Bug: ClassCastException(Invalid name: byte[]) in generic interface mocking

[Makentoshe]

Expected Behavior

Mocked method should returns ByteArray

Current Behavior

If we tries to mock the get method in the selected interface:

interface A<K, V> {
    fun get(k: K): V?
}

like this

val a = mockk<A<Any, ByteArray>>()
every { a.get(any()) } returns byteArrayOf()

the test will be crashed with an exception.

Steps to Reproduce

1. Create the interface

interface A<K, V> {
    fun get(k: K): V?
}

2. Run selected in a test case

val a = mockk<A<Any, ByteArray>>()
every { a.get(any()) } returns byteArrayOf()

Context

• MockK version: 1.8.13.kotlin13
• OS: Win10
• Kotlin version: 1.3.30
• JDK version: 1.8.0_144
• JUnit version: JUnit 4.12
• Type of test: android instrumented test

Also using androidx artifacts

Stack trace

Just a stack trace directly from my app

java.lang.ClassNotFoundException: Invalid name: byte[]
at java.lang.Class.classForName(Native Method)
at java.lang.Class.forName(Class.java:453)
at java.lang.Class.forName(Class.java:378)
at io.mockk.impl.recording.JvmAutoHinter.autoHint(JvmAutoHinter.kt:38)
at io.mockk.impl.eval.RecordedBlockEvaluator.record(RecordedBlockEvaluator.kt:36)
at io.mockk.impl.eval.EveryBlockEvaluator.every(EveryBlockEvaluator.kt:25)
at io.mockk.MockKDsl.internalEvery(API.kt:93)
at io.mockk.MockKKt.every(MockK.kt:104)
at com.makentoshe.booruchan.common.download.PreviewImageDownloadControllerATest.shouldReturnSuccessForFirst(PreviewImageDownloadControllerATest.kt:36)
at java.lang.reflect.Method.invoke(Native Method)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at androidx.test.internal.runner.junit4.statement.RunBefores.evaluate(RunBefores.java:80)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runners.Suite.runChild(Suite.java:128)
at org.junit.runners.Suite.runChild(Suite.java:27)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at androidx.test.internal.runner.TestExecutor.execute(TestExecutor.java:56)
at androidx.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:388)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:2089)

Minimal reproducible code (the gist of this issue)

dependencies {
    testImplementation "io.mockk:mockk:1.8.13.kotlin13"
    androidTestImplementation "io.mockk:mockk:1.8.13.kotlin13"
    androidTestImplementation "io.mockk:mockk-android:1.8.13.kotlin13"
 }

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

class InterfaceBugTest {

    interface BugInterface<K, V> {
        fun get(k: K): V?
    }

    @Test
    fun causeBug() {
        val bugInterface = mockk<BugInterface<Any, ByteArray>>()
        every { bugInterface.get(any()) } returns byteArrayOf()
    }
}

[oleksiyp]

Nice one

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. If you are sure that this issue is important and should not be marked as stale just put an important tag.