Use detach() instead of clear() in RegistryQuery

core/src/main/java/google/registry/beam/common/RegistryQuery.java

@@ -57,10 +57,7 @@ static <T> RegistryQuery<T> createQuery(
       Query query =
           nativeQuery ? entityManager.createNativeQuery(sql) : entityManager.createQuery(sql);
       if (parameters != null) {
-        parameters.forEach(
-            (key, value) -> {
-              query.setParameter(key, value);
-            });
+        parameters.forEach(query::setParameter);
       }
       JpaTransactionManager.setQueryFetchSize(query, QUERY_FETCH_SIZE);
       @SuppressWarnings("unchecked")
@@ -78,14 +75,12 @@ static <T> RegistryQuery<T> createQuery(
   static <T> RegistryQuery<T> createQuery(
       String jpql, @Nullable Map<String, Object> parameters, Class<T> clazz) {
     return () -> {
-      // TODO(b/193662898): switch to jpaTm().query() when it can properly detach loaded entities.
-      EntityManager entityManager = tm().getEntityManager();
-      TypedQuery<T> query = entityManager.createQuery(jpql, clazz);
+      TypedQuery<T> query = tm().query(jpql, clazz);
       if (parameters != null) {
         parameters.forEach(query::setParameter);
       }
       JpaTransactionManager.setQueryFetchSize(query, QUERY_FETCH_SIZE);
-      return query.getResultStream().map(e -> detach(entityManager, e));
+      return query.getResultStream();
     };
   }
 
@@ -100,11 +95,9 @@ static <T> RegistryQuery<T> createQuery(
    */
   static <T> RegistryQuery<T> createQuery(CriteriaQuerySupplier<T> criteriaQuery) {
     return () -> {
-      // TODO(b/193662898): switch to jpaTm().query() when it can properly detach loaded entities.
-      EntityManager entityManager = tm().getEntityManager();
-      TypedQuery<T> query = entityManager.createQuery(criteriaQuery.get());
+      TypedQuery<T> query = tm().criteriaQuery(criteriaQuery.get());
       JpaTransactionManager.setQueryFetchSize(query, QUERY_FETCH_SIZE);
-      return query.getResultStream().map(e -> detach(entityManager, e));
+      return query.getResultStream();
     };
   }
 
@@ -125,16 +118,12 @@ static <T> T detach(EntityManager entityManager, T object) {
     return object;
   }
 
-  static void detachObject(EntityManager entityManager, Object object) {
-    Class<?> objectClass = object.getClass();
-    if (objectClass.isPrimitive() || objectClass == String.class) {
+  private static void detachObject(EntityManager entityManager, @Nullable Object object) {
+    if (object == null || object instanceof String) {
       return;
     }
     try {
-      // TODO(b/193662898): choose detach() or clear() based on the type of transaction.
-      // For context, EntityManager.detach() does not remove all metadata about loaded entities.
-      // See b/193925312 or https://hibernate.atlassian.net/browse/HHH-14735 for details.
-      entityManager.clear();
+      entityManager.detach(object);
     } catch (IllegalArgumentException e) {
       // Not an entity. Do nothing.
     }

core/src/test/java/google/registry/beam/common/RegistryJpaReadTest.java

@@ -14,7 +14,9 @@
 
 package google.registry.beam.common;
 
+import static com.google.common.truth.Truth.assertThat;
 import static google.registry.persistence.transaction.JpaTransactionManagerExtension.makeRegistrar1;
+import static google.registry.persistence.transaction.TransactionManagerFactory.tm;
 import static google.registry.testing.DatabaseHelper.newHost;
 import static google.registry.testing.DatabaseHelper.newTld;
 import static google.registry.testing.DatabaseHelper.persistResource;
@@ -37,13 +39,13 @@
 import google.registry.model.eppcommon.AuthInfo.PasswordAuth;
 import google.registry.model.eppcommon.StatusValue;
 import google.registry.model.host.Host;
-import google.registry.model.host.HostBase;
 import google.registry.model.registrar.Registrar;
 import google.registry.model.tld.Tld;
 import google.registry.persistence.transaction.CriteriaQueryBuilder;
 import google.registry.persistence.transaction.JpaTestExtensions;
 import google.registry.persistence.transaction.JpaTestExtensions.JpaIntegrationTestExtension;
 import google.registry.testing.FakeClock;
+import jakarta.persistence.EntityManager;
 import java.time.Instant;
 import org.apache.beam.sdk.coders.StringUtf8Coder;
 import org.apache.beam.sdk.testing.PAssert;
@@ -91,7 +93,11 @@ void beforeEach() {
   void readWithCriteriaQuery() {
     Read<Host, String> read =
         RegistryJpaIO.read(
-                () -> CriteriaQueryBuilder.create(Host.class).build(), HostBase::getHostName)
+                () -> CriteriaQueryBuilder.create(Host.class).build(),
+                host -> {
+                  assertThat(tm().getEntityManager().contains(host)).isFalse();
+                  return host.getHostName();
+                })
             .withCoder(StringUtf8Coder.of());
     PCollection<String> repoIds = testPipeline.apply(read);
 
@@ -112,6 +118,7 @@ void readWithStringQuery() {
                 false,
                 (Object[] row) -> {
                   Domain domain = (Domain) row[0];
+                  assertThat(tm().getEntityManager().contains(domain)).isFalse();
                   String emailAddress = (String) row[1];
                   return domain.getRepoId() + "-" + emailAddress;
                 })
@@ -154,14 +161,34 @@ void readWithStringTypedQuery() {
                     + " and d.deletionTime > CAST(now() AS timestamp)",
                 ImmutableMap.of("type", Registrar.Type.REAL),
                 Domain.class,
-                Domain::getRepoId)
+                domain -> {
+                  assertThat(tm().getEntityManager().contains(domain)).isFalse();
+                  return domain.getRepoId();
+                })
             .withCoder(StringUtf8Coder.of());
     PCollection<String> repoIds = testPipeline.apply(read);
 
     PAssert.that(repoIds).containsInAnyOrder("4-COM");
     testPipeline.run();
   }
 
+  @Test
+  void detach_detachesOnlySpecifiedEntity() {
+    tm().transact(
+            () -> {
+              EntityManager entityManager = tm().getEntityManager();
+              Host host0 = entityManager.find(Host.class, hosts.get(0).getRepoId());
+              Host host1 = entityManager.find(Host.class, hosts.get(1).getRepoId());
+              assertThat(entityManager.contains(host0)).isTrue();
+              assertThat(entityManager.contains(host1)).isTrue();
+
+              RegistryQuery.detach(entityManager, host0);
+
+              assertThat(entityManager.contains(host0)).isFalse();
+              assertThat(entityManager.contains(host1)).isTrue();
+            });
+  }
+
   private void setupForJoinQuery() {
     Tld registry = newTld("com", "ABCDAPP");
     Registrar registrar =