core[minor],community[minor]: Add message id tests

langchain-core/src/messages/base.ts

@@ -11,6 +11,7 @@ export interface StoredMessageData {
   /** Response metadata. For example: response headers, logprobs, token counts. */
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   response_metadata?: Record<string, any>;
+  id?: string;
 }
 
 export interface StoredMessage {

langchain-core/src/messages/tests/base_message.test.ts

@@ -107,3 +107,23 @@ test("Deserialisation and serialisation of tool_call_id", async () => {
   const deserialized: ToolMessage = await load(JSON.stringify(message), config);
   expect(deserialized).toEqual(message);
 });
+
+test("Deserialisation and serialisation of messages with ID", async () => {
+  const config = {
+    importMap: { messages: { AIMessage } },
+    optionalImportEntrypoints: [],
+    optionalImportsMap: {},
+    secretsMap: {},
+  };
+
+  const messageId = "uuid-1234";
+
+  const message = new AIMessage({
+    content: "The sky is blue because...",
+    id: messageId,
+  });
+
+  const deserialized: AIMessage = await load(JSON.stringify(message), config);
+  expect(deserialized).toEqual(message);
+  expect(deserialized.id).toBe(messageId);
+});

libs/langchain-community/src/stores/tests/postgres.int.test.ts

@@ -11,7 +11,7 @@ describe.skip("Postgres Chat History", () => {
   beforeAll(async () => {
     pool = new pg.Pool({
       host: "127.0.0.1",
-      port: 5433,
+      port: 5432,
       user: "myuser",
       password: "ChangeMe",
       database: "api",
@@ -125,4 +125,23 @@ describe.skip("Postgres Chat History", () => {
       await newChatHistory.clear();
     }
   });
+
+  test("Can store & retrieve message IDs", async () => {
+    const blankResult = await chatHistory.getMessages();
+    expect(blankResult).toStrictEqual([]);
+
+    const aiMessageId = "ai-message-id";
+    const aiMessage = new AIMessage({
+      content: "Ozzy Osbourne",
+      id: aiMessageId,
+    });
+    await chatHistory.addMessage(aiMessage);
+
+    const expectedMessages = [aiMessage];
+
+    const resultWithHistory = await chatHistory.getMessages();
+    expect(resultWithHistory).toHaveLength(1);
+    expect(resultWithHistory).toEqual(expectedMessages);
+    expect(resultWithHistory[0].id).toEqual(aiMessageId);
+  });
 });