Apache Kafka SRMSG18304: Unknown channel

Question

I'm implementing Apache Kafka in my Kotlin Quarkus application. I've followed the guides from Quarkus and I'm now at the testing phase.

This is my test class:

import com.abnamro.ddc.pigeon.domain.core.models.events.ClassificationFinishedEvent
import io.mockk.impl.annotations.InjectMockKs
import io.mockk.impl.annotations.MockK
import io.mockk.junit5.MockKExtension
import io.quarkus.test.common.QuarkusTestResource
import io.quarkus.test.junit.QuarkusTest
import io.smallrye.reactive.messaging.providers.connectors.InMemoryConnector
import io.smallrye.reactive.messaging.providers.connectors.InMemorySink
import org.eclipse.microprofile.reactive.messaging.Emitter
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.ExtendWith

@QuarkusTest
@QuarkusTestResource(KafkaTestResourceLifecycleManager::class)
internal class CaptureCaseCompletedTopicPublisherTest {

    @MockK(relaxed = true)
    lateinit var emitter: Emitter<ClassificationFinishedEvent>

    @InjectMockKs
    lateinit var topicPublisher: CaptureCaseCompletedTopicPublisher

    var connector = InMemoryConnector()

    @MockK
    lateinit var classificationFinishedEvent: ClassificationFinishedEvent

    @Test
    internal fun `A proper ClassificationFinishedEvent should return a successful response`() {
        val incoming: InMemorySink<ClassificationFinishedEvent> = connector.sink("dial-out")

        topicPublisher.send(classificationFinishedEvent)
    }
}

And my lifecycle manager:

import io.quarkus.test.common.QuarkusTestResourceLifecycleManager
import io.smallrye.reactive.messaging.providers.connectors.InMemoryConnector

class KafkaTestResourceLifecycleManager : QuarkusTestResourceLifecycleManager {
    override fun start(): MutableMap<String, String> {
        val env: MutableMap<String, String> = HashMap()
        val props1 = InMemoryConnector.switchIncomingChannelsToInMemory("dial-in")
        val props2 = InMemoryConnector.switchOutgoingChannelsToInMemory("dial-out")
        env.putAll(props1)
        env.putAll(props2)
        return env
    }

    override fun stop() {
        InMemoryConnector.clear()
    }
}

The error I'm getting is the following: java.lang.IllegalArgumentException: SRMSG18304: Unknown channel dial-out

Now I've set my channel in my application.yml file like this:

"%test":
  mp:
    messaging:
      outgoing:
        dial-out:
          connector: smallrye-in-memory
          topic: test
      incoming:
        dial-in:
          connector: smallrye-in-memory
          topic: test

So I'm a bit lost on why the channel isn't being picked up. Does anyone have an idea?