add tests for Session.fetch()

hibernate-core/src/test/java/org/hibernate/orm/test/bytecode/enhancement/lazy/fetch/EnhancedFetchTest.java

@@ -0,0 +1,173 @@
+/*
+ * 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.bytecode.enhancement.lazy.fetch;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+import org.hibernate.Hibernate;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.SessionFactoryBuilder;
+import org.hibernate.collection.internal.PersistentSet;
+import org.hibernate.engine.spi.PersistentAttributeInterceptable;
+import org.hibernate.proxy.HibernateProxy;
+import org.hibernate.stat.Statistics;
+import org.hibernate.testing.bytecode.enhancement.BytecodeEnhancerRunner;
+import org.hibernate.testing.bytecode.enhancement.EnhancementOptions;
+import org.hibernate.testing.junit4.BaseNonConfigCoreFunctionalTestCase;
+import org.junit.After;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.util.Set;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author Gavin King
+ */
+@RunWith(BytecodeEnhancerRunner.class)
+@EnhancementOptions(lazyLoading = true)
+public class EnhancedFetchTest extends BaseNonConfigCoreFunctionalTestCase {
+
+	@Override
+	protected void configureSessionFactoryBuilder(SessionFactoryBuilder sfb) {
+		super.configureSessionFactoryBuilder( sfb );
+		sfb.applyStatisticsSupport( true );
+		sfb.applySecondLevelCacheSupport( false );
+		sfb.applyQueryCacheSupport( false );
+		sfb.applyCollectionsInDefaultFetchGroup( true );
+	}
+
+	@Override
+	protected void applyMetadataSources(MetadataSources sources) {
+		super.applyMetadataSources( sources );
+		sources.addAnnotatedClass( School.class );
+		sources.addAnnotatedClass( Student.class );
+	}
+
+	@Test
+	public void testFetch() {
+		inStatelessTransaction(
+				session -> {
+					School school = new School( "BHS" );
+					Student student = new Student( "gavin" );
+					student.school = school;
+					session.insert(school);
+					session.insert(student);
+				}
+		);
+
+		inStatelessSession(
+				session -> {
+					final Statistics stats = sessionFactory().getStatistics();
+					stats.clear();
+					final Student student = session.get( Student.class, "gavin" );
+					assertFalse( Hibernate.isInitialized( student.getSchool() ) );
+					assertFalse( student.getSchool() instanceof HibernateProxy );
+					assertTrue( student.getSchool() instanceof PersistentAttributeInterceptable );
+					long count = stats.getPrepareStatementCount();
+					session.fetch( student.getSchool() );
+					assertTrue( Hibernate.isInitialized( student.getSchool() ) );
+					assertEquals( "BHS", student.getSchool().getName() );
+
+					assertEquals( count+1, stats.getPrepareStatementCount() );
+				}
+		);
+
+		inStatelessSession(
+				session -> {
+					final Statistics stats = sessionFactory().getStatistics();
+					stats.clear();
+					final School school = session.get( School.class, "BHS" );
+					assertFalse( Hibernate.isInitialized( school.getStudents() ) );
+					assertTrue( school.getStudents() instanceof PersistentSet );
+					long count = stats.getPrepareStatementCount();
+					session.fetch( school.getStudents() );
+					assertTrue( Hibernate.isInitialized( school.getStudents() ) );
+
+					assertEquals( count+1, stats.getPrepareStatementCount() );
+				}
+		);
+	}
+
+	@After
+	public void cleanUpTestData() {
+		inTransaction(
+				session -> {
+					session.createQuery( "delete from Pupil" ).executeUpdate();
+					session.createQuery( "delete from School" ).executeUpdate();
+				}
+		);
+	}
+
+	@Entity(name = "School")
+	public static class School {
+
+		@Id
+		private String name;
+
+		private int age;
+
+		public School(String name) {
+			this.name = name;
+		}
+
+		School() {}
+
+		@OneToMany(mappedBy = "school")
+		private Set<Student> students;
+
+		public String getName() {
+			return name;
+		}
+
+		protected void setName(String name) {
+			this.name = name;
+		}
+
+		public int getAge() {
+			return age;
+		}
+
+		public void setAge(int age) {
+			this.age = age;
+		}
+
+		public Set<Student> getStudents() {
+			return students;
+		}
+	}
+
+	@Entity(name = "Pupil")
+	public static class Student {
+
+		@Id
+		private String id;
+
+		@ManyToOne(fetch = FetchType.LAZY)
+		private School school = null;
+
+		protected Student() {}
+
+		public Student(String id) {
+			this.id = id;
+		}
+
+		public String getId() {
+			return id;
+		}
+
+		public School getSchool() {
+			return school;
+		}
+	}
+}