From 72fa04d81d6a194fa5df0a000527df47ab4847f7 Mon Sep 17 00:00:00 2001
From: Michael Simons <michael@simons.ac>
Date: Mon, 6 May 2019 11:46:22 +0200
Subject: [PATCH] DATAGRAPH-1220 - Ensure Kotlin Data classes support @Id
 @Generated value. (#490)

---
 .../PersistenceConstructorsTests.java         | 59 +++++++++++++++++++
 .../constructors/domain/KotlinPerson.kt       | 12 ++++
 2 files changed, 71 insertions(+)

diff --git a/spring-data-neo4j/src/test/java/org/springframework/data/neo4j/integration/constructors/PersistenceConstructorsTests.java b/spring-data-neo4j/src/test/java/org/springframework/data/neo4j/integration/constructors/PersistenceConstructorsTests.java
index 96b1065c6..8363b499e 100644
--- a/spring-data-neo4j/src/test/java/org/springframework/data/neo4j/integration/constructors/PersistenceConstructorsTests.java
+++ b/spring-data-neo4j/src/test/java/org/springframework/data/neo4j/integration/constructors/PersistenceConstructorsTests.java
@@ -16,6 +16,7 @@
 package org.springframework.data.neo4j.integration.constructors;
 
 import static java.util.stream.Collectors.*;
+import static org.hamcrest.CoreMatchers.*;
 import static org.junit.Assert.*;
 
 import java.util.ArrayList;
@@ -24,9 +25,11 @@ import java.util.Collection;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Optional;
 import java.util.stream.StreamSupport;
 
 import org.assertj.core.util.DateUtil;
+import org.hamcrest.CoreMatchers;
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;
@@ -51,6 +54,7 @@ import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.transaction.support.TransactionTemplate;
 
 /**
  * @author Nicolas Mervaillie
@@ -82,6 +86,10 @@ public class PersistenceConstructorsTests {
 
 	@Autowired KotlinPersonRepository kotlinRepository;
 
+	@Autowired KotlinDataPersonRepository kotlinDataPersonRepository;
+
+	@Autowired TransactionTemplate transactionTemplate;
+
 	@Test
 	public void shouldHandleSimpleEntityWithConstructor() {
 
@@ -209,6 +217,49 @@ public class PersistenceConstructorsTests {
 		assertEquals("foo", persons.iterator().next().getName());
 	}
 
+	@Test // DATAGRAPH-1220
+	public void shouldSupportKotlinDataClassesWithGeneratedIds() {
+
+		KotlinDataPerson person0 = KotlinPersonKt.newDataPerson("Not to be persisted");
+
+		// Make sure we don't interfere with OGMs session cache but also don't clean it externally
+
+		KotlinDataPerson person1 = transactionTemplate
+				.execute(t -> kotlinDataPersonRepository.save(KotlinPersonKt.newDataPerson("Data Person 1")));
+		KotlinDataPerson person2 = transactionTemplate
+				.execute(t -> kotlinDataPersonRepository.save(KotlinPersonKt.newDataPerson("Data Person 2")));
+
+		// Assert that the id is actually null without database interaction
+		assertThat(person0.getId(), is(nullValue()));
+		assertThat(person1.getId(), is(notNullValue()));
+		assertThat(person2.getId(), is(notNullValue()));
+
+		// Load the rest
+		transactionTemplate.execute(t -> {
+			List<KotlinDataPerson> loadedPersons = kotlinDataPersonRepository.findAll();
+			assertThat(loadedPersons.size(), is(2));
+			assertThat(loadedPersons, CoreMatchers.hasItems(person1, person2));
+			return null;
+		});
+
+		transactionTemplate.execute(t -> {
+			Optional<KotlinDataPerson> loadedPerson1 = kotlinDataPersonRepository.findById(person1.getId());
+			Optional<KotlinDataPerson> loadedPerson2 = kotlinDataPersonRepository.findById(person2.getId());
+
+			assertThat(loadedPerson1.isPresent(), is(true));
+			assertThat(loadedPerson2.isPresent(), is(true));
+			return null;
+		});
+
+		// Double check the finder by another index field
+		transactionTemplate.execute(t -> {
+
+			Optional<KotlinDataPerson> loadedPerson1 = kotlinDataPersonRepository.findByName(person1.getName());
+			assertThat(loadedPerson1.isPresent(), is(true));
+			return null;
+		});
+	}
+
 	@Test
 	public void shouldSupportQueryResults() {
 		session.query(
@@ -245,6 +296,14 @@ public class PersistenceConstructorsTests {
 	@Repository
 	public interface KotlinPersonRepository extends Neo4jRepository<KotlinPerson, String> {}
 
+	@Repository
+	public interface KotlinDataPersonRepository extends Neo4jRepository<KotlinDataPerson, Long> {
+
+		List<KotlinDataPerson> findAll();
+
+		Optional<KotlinDataPerson> findByName(String name);
+	}
+
 	@Repository
 	public interface PersonMultipleConstructorsRepository extends Neo4jRepository<PersonMultipleConstructors, String> {}
 
diff --git a/spring-data-neo4j/src/test/kotlin/org/springframework/data/neo4j/integration/constructors/domain/KotlinPerson.kt b/spring-data-neo4j/src/test/kotlin/org/springframework/data/neo4j/integration/constructors/domain/KotlinPerson.kt
index 43013f3d8..4e5eb410b 100644
--- a/spring-data-neo4j/src/test/kotlin/org/springframework/data/neo4j/integration/constructors/domain/KotlinPerson.kt
+++ b/spring-data-neo4j/src/test/kotlin/org/springframework/data/neo4j/integration/constructors/domain/KotlinPerson.kt
@@ -15,12 +15,15 @@
  */
 package org.springframework.data.neo4j.integration.constructors.domain
 
+import org.neo4j.ogm.annotation.GeneratedValue
 import org.neo4j.ogm.annotation.Id
+import org.neo4j.ogm.annotation.Index
 import org.neo4j.ogm.annotation.NodeEntity
 import org.neo4j.ogm.annotation.Relationship
 
 /**
  * @author Nicolas Mervaillie
+ * @author Michael J. Simons
  */
 @NodeEntity
 data class KotlinPerson(
@@ -28,3 +31,12 @@ data class KotlinPerson(
         @Relationship var friendships: List<KotlinFriendship> = ArrayList()) {
 
 }
+
+@NodeEntity
+data class KotlinDataPerson(
+        @Id @GeneratedValue var id: Long? = null,
+        @Index(unique = true) var name: String
+)
+
+// Just a helper to omit the id constructor parameter completely when calling from Java.
+fun newDataPerson(name: String) = KotlinDataPerson(name = name)