observe(this,Observer<List<Museum>> {
+            Log.v("CONSOLE", "data updated $it")
+            adapter.update(it)
+        })
+     */
+    private fun setupViewModel(){
+        viewModel = ViewModelProviders.of(this,ViewModelFactory(Injection.providerRepository())).get(MuseumViewModel::class.java)
         viewModel.museums.observe(this,renderMuseums)
 
         viewModel.isViewLoading.observe(this,isViewLoadingObserver)
@@ -88,11 +96,11 @@ class MuseumActivity : AppCompatActivity() {
         layoutError.visibility=View.GONE
     }
 
-    /**
-     * If you require updated data, you can call the method "loadMuseum" here
-     */
-    override fun onResume() {
+
+     //If you require updated data, you can call the method "loadMuseum" here
+     override fun onResume() {
         super.onResume()
-        //viewModel.loadMuseums()
-    }
+        viewModel.loadMuseums()
+     }
+
 }

KotlinMVVM/app/src/main/java/com/emedinaa/kotlinmvvm/viewmodel/MuseumViewModel.kt

@@ -26,7 +26,7 @@ class MuseumViewModel(private val repository: MuseumDataSource):ViewModel() {
     "loadMuseums()" on constructor. Also, if you rotate the screen, the service will not be called.
      */
     init {
-        loadMuseums()
+        //loadMuseums()
     }
 
     fun loadMuseums(){
@@ -40,7 +40,7 @@ class MuseumViewModel(private val repository: MuseumDataSource):ViewModel() {
             override fun onSuccess(obj: Any?) {
                 _isViewLoading.postValue(false)
 
-                if(obj is List<*>){
+                if(obj!=null && obj is List<*>){
                     if(obj.isEmpty()){
                         _isEmptyList.postValue(true)
                     }else{

KotlinMVVM/app/src/test/java/com/emedinaa/kotlinmvvm/MVVMUnitTest.kt

@@ -0,0 +1,124 @@
+package com.emedinaa.kotlinmvvm
+
+import android.app.Application
+import android.content.Context
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import androidx.lifecycle.Observer
+import com.emedinaa.kotlinmvvm.data.OperationCallback
+import com.emedinaa.kotlinmvvm.model.Museum
+import com.emedinaa.kotlinmvvm.model.MuseumDataSource
+import com.emedinaa.kotlinmvvm.viewmodel.MuseumViewModel
+import org.junit.Assert
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.mockito.ArgumentCaptor
+import org.mockito.Captor
+import org.mockito.Mock
+import org.mockito.*
+import org.mockito.Mockito.*
+
+class MVVMUnitTest {
+
+    @Mock
+    private lateinit var repository: MuseumDataSource
+    @Mock private lateinit var context: Application
+
+    @Captor
+    private lateinit var operationCallbackCaptor: ArgumentCaptor<OperationCallback>
+
+    private lateinit var viewModel:MuseumViewModel
+
+    private lateinit var isViewLoadingObserver:Observer<Boolean>
+    private lateinit var onMessageErrorObserver:Observer<Any>
+    private lateinit var emptyListObserver:Observer<Boolean>
+    private lateinit var onRenderMuseumsObserver:Observer<List<Museum>>
+
+    private lateinit var museumEmptyList:List<Museum>
+    private lateinit var museumList:List<Museum>
+
+    /**
+     //https://jeroenmols.com/blog/2019/01/17/livedatajunit5/
+     //Method getMainLooper in android.os.Looper not mocked
+
+     java.lang.IllegalStateException: operationCallbackCaptor.capture() must not be null
+     */
+    @get:Rule
+    val rule = InstantTaskExecutorRule()
+
+    @Before
+    fun setup() {
+        MockitoAnnotations.initMocks(this)
+        `when`<Context>(context.applicationContext).thenReturn(context)
+
+        viewModel= MuseumViewModel(repository)
+
+        mockData()
+        setupObservers()
+    }
+
+    @Test
+    fun museumEmptyListRepositoryAndViewModel(){
+        with(viewModel){
+            loadMuseums()
+            isViewLoading.observeForever(isViewLoadingObserver)
+            //onMessageError.observeForever(onMessageErrorObserver)
+            isEmptyList.observeForever(emptyListObserver)
+            museums.observeForever(onRenderMuseumsObserver)
+        }
+
+        verify(repository, times(1)).retrieveMuseums(capture(operationCallbackCaptor))
+        operationCallbackCaptor.value.onSuccess(museumEmptyList)
+
+        Assert.assertNotNull(viewModel.isViewLoading.value)
+        //Assert.assertNotNull(viewModel.onMessageError.value) //java.lang.AssertionError
+        //Assert.assertNotNull(viewModel.isEmptyList.value)
+        Assert.assertTrue(viewModel.isEmptyList.value==true)
+        Assert.assertTrue(viewModel.museums.value?.size==0)
+    }
+
+    @Test
+    fun museumListRepositoryAndViewModel(){
+        with(viewModel){
+            loadMuseums()
+            isViewLoading.observeForever(isViewLoadingObserver)
+            museums.observeForever(onRenderMuseumsObserver)
+        }
+
+        verify(repository, times(1)).retrieveMuseums(capture(operationCallbackCaptor))
+        operationCallbackCaptor.value.onSuccess(museumList)
+
+        Assert.assertNotNull(viewModel.isViewLoading.value)
+        Assert.assertTrue(viewModel.museums.value?.size==3)
+    }
+
+    @Test
+    fun museumFailRepositoryAndViewModel(){
+        with(viewModel){
+            loadMuseums()
+            isViewLoading.observeForever(isViewLoadingObserver)
+            onMessageError.observeForever(onMessageErrorObserver)
+        }
+        verify(repository, times(1)).retrieveMuseums(capture(operationCallbackCaptor))
+        operationCallbackCaptor.value.onError("Ocurrió un error")
+        Assert.assertNotNull(viewModel.isViewLoading.value)
+        Assert.assertNotNull(viewModel.onMessageError.value)
+    }
+
+    private fun setupObservers(){
+        isViewLoadingObserver= mock(Observer::class.java) as Observer<Boolean>
+        onMessageErrorObserver= mock(Observer::class.java) as Observer<Any>
+        emptyListObserver= mock(Observer::class.java) as Observer<Boolean>
+        onRenderMuseumsObserver= mock(Observer::class.java)as Observer<List<Museum>>
+    }
+
+    private fun mockData(){
+        museumEmptyList= emptyList()
+        val mockList:MutableList<Museum>  = mutableListOf()
+        mockList.add(Museum(0,"Museo Nacional de Arqueología, Antropología e Historia del Perú",""))
+        mockList.add(Museum(1,"Museo de Sitio Pachacamac",""))
+        mockList.add(Museum(2,"Casa Museo José Carlos Mariátegui",""))
+
+        museumList= mockList.toList()
+    }
+}

KotlinMVVM/app/src/test/java/com/emedinaa/kotlinmvvm/MockitoKotlinHelper.kt

@@ -0,0 +1,9 @@
+package com.emedinaa.kotlinmvvm
+
+import org.mockito.ArgumentCaptor
+
+/**
+ * Returns ArgumentCaptor.capture() as nullable type to avoid java.lang.IllegalStateException
+ * when null is returned.
+ */
+fun <T> capture(argumentCaptor: ArgumentCaptor<T>): T = argumentCaptor.capture()

KotlinMVVM/build.gradle

@@ -45,9 +45,12 @@ ext {
     rulesVersion = '1.0.1'
     espressoVersion = '3.1.1'
     junitVersion = '4.12'
+    mockitoVersion= '2.27.0' //https://site.mockito.org/
+    archTestingVersion = '1.1.1'
 
     gsonVersion='2.8.0'
     retrofit2='2.3.0'
     gson='2.3.0'
     okhttp3='3.4.1'
+    glideVersion='4.9.0'
 }