HHH-5798 - DiscriminatorValue on abstract entity classes

Author: sebersole

hibernate-core/src/test/java/org/hibernate/orm/test/inheritance/SingleTableAbstractDiscriminatorTests.java

@@ -0,0 +1,90 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.orm.test.inheritance;
+
+import jakarta.persistence.DiscriminatorColumn;
+import jakarta.persistence.DiscriminatorValue;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Inheritance;
+import jakarta.persistence.InheritanceType;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.engine.spi.SessionFactoryImplementor;
+import org.hibernate.testing.orm.junit.Jira;
+import org.hibernate.testing.orm.junit.ServiceRegistry;
+import org.hibernate.testing.orm.junit.ServiceRegistryScope;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests that abstract classes within the hierarchy do not need {@linkplain DiscriminatorValue}
+ *
+ * @author Steve Ebersole
+ */
+@Jira( "https://hibernate.atlassian.net/browse/HHH-5798" )
+@ServiceRegistry
+public class SingleTableAbstractDiscriminatorTests {
+@Test
+void testCompliantModel(ServiceRegistryScope registryScope) {
+var model = new MetadataSources( registryScope.getRegistry() )
+.addAnnotatedClasses( Top.class, Middle.class, Bottom.class )
+.buildMetadata();
+try (var sf = (SessionFactoryImplementor) model.buildSessionFactory()) {
+}
+}
+
+@Test
+void testNonCompliantModel(ServiceRegistryScope registryScope) {
+// technically, according to JPA, this one should fail -
+//
+//	> The DiscriminatorValue annotation can only be specified on a concrete entity class.
+//
+ // we do not validate this though
+var model = new MetadataSources( registryScope.getRegistry() )
+.addAnnotatedClasses( Root.class, Trunk.class, Branch.class )
+.buildMetadata();
+try (var sf = (SessionFactoryImplementor) model.buildSessionFactory()) {
+}
+}
+
+@Entity
+@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
+@DiscriminatorColumn
+public static abstract class Top {
+@Id
+private Integer id;
+private String name;
+}
+
+@Entity
+public static abstract class Middle extends Top {
+}
+
+@Entity
+@DiscriminatorValue( "B" )
+public static class Bottom extends Middle {
+}
+
+@Entity
+@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
+@DiscriminatorColumn
+public static abstract class Root {
+@Id
+private Integer id;
+private String name;
+}
+
+@Entity
+@DiscriminatorValue( "illegal" )
+public static abstract class Trunk extends Root {
+}
+
+@Entity
+@DiscriminatorValue( "b" )
+public static class Branch extends Trunk {
+@Id
+private Integer id;
+private String name;
+}
+}