Android architecture components GithubBrowserSample unit test understanding

Question

Hi guys. I am trying to learn unit tests using Kotlin using a google github sample as a base . My code is very similar, but I can't get one of my more basic tests to work (and I don't understand it).

My main question is that the test is running sendResultToUI(),

@Test
public void sendResultToUI() {
    MutableLiveData<Resource<User>> foo = new MutableLiveData<>();
    when(userRepository.loadUser("foo")).thenReturn(foo);
    Observer<Resource<User>> observer = mock(Observer.class);
    userViewModel.getUser().observeForever(observer);
    userViewModel.setLogin("foo");
    verify(observer, never()).onChanged(any(Resource.class));
    User fooUser = TestUtil.createUser("foo");
    Resource<User> fooValue = Resource.success(fooUser);

    foo.setValue(fooValue);
    verify(observer).onChanged(fooValue);
    reset(observer);
}

From what I can say, he says:

• a) When called loadUser("foo"), instead of executing the function, just return a new guy with live data named foo.
• b) Observe current data userViewModel.getUser()
• c) A call setLogin("foo")that runs the current data and callsloadUser("foo")
• d) Verify that the watcher before getUser()that we created earlier was never started by any instance of the resource
• e) foo, , getUser() observer

, , d). :

java.lang.IllegalStateException: ArgumentMatchers.any(T::class.java) must not be null

, , onChanged . , , , - setLogin() c) switchMap, , , userRepositiory.loadUser(), getUser(), ( ). loadUser() foo, a). , - , !

: unit test, , , ( , , , , !)

    @Test
fun `send result to UI`(){
    val foo = MutableLiveData<Resource<Member>>()
    `when`(interactor.callServerLoginRepo(email, password)).thenReturn(foo)
    val observer: Observer<Resource<Member>> = mock()
    loginViewModel.member.observeForever(observer)
    loginViewModel.setLoginCredentials(email, password)
    verify<Observer<Resource<Member>>>(observer, never()).onChanged(any(Resource::class.java) as Resource<Member>)
    val fooUser = TestUtil.createMember(email)
    val fooValue = Resource.success(fooUser)

    foo.setValue(fooValue)
    verify<Observer<Resource<Member>>>(observer).onChanged(fooValue)
    reset<Observer<Resource<Member>>>(observer)
}

MockitoHelpers.kt

fun <T> any(type: Class<T>): T = Mockito.any<T>(type)

:

kotlin.TypeCastException: null cannot be cast to non-null type app.core.sdk.data.remote.response.Resource<app.core.sdk.data.model.db.Member>

at app.core.sdk.ui.login.LoginViewModelTest.send result to UI(LoginViewModelTest.kt:114)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.rules.TestWatcher$1.evaluate(TestWatcher.java:55)

2, : , , any(), any(), , . Mockito-Kotlin , any, I, , :

inline fun <reified T : Any> any() = Mockito.any(T::class.java) ?: createInstance<T>()

, , Mockito.any(), , Kotlin .

    val foo = MutableLiveData<Resource<Member>>()
    //When callServerLoginRepo() is called, return foo live data
    `when`(interactor.callServerLoginRepo(email, password)).thenReturn(foo)
    //Observe member live data
    val observer: Observer<Resource<Member>> = mock()
    loginViewModel.member.observeForever(observer)
    //Fire setLoginCredentials, and make sure it didn't touch our observed 'member' live data
    loginViewModel.setLoginCredentials(email, password)
    verify(observer, never()).onChanged(any())
    //Create a successful foo user, and set it value
    val fooUser = TestUtil.createMember(email)
    val fooValue = Resource.success(fooUser)

    foo.value = fooValue
    //Ensure setting this did indeed trigger our live data
    verify(observer).onChanged(fooValue)
    reset(observer)

Answer 1

. , .

: java- kotlin. - , , Mockito.any() , . any() kotlin. , : Mockito ?

Answer 2

, , , onChanged .

, Kotlin Mockito, Kotlin, .

https://github.com/nhaarman/mockito-kotlin

, . , :

import org.mockito.ArgumentMatchers.any

:

import com.nhaarman.mockito_kotlin.any

, Java Kotlin, ArgumentMatchers.any(T::class.java) must not be null, .

, MockitoKotlinHelpers, .