[#255] Additional test for identity generation

* Enable SQL query comments
* Quote table name
* Use @ColumnTransformer

Author: DavideD

hibernate-reactive-core/src/test/java/org/hibernate/reactive/IdentityGeneratorWithColumnTransformerTest.java

@@ -0,0 +1,132 @@
+/* Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright: Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.reactive;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CompletionStage;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+import org.hibernate.annotations.ColumnTransformer;
+import org.hibernate.cfg.AvailableSettings;
+import org.hibernate.cfg.Configuration;
+
+import org.junit.Test;
+
+import io.vertx.ext.unit.TestContext;
+
+import static org.hibernate.reactive.containers.DatabaseConfiguration.DBType.DB2;
+import static org.hibernate.reactive.containers.DatabaseConfiguration.dbType;
+
+/**
+ * Similar to {@link IdentityGeneratorTest} but enables SQL comments and uses a {@link ColumnTransformer}.
+ */
+public class IdentityGeneratorWithColumnTransformerTest extends BaseReactiveTest {
+
+	// Comments don't work with Db2
+	private static final String ENABLE_COMMENTS = String.valueOf( dbType() != DB2 );
+
+	/**
+	 * When {@link AvailableSettings#USE_GET_GENERATED_KEYS} is enabled, different
+	 * queries will be used for each datastore to get the id
+	 */
+	public static class EnableUseGetGeneratedKeys extends IdentityGeneratorWithColumnTransformerTest {
+
+		@Override
+		protected Configuration constructConfiguration() {
+			Configuration configuration = super.constructConfiguration();
+			configuration.setProperty( AvailableSettings.USE_GET_GENERATED_KEYS, "true" );
+			return configuration;
+		}
+	}
+
+	// The number of entities we want to create
+	private static final int ENTITY_NUMBER = 100;
+
+	@Override
+	protected Configuration constructConfiguration() {
+		Configuration configuration = super.constructConfiguration();
+		configuration.addAnnotatedClass( EntityWithIdentity.class );
+		configuration.setProperty( AvailableSettings.USE_SQL_COMMENTS, ENABLE_COMMENTS );
+		return configuration;
+	}
+
+	private CompletionStage<?> populateDb(TestContext context) {
+		final List<EntityWithIdentity> identities = new ArrayList<>( ENTITY_NUMBER );
+		for ( int i = 0; i < ENTITY_NUMBER; i++ ) {
+			identities.add( new EntityWithIdentity( i ) );
+		}
+		return getSessionFactory()
+				.withTransaction( (session, tx) -> session.persist( identities.toArray() ) )
+				.thenAccept( ignore -> {
+					Long assignedId = 0L;
+					for ( EntityWithIdentity identity : identities ) {
+						context.assertNotNull( identity.id );
+						context.assertTrue( identity.id > assignedId );
+						assignedId = identity.id;
+					}
+				} );
+	}
+
+	@Test
+	public void testIdentityGenerator(TestContext context) {
+		test( context, populateDb( context )
+				.thenCompose( v -> openSession() )
+				.thenCompose( session ->
+					  session.createQuery( "FROM EntityWithIdentity ORDER BY position ASC", EntityWithIdentity.class )
+					  .getResultList() )
+				.thenAccept( list -> {
+					context.assertEquals( ENTITY_NUMBER, list.size() );
+					int i = 0;
+					for ( EntityWithIdentity entity : list ) {
+						context.assertEquals( i * 2, entity.getPosition() );
+						i++;
+					}
+				} ) );
+	}
+
+	@Entity(name = "EntityWithIdentity")
+	@Table( name = "`Table with default values`")
+	private static class EntityWithIdentity {
+		private static final String PREFIX = "Entity: ";
+		@Id
+		@GeneratedValue(strategy = GenerationType.IDENTITY)
+		Long id;
+
+		@Column(unique = true)
+		String name;
+
+		@Column(name = "position")
+		@ColumnTransformer(forColumn = "position", write = "? * 2")
+		private int position;
+
+		public EntityWithIdentity() {
+		}
+
+		public EntityWithIdentity(int index) {
+			this.name =  PREFIX + index;
+			this.position = index;
+		}
+
+		public int getPosition() {
+			return position;
+		}
+
+		public void setPosition(int position) {
+			this.position = position;
+		}
+
+		@Override
+		public String toString() {
+			return id + ":" + name + ":" + position;
+		}
+	}
+}