HHH-16602 Add test for issue

hibernate-core/src/test/java/org/hibernate/orm/test/flush/LazyCollectionInitalizationPreUpdateTest.java

@@ -0,0 +1,136 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+package org.hibernate.orm.test.flush;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.hibernate.Hibernate;
+import org.hibernate.event.spi.EventType;
+import org.hibernate.event.spi.PreUpdateEvent;
+import org.hibernate.event.spi.PreUpdateEventListener;
+
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.Jira;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Marco Belladelli
+ */
+@SessionFactory
+@DomainModel( annotatedClasses = {
+		LazyCollectionInitalizationPreUpdateTest.TreeNode.class,
+		LazyCollectionInitalizationPreUpdateTest.ReferencedEntity.class,
+} )
+@Jira( "https://hibernate.atlassian.net/browse/HHH-16602" )
+public class LazyCollectionInitalizationPreUpdateTest {
+	@BeforeAll
+	public void setUp(SessionFactoryScope scope) {
+		scope.inTransaction( session -> {
+			final TreeNode first = new TreeNode( 1L, null );
+			session.persist( first );
+			final TreeNode second = new TreeNode( 2L, first );
+			final ReferencedEntity referenced = new ReferencedEntity( "referenced" );
+			session.persist( referenced );
+			second.getSomeSet().add( referenced );
+			session.persist( second );
+		} );
+	}
+
+	@AfterAll
+	public void tearDown(SessionFactoryScope scope) {
+		scope.inTransaction( session -> session.createMutationQuery( "delete from ReferencedEntity" ).executeUpdate() );
+	}
+
+	@Test
+	public void test(SessionFactoryScope scope) {
+		scope.getSessionFactory().getEventEngine().getListenerRegistry().appendListeners(
+				EventType.PRE_UPDATE,
+				Listener.class
+		);
+		scope.inTransaction( session -> {
+			final TreeNode first = session.byId( TreeNode.class ).load( 1L );
+			final TreeNode second = session.byId( TreeNode.class ).load( 2L );
+			session.remove( first );
+			session.remove( second );
+		} );
+	}
+
+	@Entity( name = "TreeNode" )
+	public static class TreeNode {
+		@Id
+		private Long id;
+
+		@ManyToOne
+		@JoinColumn( name = "parent_id" )
+		private TreeNode parent;
+
+		@OneToMany
+		private Set<ReferencedEntity> someSet = new HashSet<>();
+
+		public TreeNode() {
+		}
+
+		public TreeNode(Long id, TreeNode parent) {
+			this.id = id;
+			this.parent = parent;
+		}
+
+		public Set<ReferencedEntity> getSomeSet() {
+			return someSet;
+		}
+	}
+
+	@Entity( name = "ReferencedEntity" )
+	public static class ReferencedEntity {
+		@Id
+		@GeneratedValue
+		private Long id;
+
+		private String name;
+
+		public ReferencedEntity() {
+		}
+
+		public ReferencedEntity(String name) {
+			this.name = name;
+		}
+
+		public String getName() {
+			return name;
+		}
+	}
+
+	public static class Listener implements PreUpdateEventListener {
+		@Override
+		public boolean onPreUpdate(PreUpdateEvent event) {
+			final Object entity = event.getEntity();
+			if ( entity instanceof TreeNode ) {
+				final TreeNode treeNode = (TreeNode) entity;
+				assertThat( Hibernate.isInitialized( treeNode.getSomeSet() ) ).isFalse();
+				treeNode.getSomeSet().forEach( entry -> {
+					assertThat( entry.getName() ).isEqualTo( "referenced" );
+				} );
+				assertThat( Hibernate.isInitialized( treeNode.getSomeSet() ) ).isTrue();
+			}
+			return false;
+		}
+	}
+}