# Unit tests for methods using coroutine launch(UI) fails

**URL:** https://discuss.kotlinlang.org/t/unit-tests-for-methods-using-coroutine-launch-ui-fails/6078
**Category:** Android
**Created:** [January 4, 2018, 11:21am UTC](https://discuss.kotlinlang.org/t/unit-tests-for-methods-using-coroutine-launch-ui-fails/6078 "2018-01-04T11:21:26Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![bohsen](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/bohsen/32/4844_2.png) [@bohsen](https://discuss.kotlinlang.org/u/bohsen)
#### Post date: [January 4, 2018, 11:21am UTC](https://discuss.kotlinlang.org/t/unit-tests-for-methods-using-coroutine-launch-ui-fails/6078/1 "2018-01-04T11:21:26Z")

</div>

I’m using [kotlin coroutines](https://github.com/Kotlin/kotlinx.coroutines) and [kotlin retrofit coroutines](https://github.com/gildor/kotlin-coroutines-retrofit) to do network requests in the project I’m currently working on. But my unittests are causing problems. The problem is in the getWorklist-method in below class.

I’m using `launch(UI)`-coroutine to run a network request, but for some reason the the getWorklist-method never enters into the coroutine.  
If I change `launch(UI) { ... }` to `runBlocking { ... }` in WorklistInterctor#getWorklist() the tests all pass.

Here’s my code:

```
class WorklistInteractor @Inject
    constructor(private val worklistRepository: WorklistRepository,
        private val preferenceManager: PreferenceManager)
: NetworkInteractor, WorklistDialogContract.Interactor {

    private var job = Job()

    override fun getWorklist(listener: OnWorklistResultListener) {
        job = launch(UI) {
            val result = async {
                worklistRepository.getWorklist(
                    ip = preferenceManager.worklistIp,
                    port = preferenceManager.worklistPort).awaitResult()
            }.await()

            when (result) {
            //Successful HTTP result
                is Result.Ok -> listener.onWorklistResult(result.value)
            // Any HTTP error
                is Result.Error -> {
                    Timber.e(result.exception, "HTTP error with code %s}", result.exception.code())
                    when(result.exception.code()) {
                        401 -> listener.onInvalidCredentialsFailure()
                        500 -> listener.internalServerError()
                        503 -> listener.noServerResponseFailure()
                        else -> listener.onError(result.exception.cause.toString())
                    }
                }
            // Exception while request invocation
                is Result.Exception -> {
                    Timber.e(result.exception.cause, "Exception with cause %s", result.exception.cause.toString())
                    when(result.exception) {
                        is ConnectException -> listener.connectionRefused()
                        is SocketTimeoutException -> listener.failedToConnectToHost()
                        else -> listener.onError(result.exception.cause.toString())
                    }
                }
            }
        }
    }

    override fun cancel() {
        job.cancel()
    }
}

```

Here’s one of my unittest:

```
@Test
fun `when worklistquery returns result, pass result back through listeners OnWorklistResult()`()
        = runBlocking {

    whenever(mWorklistRepositoryMock.getWorklist(anyString(), anyInt(), anyString()))
            .thenReturn(Calls.response(expectedWorklistResult))

    mInteractor.getWorklist(mOnWorklistResultListenerMock)

    verify(mOnWorklistResultListenerMock).onWorklistResult(anyList<WorklistItem>())
}

```

I keep getting the following message when run:

> Wanted but not invoked:  
> onWorklistResultListener.onWorklistResult(  
>   
> );  
> → at com.example.dialogs.worklistdialog.WorklistInteractorTest$when worklistquery returns result, pass result back through listeners OnWorklistResult()$1.doResume(WorklistInteractorTest.kt:58)
> 
> Actually, there were zero interactions with this mock.

[Link to StackOverflow question](https://stackoverflow.com/questions/48091690/unit-testing-a-retrofit-call-that-uses-kotlin-coroutines)