cr

Author: hntrl

langchain-core/src/messages/ai.ts

@@ -275,15 +275,20 @@ export class AIMessageChunk extends BaseMessageChunk {
         (acc, chunk) => {
           const matchedChunkIndex = acc.findIndex(([match]) => {
             // If chunk has an id and index, match if both are present
-            if ("id" in chunk && "index" in chunk) {
+            if (
+              "id" in chunk &&
+              chunk.id &&
+              "index" in chunk &&
+              chunk.index !== undefined
+            ) {
               return chunk.id === match.id && chunk.index === match.index;
             }
             // If chunk has an id, we match on id
-            if ("id" in chunk) {
+            if ("id" in chunk && chunk.id) {
               return chunk.id === match.id;
             }
             // If chunk has an index, we match on index
-            if ("index" in chunk) {
+            if ("index" in chunk && chunk.index !== undefined) {
               return chunk.index === match.index;
             }
             return false;