no answer found for mocked interface functions in mockk 1.10.2

[twatzl]

Expected Behavior

Mocking an interface function should be possible.

Current Behavior

When mocking an interface function then mockk cannot find an answer.

Failure Information (for bugs)

Steps to Reproduce

1. create an interface with a function
2. write a test and try to mock the answer for one of the interface method
3. result is io.mockk.MockKException: no answer found for: MyInterface(#1).doSomethingAwesome([1], [do, something, awesome])

Context

• MockK version: 1.10.2
• OS: Windows 10 Pro 19.09
• Kotlin version: tested with 1.3.72 and 1.4.10
• JDK version: AdoptOpenJDK 11.0.6.10-hotspot
• JUnit version: JUnit 5 (could not find more information)
• Type of test: unit test

I have tested and played around a bit and it seems that this issue was introduced in 1.10.1 or 1.10.2, because with 1.10.0 the same code works. I cannot test 1.10.1 because it is only compiled for Java 14 not for Java 11.

Failure Logs

N/A

Stack trace

io.mockk.MockKException: no answer found for: MyInterface(#1).doSomethingAwesome([1], [do, something, awesome])

	at io.mockk.impl.stub.MockKStub.defaultAnswer(MockKStub.kt:90)
	at io.mockk.impl.stub.MockKStub.answer(MockKStub.kt:42)
	at io.mockk.impl.recording.states.AnsweringState.call(AnsweringState.kt:16)
	at io.mockk.impl.recording.CommonCallRecorder.call(CommonCallRecorder.kt:53)
	at io.mockk.impl.stub.MockKStub.handleInvocation(MockKStub.kt:263)
	at io.mockk.impl.instantiation.JvmMockFactoryHelper$mockHandler$1.invocation(JvmMockFactoryHelper.kt:25)
	at io.mockk.proxy.jvm.advice.Interceptor.call(Interceptor.kt:20)
	at io.mockk.proxy.jvm.advice.BaseAdvice.handle(BaseAdvice.kt:42)
	at io.mockk.proxy.jvm.advice.jvm.JvmMockKProxyInterceptor.interceptNoSuper(JvmMockKProxyInterceptor.java:45)
	at MyInterface$Subclass0.doSomethingAwesome(Unknown Source)
	at AwesomeTest.testAwesomeFunction(AwesomeTest.kt:13)
	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:389)
	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:115)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:167)
	at org.junit.jupiter.engine.execution.ThrowableCollector.execute(ThrowableCollector.java:40)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:163)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:110)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:57)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:83)
	at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$null$2(HierarchicalTestExecutor.java:92)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
	at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
	at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:92)
	at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$null$2(HierarchicalTestExecutor.java:92)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
	at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
	at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:92)
	at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:51)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:43)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:170)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
	at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)

Process finished with exit code -1

Minimal reproducible code (the gist of this issue)

I can provide the project as zip on request.

src/main/kotlin/MyInterface.kt

interface MyInterface {
    fun doSomethingAwesome(param1: List<Long>, param2: List<String>): List<String>
}

src/test/AwesomeTest.kt

import io.mockk.every
import io.mockk.mockk
import org.junit.jupiter.api.Test

class AwesomeTest {

    val myInterfaceInstance = mockk<MyInterface>()

    @Test
    fun testAwesomeFunction() {
        every { myInterfaceInstance.doSomethingAwesome(any(), any()) } returns emptyList()

        val asdf = myInterfaceInstance.doSomethingAwesome(listOf(1L), listOf("do", "something", "awesome"))
    }

}

main.kt

fun main(args: Array<String>) {
    println("Hello World!")
}

build.gradle.kts

import org.jetbrains.kotlin.gradle.tasks.KotlinCompile

plugins {
    kotlin("jvm") version "1.4.10"
    application
}
group = "eu.twatzl"
version = "1.0-SNAPSHOT"

repositories {
    mavenCentral()
}
dependencies {
    testImplementation(kotlin("test-junit5"))
    testImplementation("io.mockk:mockk:1.10.2")
}

tasks.test { useJUnitPlatform() }

tasks.withType<KotlinCompile>() {
    kotlinOptions.jvmTarget = "1.8"
}
application {
    mainClassName = "MainKt"
}

[Raibaz]

This is a duplicate of #510 which was fixed in v1.10.3.

Please upgrade your mockk dependency.

[twatzl]

Indeed. I just tested it and it works now. 👍
Thanks for the fix and sorry that I overlooked the duplicate.