add test for nested list

Signed-off-by: Gopala-Krishna.Char <gopala-krishna.char@intrafind.de>

src/test/java/org/opensearch/neuralsearch/processor/TextEmbeddingProcessorTests.java

@@ -9,11 +9,7 @@
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.*;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 import java.util.function.BiConsumer;
 import java.util.function.Supplier;
 
@@ -398,6 +394,20 @@ public void testBuildVectorOutput_withNestedMap_successful() {
         assertNotNull(actionGamesKnn);
     }
 
+    public void testBuildVectorOutput_withNestedList_successful() {
+        Map<String, Object> config = createNestedListConfiguration();
+        IngestDocument ingestDocument = createNestedListIngestDocument();
+        TextEmbeddingProcessor textEmbeddingProcessor = createInstanceWithNestedMapConfiguration(config);
+        Map<String, Object> knnMap = textEmbeddingProcessor.buildMapWithProcessorKeyAndOriginalValue(ingestDocument);
+        List<List<Float>> modelTensorList = createMockVectorResult();
+        textEmbeddingProcessor.buildNLPResult(knnMap, modelTensorList, ingestDocument.getSourceAndMetadata());
+        List<Map<String, Object>> nestedObj = (List<Map<String, Object>>) ingestDocument.getSourceAndMetadata().get("nestedField");
+        assertTrue(nestedObj.get(0).containsKey("vectorField"));
+        assertTrue(nestedObj.get(1).containsKey("vectorField"));
+        assertNotNull(nestedObj.get(0).get("vectorField"));
+        assertNotNull(nestedObj.get(1).get("vectorField"));
+    }
+
     public void test_updateDocument_appendVectorFieldsToDocument_successful() {
         Map<String, Object> config = createPlainStringConfiguration();
         IngestDocument ingestDocument = createPlainIngestDocument();
@@ -514,4 +524,22 @@ private IngestDocument createNestedMapIngestDocument() {
         result.put("favorites", favorite);
         return new IngestDocument(result, new HashMap<>());
     }
+
+    private Map<String, Object> createNestedListConfiguration(){
+        Map<String, Object> nestedConfig = new HashMap<>();
+        nestedConfig.put("textField", "vectorField");
+        Map<String, Object> result = new HashMap<>();
+        result.put("nestedField", nestedConfig);
+        return result;
+    }
+
+    private IngestDocument createNestedListIngestDocument(){
+        HashMap<String, Object> nestedObj1 = new HashMap<>();
+        nestedObj1.put("textField", "This is a text field");
+        HashMap<String, Object> nestedObj2 = new HashMap<>();
+        nestedObj2.put("textField", "This is another text field");
+        HashMap<String, Object> nestedList = new HashMap<>();
+        nestedList.put("nestedField", Arrays.asList(nestedObj1, nestedObj2));
+        return new IngestDocument(nestedList, new HashMap<>());
+    }
 }