HHH-15395 Add test for issue

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

@@ -0,0 +1,115 @@
+package org.hibernate.orm.test.jpa.criteria;
+
+import java.util.List;
+
+import org.hibernate.dialect.DerbyDialect;
+import org.hibernate.dialect.Dialect;
+import org.hibernate.dialect.function.CommonFunctionFactory;
+import org.hibernate.engine.spi.SessionFactoryImplementor;
+import org.hibernate.query.criteria.HibernateCriteriaBuilder;
+
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.orm.junit.EntityManagerFactoryScope;
+import org.hibernate.testing.orm.junit.Jpa;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.criteria.CriteriaQuery;
+import jakarta.persistence.criteria.Root;
+import org.assertj.core.data.Offset;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+@Jpa(
+		annotatedClasses = PowerFunctionTest.Person.class
+)
+@TestForIssue(jiraKey = "HHH-15395")
+public class PowerFunctionTest {
+
+	@BeforeEach
+	public void setUp(EntityManagerFactoryScope scope) {
+		scope.inTransaction(
+				entityManager -> {
+					Person person = new Person( 1L, "And", 50 );
+					entityManager.persist( person );
+				}
+		);
+	}
+
+	@Test
+	public void testIt(EntityManagerFactoryScope scope) {
+		scope.inTransaction(
+				entityManager -> {
+					HibernateCriteriaBuilder cb = (HibernateCriteriaBuilder) entityManager.getCriteriaBuilder();
+					CriteriaQuery<Double> query = cb.createQuery( Double.class );
+					Root<Person> root = query.from( Person.class );
+
+					query.select( cb.power( root.get( "age" ), 2 ) );
+
+					List<Double> results = entityManager.createQuery( query ).getResultList();
+
+					assertThat( results.size() ).isEqualTo( 1 );
+
+					if ( getDialect( scope ) instanceof DerbyDialect ) {
+						/**
+						 for Derby dialect we are emulating the power function see {@link CommonFunctionFactory#power_expLn()}.
+						 */
+						assertThat( results.get( 0 ) ).isEqualTo( 2500D, Offset.offset( 0.000000000001 ) );
+					}
+					else {
+						assertThat( results.get( 0 ) ).isEqualTo( 2500D );
+					}
+				}
+		);
+	}
+
+	private Dialect getDialect(EntityManagerFactoryScope scope) {
+		return ((SessionFactoryImplementor) scope.getEntityManagerFactory()).getJdbcServices().getDialect();
+	}
+
+	@Entity(name = "Person")
+	public static class Person {
+		@Id
+		private Long id;
+
+		private String name;
+
+		private int age;
+
+		public Person() {
+		}
+
+		public Person(Long id, String name, int age) {
+			this.id = id;
+			this.name = name;
+			this.age = age;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+		public void setId(Long id) {
+			this.id = id;
+		}
+
+		public String getName() {
+			return name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+
+		public int getAge() {
+			return age;
+		}
+
+		public void setAge(int age) {
+			this.age = age;
+		}
+
+	}
+}