ISSUE-32936 | Allow plugging in Hibernate ORM's TypeContributor and FunctionContributor

extensions/hibernate-orm/deployment/src/main/java/io/quarkus/hibernate/orm/deployment/ClassNames.java

@@ -71,6 +71,8 @@ private static DotName createConstant(String fqcn) {
     public static final DotName FORMAT_MAPPER = createConstant("org.hibernate.type.format.FormatMapper");
     public static final DotName JSON_FORMAT = createConstant("io.quarkus.hibernate.orm.JsonFormat");
     public static final DotName XML_FORMAT = createConstant("io.quarkus.hibernate.orm.XmlFormat");
+    public static final DotName FUNCTION_CONTRIBUTOR = createConstant("org.hibernate.boot.model.FunctionContributor");
+    public static final DotName
 
     public static final List<DotName> GENERATORS = List.of(
             createConstant("org.hibernate.generator.Assigned"),

extensions/hibernate-orm/deployment/src/main/java/io/quarkus/hibernate/orm/deployment/HibernateOrmCdiProcessor.java

@@ -92,7 +92,8 @@ public class HibernateOrmCdiProcessor {
             ClassNames.TENANT_CONNECTION_RESOLVER,
             ClassNames.INTERCEPTOR,
             ClassNames.STATEMENT_INSPECTOR,
-            ClassNames.FORMAT_MAPPER);
+            ClassNames.FORMAT_MAPPER,
+            ClassNames.FUNCTION_CONTRIBUTOR);
 
     @BuildStep
     AnnotationsTransformerBuildItem convertJpaResourceAnnotationsToQualifier(

extensions/hibernate-orm/deployment/src/test/java/io/quarkus/hibernate/orm/functioncontributors/CustomFunctionContributor.java

@@ -0,0 +1,63 @@
+package io.quarkus.hibernate.orm.functioncontributors;
+
+import io.quarkus.hibernate.orm.PersistenceUnitExtension;
+import jakarta.enterprise.context.ApplicationScoped;
+import org.hibernate.boot.model.FunctionContributions;
+import org.hibernate.boot.model.FunctionContributor;
+import org.hibernate.metamodel.model.domain.ReturnableType;
+import org.hibernate.query.sqm.function.AbstractSqmSelfRenderingFunctionDescriptor;
+import org.hibernate.query.sqm.produce.function.StandardArgumentsValidators;
+import org.hibernate.query.sqm.produce.function.StandardFunctionArgumentTypeResolvers;
+import org.hibernate.query.sqm.produce.function.StandardFunctionReturnTypeResolvers;
+import org.hibernate.sql.ast.SqlAstNodeRenderingMode;
+import org.hibernate.sql.ast.SqlAstTranslator;
+import org.hibernate.sql.ast.spi.SqlAppender;
+import org.hibernate.sql.ast.tree.SqlAstNode;
+import org.hibernate.type.StandardBasicTypes;
+import org.hibernate.type.spi.TypeConfiguration;
+
+import java.util.List;
+
+import static org.hibernate.query.sqm.produce.function.FunctionParameterType.STRING;
+
+@ApplicationScoped
+@PersistenceUnitExtension
+public class CustomFunctionContributor implements FunctionContributor {
+    @Override
+    public void contributeFunctions(FunctionContributions functionContributions) {
+        functionContributions.getFunctionRegistry().register(
+                "addHardcodedSuffix",
+                new HardcodedSuffixFunction(
+                        functionContributions.getTypeConfiguration(), "_some_suffix"
+                )
+        );
+    }
+
+    private static final class HardcodedSuffixFunction extends AbstractSqmSelfRenderingFunctionDescriptor {
+        private final String suffix;
+
+        private HardcodedSuffixFunction(TypeConfiguration typeConfiguration, String suffix) {
+            super("addHardcodedSuffix",
+                    StandardArgumentsValidators.exactly(1),
+                    StandardFunctionReturnTypeResolvers.invariant(
+                            typeConfiguration.getBasicTypeRegistry().resolve(StandardBasicTypes.STRING)
+                    ),
+                    StandardFunctionArgumentTypeResolvers.impliedOrInvariant(typeConfiguration, STRING)
+            );
+
+            this.suffix = suffix;
+        }
+
+        @Override
+        public void render(
+                SqlAppender sqlAppender,
+                List<? extends SqlAstNode> sqlAstArguments,
+                ReturnableType<?> returnType,
+                SqlAstTranslator<?> walker
+        ) {
+            sqlAppender.appendSql('(');
+            walker.render(sqlAstArguments.get(0), SqlAstNodeRenderingMode.DEFAULT);
+            sqlAppender.appendSql(" || '" + suffix + "')");
+        }
+    }
+}

extensions/hibernate-orm/deployment/src/test/java/io/quarkus/hibernate/orm/functioncontributors/FunctionContributorTest.java

@@ -0,0 +1,33 @@
+package io.quarkus.hibernate.orm.functioncontributors;
+
+import io.quarkus.test.QuarkusUnitTest;
+import jakarta.inject.Inject;
+import jakarta.persistence.EntityManager;
+import jakarta.transaction.Transactional;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class FunctionContributorTest {
+    @RegisterExtension
+    static QuarkusUnitTest runner = new QuarkusUnitTest()
+            .withApplicationRoot((jar) -> jar
+                    .addClass(MyEntity.class)
+                    .addClass(CustomFunctionContributor.class));
+
+    @Inject
+    EntityManager entityManager;
+
+    @Test
+    @Transactional
+    public void test() {
+        MyEntity entity = new MyEntity();
+        entity.setName("some_name");
+        entityManager.persist(entity);
+
+        assertThat(entityManager.createQuery("select addHardcodedSuffix(e.name) from MyEntity e", String.class)
+                .getSingleResult())
+                .isEqualTo("some_name_some_suffix");
+    }
+}

extensions/hibernate-orm/deployment/src/test/java/io/quarkus/hibernate/orm/functioncontributors/MyEntity.java

@@ -0,0 +1,30 @@
+package io.quarkus.hibernate.orm.functioncontributors;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+
+@Entity
+public class MyEntity {
+    @Id
+    private long id;
+
+    private String name;
+
+    public MyEntity() {}
+
+    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;
+    }
+}

extensions/hibernate-orm/runtime/src/main/java/io/quarkus/hibernate/orm/runtime/PersistenceUnitUtil.java

@@ -36,10 +36,12 @@ public static Annotation qualifier(String persistenceUnitName) {
         }
     }
 
-    public static <T> InjectableInstance<T> singleExtensionInstanceForPersistenceUnit(Class<T> beanType,
+    public static <T> InjectableInstance<T> singleExtensionInstanceForPersistenceUnit(
+            Class<T> beanType,
             String persistenceUnitName,
-            Annotation... additionalQualifiers) {
-        InjectableInstance<T> instance = extensionInstanceForPersistenceUnit(beanType, persistenceUnitName,
+            Annotation... additionalQualifiers
+    ) {
+        InjectableInstance<T> instance = extensionInstancesForPersistenceUnit(beanType, persistenceUnitName,
                 additionalQualifiers);
         if (instance.isAmbiguous()) {
             List<String> ambiguousClassNames = instance.handlesStream().map(h -> h.getBean().getBeanClass().getCanonicalName())
@@ -52,8 +54,11 @@ public static <T> InjectableInstance<T> singleExtensionInstanceForPersistenceUni
         return instance;
     }
 
-    public static <T> InjectableInstance<T> extensionInstanceForPersistenceUnit(Class<T> beanType, String persistenceUnitName,
-            Annotation... additionalQualifiers) {
+    public static <T> InjectableInstance<T> extensionInstancesForPersistenceUnit(
+            Class<T> beanType,
+            String persistenceUnitName,
+            Annotation... additionalQualifiers
+    ) {
         if (additionalQualifiers.length == 0) {
             return Arc.container().select(beanType, new PersistenceUnitExtension.Literal(persistenceUnitName));
         } else {

extensions/hibernate-orm/runtime/src/main/java/io/quarkus/hibernate/orm/runtime/boot/FastBootMetadataBuilder.java

 See <<programmatically-resolving-tenants-connections>>. 
 ==== Plugging in other custom components 
 The Quarkus extension for Hibernate ORM will automatically 
 inject components annotated with `@PersistenceUnitExtension` into Hibernate Search. 
 The annotation can optionally target a specific persistence unit with `@PersistenceUnitExtension(name = "nameOfYourPU")`. 
 This feature is available for the following component types: 
 `org.hibernate.Interceptor`:: 
 See <<interceptors>>. 
 `org.hibernate.resource.jdbc.spi.StatementInspector`:: 
 See <<statement_inspectors>>. 
 `org.hibernate.type.format.FormatMapper`:: 
 See <<json_xml_serialization_deserialization>>. 
 `io.quarkus.hibernate.orm.runtime.tenant.TenantResolver`:: 
 See <<multitenancy>>. 
 `io.quarkus.hibernate.orm.runtime.tenant.TenantConnectionResolver`:: 
 See <<programmatically-resolving-tenants-connections>>. 
@@ -29,6 +29,7 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Collectors;
 
+import io.quarkus.hibernate.orm.runtime.PersistenceUnitUtil;
 import jakarta.persistence.PersistenceException;
 import jakarta.persistence.PersistenceUnitTransactionType;
 
@@ -39,6 +40,8 @@
 import org.hibernate.boot.archive.scan.spi.Scanner;
 import org.hibernate.boot.beanvalidation.BeanValidationIntegrator;
 import org.hibernate.boot.internal.MetadataImpl;
+import org.hibernate.boot.model.FunctionContributor;
+import org.hibernate.boot.model.TypeContributor;
 import org.hibernate.boot.model.process.spi.ManagedResources;
 import org.hibernate.boot.model.process.spi.MetadataBuildingProcess;
 import org.hibernate.boot.registry.StandardServiceRegistry;
@@ -188,6 +191,9 @@ public FastBootMetadataBuilder(final QuarkusPersistenceUnitDefinition puDefiniti
 
         applyMetadataBuilderContributor();
 
+        applyTypeContributors();
+        applyFunctionContributors();
+
         // Unable to automatically handle:
         // AvailableSettings.ENHANCER_ENABLE_DIRTY_TRACKING,
         // AvailableSettings.ENHANCER_ENABLE_LAZY_INITIALIZATION,
@@ -663,6 +669,16 @@ private void applyMetadataBuilderContributor() {
         }
     }
 
+    private void applyTypeContributors() {
+        PersistenceUnitUtil.extensionInstancesForPersistenceUnit(TypeContributor.class, persistenceUnit.getName())
+                .stream().forEach(metamodelBuilder::applyTypes);
+    }
+
+    private void applyFunctionContributors() {
+        PersistenceUnitUtil.extensionInstancesForPersistenceUnit(FunctionContributor.class, persistenceUnit.getName())
+                .stream().forEach(metamodelBuilder::applyFunctions);
+    }
+
     @SuppressWarnings("unchecked")
     private <T> T loadSettingInstance(String settingName, Object settingValue, Class<T> clazz) {
         T instance = null;