How can we mock `FirebaseAuth.getInstance().signInWithCustomToken(token).addOnCompleteListener{}` a...

# android

[Kulwinder Singh]

How can we mock FirebaseAuth.getInstance().signInWithCustomToken(token).addOnCompleteListener{} and other Task like addOnSuccessListener and addOnFailureListener
using MockK ?

[Samme Kleijn]

I used to do a similar thing like this:

@MockK(relaxed = true)
private lateinit var mockTask: Task<List<FirebaseVisionBarcode>>

every { mockTask.addOnFailureListener(any()) } answers {
   firstArg<OnFailureListener>().onFailure(mockk())
   mockTask
}

To mock invoke a failure

[Matej Drobnič]

Don't mock tasks

[Matej Drobnič]

return real tasks, for example Tasks.forException(...)

[Kulwinder Singh]

for FirebaseAuth.getInstance().signInWithCustomToken(token).addOnCompleteListener
i have created

lateinit var mockAuthTask: Task<AuthResult>
...
beforeEachTest{
.....
every { mockAuthTask.addOnSuccessListener(any()) } answers { firstArg<OnCompleteListener<AuthResult>>().onComplete(mockk()) }
}

[Kulwinder Singh]

but its not working how can i do it @Samme Kleijn

[Kulwinder Singh]

@Matej Drobnič can you please give me more info

[Kulwinder Singh]

?

[Matej Drobnič]

instead of whole mock stuff, just create dummy AuthResult and create real task:

val result = AuthResult(...)
val authTask = Tasks.forResult(result)

[Kulwinder Singh]

@Matej Drobnič but AuthResult is interface i don't know how to implement that class as Concrete

[Kulwinder Singh]

for this do i also have to update real code(UseCases,Repositories) or just tests? @Matej Drobnič, because i'm not in situation to update real UseCases or repositories i am just fixing mocking issues

[Kulwinder Singh]

actually i have tried as @Samme Kleijn suggested, but i'm getting this Failure(e=io.mockk.MockKException: no answer found for: Task(#17).getException()) i think i'm getting this because we are sending AuthResult as mockobject but now i don't know how to solve it 😞

[Matej Drobnič]

just tests

[Matej Drobnič]

you can use mockk() instead of implementing AuthResult I guess

[Matej Drobnič]

or you can create your own FakeAuthResult class that implements the interface

[Kulwinder Singh]

@Matej Drobnič actually mock(relaxed=true) worked

[Kulwinder Singh]

but this is mocked, but as you said don't mock tasks and return real, what is Tasks.forExceptions() and how can i return real tasks, is it going to connect to connect Firebase server and return real tasks ? @Matej Drobnič

[Matej Drobnič]

Task is just a wraper that can return either result or exception

[Matej Drobnič]

it will not go to firebase

[Matej Drobnič]

Tasks.forResult(mockk()) is a good compromise

[Matej Drobnič]

you don't mock the task, but you mock real value

[Matej Drobnič]

but it would be even better if you don't mock anything and just return concrete AuthResult

[Kulwinder Singh]

Thanks @Matej Drobnič & @Samme Kleijn, both of yours solutions really helped me.

[Kulwinder Singh]

after working everything currently i'm getting

no answer found for: SomeClass(#3).setSomeVariable(dummy)

[Kulwinder Singh]

how can i add every for setters of fields ?

[luke]

Try here: https://mockk.io/#property-backing-fields