NullPointerException while using 'and' matcher with capture

Failure Information (for bugs)

I’ve updated:

• mockk from 1.9.3 to 1.11.0
• kotlin 1.4.30 to 1.5.10 and after that, the code below throws NPE.

Steps to Reproduce

Run code below

Context

• MockK version: 1.11.0
• OS: macos Catalina 10.15.7
• Kotlin version: 1.5.10
• JDK version: 11.0.10
• JUnit version: 5.7.2
• Type of test: unit test

Stack trace

java.lang.NullPointerException
	at org.proj.userservice.domain.model.DeviceToken.hashCode(domain.kt)
	at io.mockk.AndOrMatcher.hashCode(Matchers.kt)
	at java.base/java.util.ArrayList.hashCodeRange(ArrayList.java:627)
	at java.base/java.util.ArrayList.hashCode(ArrayList.java:614)
	at io.mockk.InvocationMatcher.hashCode(API.kt:3782)
	at java.base/java.util.HashMap.hash(HashMap.java:339)
	at java.base/java.util.HashMap.get(HashMap.java:552)
	at java.base/java.util.Collections$SynchronizedMap.get(Collections.java:2594)
	at io.mockk.impl.InternalPlatform.customComputeIfAbsent(InternalPlatform.kt:39)
	at io.mockk.impl.stub.MockKStub$childMockK$$inlined$synchronized$lambda$1.invoke(MockKStub.kt:192)
	at io.mockk.impl.recording.CommonCallRecorder.safeExec(CommonCallRecorder.kt:72)
	at io.mockk.impl.log.SafeToString.exec(SafeToString.kt:10)
	at io.mockk.impl.stub.MockKStub.childMockK(MockKStub.kt:191)
	at io.mockk.impl.recording.PermanentMocker.permamentize(PermanentMocker.kt:48)
	at io.mockk.impl.recording.PermanentMocker.mock(PermanentMocker.kt:24)
	at io.mockk.impl.recording.states.RecordingState.mockPermanently(RecordingState.kt:121)
	at io.mockk.impl.recording.states.RecordingState.round(RecordingState.kt:33)
	at io.mockk.impl.recording.CommonCallRecorder.round(CommonCallRecorder.kt:50)
	at io.mockk.impl.eval.RecordedBlockEvaluator.record(RecordedBlockEvaluator.kt:63)
	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)

val kotestVersion = "4.6.0"
val kotestExtVersion = "1.0.0"

fun kotest(moduleName: String, version: String = kotestVersion) = "io.kotest:kotest-$moduleName-jvm:$version"
fun kotestExt(moduleName: String, version: String = kotestExtVersion) = "io.kotest.extensions:kotest-$moduleName:$version"

dependencies {
    testImplementation("org.junit.jupiter:junit-jupiter:5.7.2")
    testImplementation(kotest("runner-junit5"))
    testImplementation(kotest("property"))
    testImplementation(kotestExt("property-arrow")) {
        exclude("io.arrow-kt")
    }
    testImplementation(kotest("assertions-core"))
    testImplementation(kotestExt("assertions-arrow")) {
        exclude("io.arrow-kt")
    }
    testImplementation(kotestExt("extensions-testcontainers"))
    testImplementation(kotestExt("extensions-spring"))
    testImplementation(springBoot("test")) {
        exclude(module = "junit")
        exclude(module = "mockito-core")
    }
    testImplementation("io.mockk:mockk:1.11.0")
}

class Spec: FreeSpec({

    data class DevicePinToken(
      val userId: UUID,
      val deviceId: String,
      val creationTime: LocalDateTime
    )

    open class Mockks {
            val service: DeviceService = mockk()
            val deviceSlot = slot<DeviceToken>()
    
            init {
                every { // Failed here
                    service.upsertDeviceToken(
                        and(
                            capture(deviceSlot), 
                            match { it.deviceId == deviceId && it.userId == userId}
                        )
                    )
                } just Runs

     "any spec" {
            with(Mockks()) { // Mockks initialization failed

            }
     }
})

[untra]

I am reproducing this myself. glad I found someone has already made a github issue. defiantly looks like the and matcher calls equality operation, which calls hashcode, which tested objects may not define or be capable of responding to.

[gmazzo]

It seems the one in the android codebase has this issue fixed already:

        if (classBeingRedefined == null) {
            return classfileBuffer
        }

https://github.com/mockk/mockk/blob/master/modules/mockk-agent-android/src/main/kotlin/io/mockk/proxy/android/transformation/InliningClassTransformer.kt#L30

So both InliningClassTransformer classes have diverged. I’m going to open a PR to fix the JVM one as well