mocking a private function with suspend higher order function as argument with Mockk

Question

Actually issue is, i am unable to mock a private function due to suspendable lambda as arguement (val condition: suspend () -> AppResult<Playlist>)

So, in that regard i need your assistance.

Code to be tested,

class UserPlayListManagerImpl(
private val dispatcher: AppCoroutineDispatchers,
private val createPlayListUseCase: CreatePlayListUseCase
) : UserPlayListManager, CoroutineScope {

override lateinit var selectedPlayList: Playlist

init {
    createEmptyPlayListForCurrentUser()
    setSelectedPlaylist()
}

override fun createEmptyPlayListForCurrentUser() {
    evaluateSealedClassWithCondition(condition = {
        createPlayListUseCase(selectedUser)
    }, success = {
        listOfPlayListForCurrentUser.add(it)
    })
}


private fun evaluateSealedClassWithCondition(
    condition: suspend () -> AppResult<Playlist>,
    success: (Playlist) -> Unit, error: (String) -> Unit = {}
) {
    launch( handler) {
        when (val data = condition()) {
            is AppError -> {
                withContext(dispatcher.main) {
                    error(data.message!!)
                }
            }

            is AppSuccess -> {
                withContext(dispatcher.main) {
                    success(data.data)
                }
            }
        }
    }
}

override val coroutineContext: CoroutineContext
    get() = dispatcher.io + Job()

lateinit var errorMessage: String

private val handler : CoroutineExceptionHandler
    get() = CoroutineExceptionHandler { _, exception ->
            errorMessage = exception.localizedMessage ?: "An Error occurred"
        }
}

Test file:

@ExtendWith(value = [MockKExtension::class, InstantExecutorExtension::class])
class UserPlayListManagerImplTest {

@JvmField
@RegisterExtension
val coroutinesTestRule = MainCoroutineRule()

@MockK
lateinit var createPlayListUseCase: CreatePlayListUseCase

@MockK
lateinit var addTrackUseCase: AddTrackUseCase

@MockK
lateinit var deleteTrackUseCase: DeleteTrackUseCase

lateinit var userPlayListManager: UserPlayListManagerImpl

@BeforeEach
fun setUp() {
    MockKAnnotations.init(this, relaxed = true)

    userPlayListManager = spyk(UserPlayListManagerImpl(
        coroutinesTestRule.testDispatcherProvider, createPlayListUseCase,
        addTrackUseCase, deleteTrackUseCase), recordPrivateCalls = true)
}

@Test
fun `Create an empty playlist for loggedIn User`() = coroutinesTestRule.runBlockingTest {

    val condition: suspend () -> AppResult<Playlist> = {
        createPlayListUseCase(getTestNormalUser())
    }

    val success: (Playlist) -> Unit = mockk(relaxed = true)
    val error: (String) -> Unit = mockk(relaxed = true)

    coEvery {
        createPlayListUseCase(any())
    } returns AppSuccess(createEmptyPlayList(getTestNormalUser()))

    every {
        userPlayListManager invoke "evaluateSealedClassWithCondition" withArguments
                listOf(condition, success, error)
    } returns Unit

    userPlayListManager.createEmptyPlayListForCurrentUser()

    verify {
        userPlayListManager invoke "evaluateSealedClassWithCondition" withArguments
                listOf(condition, success, error)
    }
}

}

Exception:

can't find function evaluateSealedClassWithCondition(() -> app.template.base.useCases.AppResult<reprator.module.modulea.modals.Playlist>, Function1(#5), Function1(#6)) of class reprator.module.modulea.UserPlayListManagerImpl for dynamic call.
If you were trying to verify a private function, make sure to provide type information to exactly match the functions signature.
io.mockk.MockKException: can't find function evaluateSealedClassWithCondition(() -> app.template.base.useCases.AppResult<reprator.module.modulea.modals.Playlist>, Function1(#5), Function1(#6)) of class reprator.module.modulea.UserPlayListManagerImpl for dynamic call.
If you were trying to verify a private function, make sure to provide type information to exactly match the functions signature.
    at io.mockk.InternalPlatformDsl.dynamicCall(InternalPlatformDsl.kt:126)
    at io.mockk.MockKMatcherScope$DynamicCallLong.withArguments(API.kt:1989)
    at reprator.module.modulea.UserPlayListManagerImplTest$Create an empty playlist for loggedIn User$1$2.invoke(UserPlayListManagerImplTest.kt:68)
    at reprator.module.modulea.UserPlayListManagerImplTest$Create an empty playlist for loggedIn User$1$2.invoke(UserPlayListManagerImplTest.kt:67)
    at io.mockk.impl.eval.RecordedBlockEvaluator$record$block$1.invoke(RecordedBlockEvaluator.kt:25)
    at io.mockk.impl.eval.RecordedBlockEvaluator$enhanceWithRethrow$1.invoke(RecordedBlockEvaluator.kt:78)
    at io.mockk.impl.recording.JvmAutoHinter.autoHint(JvmAutoHinter.kt:23)
    at io.mockk.impl.eval.RecordedBlockEvaluator.record(RecordedBlockEvaluator.kt:40)
    at io.mockk.impl.eval.EveryBlockEvaluator.every(EveryBlockEvaluator.kt:30)
    at io.mockk.MockKDsl.internalEvery(API.kt:92)
    at io.mockk.MockKKt.every(MockK.kt:98)
    at reprator.module.modulea.UserPlayListManagerImplTest$Create an empty playlist for loggedIn User$1.invokeSuspend(UserPlayListManagerImplTest.kt:67)
    at reprator.module.modulea.UserPlayListManagerImplTest$Create an empty playlist for loggedIn User$1.invoke(UserPlayListManagerImplTest.kt)
    at reprator.module.modulea.UserPlayListManagerImplTest$Create an empty playlist for loggedIn User$1.invoke(UserPlayListManagerImplTest.kt)
    at kotlinx.coroutines.test.TestBuildersKt$runBlockingTest$deferred$1.invokeSuspend(TestBuilders.kt:50)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
    at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
    at kotlinx.coroutines.test.TestCoroutineDispatcher.dispatch(TestCoroutineDispatcher.kt:50)
    at kotlinx.coroutines.internal.DispatchedContinuationKt.resumeCancellableWith(DispatchedContinuation.kt:322)
    at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:30)
    at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable$default(Cancellable.kt:25)
    at kotlinx.coroutines.CoroutineStart.invoke(CoroutineStart.kt:110)
    at kotlinx.coroutines.AbstractCoroutine.start(AbstractCoroutine.kt:126)
    at kotlinx.coroutines.BuildersKt__Builders_commonKt.async(Builders.common.kt:91)
    at kotlinx.coroutines.BuildersKt.async(Unknown Source)
    at kotlinx.coroutines.BuildersKt__Builders_commonKt.async$default(Builders.common.kt:82)
    at kotlinx.coroutines.BuildersKt.async$default(Unknown Source)
    at kotlinx.coroutines.test.TestBuildersKt.runBlockingTest(TestBuilders.kt:49)
    at kotlinx.coroutines.test.TestBuildersKt.runBlockingTest(TestBuilders.kt:73)
    at reprator.module.modulea.UserPlayListManagerImplTest.Create an empty playlist for loggedIn User(UserPlayListManagerImplTest.kt:54)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:725)
    at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
    at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
    at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$7(TestMethodTestDescriptor.java:214)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:210)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:135)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:66)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:151)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
    at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
    at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)
    at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.processAllTestClasses(JUnitPlatformTestClassProcessor.java:99)
    at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.access$000(JUnitPlatformTestClassProcessor.java:79)
    at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor.stop(JUnitPlatformTestClassProcessor.java:75)
    at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:61)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
    at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
    at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
    at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
    at com.sun.proxy.$Proxy2.stop(Unknown Source)
    at org.gradle.api.internal.tasks.testing.worker.TestWorker.stop(TestWorker.java:135)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
    at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
    at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:182)
    at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:164)
    at org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:414)
    at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
    at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
    at java.base/java.lang.Thread.run(Thread.java:834)

have your class return a playlist, and unit test the correct playlist is returned. (instead of verifying an internal method was called) — Blundell, Oct 21 '21 at 15:28
@Blundell, thanks for the time, but that's separate use case, i had already unit test for that. I think it's due to suspend highier order function, as simple higher order function are working properly — Reprator, Oct 21 '21 at 15:52
@Blundell, any idea on this workaround, https://github.com/mockk/mockk/issues/339 — Reprator, Oct 21 '21 at 16:28
I just wouldn't do this :-) If you already have a test for that, then why do you need to double test the internals? Make sure you aren't entangling your code with your tests and making refactoring near impossible in the future — Blundell, Oct 22 '21 at 12:25

mocking a private function with suspend higher order function as argument with Mockk

0 Answers0