create EventStreamInMemoryTest

src/main/kotlin/eventDemo/libs/event/EventStoreInMemory.kt

@@ -7,5 +7,5 @@ class EventStoreInMemory<E : Event<ID>, ID : AggregateId> : EventStore<E, ID> {
   private val streams: ConcurrentMap<ID, EventStream<E>> = ConcurrentHashMap()
 
   override fun getStream(aggregateId: ID): EventStream<E> =
-    streams.computeIfAbsent(aggregateId) { EventStreamInMemory() }
+    streams.computeIfAbsent(aggregateId) { EventStreamInMemory(aggregateId) }
 }

src/main/kotlin/eventDemo/libs/event/EventStreamInMemory.kt

@@ -9,11 +9,18 @@ import java.util.concurrent.ConcurrentLinkedQueue
  *
  * All methods are implemented.
  */
-class EventStreamInMemory<E : Event<*>> : EventStream<E> {
+class EventStreamInMemory<E : Event<ID>, ID : AggregateId>(
+  val aggregateId: ID,
+) : EventStream<E> {
   private val logger = KotlinLogging.logger {}
   private val events: Queue<E> = ConcurrentLinkedQueue()
 
   override fun publish(event: E) {
+    if (event.aggregateId != aggregateId) {
+      throw EventStreamPublishException(
+        "You cannot publish this event in this stream because it has a different aggregateId!",
+      )
+    }
     if (events.none { it.eventId == event.eventId }) {
       events.add(event)
       logger.info { "Event published" }

src/main/kotlin/eventDemo/libs/event/EventStreamPublishException.kt

@@ -0,0 +1,5 @@
+package eventDemo.libs.event
+
+class EventStreamPublishException(
+  override val message: String,
+) : Exception(message)