Fix issue persisting entity mapped with non-nullable association

hibernate-reactive-core/src/main/java/org/hibernate/reactive/engine/ReactiveActionQueue.java

@@ -34,7 +34,6 @@
 import org.hibernate.action.spi.BeforeTransactionCompletionProcess;
 import org.hibernate.action.spi.Executable;
 import org.hibernate.cache.CacheException;
-import org.hibernate.engine.internal.NonNullableTransientDependencies;
 import org.hibernate.engine.spi.ActionQueue;
 import org.hibernate.engine.spi.EntityEntry;
 import org.hibernate.engine.spi.ExecutableList;
@@ -343,24 +342,25 @@ private CompletionStage<Void> addInsertAction(ReactiveEntityInsertAction insert)
 			ret = ret.thenCompose( v -> executeInserts() );
 		}
 
-		NonNullableTransientDependencies nonNullableTransientDependencies = insert.findNonNullableTransientEntities();
-		if ( nonNullableTransientDependencies == null ) {
-			LOG.tracev( "Adding insert with no non-nullable, transient entities: [{0}]", insert );
-			ret = ret.thenCompose( v -> addResolvedEntityInsertAction( insert ) );
-		}
-		else {
-			if ( LOG.isTraceEnabled() ) {
-				LOG.tracev( "Adding insert with non-nullable, transient entities; insert=[{0}], dependencies=[{1}]",
-							insert,
-							nonNullableTransientDependencies.toLoggableString( insert.getSession() )
-				);
-			}
-			if ( unresolvedInsertions == null ) {
-				unresolvedInsertions = new UnresolvedEntityInsertActions();
-			}
-			unresolvedInsertions.addUnresolvedEntityInsertAction( (AbstractEntityInsertAction) insert, nonNullableTransientDependencies );
-		}
-		return ret;
+		return ret
+				.thenCompose( v -> insert.reactiveFindNonNullableTransientEntities() )
+				.thenCompose( nonNullables -> {
+					if ( nonNullables == null ) {
+						LOG.tracev( "Adding insert with no non-nullable, transient entities: [{0}]", insert );
+						return addResolvedEntityInsertAction( insert );
+					}
+					else {
+						if ( LOG.isTraceEnabled() ) {
+							LOG.tracev( "Adding insert with non-nullable, transient entities; insert=[{0}], dependencies=[{1}]", insert, nonNullables.toLoggableString( insert.getSession() ) );
+						}
+						if ( unresolvedInsertions == null ) {
+							unresolvedInsertions = new UnresolvedEntityInsertActions();
+						}
+						unresolvedInsertions
+								.addUnresolvedEntityInsertAction( (AbstractEntityInsertAction) insert, nonNullables );
+						return voidFuture();
+					}
+				} );
 	}
 
 	private CompletionStage<Void> addResolvedEntityInsertAction(ReactiveEntityInsertAction insert) {

hibernate-reactive-core/src/main/java/org/hibernate/reactive/engine/impl/ForeignKeys.java

@@ -9,9 +9,11 @@
 import org.hibernate.HibernateException;
 import org.hibernate.TransientObjectException;
 import org.hibernate.bytecode.enhance.spi.LazyPropertyInitializer;
+import org.hibernate.engine.internal.NonNullableTransientDependencies;
 import org.hibernate.engine.spi.EntityEntry;
 import org.hibernate.engine.spi.SelfDirtinessTracker;
 import org.hibernate.engine.spi.SessionImplementor;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.internal.util.StringHelper;
 import org.hibernate.persister.entity.EntityPersister;
 import org.hibernate.proxy.HibernateProxy;
@@ -359,6 +361,92 @@ public static CompletionStage<Object> getEntityIdentifierIfNotUnsaved(
 		}
 	}
 
+	public static CompletionStage<NonNullableTransientDependencies> findNonNullableTransientEntities(
+			String entityName,
+			Object entity,
+			Object[] values,
+			boolean isEarlyInsert,
+			SharedSessionContractImplementor session) {
+
+		final EntityPersister persister = session.getEntityPersister( entityName, entity );
+		final Type[] types = persister.getPropertyTypes();
+		final Nullifier nullifier = new Nullifier( entity, false, isEarlyInsert, (SessionImplementor) session, persister );
+		final String[] propertyNames = persister.getPropertyNames();
+		final boolean[] nullability = persister.getPropertyNullability();
+		final NonNullableTransientDependencies nonNullableTransientEntities = new NonNullableTransientDependencies();
+
+		return loop( 0, types.length,
+				i -> collectNonNullableTransientEntities(
+						nullifier,
+						values[i],
+						propertyNames[i],
+						types[i],
+						nullability[i],
+						session,
+						nonNullableTransientEntities
+				)
+		).thenApply( r -> nonNullableTransientEntities.isEmpty() ? null : nonNullableTransientEntities );
+	}
+
+	private static CompletionStage<Void> collectNonNullableTransientEntities(
+			Nullifier nullifier,
+			Object value,
+			String propertyName,
+			Type type,
+			boolean isNullable,
+			SharedSessionContractImplementor session,
+			NonNullableTransientDependencies nonNullableTransientEntities) {
+
+		if ( value == null ) {
+			return voidFuture();
+		}
+
+		if ( type.isEntityType() ) {
+			final EntityType entityType = (EntityType) type;
+			if ( !isNullable && !entityType.isOneToOne() ) {
+				return nullifier
+						.isNullifiable( entityType.getAssociatedEntityName(), value )
+						.thenAccept( isNullifiable -> {
+							if ( isNullifiable ) {
+								nonNullableTransientEntities.add( propertyName, value );
+							}
+						} );
+			}
+		}
+		else if ( type.isAnyType() ) {
+			if ( !isNullable ) {
+				return nullifier
+						.isNullifiable( null, value )
+						.thenAccept( isNullifiable -> {
+							if ( isNullifiable ) {
+								nonNullableTransientEntities.add( propertyName, value );
+							}
+						} );
+			};
+		}
+		else if ( type.isComponentType() ) {
+			final CompositeType actype = (CompositeType) type;
+			final boolean[] subValueNullability = actype.getPropertyNullability();
+			if ( subValueNullability != null ) {
+				final String[] subPropertyNames = actype.getPropertyNames();
+				final Object[] subvalues = actype.getPropertyValues( value, session );
+				final Type[] subtypes = actype.getSubtypes();
+				return loop( 0, subtypes.length,
+						i -> collectNonNullableTransientEntities(
+								nullifier,
+								subvalues[i],
+								subPropertyNames[i],
+								subtypes[i],
+								subValueNullability[i],
+								session,
+								nonNullableTransientEntities
+						)
+				);
+			}
+		}
+
+		return voidFuture();
+	}
 
 	/**
 	 * Disallow instantiation

hibernate-reactive-core/src/main/java/org/hibernate/reactive/engine/impl/ReactiveEntityInsertAction.java

@@ -87,4 +87,8 @@ default CompletionStage<Void> reactiveMakeEntityManaged() {
 						isVersionIncrementDisabled()
 				));
 	}
+
+	default CompletionStage<NonNullableTransientDependencies> reactiveFindNonNullableTransientEntities() {
+		return ForeignKeys.findNonNullableTransientEntities( getPersister().getEntityName(), getInstance(), getState(), isEarlyInsert(), getSession() );
+	}
 }

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

@@ -0,0 +1,153 @@
+/* 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 javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+import javax.persistence.OneToMany;
+import javax.persistence.Table;
+
+import org.hibernate.cfg.Configuration;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import io.vertx.ext.unit.TestContext;
+
+public class NonNullableManyToOneTest extends BaseReactiveTest {
+
+	@Override
+	protected Configuration constructConfiguration() {
+		Configuration configuration = super.constructConfiguration();
+		configuration.addAnnotatedClass( Dealer.class );
+		configuration.addAnnotatedClass( Artist.class );
+		configuration.addAnnotatedClass( Painting.class );
+		return configuration;
+	}
+
+	@Before
+	public void populateDB(TestContext context) {
+		Artist artist = new Artist( "Grand Master Painter" );
+		artist.id = 1L;
+		Dealer dealer = new Dealer( "Dealer" );
+		dealer.id = 1L;
+		Painting painting = new Painting( "Mona Lisa");
+		painting.id = 2L;
+		artist.addPainting( painting );
+		dealer.addPainting( painting );
+
+		test( context, getMutinySessionFactory()
+				.withTransaction( s -> s.persistAll( painting, artist, dealer ) ) );
+	}
+
+	@After
+	public void cleanDB(TestContext context) {
+		test( context, deleteEntities( "Painting", "Artist" ) );
+	}
+
+	@Test
+	public void testNonNullableSuccess(TestContext context) {
+		test(
+				context,
+				getMutinySessionFactory().withTransaction( session -> session
+								.createQuery( "from Artist", Artist.class )
+								.getSingleResult().chain( a -> session.fetch( a.paintings ) )
+								.invoke( paintings -> {
+									context.assertNotNull( paintings );
+									context.assertEquals( 1, paintings.size() );
+									context.assertEquals( "Mona Lisa", paintings.get( 0 ).name );
+								} ) )
+						.chain( () -> getMutinySessionFactory().withTransaction( s1 -> s1
+										.createQuery( "from Dealer", Dealer.class )
+										.getSingleResult().chain( d -> s1.fetch( d.paintings ) )
+										.invoke( paintings -> {
+											context.assertNotNull( paintings );
+											context.assertEquals( 1, paintings.size() );
+											context.assertEquals( "Mona Lisa", paintings.get( 0 ).name );
+										} )
+								)
+						)
+		);
+	}
+
+	@Entity(name = "Painting")
+	@Table(name = "painting")
+	public static class Painting {
+		@Id
+		Long id;
+		String name;
+
+		@JoinColumn(nullable = false)
+		@ManyToOne(optional = true)
+		Artist author;
+
+		@JoinColumn(nullable = true)
+		@ManyToOne(optional = false)
+		Dealer dealer;
+
+		public Painting() {
+		}
+
+		public Painting(String name) {
+			this.name = name;
+		}
+	}
+
+	@Entity(name = "Artist")
+	@Table(name = "artist")
+	public static class Artist {
+
+		@Id
+		Long id;
+		String name;
+
+		@OneToMany(mappedBy = "author")
+		List<Painting> paintings = new ArrayList<>();
+
+		public Artist() {
+		}
+
+		public Artist(String name) {
+			this.name = name;
+		}
+
+		public void addPainting(Painting painting) {
+			this.paintings.add( painting );
+			painting.author = this;
+		}
+
+	}
+
+	@Entity(name = "Dealer")
+	@Table(name = "dealer")
+	public static class Dealer {
+
+		@Id
+		Long id;
+		String name;
+
+		@OneToMany(mappedBy = "dealer")
+		List<Painting> paintings = new ArrayList<>();
+
+		public Dealer() {
+		}
+
+		public Dealer(String name) {
+			this.name = name;
+		}
+
+		public void addPainting(Painting painting) {
+			this.paintings.add( painting );
+			painting.dealer = this;
+		}
+
+	}
+}