HHH-16905 Add Test for Issue

hibernate-core/src/test/java/org/hibernate/orm/test/jpa/criteria/nestedfetch/NestedFetchTest.java

@@ -0,0 +1,164 @@
+package org.hibernate.orm.test.jpa.criteria.nestedfetch;
+
+import java.io.Serializable;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.hibernate.testing.orm.junit.EntityManagerFactoryScope;
+import org.hibernate.testing.orm.junit.Jira;
+import org.hibernate.testing.orm.junit.Jpa;
+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.Embeddable;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.PrimaryKeyJoinColumn;
+import jakarta.persistence.criteria.CriteriaBuilder;
+import jakarta.persistence.criteria.CriteriaQuery;
+import jakarta.persistence.criteria.Fetch;
+import jakarta.persistence.criteria.JoinType;
+import jakarta.persistence.criteria.Root;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+@Jpa( annotatedClasses = {
+		NestedFetchTest.RootEntity.class,
+		NestedFetchTest.Chil1PK.class,
+		NestedFetchTest.Child1Entity.class,
+		NestedFetchTest.Child2Entity.class,
+} )
+@Jira( "https://hibernate.atlassian.net/browse/HHH-16905" )
+public class NestedFetchTest {
+	@BeforeAll
+	public void setUp(EntityManagerFactoryScope scope) {
+		scope.inTransaction( entityManager -> {
+			final RootEntity root = new RootEntity();
+			entityManager.persist( root );
+			final Child2Entity child2 = new Child2Entity( "222" );
+			entityManager.persist( child2 );
+			final Child1Entity child1 = new Child1Entity( root, child2 );
+			entityManager.persist( child1 );
+		} );
+	}
+
+	@AfterAll
+	public void tearDown(EntityManagerFactoryScope scope) {
+		scope.inTransaction( entityManager -> {
+			entityManager.createQuery( "delete from Child1Entity" ).executeUpdate();
+			entityManager.createQuery( "delete from Child2Entity" ).executeUpdate();
+			entityManager.createQuery( "delete from RootEntity" ).executeUpdate();
+		} );
+	}
+
+	@Test
+	public void testNestedFetch(EntityManagerFactoryScope scope) {
+		RootEntity rootEntity = scope.fromTransaction( entityManager -> {
+			final CriteriaBuilder cb = entityManager.getCriteriaBuilder();
+			final CriteriaQuery<RootEntity> cq = cb.createQuery( RootEntity.class );
+			final Root<RootEntity> fromRoot = cq.from( RootEntity.class );
+			final Fetch<RootEntity, Child1Entity> fetchDepth1 = fromRoot.fetch(
+					"child1Entities",
+					JoinType.LEFT
+			);
+			final Fetch<Child1Entity, Child2Entity> fetchDepth2 = fetchDepth1.fetch(
+					"child2Entity",
+					JoinType.LEFT
+			);
+			return entityManager.createQuery( cq.select( fromRoot ) ).getSingleResult();
+		} );
+		//dependent relations should already be fetched and be available outside the transaction
+		assertThat( rootEntity.getChild1Entities().size() ).isEqualTo( 1 );
+		final Child1Entity depth1Entity = rootEntity.getChild1Entities().iterator().next();
+		final Child2Entity depth2Entity = depth1Entity.getChild2Entity();
+		assertThat( depth2Entity ).isNotNull();
+		assertThat( depth2Entity.getVal() ).isEqualTo( "222" );
+	}
+
+	@Entity( name = "RootEntity" )
+	public static class RootEntity {
+		@Id
+		@GeneratedValue
+		private int id;
+
+		@OneToMany( mappedBy = "rootEntity" )
+		private Set<Child1Entity> child1Entities;
+
+		public Set<Child1Entity> getChild1Entities() {
+			return child1Entities;
+		}
+	}
+
+	@Embeddable
+	public static class Chil1PK implements Serializable {
+		@ManyToOne( fetch = FetchType.LAZY )
+		@JoinColumn( name = "rootId", referencedColumnName = "id", nullable = false )
+		private RootEntity rootEntity;
+
+		@ManyToOne( fetch = FetchType.LAZY )
+		@JoinColumn( name = "child2Id", referencedColumnName = "id", nullable = false )
+		private Child2Entity child2Entity;
+	}
+
+	@Entity( name = "Child1Entity" )
+	@IdClass( Chil1PK.class )
+	public static class Child1Entity {
+		@Id
+		@PrimaryKeyJoinColumn( name = "rootId", referencedColumnName = "id" )
+		@ManyToOne( fetch = FetchType.LAZY )
+		private RootEntity rootEntity;
+
+		@Id
+		@PrimaryKeyJoinColumn( name = "child2Id", referencedColumnName = "id" )
+		@ManyToOne( fetch = FetchType.LAZY )
+		private Child2Entity child2Entity;
+
+		public Child1Entity() {
+		}
+
+		public Child1Entity(RootEntity rootEntity, Child2Entity child2Entity) {
+			this.rootEntity = rootEntity;
+			this.child2Entity = child2Entity;
+		}
+
+		public Child2Entity getChild2Entity() {
+			return child2Entity;
+		}
+	}
+
+
+	@Entity( name = "Child2Entity" )
+	public static class Child2Entity {
+		@Id
+		@GeneratedValue
+		private int id;
+
+		@OneToMany( mappedBy = "child2Entity" )
+		private Set<Child1Entity> child1Entities = new HashSet<>();
+
+		private String val;
+
+		public Child2Entity() {
+		}
+
+		public Child2Entity(String val) {
+			this.val = val;
+		}
+
+		public String getVal() {
+			return val;
+		}
+
+		public Set<Child1Entity> getChild1Entities() {
+			return child1Entities;
+		}
+	}
+}