HHH-11233 - JPA SQL function with no arguments can only be called if we provide a comma

hibernate-core/src/main/antlr/hql.g

@@ -727,7 +727,7 @@ primaryExpression
 	;
 
 jpaFunctionSyntax!
-    : i:IDENT OPEN n:QUOTED_STRING COMMA a:exprList CLOSE {
+    : i:IDENT OPEN n:QUOTED_STRING (COMMA a:exprList)? CLOSE {
     	final String functionName = unquote( #n.getText() );
 
     	if ( functionName.equalsIgnoreCase( "cast" ) ) {

hibernate-core/src/test/java/org/hibernate/test/sql/function/JpaFunctionTest.java

@@ -0,0 +1,134 @@
+/*
+ * 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.test.sql.function;
+
+import java.sql.Timestamp;
+import java.util.Date;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+import org.hibernate.dialect.H2Dialect;
+import org.hibernate.hql.internal.ast.QuerySyntaxException;
+import org.hibernate.jpa.test.BaseEntityManagerFunctionalTestCase;
+
+import org.hibernate.testing.RequiresDialect;
+import org.hibernate.testing.TestForIssue;
+import org.junit.Test;
+
+import org.jboss.logging.Logger;
+
+import static org.hibernate.testing.transaction.TransactionUtil.doInJPA;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+/**
+ * @author Vlad Mihalcea
+ */
+@TestForIssue( jiraKey = "HHH-11620")
+@RequiresDialect(H2Dialect.class)
+public class JpaFunctionTest extends BaseEntityManagerFunctionalTestCase {
+
+	private static final Logger log = Logger.getLogger( JpaFunctionTest.class );
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class<?>[] {
+			Event.class
+		};
+	}
+
+	@Override
+	protected void afterEntityManagerFactoryBuilt() {
+		super.afterEntityManagerFactoryBuilt();
+		doInJPA( this::entityManagerFactory, entityManager -> {
+			Event event = new Event();
+			event.setId( 1L );
+			event.setMessage( "ABC" );
+			event.setCreatedOn( Timestamp.valueOf( "9999-12-31 00:00:00" ) );
+			entityManager.persist( event );
+		} );
+	}
+
+	@Test
+	public void testWithoutComma() {
+		doInJPA( this::entityManagerFactory, entityManager -> {
+			Date now = entityManager.createQuery(
+				"select FUNCTION('now') " +
+				"from Event " +
+				"where id = :id", Date.class)
+			.setParameter( "id", 1L )
+			.getSingleResult();
+			log.infof( "Current time: {}", now );
+		} );
+	}
+
+	@Test
+	public void testWithoutCommaFail() {
+		try {
+			doInJPA( this::entityManagerFactory, entityManager -> {
+				String result = entityManager.createQuery(
+						"select FUNCTION('substring' 'abc', 1,2) " +
+								"from Event " +
+								"where id = :id", String.class)
+						.setParameter( "id", 1L )
+						.getSingleResult();
+				fail("Should have thrown exception");
+			} );
+		}
+		catch ( Exception e ) {
+			assertEquals( QuerySyntaxException.class, e.getCause().getClass() );
+		}
+	}
+
+	@Test
+	public void testWithComma() {
+		doInJPA( this::entityManagerFactory, entityManager -> {
+			Date now = entityManager.createQuery(
+					"select FUNCTION('now',) " +
+							"from Event " +
+							"where id = :id", Date.class)
+					.setParameter( "id", 1L )
+					.getSingleResult();
+			log.infof( "Current time: {}", now );
+		} );
+	}
+
+	@Entity(name = "Event")
+	public static class Event {
+
+		@Id
+		private Long id;
+
+		private Date createdOn;
+
+		private String message;
+
+		public Long getId() {
+			return id;
+		}
+
+		public void setId(Long id) {
+			this.id = id;
+		}
+
+		public Date getCreatedOn() {
+			return createdOn;
+		}
+
+		public void setCreatedOn(Date createdOn) {
+			this.createdOn = createdOn;
+		}
+
+		public String getMessage() {
+			return message;
+		}
+
+		public void setMessage(String message) {
+			this.message = message;
+		}
+	}
+}