GH-2154 - Return new instance after incrementing version property on immutables.

This fixes #2154.

Author: michael-simons

src/main/java/org/springframework/data/neo4j/core/mapping/callback/OptimisticLockingSupport.java

@@ -39,23 +39,24 @@ Object getAndIncrementVersionPropertyIfNecessary(Object entity) {
 		Neo4jPersistentEntity<?> neo4jPersistentEntity = (Neo4jPersistentEntity<?>) mappingContext
 				.getRequiredNodeDescription(entity.getClass());
 
-		if (neo4jPersistentEntity.hasVersionProperty()) {
-			PersistentPropertyAccessor<Object> propertyAccessor = neo4jPersistentEntity.getPropertyAccessor(entity);
-			Neo4jPersistentProperty versionProperty = neo4jPersistentEntity.getRequiredVersionProperty();
+		if (!neo4jPersistentEntity.hasVersionProperty()) {
+			return entity;
+		}
 
-			if (!Long.class.isAssignableFrom(versionProperty.getType())) {
-				return entity;
-			}
+		PersistentPropertyAccessor<Object> propertyAccessor = neo4jPersistentEntity.getPropertyAccessor(entity);
+		Neo4jPersistentProperty versionProperty = neo4jPersistentEntity.getRequiredVersionProperty();
 
-			Long versionPropertyValue = (Long) propertyAccessor.getProperty(versionProperty);
+		if (!Long.class.isAssignableFrom(versionProperty.getType())) {
+			return entity;
+		}
 
-			long newVersionValue = 0;
-			if (versionPropertyValue != null) {
-				newVersionValue = versionPropertyValue + 1;
-			}
+		Long versionPropertyValue = (Long) propertyAccessor.getProperty(versionProperty);
 
-			propertyAccessor.setProperty(versionProperty, newVersionValue);
+		long newVersionValue = 0;
+		if (versionPropertyValue != null) {
+			newVersionValue = versionPropertyValue + 1;
 		}
-		return entity;
+		propertyAccessor.setProperty(versionProperty, newVersionValue);
+		return propertyAccessor.getBean();
 	}
 }

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

@@ -33,6 +33,8 @@
 import org.springframework.context.annotation.Configuration;
 import org.springframework.dao.OptimisticLockingFailureException;
 import org.springframework.data.neo4j.config.AbstractNeo4jConfig;
+import org.springframework.data.neo4j.core.Neo4jTemplate;
+import org.springframework.data.neo4j.integration.shared.common.ImmutableVersionedThing;
 import org.springframework.data.neo4j.integration.shared.common.VersionedThing;
 import org.springframework.data.neo4j.integration.shared.common.VersionedThingWithAssignedId;
 import org.springframework.data.neo4j.repository.Neo4jRepository;
@@ -270,6 +272,18 @@ void shouldFailOnDeleteByEntityWithWrongVersion(@Autowired VersionedThingWithAss
 		assertThatExceptionOfType(OptimisticLockingFailureException.class).isThrownBy(() -> repository.delete(thing));
 	}
 
+	@Test // GH-2154
+	void immutablesShouldWork(@Autowired Neo4jTemplate neo4jTemplate) {
+
+		ImmutableVersionedThing immutableVersionedThing = new ImmutableVersionedThing(23L, "Hello");
+
+		immutableVersionedThing = neo4jTemplate.save(immutableVersionedThing);
+		assertThat(immutableVersionedThing.getMyVersion()).isNotNull();
+
+		ImmutableVersionedThing copy = immutableVersionedThing.withMyVersion(4711L).withName("World");
+		assertThatExceptionOfType(OptimisticLockingFailureException.class).isThrownBy(() -> neo4jTemplate.save(copy));
+	}
+
 	interface VersionedThingRepository extends Neo4jRepository<VersionedThing, Long> {}
 
 	interface VersionedThingWithAssignedIdRepository extends Neo4jRepository<VersionedThingWithAssignedId, Long> {}

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

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2011-2021 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 lombok.Getter;
+import lombok.With;
+
+import org.springframework.data.annotation.Version;
+import org.springframework.data.neo4j.core.schema.Id;
+import org.springframework.data.neo4j.core.schema.Node;
+
+/**
+ * @author Michael J. Simons
+ */
+@Node
+@Getter
+public class ImmutableVersionedThing {
+
+	@Id
+	private final Long id;
+
+	@Version
+	@With
+	private final Long myVersion;
+
+	@With
+	private final String name;
+
+	public ImmutableVersionedThing(Long id, String name) {
+		this(id, null, name);
+	}
+
+	private ImmutableVersionedThing(Long id, Long myVersion, String name) {
+		this.id = id;
+		this.myVersion = myVersion;
+		this.name = name;
+	}
+}