#50 - Better account for annotation attributes without default values

Author: sebersole

src/main/java/org/hibernate/models/internal/AbstractTypeDescriptor.java

@@ -33,9 +33,15 @@ public V createValue(
 			AttributeDescriptor<?> attributeDescriptor,
 			AnnotationTarget target,
 			SourceModelBuildingContext context) {
+		final Object defaultValue = attributeDescriptor.getAttributeMethod().getDefaultValue();
+		if ( defaultValue == null ) {
+			// a non-defaulted attribute, just return null for the baseline
+			return null;
+		}
+
 		//noinspection unchecked
 		final ValueWrapper<V, Object> valueWrapper = (ValueWrapper<V, Object>) createJdkWrapper( context );
-		return valueWrapper.wrap( attributeDescriptor.getAttributeMethod().getDefaultValue(), target, context );
+		return valueWrapper.wrap( defaultValue, target, context );
 	}
 
 	@Override

src/test/java/org/hibernate/models/annotations/DefaultValueTests.java

@@ -0,0 +1,89 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright: Red Hat Inc. and Hibernate Authors
+ */
+
+package org.hibernate.models.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.hibernate.models.internal.SourceModelBuildingContextImpl;
+import org.hibernate.models.spi.AnnotationDescriptor;
+import org.hibernate.models.spi.AnnotationDescriptorRegistry;
+import org.hibernate.models.spi.AnnotationUsage;
+import org.hibernate.models.spi.AttributeDescriptor;
+import org.hibernate.models.spi.ClassDetails;
+import org.hibernate.models.spi.ClassDetailsRegistry;
+import org.hibernate.models.spi.MutableAnnotationUsage;
+
+import org.junit.jupiter.api.Test;
+
+import org.jboss.jandex.Index;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.hibernate.models.SourceModelTestHelper.buildJandexIndex;
+import static org.hibernate.models.SourceModelTestHelper.createBuildingContext;
+
+/**
+ * @author Steve Ebersole
+ */
+public class DefaultValueTests {
+	@Test
+	void testWithJandex() {
+		doTest( buildJandexIndex( SimpleEntity.class ) );
+	}
+
+	@Test
+	void testWithoutJandex() {
+		doTest( null );
+	}
+
+	private void doTest(Index index) {
+		final SourceModelBuildingContextImpl buildingContext = createBuildingContext( index, TestEntity.class );
+		final AnnotationDescriptorRegistry descriptorRegistry = buildingContext.getAnnotationDescriptorRegistry();
+
+		final AnnotationDescriptor<CustomAnnotation> descriptor = descriptorRegistry.getDescriptor( CustomAnnotation.class );
+		final List<String> attributeNames = descriptor
+				.getAttributes()
+				.stream()
+				.map( AttributeDescriptor::getName )
+				.toList();
+		assertThat( attributeNames ).contains( "name", "someClassValue" );
+		assertThat( descriptor.findAttribute( "someClassValue" ) ).isNotNull();
+
+		final ClassDetailsRegistry classDetailsRegistry = buildingContext.getClassDetailsRegistry();
+		final ClassDetails entityClassDetails = classDetailsRegistry.getClassDetails( TestEntity.class.getName() );
+		final AnnotationUsage<CustomAnnotation> annotationUsage = entityClassDetails.getAnnotationUsage( CustomAnnotation.class );
+		assertThat( annotationUsage.getClassDetails( "someClassValue" ) ).isNotNull();
+		assertThat( annotationUsage.getClassDetails( "someClassValue" ).toJavaClass() ).isEqualTo( Entity.class );
+
+		final MutableAnnotationUsage<CustomAnnotation> created = descriptor.createUsage( null, buildingContext );
+	}
+
+	@Target( ElementType.TYPE )
+	@Retention( RetentionPolicy.RUNTIME )
+	public @interface CustomAnnotation {
+		String name();
+		Class someClassValue();
+	}
+
+	@Entity(name="TestEntity")
+	@Table(name="TestEntity")
+	@CustomAnnotation( name="tester", someClassValue = Entity.class )
+	public static class TestEntity {
+		@Id
+		private Integer id;
+		private String name;
+	}
+}