DATAGRAPH-1469 - Fix bidirectional relationship properties persistence.

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

@@ -19,6 +19,7 @@ import java.util.AbstractMap.SimpleEntry;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
+import java.util.Objects;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
@@ -108,5 +109,22 @@ public final class MappingSupport {
 		Object getRelatedEntity() {
 			return relatedEntity;
 		}
+
+		@Override
+		public boolean equals(Object o) {
+			if (this == o) {
+				return true;
+			}
+			if (o == null || getClass() != o.getClass()) {
+				return false;
+			}
+			RelationshipPropertiesWithEntityHolder that = (RelationshipPropertiesWithEntityHolder) o;
+			return relationshipProperties.equals(that.relationshipProperties) && relatedEntity.equals(that.relatedEntity);
+		}
+
+		@Override
+		public int hashCode() {
+			return Objects.hash(relationshipProperties, relatedEntity);
+		}
 	}
 }

src/test/java/org/springframework/data/neo4j/integration/imperative/RepositoryIT.java

@@ -88,6 +88,7 @@ import org.springframework.data.neo4j.integration.shared.common.AltLikedByPerson
 import org.springframework.data.neo4j.integration.shared.common.AltPerson;
 import org.springframework.data.neo4j.integration.shared.common.AnotherThingWithAssignedId;
 import org.springframework.data.neo4j.integration.shared.common.BidirectionalEnd;
+import org.springframework.data.neo4j.integration.shared.common.BidirectionalSameEntity;
 import org.springframework.data.neo4j.integration.shared.common.BidirectionalStart;
 import org.springframework.data.neo4j.integration.shared.common.Club;
 import org.springframework.data.neo4j.integration.shared.common.ClubRelationship;
@@ -2124,6 +2125,35 @@ class RepositoryIT {
 				assertThat(records).hasSize(1);
 			}
 		}
+
+		@Test // DATAGRAPH-1469
+		void saveBidirectionalSameEntityRelationship(@Autowired BidirectionalSameEntityRepository repository) {
+			BidirectionalSameEntity entity1 = new BidirectionalSameEntity("e1");
+			BidirectionalSameEntity entity2 = new BidirectionalSameEntity("e2");
+
+			BidirectionalSameEntity.BidirectionalSameRelationship e1KnowsE2 =
+					new BidirectionalSameEntity.BidirectionalSameRelationship(entity2);
+			BidirectionalSameEntity.BidirectionalSameRelationship e2KnowsE1 =
+					new BidirectionalSameEntity.BidirectionalSameRelationship(entity1);
+
+			entity1.setKnows(Collections.singletonList(e1KnowsE2));
+			entity2.setKnows(Collections.singletonList(e2KnowsE1));
+
+			repository.save(entity1);
+			try (Session session = createSession()) {
+				List<Record> records = session.run(
+						"MATCH (e:BidirectionalSameEntity{id:'e1'})-[:KNOWS]->(:BidirectionalSameEntity{id:'e2'}) RETURN e")
+						.list();
+
+				assertThat(records).hasSize(1);
+
+				records = session.run(
+						"MATCH (e:BidirectionalSameEntity{id:'e2'})-[:KNOWS]->(:BidirectionalSameEntity{id:'e1'}) RETURN e")
+						.list();
+
+				assertThat(records).hasSize(1);
+			}
+		}
 	}
 
 	@Nested
@@ -3597,6 +3627,8 @@ class RepositoryIT {
 	interface EntityWithRelationshipPropertiesPathRepository
 			extends Neo4jRepository<EntityWithRelationshipPropertiesPath, Long> {}
 
+	interface BidirectionalSameEntityRepository extends Neo4jRepository<BidirectionalSameEntity, String> {}
+
 	@SpringJUnitConfig(Config.class)
 	static abstract class IntegrationTestBase {
 

src/test/java/org/springframework/data/neo4j/integration/shared/common/BidirectionalSameEntity.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2011-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.neo4j.integration.shared.common;
+
+import org.springframework.data.neo4j.core.schema.Id;
+import org.springframework.data.neo4j.core.schema.Node;
+import org.springframework.data.neo4j.core.schema.Relationship;
+import org.springframework.data.neo4j.core.schema.Relationship.Direction;
+import org.springframework.data.neo4j.core.schema.RelationshipProperties;
+import org.springframework.data.neo4j.core.schema.TargetNode;
+
+import java.util.List;
+
+/**
+ * @author Gerrit Meier
+ */
+@Node
+public class BidirectionalSameEntity {
+
+	@Id
+	private String id;
+
+	@Relationship(type = "KNOWS", direction = Direction.OUTGOING)
+	private List<BidirectionalSameRelationship> knows;
+
+	public BidirectionalSameEntity(String id) {
+		this.id = id;
+	}
+
+	public void setKnows(List<BidirectionalSameRelationship> knows) {
+		this.knows = knows;
+	}
+
+	/**
+	 * Relationship properties class for the same relationship.
+	 */
+	@RelationshipProperties
+	public static class BidirectionalSameRelationship {
+
+		public BidirectionalSameRelationship(BidirectionalSameEntity entity) {
+			this.entity = entity;
+		}
+
+		@TargetNode
+		BidirectionalSameEntity entity;
+	}
+}