Hi guys I am injecting <https developer android com kotlin c kotlinlang #koin

val dispatcherModule = module {
    // Dispatchers
    single(named(DISPATCHER_IO)) {
        <http://Dispatchers.IO|Dispatchers.IO>
    }
}

// some other place to use startKoin
startKoin { modules(
                listOf(dispatcherModule)) }

class PairViewModelTest {

    @get:Rule
    val testInstantTaskExecutorRule: TestRule = TestMainCoroutineRule()

    @get:Rule
    val koinTestRule = KoinTestRule.create {
        modules(dispatcherModule)
    }

    @MockK private lateinit var mockCoroutineDispatcher: CoroutineDispatcher

    private val subject by lazy { spyk(PairViewModelTest(mockCoroutineDispatcher))}

    @Before
    fun setUp() {
        MockKAnnotations.init(this, relaxed = true)
        loadKoinModules(module {
            factory {
                mockCoroutineDispatcher
            }
        })
    }
   /// more test here which is failed
}

my all tests are failed

So what is wrong in here?

class java.lang.Object cannot be cast to class java.lang.Boolean (java.lang.Object and java.lang.Boolean are in module java.base of loader 'bootstrap')
java.lang.ClassCastException: class java.lang.Object cannot be cast to class java.lang.Boolean (java.lang.Object and java.lang.Boolean are in module java.base of loader 'bootstrap')

@arnaud.giuliani any suggestion for this?

abbic

02/23/2023, 2:47 PM

I think the problem is that, to test a class that uses coroutines, you need to pass a real dispatcher. try looking at this

https://blog.logrocket.com/better-kotlin-coroutine-unit-testing/

I personally dont see the need to use Koin at all in a test like this, but i havent worked with koin closely enough to make that claim strongly

KotlinLeaner

02/23/2023, 2:53 PM

Thanks for sharing the above document. ~~The document which you shared is very complicated. I think there is a better way of doing it in koin.~~

abbic

02/23/2023, 3:51 PM

i think that document is about as straightforward as it gets about testing coroutines...

certainly you cant mock the dispatcher

KotlinLeaner

02/23/2023, 5:59 PM

Yeah I get it now. Thanks for great guidance. It works with above document.

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