[issue-511] Fix serialization of additional data on Collections

Author: Carlos Bouzón García

.gitignore

@@ -33,3 +33,4 @@ hs_err_pid*
 /target/
 /pom.xml
 local.properties
+.idea

src/main/java/com/microsoft/graph/serializer/DefaultSerializer.java

@@ -287,9 +287,34 @@ private JsonObject getChildAdditionalData(IJsonBackedObject serializableObject,
 						}
 					}
 				}
-				// If the object is a valid Graph object, add its additional data
-				else if (fieldObject != null && fieldObject instanceof IJsonBackedObject) {
-					IJsonBackedObject serializableChild = (IJsonBackedObject) fieldObject;
+                // If the object is a list of Graph objects, iterate through elements
+                else if (fieldObject instanceof List) {
+                    if(outJson != null
+                            && outJson.get(field.getName()) != null
+                            && outJson.get(field.getName()).isJsonArray()) {
+                        final List<?> fieldObjectList = (List<?>) fieldObject;
+                        for (int index = 0; index < fieldObjectList.size(); index++) {
+                            Object element = fieldObjectList.get(index);
+                            JsonObject jsonElement = outJson
+                                    .get(field.getName())
+                                    .getAsJsonArray()
+                                    .get(index)
+                                    .getAsJsonObject();
+                            if (element instanceof IJsonBackedObject) {
+                                AdditionalDataManager elementAdditionalData = ((IJsonBackedObject) element)
+                                        .additionalDataManager();
+                                addAdditionalDataToJson(
+                                        elementAdditionalData,
+                                        jsonElement
+                                );
+                                outJson = getChildAdditionalData((IJsonBackedObject) element, jsonElement);
+                            }
+                        }
+                    }
+                }
+                // If the object is a valid Graph object, add its additional data
+                else if (fieldObject != null && fieldObject instanceof IJsonBackedObject) {
+                    IJsonBackedObject serializableChild = (IJsonBackedObject) fieldObject;
 					AdditionalDataManager childAdditionalData = serializableChild.additionalDataManager();
 					if(outJson != null && field != null && outJson.get(field.getName()) != null && outJson.get(field.getName()).isJsonObject()) {
 						addAdditionalDataToJson(childAdditionalData, outJson.get(field.getName()).getAsJsonObject());

src/test/java/com/microsoft/graph/serializer/AdditionalDataTests.java

@@ -6,6 +6,7 @@
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
+import com.microsoft.graph.models.extensions.*;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -18,15 +19,8 @@
 import com.microsoft.graph.functional.TestBase;
 import com.microsoft.graph.http.HttpMethod;
 import com.microsoft.graph.logger.DefaultLogger;
-import com.microsoft.graph.models.extensions.Drive;
-import com.microsoft.graph.models.extensions.DriveItemCreateUploadSessionBody;
-import com.microsoft.graph.models.extensions.DriveItemUploadableProperties;
-import com.microsoft.graph.models.extensions.Entity;
-import com.microsoft.graph.models.extensions.PlannerAssignment;
-import com.microsoft.graph.models.extensions.PlannerAssignments;
-import com.microsoft.graph.models.extensions.PlannerTask;
-import com.microsoft.graph.models.extensions.PlannerTaskDetails;
-import com.microsoft.graph.models.extensions.User;
+
+import java.util.Collections;
 
 public class AdditionalDataTests {
 	public DefaultSerializer serializer;
@@ -150,4 +144,20 @@ public void testHashMapProperties() {
 		assertTrue(taskDetails.checklist.get("d280ed1a-9f6b-4f9c-a962-fb4d00dc50ff").title.equals("Try reading task details"));
 		assertTrue(taskDetails.checklist.get("d280ed1a-9f6b-4f9c-a962-fb4d00dc50ff").lastModifiedBy.user.additionalDataManager().get("customProp").getAsString().equals("somestring"));
 	}
+
+	@Test
+	public void testSerializeAdditionalDataOnCollections() {
+		ChatMessage chatMessage = new ChatMessage();
+		ChatMessageMention chatMessageMention = new ChatMessageMention();
+		chatMessageMention.additionalDataManager().put("helloWorld", new JsonPrimitive("3.141516"));
+		IdentitySet identitySet = new IdentitySet();
+		identitySet.additionalDataManager().put("identitySetKey", new JsonPrimitive("identitySetValue"));
+		chatMessageMention.mentioned = identitySet;
+		chatMessage.mentions = Collections.singletonList(chatMessageMention);
+		String output = serializer.serializeObject(chatMessage);
+		assertTrue(output.contains("helloWorld"));
+		assertTrue(output.contains("3.141516"));
+		assertTrue(output.contains("identitySetKey"));
+		assertTrue(output.contains("identitySetValue"));
+	}
 }