[Blazebit#724] Test and fix for select fetching of optional correlati…

…on basis

entity-view/impl/src/main/java/com/blazebit/persistence/view/impl/objectbuilder/transformer/correlation/AbstractCorrelatedBatchTupleListTransformer.java

@@ -203,27 +203,31 @@ public List<Object[]> transform(List<Object[]> tuples) {
             while (tupleListIter.hasNext()) {
                 Object[] tuple = tupleListIter.next();
                 Object correlationValue = tuple[startIndex];
+
                 TuplePromise tupleIndexValue = correlationValues.get(correlationValue);
 
                 if (tupleIndexValue == null) {
                     tupleIndexValue = new TuplePromise(startIndex);
                     tupleIndexValue.add(tuple);
                     correlationValues.put(correlationValue, tupleIndexValue);
 
-                    if (correlationBasisEntity != null) {
-                        correlationParams.add(em.getReference(correlationBasisEntity, tuple[startIndex]));
-                    } else {
-                        correlationParams.add(tuple[startIndex]);
-                    }
-
-                    if (batchSize == correlationParams.realSize()) {
-                        Object defaultKey;
+                    // Can't correlate null
+                    if (correlationValue != null) {
                         if (correlationBasisEntity != null) {
-                            defaultKey = jpaProvider.getIdentifier(correlationParams.get(0));
+                            correlationParams.add(em.getReference(correlationBasisEntity, correlationValue));
                         } else {
-                            defaultKey = correlationParams.get(0);
+                            correlationParams.add(correlationValue);
+                        }
+
+                        if (batchSize == correlationParams.realSize()) {
+                            Object defaultKey;
+                            if (correlationBasisEntity != null) {
+                                defaultKey = jpaProvider.getIdentifier(correlationParams.get(0));
+                            } else {
+                                defaultKey = correlationParams.get(0);
+                            }
+                            batchLoad(correlationValues, correlationParams, null, defaultKey, viewRootJpqlMacro, BatchCorrelationMode.VALUES);
                         }
-                        batchLoad(correlationValues, correlationParams, null, defaultKey, viewRootJpqlMacro, BatchCorrelationMode.VALUES);
                     }
                 } else {
                     tupleIndexValue.add(tuple);

entity-view/testsuite/src/test/java/com/blazebit/persistence/view/testsuite/fetch/subview/SubviewFetchTest.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2014 - 2019 Blazebit.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.blazebit.persistence.view.testsuite.fetch.subview;
+
+import com.blazebit.persistence.CriteriaBuilder;
+import com.blazebit.persistence.testsuite.base.jpa.category.NoDatanucleus;
+import com.blazebit.persistence.testsuite.base.jpa.category.NoEclipselink;
+import com.blazebit.persistence.testsuite.base.jpa.category.NoOpenJPA;
+import com.blazebit.persistence.testsuite.entity.Document;
+import com.blazebit.persistence.testsuite.entity.Person;
+import com.blazebit.persistence.testsuite.tx.TxVoidWork;
+import com.blazebit.persistence.view.EntityViewManager;
+import com.blazebit.persistence.view.EntityViewSetting;
+import com.blazebit.persistence.view.EntityViews;
+import com.blazebit.persistence.view.spi.EntityViewConfiguration;
+import com.blazebit.persistence.view.testsuite.AbstractEntityViewTest;
+import com.blazebit.persistence.view.testsuite.fetch.subview.model.DocumentSelectSubviewTestView;
+import com.blazebit.persistence.view.testsuite.fetch.subview.model.PersonSelectSubview;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+import javax.persistence.EntityManager;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ *
+ * @author Christian Beikov
+ * @since 1.2.0
+ */
+public class SubviewFetchTest extends AbstractEntityViewTest {
+
+    protected Document doc1;
+
+    @Override
+    public void setUpOnce() {
+        cleanDatabase();
+        transactional(new TxVoidWork() {
+            @Override
+            public void work(EntityManager em) {
+                doc1 = new Document("doc1");
+
+                Person o1 = new Person("pers1");
+
+                doc1.setOwner(o1);
+
+                doc1.getStrings().add("s1");
+                doc1.getStrings().add("s2");
+
+                em.persist(o1);
+
+                em.persist(doc1);
+
+                o1.setPartnerDocument(doc1);
+            }
+        });
+    }
+
+    @Before
+    public void setUp() {
+        doc1 = cbf.create(em, Document.class).where("name").eq("doc1").fetch("partners").getResultList().get(0);
+    }
+
+    @Test
+    // NOTE: Eclipselink and Datanucleus don't support the single valued id access optimization which causes a cyclic join dependency
+    @Category({ NoDatanucleus.class, NoOpenJPA.class, NoEclipselink.class })
+    public void testSubqueryFetch() {
+        EntityViewConfiguration cfg = EntityViews.createDefaultConfiguration();
+        cfg.addEntityView(DocumentSelectSubviewTestView.class);
+        cfg.addEntityView(PersonSelectSubview.class);
+        EntityViewManager evm = cfg.createEntityViewManager(cbf);
+
+        CriteriaBuilder<Document> criteria = cbf.create(em, Document.class, "d").orderByAsc("id");
+        EntityViewSetting<DocumentSelectSubviewTestView, CriteriaBuilder<DocumentSelectSubviewTestView>> setting = EntityViewSetting.create(DocumentSelectSubviewTestView.class);
+        CriteriaBuilder<DocumentSelectSubviewTestView> cb = evm.applySetting(setting, criteria);
+        List<DocumentSelectSubviewTestView> results = cb.getResultList();
+
+        assertEquals(1, results.size());
+    }
+}

entity-view/testsuite/src/test/java/com/blazebit/persistence/view/testsuite/fetch/subview/model/DocumentSelectSubviewTestView.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2014 - 2019 Blazebit.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.blazebit.persistence.view.testsuite.fetch.subview.model;
+
+import com.blazebit.persistence.testsuite.entity.Document;
+import com.blazebit.persistence.view.EntityView;
+import com.blazebit.persistence.view.IdMapping;
+
+/**
+ *
+ * @author Christian Beikov
+ * @since 1.4.0
+ */
+@EntityView(Document.class)
+public interface DocumentSelectSubviewTestView {
+
+    @IdMapping
+    public Long getId();
+
+    public PersonSelectSubview getResponsiblePerson();
+
+}

entity-view/testsuite/src/test/java/com/blazebit/persistence/view/testsuite/fetch/subview/model/PersonSelectSubview.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2014 - 2019 Blazebit.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.blazebit.persistence.view.testsuite.fetch.subview.model;
+
+import com.blazebit.persistence.testsuite.entity.Document;
+import com.blazebit.persistence.testsuite.entity.Person;
+import com.blazebit.persistence.view.EntityView;
+import com.blazebit.persistence.view.FetchStrategy;
+import com.blazebit.persistence.view.IdMapping;
+import com.blazebit.persistence.view.Mapping;
+
+import java.util.Set;
+
+/**
+ *
+ * @author Christian Beikov
+ * @since 1.4.0
+ */
+@EntityView(Person.class)
+public interface PersonSelectSubview {
+
+    @IdMapping
+    public Long getId();
+
+    @Mapping(fetch = FetchStrategy.SELECT)
+    public Set<Document> getOwnedDocuments();
+
+}