I am trying to use mockito in kotlin. I created the following test:
class HeroesDataSourceTest {
@Mock
lateinit var heroesRepository: HeroesRepository
@Mock
lateinit var params: PageKeyedDataSource.LoadInitialParams<Int>
@Mock
lateinit var callback: PageKeyedDataSource.LoadInitialCallback<Int, Heroes.Hero>
val hero = Heroes.Hero(1, "superman", "holasuperman", 1, null, null)
val results = Arrays.asList(hero)
val data = Heroes.Data(results)
val dataResult = Heroes.DataResult(data)
val compositeDisposable = CompositeDisposable()
lateinit var heroesDataSource: HeroesDataSource
private val heroesPublishSubject = PublishSubject.create<Heroes.DataResult>()
@Before
fun initTest(){
MockitoAnnotations.initMocks(this)
}
@Test
fun testLoadInitialSuccess(){
`when`(heroesRepository.getHeroes(ArgumentMatchers.anyInt())).thenReturn(heroesPublishSubject.singleOrError())
heroesDataSource = HeroesDataSource(heroesRepository, compositeDisposable)
val testObserver = TestObserver<Heroes.DataResult>()
heroesDataSource.loadInitial(params, callback)
heroesPublishSubject.onNext(dataResult)
testObserver.assertComplete()
}
}
But when I execute it in the line when(heroesRepository.getHeroes(ArgumentMatchers.anyInt())).thenReturn(heroesPublishSubject.singleOrError()) it just enter to getHeroes method instead of mocking it (and for sure since heroesRepository is not initialized because is mocket the method fails). I use this tons of times in java and it never gave me a single problem. What I have to do in kotlin to mock it properly?
EDIT
Here I put also HeroesRepository class
open class HeroesRepository {
val privateKey = "5009bb73066f50f127907511e70f691cd3f2bb2c"
val publicKey = "51ef4d355f513641b490a80d32503852"
val apiDataSource = DataModule.create()
val pageSize = 20
fun getHeroes(page: Int): Single<Heroes.DataResult> {
val now = Date().time.toString()
val hash = generateHash(now + privateKey + publicKey)
val offset: Int = page * pageSize
return apiDataSource.getHeroes(now, publicKey, hash, offset, pageSize)
}
fun generateHash(variable: String): String {
val md = MessageDigest.getInstance("MD5")
val digested = md.digest(variable.toByteArray())
return digested.joinToString("") {
String.format("%02x", it)
}
}
}
Without adding another dependency, you can replace using the @Mock annotation with a helper function somewhere:
inline fun <reified T> mock(): T =
Mockito.mock(T::class.java)
// To avoid having to use backticks for "when"
fun <T> whenever(methodCall: T): OngoingStubbing<T> =
Mockito.`when`(methodCall)
Then in your test:
val heroesRepository: HeroesRepository = mock()
@Test
fun yourTest() {
whenever(heroesRepository.getHeroes(ArgumentMatchers.anyInt()))
.thenReturn(heroesPublishSubject.singleOrError())
}
Like you had before. This should work, because you're not expecting Mockito to deal with @Mock lateinit var, which it seems to be struggling with, and instead instantiating the mock yourself.
Mockito is not quite compatible with kotlin, you can use mockito-kotlin resource instead. Check out this reference: https://github.com/nhaarman/mockito-kotlin
You can easily mock objects like so:
val heroesRepository = mock<HeroesRepository>()
Then you can use it as you use mockito
FWIW, the reason that the when statement is just calling the actual function is because the function itself (getHeroes) is not marked as open.
So even though the class is non-final the method is final and not mocked.