How to inject a mocked ViewModel in a RoboElectric test using Koin - android

I'm pretty new in Android development and currently, I'm testing a basic activity with Roboelectric and Koin.
Code:
class SplashActivity : AppCompatActivity() {
private val viewModel: LoginViewModel by viewModel()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_splash)
Stetho.initializeWithDefaults(this)
val user = viewModel.getPersistedUser()
if (user != null) {
viewModel.setUser(user)
startActivity(HomeActivity.getStartIntent(this))
} else {
startActivity(LoginActivity.getStartIntent(this))
}
}
}
val appModule = module(override = true) {
...
viewModel<LoginViewModel>()
}
Now all I want to do in the test is to inject a mocked version of the viewModel to simulate the response of the method getPersistedUser.
How can I do that with Roboelectric and Koin?

First, if you want to write UI test for SplashActivity. Better to use Expresso testing framework (https://developer.android.com/training/testing/espresso)
Second, if you want to mock your viewmodel with Koin in your test, you can load your Koin modules then declare your viewmodel mock, code will be similar like this
class SplashActivityTest : AutoCloseKoinTest() {
private val viewModel: LoginViewModel by inject()
#Before
fun before() {
koinApplication {
loadModules(appModule)
}
declareMock<LoginViewModel> {
given(getPersistedUser()).willReturn { User(username, password) }
}
}
#Test
fun loadCurrentUserWhenActivityInit() {
// verify your test here
}
}
More details here https://start.insert-koin.io/#/getting-started/testing

Related

Jetpack Compose instrument test with #HiltViewModel

So I want to test my jetpack compose project. It's easy enough running an instrument test following [these instructions]1 on android dev site, but when you add #HiltViewModel injection into the combination things get complicated.
I'm trying to test a pretty simple compose screen with a ViewModel that has an #Inject constructor.
The screen itself looks like this:
#Composable
fun LandingScreen() {
val loginViewModel: LoginViewModel = viewModel()
MyTheme {
Surface(color = MaterialTheme.colors.background) {
val user by loginViewModel.user.observeAsState()
if (user != null) {
MainScreen()
} else {
LoginScreen(loginViewModel)
}
}
}
}
and this is the view model:
#HiltViewModel
class LoginViewModel #Inject constructor(private val userService: UserService) : ViewModel() {
val user = userService.loggedInUser.asLiveData()
}
User service is of course backed by a room database and the loggedInUser property returns a Flow.
Things work as expected on standard run but when trying to run it in an instrument test it can't inject the view model.
#HiltAndroidTest
class LandingScreenTest {
#get:Rule
var hiltRule = HiltAndroidRule(this)
#get:Rule
val composeTestRule = createComposeRule()
#Inject
lateinit var loginViewModel: LoginViewModel
#Before
fun init() {
hiltRule.inject()
}
#Test
fun MyTest() {
composeTestRule.setContent {
MyTheme {
LandingScreen()
}
}
composeTestRule.onNodeWithText("Welcome").assertIsDisplayed()
}
}
Injection of an #HiltViewModel class is prohibited since it does not
create a ViewModel instance correctly. Access the ViewModel via the
Android APIs (e.g. ViewModelProvider) instead. Injected ViewModel:
com.example.viewmodels.LoginViewModel
How do you make that work with the ViewModelProvider instead of the #HiltViewModel?
Hilt needs an entry point to inject fields. In this case that would probably be an Activity annotated with #AndroidEntryPoint. You can use your MainActivity for that, but that would mean that you would then have to add code to every test to navigate to the desired screen which could be tedious depending on the size of your app, and is not feasible if your project is multimodule and your current Test file does not have access to MainActivity. Instead, you could create a separate dummy Activity whose sole purpose is to host your composable (in this case LoginScreen) and annotate it with #AndroidEntryPoint. Make sure to put it into a debug directory so it's not shipped with the project. Then you can use createAndroidComposeRule<Activity>() to reference that composable. You dont need to inject the ViewModel directly so get rid of that line too.
In the end your Test File should look like this:
#HiltAndroidTest
class LandingScreenTest {
#get:Rule(order = 0)
val hiltRule = HiltAndroidRule(this)
#get:Rule(order = 1)
val composeRule = createAndroidComposeRule<LoginTestActivity>()
#Before
fun init() {
hiltRule.inject()
}
#Test
fun MyTest() {
composeTestRule.onNodeWithText("Welcome").assertIsDisplayed()
}
}
And your your dummy activity can look like this:
#AndroidEntryPoint
class LoginTestActivity : ComponentActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContent {
LoginScreen()
}
}
}
And the debug directory would look like this:debug directory with dummy activity
Yes the debug directory has its own manifest and that is where you should add the dummy activity. set exported to false.
Try to do something like this:
#HiltAndroidTest
class LandingScreenTest {
#get:Rule
var hiltRule = HiltAndroidRule(this)
#get:Rule
val composeTestRule = createComposeRule()
// Remove this line #Inject
lateinit var loginViewModel: LoginViewModel
#Before
fun init() {
hiltRule.inject()
}
#Test
fun MyTest() {
composeTestRule.setContent {
loginViewModel= hiltViewModel() // Add this line
MyTheme {
LandingScreen()
}
}
composeTestRule.onNodeWithText("Welcome").assertIsDisplayed()
}
}
You must annotate any UI test that uses Hilt with #HiltAndroidTest. This annotation is responsible for generating the Hilt components for each test.
https://developer.android.com/training/dependency-injection/hilt-testing

Is there away to mock ViewModel that is inside of a fragment

Is there a way to mock ViewModel that's built is inside of a fragment? I'm trying to run some tests on a fragment, one of the fragment functions interacts with the ViewModel, I would like to run the test function and provided a mocked result for the ViewModel. Is this even possilbe?
MyFragment
class MyFragment : Fragment() {
#Inject
lateinit var viewModel: MyViewModel
override fun onCreate(savedInstanceState: Bundle?) {
(requireActivity().application as MyApplication).appComponent.inject(this)
super.onCreate(savedInstanceState)
}
}
Test
#RunWith(RoboeltricTestRunner::) {
#Before
fun setup() {
FragmentScenario.Companion.launchIncontainer(MyFragment::class.java)
}
}
Yeah, just mark your ViewModel open and then you can create a mock implementation on top of it.
open class MyViewModel: ViewModel() {
fun myMethodINeedToMock() {
}
}
class MockMyViewModel: MyViewModel() {
override fun myMethodINeedToMock() {
// don't call super.myMethodINeedToMock()
}
}
So, register your MockMyViewModel to the DI framework when testing.
I thought I would post this for anyone else struggling to find a solution. You'll want to use a Fragment Factory, that has a dependency on the ViewModel. Injecting the ViewModel into the fragments constructor allows the ViewModel to easliy be mocked. There are a few steps that need to be completed for a FragmentFactory but it's not that complicated once you do a couple of them.
Fragment Add the ViewModel into the constructor.
class MyFragment(private val viewModel: ViewModel) : Fragment {
...
}
FragmentFactory, allows fragments to have dependencies in the constructor.
class MyFragmentFactory(private val viewModel: MyViewModel) : FragmentFactory() {
override fun instantiate(classLoader: ClassLoader, className: String): Fragment {
return when(className) {
MyFirstFragment::class.java.name -> {
MyFragment(viewModel)
}
// You could use this factory for multiple Fragments.
MySecondFragment::class.java.name -> {
MySecondFragment(viewModel)
}
// You also don't have to pass the dependency
MyThirdFragment::class.java.name -> {
MyThirdFragment()
}
else -> super.instantiate(classLoader, className)
}
}
}
Main Activity
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
// Create your ViewModel
val viewModel = ViewModelProvider(this).get(MainViewModel::class.java)
// create the FragmentFactory and the viewModel dependency.
supportFragmentManager.fragmentFactory = MainFragmentFactory(viewModel)
// FragmentFactory needs to be created before super in an activity.
super.onCreate(savedInstanceState)
}
}
Test
#RunWith(RobolectricTestRunner::class)
class MyFragmentUnitTest {
#Before
fun setup() {
val viewModel: MainViewModel = mock(MyViewModel::class.java)
...
}
}

Android Test Koin NoBeanDefFoundException

I'm trying to do some Android Tests with Koin and so far, it is not a success.
I want to test a basic Activity with a ViewModel, injected by Koin.
I already read posts like NoBeanDefFoundException with Mock ViewModel, testing with Koin, Espresso but so far I still have the error.
Here is the code relative to the tests configuration
A specific app that start with no module.
class MyTestApplication : Application() {
override fun onCreate() {
super.onCreate()
startKoin { emptyList<Module>() }
}
}
A specific runner that uses the test app
class OccazioTestRunner : AndroidJUnitRunner() {
override fun newApplication(
cl: ClassLoader?,
className: String?,
context: Context?
): Application {
return super.newApplication(cl, MyTestApplication::class.java.name, context)
}
}
That is defined in my app build.gradle to be used as runner
android {
defaultConfig {
testInstrumentationRunner "fr.dsquad.occazio.occazio.OccazioTestRunner"
}
}
And now the code I want to test
In my MyActivity
class MyActivity : AppCompatActivity(R.layout.activity_my) {
private val myViewModel by viewModel<MyViewModel>()
// Some code
}
And the viewmodel
class MyViewModel(private val useCase: MyUseCase): ViewModel() {
// Some code
}
And finally, the test itself (in androidTest)
#LargeTest
class MyActivityTest : KoinTest {
private lateinit var mockUseCase: MyUseCase
#JvmField
#Rule
val activityRule = activityScenarioRule<MyActivity>()
#Before
fun setup() {
mockUseCase = mock(MyUseCase::class.java)
startKoin {
modules(module { viewModel { MyViewModel(mockUseCase) } })
}
// I've also tried this
loadKoinModules(
module { viewModel { MyViewModel(mockUseCase) } }
)
}
#After
fun cleanUp() {
stopKoin()
}
#Test
fun someTest() = runBlocking {
// Mock the usecase response
`when`(mockUseCase.doSomething()).thenReturn("taratata")
// Start the scenario
val scenario = activityRule.scenario
// Verify we call the getUserId
// Activity is supposed to call the view model that will call the method doSomethingAdterThat.
verify(mockUseCase, times(1)).doSomethingAfterThat()
return#runBlocking
}
}
And so far, everytime I run this code I have this error
org.koin.core.error.NoBeanDefFoundException:
No definition found for 'mypackage.MyViewModel' has been found. Check your module definitions.
What is interesting is that, when
I change the rule activityScenarioRule by the old deprecated ActivityTestRule(SplashScreenActivity::class.java, true, false)
I change val scenario = activityRule.scenario by val scenario = activityRule.launchActivity(null)
I use loadKoinModules and not startKoin in setUp
Two things happen
When my test is started alone (via Android Studio): it passes.
When my test is started with other tests (by the class or with connectedAndroidTest), only one of them passes and old the others are KO.
So I have two questions in fact here.
How can I make this test work with activityScenarioRule ?
How can I make them "all" work (and not start them one by one to make them work) ?
Ok, don't ask me how it works but I figured it out.
First of all, as I needed config I followed this https://medium.com/stepstone-tech/better-tests-with-androidxs-activityscenario-in-kotlin-part-1-6a6376b713ea .
I've done 3 things
First, I needed to configure koin before startup, to do that, I needed to use ActivityScenario.launch() with an intent that I defined earlier
private val intent = Intent(ApplicationProvider.getApplicationContext(), MyActivity::class.java)
var activityRule : ActivityScenario<MyActivity>? = null
// And then I can start my activity calling
activityRule = ActivityScenario.launch(intent)
Then "KoinApp was not started"... I just replaced the loadKoinModules block with the startKoin one in setUp
startKoin { modules(module { viewModel { MyViewModel(mockUseCase) } }) }
Finally, it worked for 1 test, but the others were failing because "KoinAppAlreadyStartedException" like the stopKoin() was not called. So I found out that I should extend AutoCloseKoinTest instead of KoinTest.. But no success.
In the end, I've put a stopKoin() before the startKoin and now, everything works like a charm.
Here is my complete code that works
#LargeTest
class MyActivityTest : KoinTest() {
private val intent = Intent(ApplicationProvider.getApplicationContext(), MyActivity::class.java)
var activityRule : ActivityScenario<MyActivity>? = null
private lateinit var mockUseCase: MyUseCase
#Before
fun setup() {
mockUseCase = mock(MyUseCase::class.java)
stopKoin()
startKoin {
modules(module { viewModel { MyViewModel(mockUseCase) } })
}
}
#After
fun cleanUp() {
activityRule?.close()
}
#Test
fun someTest() = runBlocking {
// Mock the usecase response
`when`(mockUseCase.doSomething()).thenReturn("taratata")
// Start the rule
val activityRule = ActivityScenario.launch(intent)
// Verify we call the getUserId
// Activity is supposed to call the view model that will call the method doSomethingAdterThat.
verify(mockUseCase, times(1)).doSomethingAfterThat()
return#runBlocking
}
}
Ho, I've also added this code to my two Applications
override fun onTerminate() {
super.onTerminate()
stopKoin()
}
Just to be sure !

Koin Android: org.koin.error.NoBeanDefFoundException when Inject Repository

I make project with mvvm pattern with koin for DI, but i always have No definition found repository
I alredy define repository in module app before viewmodel, but i get some error
Gradle app
// Koin for Android
implementation "org.koin:koin-android:$rootProject.koin_version"
// Koin Android Scope features
implementation "org.koin:koin-androidx-scope:$rootProject.koin_version"
// Koin Android ViewModel features
implementation "org.koin:koin-androidx-viewmodel:$rootProject.koin_version"
module
val dataModule = module {
//remoteData
single { AppRemoteData() }
//repository
single{ AppRepository(get()) as AppDataSource}
// viewmodel
viewModel{ ListHomeViewModel(get()) }
viewModel { LoginViewModel(get()) }
define module
val myAppModule = listOf(appModule, dataModule)
in app
startKoin {
androidLogger(Level.DEBUG)
androidContext(this#MainApp)
modules(myAppModule)
}
Repository class
class AppRepository(val appRemoteDataSource: AppRemoteData) : AppDataSource {
override fun loginAccount(email: String, password: String) : LiveData<String> {
val data = MutableLiveData<String>()
appRemoteDataSource.loginAccount(email,password,object : AppDataSource.LoginCallback{
override fun onSucces(id: String?) {
//berhasil
data.postValue(id)
}
override fun onFailed(message: String?) {
data.postValue(message)
d(message)
}
override fun onFailure(message: String?) {
data.postValue(message)
d(message)
}
})
return data
}
AppRemoteData
class AppRemoteData {
val ref = FirebaseDatabase.getInstance().getReference("user")
var auth = FirebaseAuth.getInstance()
fun loginAccount(email: String, password: String, callback: AppDataSource.LoginCallback) {
auth.signInWithEmailAndPassword(email, password)
.addOnCompleteListener {
task ->
if(task.isComplete){
callback.onSucces(task.result?.user?.providerId)
}else{
callback.onFailed(task.exception?.localizedMessage)
}
}
}}
here error message
if in your ViewModel has an interface as parameter.
class MyViewModel(val interfaceName: InterfaceName) : ViewModel()
In your module definition use singleBy<> Instead of Single().
singleBy<InterfaceName,InterfaceNameImplementation>()
Finally in for your ViewModel
viewModel { MyViewModel(get()) }
This worked for me in Koin 2.0
Hope it helps :)
The error message is telling you that Koin couldn't create a LoginViewModel instance for you, because it would've had to provide an instance of AppRepository during its creation, but you didn't tell it how to do that.
My guess is that you've accidentally used the AppRepository type in the LoginViewModel constructor directly, instead of using your AppDataSource that you've bound the repository instance to in your module.
So if you have something like this, that would require an AppRepository specifically:
class LoginViewModel(val dataSource: AppRepository) : ViewModel()
You should replace it with this, where you're only asking Koin for an AppDataSource, which you did configure it to be able to provide:
class LoginViewModel(val dataSource: AppDataSource) : ViewModel()

Callback not executed in Android unit test with injected mock object

I am new to unit testing in Android and have gone through several tutorials to get myself familiar with mockito and robolectric.
My app is using Dagger 2 to inject my EventService into my MainActivity. For my MainActivityUnitTest, I have set up a TestServicesModule to provide a mocked version of EventService so that I can use Robolectric to run unit tests against my MainActivity
I'm having an issue getting the ServiceCallback on my EventService.getAllEvents(callback: ServiceCallback) to execute in the unit test. I have verified in the #Setup of my MainActivityUnitTest class that the EventService is being injected as a mocked object. I have gone through several tutorials and blog posts and as far as I can tell, I am doing everything correctly. The refreshData() function in MainActivity is getting called successfully, and I can see that the call to eventsService.getAllEvents(callback) is being executed. But the doAnswer {} lambda function is never getting executed.
Here's my relevant code:
AppComponent.kt
#Singleton
#Component(modules = [
AppModule::class,
ServicesModule::class,
FirebaseModule::class
])
interface AppComponent {
fun inject(target: MainActivity)
}
ServicesModule.kt
#Module
open class ServicesModule {
#Provides
#Singleton
open fun provideEventService(db: FirebaseFirestore): EventsService {
return EventsServiceImpl(db)
}
}
EventsService.kt
interface EventsService {
fun getAllEvents(callback: ServiceCallback<List<Event>>)
fun getEvent(id: String, callback: ServiceCallback<Event?>)
}
MainActivity.kt
class MainActivity : AppCompatActivity() {
#Inject lateinit var eventsService: EventsService
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
(application as App).appComponent.inject(this)
...
}
override fun onStart() {
super.onStart()
refreshData()
}
eventsService.getAllEvents(object: ServiceCallback<List<Event>> {
override fun onCompletion(result: List<Event>) {
viewModel.allEvents.value = result
loading_progress.hide()
}
})
}
Now we get into the tests:
TestAppComponent.kt
#Singleton
#Component(modules = [
TestServicesModule::class
])
interface TestAppComponent : AppComponent {
fun inject(target: MainActivityUnitTest)
}
TestServicesModule.kt
#Module
class TestServicesModule {
#Provides
#Singleton
fun provideEventsService(): EventsService {
return mock()
}
}
MainActivityUnitTest.kt
#RunWith(RobolectricTestRunner::class)
#Config(application = TestApp::class)
class MainActivityUnitTest {
#Inject lateinit var eventsService: EventsService
#Before
fun setup() {
val testComponent = DaggerTestAppComponent.builder().build()
testComponent.inject(this)
}
#Test
fun givenActivityStarted_whenLoadFailed_shouldDisplayNoEventsMessage() {
val events = ArrayList<Event>()
doAnswer {
//this block is never hit during debug
val callback: ServiceCallback<List<Event>> = it.getArgument(0)
callback.onCompletion(events)
}.whenever(eventsService).getAllEvents(any())
val activity = Robolectric.buildActivity(MainActivity::class.java).create().start().visible().get()
val noEventsView = activity.findViewById(R.id.no_events) as View
//this always evaluates to null because the callback is never set from the doAnswer lambda
assertThat(callback).isNotNull()
verify(callback)!!.onCompletion(events)
assertThat(noEventsView.visibility).isEqualTo(View.VISIBLE)
}
}
Edit: Adding App and TestApp
open class App : Application() {
private val TAG = this::class.qualifiedName
lateinit var appComponent: AppComponent
override fun onCreate() {
super.onCreate()
appComponent = initDagger(this)
}
open fun initDagger(app: App): AppComponent {
return DaggerAppComponent.builder().appModule(AppModule(app)).build()
}
}
class TestApp : App() {
override fun initDagger(app: App): AppComponent {
return DaggerTestAppComponent.builder().build()
}
}
It looks like you're using a different component to inject your test and activity. As they're different components I suspect you are using 2 different instances of the eventsService.
Your test uses a local DaggerTestAppComponent.
#Inject lateinit var eventsService: EventsService
#Before
fun setup() {
val testComponent = DaggerTestAppComponent.builder().build()
testComponent.inject(this)
}
While your Activity uses the appComponent from the application.
class MainActivity : AppCompatActivity() {
#Inject lateinit var eventsService: EventsService
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
(application as App).appComponent.inject(this)
...
}
To overcome this you may consider adding a test version of your application class, this would allow you to replace the AppComponent in your application with your TestAppComponent. Robolectric should allow you to create a test application as follows: http://robolectric.org/custom-test-runner/

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