GH-1056 - Switch to object identity comparison when looking up event publications.

We now rather use an object identity comparison in TargetEventPublication.isAssociatedWith(…) instead of an ….equals(…) as that would return the wrong publication for identical events.

Author: odrotbohm

spring-modulith-events/spring-modulith-events-core/src/main/java/org/springframework/modulith/events/core/TargetEventPublication.java

@@ -75,7 +75,7 @@ default boolean isIdentifiedBy(PublicationTargetIdentifier identifier) {
 	}
 
 	/**
-	 * Returns whether the {@link TargetEventPublication} is associated with the given event and
+	 * Returns whether the {@link TargetEventPublication} is associated with the given event instance and
 	 * {@link PublicationTargetIdentifier}.
 	 *
 	 * @param event must not be {@literal null}.
@@ -87,6 +87,6 @@ default boolean isAssociatedWith(Object event, PublicationTargetIdentifier ident
 		Assert.notNull(event, "Event must not be null!");
 		Assert.notNull(identifier, "PublicationTargetIdentifier must not be null!");
 
-		return isIdentifiedBy(identifier) && getEvent().equals(event);
+		return isIdentifiedBy(identifier) && getEvent() == event;
 	}
 }

spring-modulith-events/spring-modulith-events-core/src/test/java/org/springframework/modulith/events/core/DefaultEventPublicationRegistryUnitTests.java

@@ -82,6 +82,24 @@ void removesFailingResubmissionFromInProgressPublications() {
 		assertThat(registry.getPublicationsInProgress()).isEmpty();
 	}
 
+	@Test // GH-1056
+	void obtainsCorrectInProgressPublicationForIdenticalEvents() {
+
+		var inProgress = createRegistry(Instant.now()).getPublicationsInProgress();
+
+		var identifier = PublicationTargetIdentifier.of("id");
+
+		var firstEvent = new SampleEvent("Foo");
+		var secondEvent = new SampleEvent("Foo");
+
+		var first = inProgress.register(TargetEventPublication.of(firstEvent, identifier));
+		var second = inProgress.register(TargetEventPublication.of(secondEvent, identifier));
+
+		assertThat(inProgress.getPublication(firstEvent, identifier)).containsSame(first);
+		assertThat(inProgress.getPublication(secondEvent, identifier)).containsSame(second);
+
+	}
+
 	private DefaultEventPublicationRegistry createRegistry(Instant instant) {
 
 		var clock = Clock.fixed(instant, ZoneId.systemDefault());
@@ -94,4 +112,6 @@ private Consumer<TargetEventPublication> failingConsumer() {
 			throw new IllegalStateException();
 		};
 	}
+
+	record SampleEvent(String payload) {}
 }

spring-modulith-events/spring-modulith-events-core/src/test/java/org/springframework/modulith/events/core/TargetEventPublicationUnitTests.java

@@ -51,4 +51,19 @@ void publicationIsIncompleteByDefault() {
 		assertThat(publication.isCompleted()).isFalse();
 		assertThat(publication.getCompletionDate()).isNotPresent();
 	}
+
+	@Test // GH-1056
+	void isOnlyAssociatedWithTheVerySameEventInstance() {
+
+		var first = new SampleEvent("Foo");
+		var second = new SampleEvent("Foo");
+
+		var identifier = PublicationTargetIdentifier.of("id");
+		var publication = TargetEventPublication.of(first, identifier);
+
+		assertThat(publication.isAssociatedWith(first, identifier)).isTrue();
+		assertThat(publication.isAssociatedWith(second, identifier)).isFalse();
+	}
+
+	record SampleEvent(String payload) {}
 }