From 34f05d183a96234c5a7d3f9558503f71b14474cf Mon Sep 17 00:00:00 2001
From: Gavin <gavin@hibernate.org>
Date: Sun, 9 Apr 2023 17:00:17 +0200
Subject: [PATCH] cast DateTimes to Instants and vice versa

---
 .../hibernate/type/spi/TypeConfiguration.java |  2 ++
 .../orm/test/query/hql/FunctionTests.java     | 29 +++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/hibernate-core/src/main/java/org/hibernate/type/spi/TypeConfiguration.java b/hibernate-core/src/main/java/org/hibernate/type/spi/TypeConfiguration.java
index 69d33c8a31..6dfe4e04c3 100644
--- a/hibernate-core/src/main/java/org/hibernate/type/spi/TypeConfiguration.java
+++ b/hibernate-core/src/main/java/org/hibernate/type/spi/TypeConfiguration.java
@@ -14,6 +14,7 @@ import java.math.BigInteger;
 import java.sql.Time;
 import java.sql.Timestamp;
 import java.time.Duration;
+import java.time.Instant;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
@@ -340,6 +341,7 @@ public class TypeConfiguration implements SessionFactoryObserver, Serializable {
 			case "biginteger": return getBasicTypeForJavaType( BigInteger.class );
 			case "bigdecimal": return getBasicTypeForJavaType( BigDecimal.class );
 			case "duration": return getBasicTypeForJavaType( Duration.class );
+			case "instant": return getBasicTypeForJavaType( Instant.class );
 			case "binary": return getBasicTypeForJavaType( byte[].class );
 			//this one is very fragile ... works well for BIT or BOOLEAN columns only
 			//works OK, I suppose, for integer columns, but not at all for char columns
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/query/hql/FunctionTests.java b/hibernate-core/src/test/java/org/hibernate/orm/test/query/hql/FunctionTests.java
index e23d509cec..8450bdfe2b 100644
--- a/hibernate-core/src/test/java/org/hibernate/orm/test/query/hql/FunctionTests.java
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/query/hql/FunctionTests.java
@@ -33,6 +33,7 @@ import org.junit.jupiter.api.Test;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.time.ZoneOffset;
 import java.util.Date;
 import java.sql.Time;
 import java.sql.Timestamp;
@@ -864,6 +865,9 @@ public class FunctionTests {
 					assertThat( session.createQuery("select cast(time 12:13:14 as String)", String.class).getSingleResult(), anyOf( is("12:13:14"), is("12:13:14.0000"), is("12.13.14") ) );
 					assertThat( session.createQuery("select cast(datetime 1911-10-09 12:13:14 as String)", String.class).getSingleResult(), anyOf( startsWith("1911-10-09 12:13:14"), startsWith("1911-10-09-12.13.14") ) );
 
+					assertThat( session.createQuery("select cast(local datetime as Instant)", Instant.class).getSingleResult(), instanceOf(Instant.class) );
+					assertThat( session.createQuery("select cast(offset datetime as Instant)", Instant.class).getSingleResult(), instanceOf(Instant.class) );
+
 					assertThat( session.createQuery("select cast(1 as NumericBoolean)", Boolean.class).getSingleResult(), is(true) );
 					assertThat( session.createQuery("select cast(0 as NumericBoolean)", Boolean.class).getSingleResult(), is(false) );
 					assertThat( session.createQuery("select cast(true as YesNo)", Boolean.class).getSingleResult(), is(true) );
@@ -1246,6 +1250,31 @@ public class FunctionTests {
 		);
 	}
 
+	@Test
+	public void testInstantCast(SessionFactoryScope scope) {
+		scope.inTransaction(
+				session -> {
+					Instant instant = Instant.ofEpochSecond(123456789);
+					assertEquals( instant,
+							session.createQuery("select cast(?1 as Instant)", Instant.class)
+									.setParameter( 1, instant.atOffset(ZoneOffset.UTC) )
+									.getSingleResult() );
+					assertEquals( instant,
+							session.createQuery("select cast(?1 as Instant)", Instant.class)
+									.setParameter( 1, instant.atOffset(ZoneOffset.UTC).toLocalDateTime() )
+									.getSingleResult() );
+					assertEquals( instant.atOffset(ZoneOffset.UTC),
+							session.createQuery("select cast(?1 as OffsetDateTime)", OffsetDateTime.class)
+									.setParameter( 1, instant )
+									.getSingleResult() );
+					assertEquals( instant.atOffset(ZoneOffset.UTC).toLocalDateTime(),
+							session.createQuery("select cast(?1 as LocalDateTime)", LocalDateTime.class)
+									.setParameter( 1, instant )
+									.getSingleResult() );
+				}
+		);
+	}
+
 	@Test
 	public void testDurationCast(SessionFactoryScope scope) {
 		scope.inTransaction(