Mockito does'nt mock repository - android

i'm try to test my ViewModel with mockito.
This is my TestClass:
#RunWith(JUnit4::class)
class RatesViewModelTest {
#Rule #JvmField
open val instantExecutorRule = InstantTaskExecutorRule()
#Mock
var observer: Observer<Pair<ArrayList<CurrencyExchangerModel>,Boolean>>? = null
#Mock
private lateinit var repository: RatesRepository
private var currencyList = ArrayList<CurrencyModel>()
private lateinit var viewModel : RatesViewModel
#Before
fun setUp(){
MockitoAnnotations.initMocks(this)
currencyList.add(CurrencyModel("BASE"))
viewModel = RatesViewModel(repository!!)
viewModel.getCurrencyExchangerObservableList().observeForever(observer!!)
}
#Test
fun testNull(){
Mockito.`when`(repository.getFlowableRates()).thenReturn( Flowable.just(currencyList) )
assertTrue(viewModel.getCurrencyExchangerObservableList().hasObservers())
}
}
When this method is invoked:
Mockito.`when`(repository.getFlowableRates()).thenReturn( Flowable.just(currencyList) )
I got this error:
kotlin.UninitializedPropertyAccessException: lateinit property db has
not been initialized
Here the repository:
open class RatesRepository(context:Context) : BaseRepository(context){
#Inject
lateinit var ratesAPI: RatesAPI
#Inject
lateinit var db: Database
/**
* load the updated chatList from API
*/
fun loadCurrencyRatesFromAPI(): Single<ArrayList<CurrencyModel>> {
val supportedCurrency = context.resources.getStringArray(R.array.currencies)
return ratesAPI.getLatestRates(EUR_CURRENCY_ID).map { RatesConverter.getRatesListFromDTO(it,supportedCurrency) }
}
/**
* save rates on DB
*/
fun saveCurrencyRatesOnDB(list:ArrayList<CurrencyModel>): Completable {
return db.currencyRatesDAO().insertAll(list)
}
/**
* get flawable rates from DB
*/
fun getFlowableRates(): Flowable<List<CurrencyModel>> {
return db.currencyRatesDAO().getAll()
}
companion object {
const val EUR_CURRENCY_ID = "EUR" //BASE
}
}
What i'm doing wrong ?
Thx !

When you define behaviour of a mock and use the when(...).then(...) notation of mockito,
the method itself is invoked (by mockito, normally not relevant for your test).
In your case that is a problem because db is not initialized.
To avoid this issues use the doReturn(...).when(...) syntax in these cases,
which does not cause the method invocation.
Mockito.doReturn(Flowable.just(currencyList)).when(repository).getFlowableRates();
(You might need to adjust this java syntax to make it kotlin compatible)

Related

How to test getter, setter method of a LiveData Android?

I am using Hilt for DI in my project. I am trying write unit test cases for LiveData object, but it's not coming under coverage.
ViewModel
#HiltViewModel
class HealthDiagnosticsViewModel #Inject constructor(
private var networkHelper: NetworkHelper
) : ViewModel() {
var result = MutableLiveData<Int>()
.....
}
My unit test class is as below:
HealthViewModelTest
#HiltAndroidTest
#RunWith(RobolectricTestRunner::class)
#Config(application = HiltTestApplication::class)
class HealthDiagnosticsViewModelTest{
#get:Rule
var hiltRule = HiltAndroidRule(this)
#Inject
lateinit var networkHelper: NetworkHelper
lateinit var healthDiagnosticsViewModel: HealthDiagnosticsViewModel
#Before
fun setUp() {
hiltRule.inject()
healthDiagnosticsViewModel = HealthDiagnosticsViewModel(networkHelper)
}
#Test
fun testGetResult() {
val result = healthDiagnosticsViewModel.result.value
Assert.assertEquals(null, result)
}
#Test
fun testSetResult() {
healthDiagnosticsViewModel.result.value = 1
Assert.assertEquals(1, healthDiagnosticsViewModel.result.value)
}
}
Test Cases are passed but it's not coming under method coverage.
I'll share with you the an example of my code that would solve your problem.
I'm usnig ViewModel with Dagger Hilt
You don't have to use Robelectric, you can use MockK library.
Replace your HiltRule with this Rule:
#get:Rule
var rule: TestRule = InstantTaskExecutorRule()
This is my ViewModel class
using MockK, you can mock the networkHelper class without Hilt.
So, your setup method will be like that:
lateinit var networkHelper: NetworkHelper
......
......
......
#Before
fun setUp() {
networkHelper = mockk<NetworkHelper>()
healthDiagnosticsViewModel = HealthDiagnosticsViewModel(networkHelper)
}
4)The most important part in your test is to Observe to the LiveData first.
#Test
fun testGetResult() {
healthDiagnosticsViewModel.result.observeForever {}
val result = healthDiagnosticsViewModel.result.value
Assert.assertEquals(null, result)
}
You can observe to the livedata for each unit test, but keep in mind to Observe first before change data.

What is the best way to test a function in my viewModel?

I started to implement automated tests recently and I have a little doubt of how to test my ViewModel functions. My project follows some clean architecture concepts, I'm using lib kotlin for mockito (https://github.com/nhaarman/mockito-kotlin) and I would like to do the following test: When call makeLoginUser get success then set loginUserLiveData .
I have studied some concepts and I know the tests I should do, but I am still in doubt as to how to do them, which objects should I mock for a given test and which should be instantiated. I needed a small example to address me.
Here is my test class and some classes of the structure of my project.
TestClass
#RunWith(JUnit4::class)
class MainViewModelTest {
#get:Rule
var instantTaskExecutorRule = InstantTaskExecutorRule()
#Mock
private lateinit var myRepository: MyRepository
private lateinit var loginUserUseCase: LoginUserUseCase
private lateinit var checkUserAuthenticatedUsecase: CheckUserAuthenticatedUsecase
private lateinit var logoutUserUseCase: LogoutUserUseCase
private lateinit var mainViewModel: MainViewModel
#Before
fun setUp() {
MockitoAnnotations.initMocks(this)
}
#Test
fun `When call makeLoginUser get success then set loginUserLiveData`() {
// prepare
myRepository = mock { // should I mock or instantiate?
on { execLoginUser(ArgumentMatchers.anyString(), ArgumentMatchers.anyString()) } doReturn Flowable.just(true)
}
loginUserUseCase = mock { // should I mock or instantiate?
on { execute(ArgumentMatchers.anyMap()) } doReturn Flowable.just(true)
}
mainViewModel = MainViewModel(loginUserUseCase, checkUserAuthenticatedUsecase, logoutUserUseCase)
val observer = mock<Observer<ResultState<Boolean>>> { mock }
// Execute
mainViewModel.makeLoginUser("test#gmail.com", "123456")
// Check
// ?
}
}
ViewModel
// components 'LoginUserUseCase', 'CheckUserAuthenticatedUsecase' and 'LogoutUserUseCase' injected via koin
class MainViewModel(
private val loginUserUseCase: LoginUserUseCase,
private val checkUserAuthenticatedUsecase: CheckUserAuthenticatedUsecase,
private val logoutUserUsecase: LogoutUserUseCase
): BaseViewModel() {
val loginUserLiveData = MutableLiveData<ResultState<Boolean>>()
val userAuthenticatedLiveData = MutableLiveData<ResultState<Boolean>>()
val logoutUserLiveData = MutableLiveData<ResultState<Boolean>>()
fun makeLoginUser(email: String, password: String) {
loginUserLiveData.postValue(ResultState.Loading())
loginUserUseCase.execute(mapOf(EMAIL to email, PASSWORD to password))
.subscribe({
loginUserLiveData.postValue(ResultState.Success(it))
}, {
loginUserLiveData.postValue(ResultState.Error(it))
}).addTo(disposables)
}
...
}
UseCase Domain Class
// components 'ThreadExecutor' and 'PostExecutionThread' injected via koin
abstract class FlowableUseCase<T, in Params> constructor(
private val threadExecutor: ThreadExecutor,
private val postExecutionThread: PostExecutionThread) {
protected abstract fun buildUseCaseObservable(params: Params? = null): Flowable<T>
open fun execute(params: Params? = null): Flowable<T> {
return this.buildUseCaseObservable(params)
.subscribeOn(Schedulers.from(threadExecutor))
.observeOn(postExecutionThread.scheduler)
}
}
Abstraction UseCases
// components 'MyRepository', 'ThreadExecutor' and 'PostExecutionThread' injected via koin
// 'MyRepository' abstracts remote and local data repository
class LoginUserUseCase(
private val myRepository: MyRepository,
threadExecutor: ThreadExecutor,
postExecutionThread: PostExecutionThread
): FlowableUseCase<Boolean, Map<String, Any>?>(threadExecutor, postExecutionThread) {
override fun buildUseCaseObservable(params: Map<String, Any>?) = myRepository
.execLoginUser(
params?.get(EMAIL) as String,
params[PASSWORD] as String
)
}

How to unit test LiveData Transformations

I clearly don't understand how to unit test business logic inside Transformation. In my specific case I need to test Transformations.map, but I guess Transformations.switchmap would be the same.
The following is just an example of my scenario, and what I'd like to achieve.
MyViewModel.kt
class MyViewModel: ViewModel() {
private val _sampleLiveDataIwannaTest : MutableLiveData<Int> = MutableLiveData()
val sampleLiveDataIWannaTest: Livedata<Int> = _sampleLiveDataIWannaTest
// ...
val liveDataImNotInterestedIn = Transformations.map(myRepository.streamingData){
streaming->
_sampleLiveDataIwannaTest.postValue(streaming.firstElementValue +streaming.lastElementValue)
streaming
}
// ...
}
With:
val liveDataImNotInteresedIn : LiveData<Foo>
myRepository.streamingData : LiveData<Foo>
myRepository.streamingData is a data source that wakes up the Transformations.map which, in turn, starts the business logic I'm interested in (the value posted in _sampleLiveDataIwannaTest). In this particular test, I don't care about anything else.
MyViewModelTest.kt
class MyViewModelTest {
#get:Rule val rule = InstantTaskExecutorRule()
#RelaxedMockK
lateinit var myRepository : MyRepository
#OverrideMockKs
lateinit var sut: MyViewModel
#Before
fun setUp() {
MockKAnnotations.init(this, relaxUnitFun = true)
}
#Test
fun Transformations_Test(){
sut.liveDataImNotInterestedIn.observeForever{}
// 1)I really don't know how to mock the livedata that returns from
// myRepository.streamingData . Something like this is correct?
// every{myRepository.streamingData}.returns{< LiveData of type Int > }
// 2) I wish to write this kind of test:
//
// assertEquals(5, sampleLiveDataIWannaTest.value)
}
I'm using MockK instead of Mockito.
The unit test code will look like this:
class MyViewModelTest {
#get:Rule
val rule = InstantTaskExecutorRule()
#RelaxedMockK
lateinit var myRepository : MyRepository
#RelaxedMockK
lateinit var mockedSampleLiveDataIWannaTest : Observer<Int>
#OverrideMockKs
lateinit var sut: MyViewModel
#Before
fun setUp() {
MockKAnnotations.init(this, relaxUnitFun = true)
}
#Test
fun Transformations_Test(){
val expected = (*YOUR EXPECTED DATA HERE FROM REPOSITORY*)
every { myRepository.streamingData() } answers { expected }
sut.sampleLiveDataIWannaTest.observeForever(mockedSampleLiveDataIWannaTest)
verify { myRepository.streamingData() }
verify() { mockedSampleLiveDataIWannaTest.onChanged(Int) }
confirmVerified(myRepository, mockedSampleLiveDataIWannaTest)
}
if your repository is using coroutines then change every to coEvery and verify to coVerify
to learn more about MockK: https://mockk.io/

why mocked object function throws nulls instead of mocked data when using RobolectricTestRunner?

i have this test class running with MockitoJUnitRunner before and then i added RoboLectric, now i use RobolectricTestRunner
So the first thing it tryed is running my old tests but just changing the runner and the test now always fail. I do not really understand what is happening here, i am just trying to make my old test work with RobolectricTestRunner without stop using Mockito.
My Code before changing to RoboLectric (TEST PASS SUCCESSFULLY)
#RunWith(MockitoJUnitRunner::class)
class LauncherViewModelTest {
companion object {
#ClassRule
#JvmField
val schedulers = RxImmediateeSchedulerRule()
}
#Rule
#JvmField
val rule = InstantTaskExecutorRule()
#Mock
private lateinit var mockContext: MyApplication
#Mock
private lateinit var mockedDatabase: MyDatabase
#Mock
private lateinit var session: Session
//
#Mock
lateinit var mockedDatabaseRxWrapper: DatabaseRxWrapper
/** Evaluated class **/
#InjectMocks
lateinit var launcherViewModel: LauncherViewModel
#Test
fun checkIfHasSessionSuccess() {
val sessionFlowable: Flowable<Session> = Flowable.fromCallable { session }
FieldSetter.setField(launcherViewModel,
launcherViewModel.javaClass.getDeclaredField("databaseRxWrapper"), mockedDatabaseRxWrapper)
doReturn(sessionFlowable).`when`(mockedDatabaseRxWrapper).getSession()
launcherViewModel.checkIfHasSession()
//$hasSession is a mutable live data
Assert.assertEquals(true, launcherViewModel.hasSession.value)
}
}
My Code after changing to RoboLectric : (DatabaseRxWrapper.getSession() returns always null even when i use Mockito.doReturn().when())
#RunWith(RobolectricTestRunner::class)
class LauncherViewModelTest {
companion object {
#ClassRule
#JvmField
val schedulers = RxImmediateeSchedulerRule()
}
#Rule
#JvmField
val rule = InstantTaskExecutorRule()
#get:Rule
val mockitoRule = MockitoJUnit.rule()
#Mock
private lateinit var mockContext: MyApplication
#Mock
private lateinit var mockedDatabase: MyDatabase
#Mock
private lateinit var session: Session
//
#Mock
lateinit var mockedDatabaseRxWrapper: DatabaseRxWrapper
/** Evaluated class **/
#InjectMocks
lateinit var launcherViewModel: LauncherViewModel
#Test
fun checkIfHasSessionSuccess() {
val sessionFlowable: Flowable<Session> = Flowable.fromCallable { session }
FieldSetter.setField(launcherViewModel,
launcherViewModel.javaClass.getDeclaredField("databaseRxWrapper"), mockedDatabaseRxWrapper)
doReturn(sessionFlowable).`when`(mockedDatabaseRxWrapper).getSession()
launcherViewModel.checkIfHasSession()
//$hasSession is a mutable live data
Assert.assertEquals(true, launcherViewModel.hasSession.value)
}
}
Class under Test
class LauncherViewModel(application: Application) : AndroidViewModel(application) {
#Inject
lateinit var databaseRxWrapper: DatabaseRxWrapper
val hasSession: MutableLiveData<Boolean> = MutableLiveData()
val application by lazy { getApplication<MyApplication>() }
init {
application.getAppComponent()?.inject(this)
}
fun saveLocation(location: Location) = sharedPreferenceManager.saveLocation(location)
fun checkIfHasSession() {
databaseRxWrapper.getSession()
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe({
hasSession.postValue(true)
}, {
hasSession.postValue(false)
})
}
}
I found that you don't need the rule for rewriting the configuration of RX if you are running with Robolectric
So the code worked after deleting this classrule:
companion object {
#ClassRule
#JvmField
val schedulers = RxImmediateeSchedulerRule()
}

Android Unit Testing with Mockito for External REST API calls

I am new to JUnit test cases in Android. I heard that by using Mockito we can achieve easily.
My Android Class makes an external call to a REST API Service (Retrofit) that returns a JSON response. I have to mock that response (hardcoded JSON) and write test cases.
Please share your idea how to achieve this.
i am able to achieve.
updating with a piece of code.
class GenerateTripViewModelTest {
#Mock
private lateinit var mockRepository: GenerateTripRepository
private val schedulerProvider = SchedulerProvider(Schedulers.trampoline(), Schedulers.trampoline())
private lateinit var generateTripViewModel: GenerateTripViewModel
#Before
fun setUp() {
MockitoAnnotations.initMocks(this)
generateTripViewModel = GenerateTripViewModel(mockRepository, schedulerProvider)
}
#Test
fun SearchSuccessCase() {
val tripReq = GenerateTripReqModel(ArrayList<String>(),"123","xxxx","xxxx")
Mockito.`when`(mockRepository.generateTrip(tripReq)).thenReturn(Observable.just(GenerateTripResModel("")))
val testObserver = TestObserver<GenerateTripResModel>()
generateTripViewModel.generateTrip(tripReq).subscribe(testObserver)
testObserver.assertNoErrors()
}
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
class GenerateTripViewModel #Inject constructor(private val generateTripRepository: GenerateTripRepository,private val schedulerProvider: SchedulerProvider) : ViewModel() {
fun generateTrip(reqModel: GenerateTripReqModel) = generateTripRepository.generateTrip(reqModel)
}
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
#Singleton
class GenerateTripRepository #Inject constructor(
private val apiServices: ApiServices, private val context: Context,
private val appExecutors: AppExecutors = AppExecutors()) {
/**
* Generate Trip
*/
fun generateTrip(reqModel: GenerateTripReqModel): Observable<GenerateTripResModel> = apiServices.generateTrip(reqModel)
}
class Test{
#Mock
lateinit var redditApiService: RedditApiService
lateinit var postSettingsViewModel: PostSettingsViewModel
#Before
fun setUp() {
initMocks(this)
postSettingsViewModel = PostSettingsViewModel(redditApiService, userRepo)
}
#Test
fun testApi(){
Mockito.`when`(redditApiService.getSubreddits("asd")).thenReturn(Single
.just<SubredditResponse>(SubredditResponse(listOf(Subreddit("first")))))
//make your tests
}
}
You can use viewmodel or presenter and pass your api service there. With mockito you can specify function call and its return value. Mockito.when(api.get()).thenReturn(new Result()).
You can check google samples: https://github.com/googlesamples/android-architecture-components/blob/master/GithubBrowserSample/app/src/test/java/com/android/example/github/api/GithubServiceTest.kt
You can use product flavors for mock your response or user MockWebServer library or replace your retrofit interface with you implementation what return json from assets
upd: I misunderstood the question. I agree with Phowner Biring

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