test for filtering @OneToMany associations by discriminator

see https://github.com/eclipse-ee4j/jpa-api/issues/39#issuecomment-830112571

hibernate-core/src/test/java/org/hibernate/orm/test/discriminatedcollections/Account.java

@@ -0,0 +1,92 @@
+package org.hibernate.orm.test.discriminatedcollections;
+
+import javax.persistence.DiscriminatorColumn;
+import javax.persistence.DiscriminatorValue;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
+
+@Entity
+@DiscriminatorColumn(name = "account_type")
+abstract class Account {
+
+    Account() {}
+
+    Account(Client client) {
+        this.client = client;
+        amount = 0.0;
+        rate = 12.0;
+    }
+
+    @Id @GeneratedValue
+    private Long id;
+
+    public Long getId() {
+        return id;
+    }
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    private Client client;
+
+    public Client getClient() {
+        return client;
+    }
+
+    private double amount;
+
+    public double getAmount() {
+        return amount;
+    }
+
+    public void setAmount(double amount) {
+        this.amount = amount;
+    }
+
+    private Double rate;
+
+    public Double getRate() {
+        return rate;
+    }
+
+    public void setRate(Double rate) {
+        this.rate = rate;
+    }
+
+    public abstract AccountType getType();
+}
+
+@Entity
+@DiscriminatorValue("D")
+class DebitAccount extends Account {
+
+    public DebitAccount() {
+    }
+
+    public DebitAccount(Client client) {
+        super(client);
+    }
+
+    @Override
+    public AccountType getType() {
+        return AccountType.DEBIT;
+    }
+}
+
+@Entity
+@DiscriminatorValue("C")
+class CreditAccount extends Account {
+
+    public CreditAccount() {
+    }
+
+    public CreditAccount(Client client) {
+        super(client);
+    }
+
+    @Override
+    public AccountType getType() {
+        return AccountType.CREDIT;
+    }
+}

hibernate-core/src/test/java/org/hibernate/orm/test/discriminatedcollections/AccountType.java

@@ -0,0 +1,6 @@
+package org.hibernate.orm.test.discriminatedcollections;
+
+public enum AccountType {
+    DEBIT,
+    CREDIT
+}

hibernate-core/src/test/java/org/hibernate/orm/test/discriminatedcollections/Client.java

@@ -0,0 +1,48 @@
+package org.hibernate.orm.test.discriminatedcollections;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.OneToMany;
+import java.util.HashSet;
+import java.util.Set;
+
+@Entity
+class Client {
+
+    @Id @GeneratedValue
+    private Long id;
+
+    public Long getId() {
+        return id;
+    }
+
+    private String name;
+
+    public String getName() {
+        return name;
+    }
+
+    @OneToMany(cascade = CascadeType.ALL, mappedBy = "client", fetch = FetchType.LAZY)
+    private Set<DebitAccount> debitAccounts = new HashSet<>();
+
+    @OneToMany(cascade = CascadeType.ALL, mappedBy = "client", fetch = FetchType.LAZY)
+    private Set<CreditAccount> creditAccounts = new HashSet<>();
+
+    Client() {}
+
+    Client(String name) {
+        this.name = name;
+    }
+
+    public Set<CreditAccount> getCreditAccounts() {
+        return creditAccounts;
+    }
+
+    public Set<DebitAccount> getDebitAccounts() {
+        return debitAccounts;
+    }
+}
+

hibernate-core/src/test/java/org/hibernate/orm/test/discriminatedcollections/TempTest.java

@@ -0,0 +1,85 @@
+/*
+ * 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.discriminatedcollections;
+
+import org.hibernate.Session;
+import org.hibernate.query.criteria.JpaCriteriaQuery;
+import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;
+import org.junit.Test;
+
+import javax.persistence.criteria.JoinType;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+/**
+ * @author Gavin King
+ */
+public class TempTest extends BaseCoreFunctionalTestCase {
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class[] { Client.class, Account.class, DebitAccount.class, CreditAccount.class };
+	}
+
+	@Test
+	public void test() {
+		Client c = new Client("Gavin");
+		DebitAccount da = new DebitAccount(c);
+		CreditAccount ca = new CreditAccount(c);
+		c.getDebitAccounts().add(da);
+		c.getCreditAccounts().add(ca);
+		Session session = openSession();
+		session.beginTransaction();
+		session.persist(c);
+		session.getTransaction().commit();
+		session.close();
+
+		session = openSession();
+		Client client = session.find(Client.class, c.getId());
+		assertEquals(1, client.getDebitAccounts().size());
+		assertEquals(1, client.getCreditAccounts().size());
+		assertNotEquals(client.getDebitAccounts().iterator().next().getId(),
+				client.getCreditAccounts().iterator().next().getId());
+		session.close();
+
+		session = openSession();
+		client = session.createQuery("from Client", Client.class).getSingleResult();
+		assertEquals(1, client.getDebitAccounts().size());
+		assertEquals(1, client.getCreditAccounts().size());
+		assertNotEquals(client.getDebitAccounts().iterator().next().getId(),
+				client.getCreditAccounts().iterator().next().getId());
+		session.close();
+
+		session = openSession();
+		client = session.createQuery("from Client c left join fetch c.debitAccounts", Client.class).getSingleResult();
+		assertEquals(1, client.getDebitAccounts().size());
+		assertEquals(1, client.getCreditAccounts().size());
+		assertNotEquals(client.getDebitAccounts().iterator().next().getId(),
+				client.getCreditAccounts().iterator().next().getId());
+		session.close();
+
+		session = openSession();
+		client = session.createQuery("from Client c left join fetch c.debitAccounts left join fetch c.creditAccounts", Client.class).getSingleResult();
+		assertEquals(1, client.getDebitAccounts().size());
+		assertEquals(1, client.getCreditAccounts().size());
+		assertNotEquals(client.getDebitAccounts().iterator().next().getId(),
+				client.getCreditAccounts().iterator().next().getId());
+		session.close();
+
+		session = openSession();
+		JpaCriteriaQuery<Client> query = sessionFactory().getCriteriaBuilder().createQuery(Client.class);
+		query.from(Client.class).fetch(Client_.creditAccounts, JoinType.LEFT);
+		client = session.createQuery(query).getSingleResult();
+		assertEquals(1, client.getDebitAccounts().size());
+		assertEquals(1, client.getCreditAccounts().size());
+		assertNotEquals(client.getDebitAccounts().iterator().next().getId(),
+				client.getCreditAccounts().iterator().next().getId());
+		session.close();
+	}
+}
+