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kotlinlang

Hi guys, I am injecting <https://developer.android.com/kotlin/coroutines/coroutines-best-practices#inject-dispatchers|Dispacters.IO> in m project. Like this
```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

```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')```

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

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.~

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

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