GH-2289 - Improved check for observe detection.

Author: meistermeier

src/main/java/org/springframework/data/neo4j/core/mapping/DefaultNeo4jPersistentProperty.java

@@ -143,32 +143,33 @@ protected Association<Neo4jPersistentProperty> createAssociation() {
 			}
 		}
 
-		Relationship outgoingRelationship = this.findAnnotation(Relationship.class);
+		Relationship relationship = this.findAnnotation(Relationship.class);
 
 		String type;
-		if (outgoingRelationship != null && StringUtils.hasText(outgoingRelationship.type())) {
-			type = outgoingRelationship.type();
+		if (relationship != null && StringUtils.hasText(relationship.type())) {
+			type = relationship.type();
 		} else {
 			type = deriveRelationshipType(this.getName());
 		}
 
-		Relationship.Direction direction = Relationship.Direction.OUTGOING;
-		if (outgoingRelationship != null) {
-			direction = outgoingRelationship.direction();
-		}
+		Relationship.Direction direction = relationship != null
+				? relationship.direction()
+				: Relationship.Direction.OUTGOING;
 
 		// Try to determine if there is a relationship definition that expresses logically the same relationship
 		// on the other end.
 		Optional<RelationshipDescription> obverseRelationshipDescription = obverseOwner.getRelationships().stream()
-				.filter(rel -> rel.getType().equals(type) && rel.getTarget().equals(this.getOwner())).findFirst();
+				.filter(rel -> rel.getType().equals(type)
+						&& rel.getTarget().equals(this.getOwner())
+						&& rel.getDirection() == direction.inverse()).findFirst();
 
 		DefaultRelationshipDescription relationshipDescription = new DefaultRelationshipDescription(this,
 				obverseRelationshipDescription.orElse(null), type, dynamicAssociation, (NodeDescription<?>) getOwner(),
 				this.getName(), obverseOwner, direction, relationshipPropertiesClass);
 
 		// Update the previous found, if any, relationship with the newly created one as its counterpart.
 		obverseRelationshipDescription
-				.ifPresent(relationship -> relationship.setRelationshipObverse(relationshipDescription));
+				.ifPresent(observeRelationship -> observeRelationship.setRelationshipObverse(relationshipDescription));
 
 		return relationshipDescription;
 	}

src/main/java/org/springframework/data/neo4j/core/schema/Relationship.java

@@ -53,7 +53,11 @@ enum Direction {
 		/**
 		 * Describes an incoming relationship.
 		 */
-		INCOMING
+		INCOMING;
+
+		public Direction inverse() {
+			return this == OUTGOING ? INCOMING : OUTGOING;
+		}
 	}
 
 	/**

src/test/java/org/springframework/data/neo4j/core/mapping/DefaultNeo4jPersistentEntityTest.java

@@ -30,6 +30,7 @@
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
 import org.springframework.data.annotation.Transient;
+import org.springframework.data.mapping.AssociationHandler;
 import org.springframework.data.mapping.MappingException;
 import org.springframework.data.neo4j.core.schema.DynamicLabels;
 import org.springframework.data.neo4j.core.schema.GeneratedValue;
@@ -129,6 +130,26 @@ void doesFailOnRelationshipPropertiesWithMissingTargetNode() {
 							.getPersistentEntity(EntityWithInCorrectRelationshipProperties.class))
 					.withMessageContaining("Missing @TargetNode declaration in");
 		}
+
+		@Test // DATAGRAPH-2289
+		void correctlyFindRelationshipObverse() {
+			Neo4jMappingContext neo4jMappingContext = new Neo4jMappingContext();
+			Neo4jPersistentEntity<?> persistentEntity = neo4jMappingContext.getPersistentEntity(EntityWithBidirectionalRelationship.class);
+			persistentEntity.doWithAssociations((AssociationHandler<Neo4jPersistentProperty>) a -> {
+				RelationshipDescription rd = (RelationshipDescription) a;
+				assertThat(rd.getRelationshipObverse()).isNotNull();
+			});
+		}
+
+		@Test // DATAGRAPH-2289
+		void correctlyFindRelationshipObverseWithRelationshipProperties() {
+			Neo4jMappingContext neo4jMappingContext = new Neo4jMappingContext();
+			Neo4jPersistentEntity<?> persistentEntity = neo4jMappingContext.getPersistentEntity(EntityWithBidirectionalRelationshipProperties.class);
+			persistentEntity.doWithAssociations((AssociationHandler<Neo4jPersistentProperty>) a -> {
+				RelationshipDescription rd = (RelationshipDescription) a;
+				assertThat(rd.getRelationshipObverse()).isNotNull();
+			});
+		}
 	}
 
 	@Nested
@@ -491,4 +512,43 @@ static class HasNoTargetNodeRelationshipProperties {
 		@Id @GeneratedValue
 		private Long id;
 	}
+
+	@Node
+	static class EntityWithBidirectionalRelationship {
+
+		@Id @GeneratedValue
+		private Long id;
+
+		@Relationship("KNOWS")
+		List<EntityWithBidirectionalRelationship> knows;
+
+		@Relationship(type = "KNOWS" , direction = Relationship.Direction.INCOMING)
+		List<EntityWithBidirectionalRelationship> knownBy;
+
+	}
+
+	@Node
+	static class EntityWithBidirectionalRelationshipProperties {
+
+		@Id @GeneratedValue
+		private Long id;
+
+		@Relationship("KNOWS")
+		List<BidirectionalRelationshipProperties> knows;
+
+		@Relationship(type = "KNOWS" , direction = Relationship.Direction.INCOMING)
+		List<BidirectionalRelationshipProperties> knownBy;
+
+	}
+
+	@RelationshipProperties
+	static class BidirectionalRelationshipProperties {
+
+		@Id @GeneratedValue
+		private Long id;
+
+		@TargetNode
+		EntityWithBidirectionalRelationshipProperties target;
+	}
+
 }