SOLR-8762: respond child docs in DIH debug

solr/CHANGES.txt

@@ -315,6 +315,8 @@ Other Changes
 
 * SOLR-8437: Improve RAMDirectory details in sample solrconfig files (Mark Miller, Varun Thacker)
 
+* SOLR-8762: return child docs in DIH debug (Gopikannan Venugopalsamy via Mikhail Khludnev)
+
 ==================  6.6.0 ==================
 
 Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release.

solr/contrib/dataimporthandler/src/java/org/apache/solr/handler/dataimport/DebugInfo.java

@@ -16,6 +16,7 @@
  */
 package org.apache.solr.handler.dataimport;
 
+import java.util.AbstractList;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -25,7 +26,35 @@ import org.apache.solr.common.util.NamedList;
 import org.apache.solr.common.util.StrUtils;
 
 public class DebugInfo {
-  public List<SolrInputDocument> debugDocuments = new ArrayList<>(0);
+
+  private static final class ChildRollupDocs extends AbstractList<SolrInputDocument> {
+
+    private List<SolrInputDocument> delegate = new ArrayList<>();
+
+    @Override
+    public SolrInputDocument get(int index) {
+      return delegate.get(index);
+    }
+
+    @Override
+    public int size() {
+      return delegate.size();
+    }
+
+    public boolean add(SolrInputDocument e) {
+      SolrInputDocument transformed = e.deepCopy();
+      if (transformed.hasChildDocuments()) {
+        ChildRollupDocs childList = new ChildRollupDocs();
+        childList.addAll(transformed.getChildDocuments());
+        transformed.addField("_childDocuments_", childList);
+        transformed.getChildDocuments().clear();
+      }
+      return delegate.add(transformed);
+    }
+  }
+
+  public List<SolrInputDocument> debugDocuments = new ChildRollupDocs();
+
   public NamedList<String> debugVerboseOutput = null;
   public boolean verbose;
   
@@ -34,3 +63,4 @@ public class DebugInfo {
     debugVerboseOutput = new NamedList<>();
   }
 }
+

solr/contrib/dataimporthandler/src/test/org/apache/solr/handler/dataimport/AbstractDataImportHandlerTestCase.java

@@ -80,11 +80,11 @@ public abstract class AbstractDataImportHandlerTestCase extends
     }
   }
 
-  protected void runFullImport(String dataConfig) throws Exception {
+  protected String runFullImport(String dataConfig) throws Exception {
     LocalSolrQueryRequest request = lrf.makeRequest("command", "full-import",
             "debug", "on", "clean", "true", "commit", "true", "dataConfig",
             dataConfig);
-    h.query("/dataimport", request);
+    return h.query("/dataimport", request);
   }
 
   protected void runDeltaImport(String dataConfig) throws Exception {

solr/contrib/dataimporthandler/src/test/org/apache/solr/handler/dataimport/TestHierarchicalDocBuilder.java

@@ -39,6 +39,7 @@ import org.apache.solr.common.util.StrUtils;
 import org.apache.solr.handler.dataimport.config.ConfigNameConstants;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.search.SolrIndexSearcher;
+import org.apache.solr.util.TestHarness;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.BeforeClass;
@@ -118,7 +119,7 @@ public class TestHierarchicalDocBuilder extends AbstractDataImportHandlerTestCas
 
     List<String> parentIds = createDataIterator("select * from PARENT", parentType, parentType, parentsNum);
     Collections.shuffle(parentIds, random());
-    String parentId1 = parentIds.get(0);
+    final String parentId1 = parentIds.get(0);
     String parentId2 = parentIds.get(1);
     
     //parent 1 children
@@ -129,20 +130,23 @@ public class TestHierarchicalDocBuilder extends AbstractDataImportHandlerTestCas
     childrenNum += childrenIds.size();
     
     // grand children of first parent first child
-    String childId = childrenIds.get(0);
+    final String childId = childrenIds.get(0);
     String description = "grandchild of first parent, child of " + childId + " child";
     select = "select * from GRANDCHILD where parent_id='" + childId + "'";
     List<String> grandChildrenIds = createDataIterator(select, grandChildType, description, atLeast(2));
     grandChildrenNum += grandChildrenIds.size();
     
     // grand children of first parent second child
-    childId = childrenIds.get(1);
+    {
-    description = "grandchild of first parent, child of " + childId + " child";
+      String childId2 = childrenIds.get(1);
-    select = "select * from GRANDCHILD where parent_id='" + childId + "'";
+      description = "grandchild of first parent, child of " + childId2 + " child";
-    List<String> grandChildrenIds2 = createDataIterator(select, grandChildType, description, atLeast(2));
+      select = "select * from GRANDCHILD where parent_id='" + childId2 + "'";
+    }
+    final List<String> grandChildrenIds2 = createDataIterator(select, grandChildType, description, atLeast(2));
     grandChildrenNum += grandChildrenIds2.size();
     
-    grandChildrenIds.addAll(grandChildrenIds2);
+    List<String> allGrandChildrenIds = new ArrayList<>(grandChildrenIds);
+    allGrandChildrenIds.addAll(grandChildrenIds2);
         
     // third children of first parent has no grand children
     
@@ -155,7 +159,14 @@ public class TestHierarchicalDocBuilder extends AbstractDataImportHandlerTestCas
     
     int totalDocsNum = parentsNum + childrenNum + grandChildrenNum;
     
-    runFullImport(THREE_LEVEL_HIERARCHY_CONFIG);
+    String resp = runFullImport(THREE_LEVEL_HIERARCHY_CONFIG);
+    String xpath = "//arr[@name='documents']/lst/arr[@name='id' and .='"+parentId1+"']/../"+
+      "arr[@name='_childDocuments_']/lst/arr[@name='id' and .='"+childId+"']/../"+
+      "arr[@name='_childDocuments_']/lst/arr[@name='id' and .='"+grandChildrenIds.get(0)+"']";
+    String results = TestHarness.validateXPath(resp, 
+           xpath);
+    assertTrue("Debug documents does not contain child documents\n"+resp+"\n"+ xpath+
+                                                        "\n"+results, results == null);
     
     assertTrue("Update request processor processAdd was not called", TestUpdateRequestProcessor.processAddCalled);
     assertTrue("Update request processor processCommit was not callled", TestUpdateRequestProcessor.processCommitCalled);
@@ -169,7 +180,7 @@ public class TestHierarchicalDocBuilder extends AbstractDataImportHandlerTestCas
 
     // let's check BlockJoin
     // get first parent by any grand children
-    String randomGrandChildId = grandChildrenIds.get(random().nextInt(grandChildrenIds.size()));
+    String randomGrandChildId = allGrandChildrenIds.get(random().nextInt(allGrandChildrenIds.size()));
     Query query = createToParentQuery(parentType, FIELD_ID, randomGrandChildId);
     assertSearch(query, FIELD_ID, parentId1);