Spyk'ed object can't be unmocked which leads to OutOfMemoryError

[bakomchik]

Expected Behavior

unmock(spyk()) -- works
No java.lang.OutOfMemoryError: Java heap space error occurred.

Current Behavior

java.lang.OutOfMemoryError: Java heap space occurs

unmock(spyk()) -- does not unmock spyk'ed object

Failure Information (for bugs)

Context

We have a lot of SpringBoot tests .
We annotated @Lazy bean with @SpykBean in our TestCaseBase class
And sometimes new spring context created and bean get spyked again and it leads to OutOfMemoryError
because spiked object can't be unmocked/unspyked

• MockK version: implementation("io.mockk:mockk:1.13.3")

• OS: Darwin 21.6.0 Darwin Kernel Version 21.6.0: Thu Sep 29 20:13:56 PDT 2022; root:xnu-8020.240.7~1/RELEASE_ARM64_T6000 arm64

• Kotlin version: 1.7.21

• JDK version: openjdk 11.0.16.1 2022-08-12 OpenJDK Runtime Environment Homebrew (build 11.0.16.1+0) OpenJDK 64-Bit Server VM Homebrew (build 11.0.16.1+0, mixed mode)

• Type of test: unit test

Minimal reproducible code (the gist of this issue)

// -----------------------[ GRADLE DEFINITIONS ] -----------------------
dependencies {
    testImplementation(kotlin("test"))
    implementation("io.mockk:mockk:1.13.3")
}

tasks.test {
    useJUnitPlatform()
}

tasks.withType<KotlinCompile> {
    kotlinOptions.jvmTarget = "1.8"
}

application {
    mainClass.set("MainKt")
}
// -----------------------[ YOUR CODE STARTS HERE ] -----------------------


fun main(args: Array<String>) {
    (0..1000).forEach {
        val spyk = spyk(LazySpringBeanWhichHoldsReferenceForBeanFactory(ByteArray(10 * 1024 * 1024)))
        every { spyk.doSmth() } returns "Wow"
        spyk.doSmth();
        clearMocks(spyk)
        unmockkObject(spyk)
    }
}

class LazySpringBeanWhichHoldsReferenceForBeanFactory(val beanFactory: ByteArray){
    fun doSmth():String{
            return "Smth"
    }
}

[bakomchik]

Path to gc roots

The object kept by these strong references an can't be collected by gc

[bakomchik]

Looks like original object can't be collected by GC and removed from all maps due to strong reference via path

[bakomchik]

I've created pull request https://github.com/mockk/mockk/pull/1018/files

[bakomchik]

I found that mock(proxy) objects ,that supposed to be collected by gc, can't be collected despite the fact that weak reference used for storing these objects in WeakMockHandlersMap, because of these proxy objects are strongly reachable via dispose routine

[mabwah-arista]

It seems the fix for #997 undid this, as now I'm seeing memory leaks due to spy objects not being GCed once cleared. There must be a way to allow these objects to be GCed when calling clearAllMocks while not having them disappear while they're still needed.

@Raibaz do you have any recommendations? Also worth noting that the unit test added in #1018 doesn't actually detect it as it's broken but the tests are passing (I assume).