[Security solution] Streaming tool fix (#181194)

x-pack/plugins/elastic_assistant/server/lib/langchain/execute_custom_llm_chain/index.test.ts

@@ -16,7 +16,7 @@ import { mockActionResponse } from '../../../__mocks__/action_result_data';
 import { langChainMessages } from '../../../__mocks__/lang_chain_messages';
 import { ESQL_RESOURCE } from '../../../routes/knowledge_base/constants';
 import { callAgentExecutor } from '.';
-import { Stream } from 'stream';
+import { PassThrough, Stream } from 'stream';
 import { ActionsClientChatOpenAI, ActionsClientLlm } from '@kbn/elastic-assistant-common/impl/llm';
 
 jest.mock('@kbn/elastic-assistant-common/impl/llm', () => ({
@@ -48,6 +48,25 @@ jest.mock('../elasticsearch_store/elasticsearch_store', () => ({
     isModelInstalled: jest.fn().mockResolvedValue(true),
   })),
 }));
+const mockStream = new PassThrough();
+const mockPush = jest.fn();
+jest.mock('@kbn/ml-response-stream/server', () => ({
+  streamFactory: jest.fn().mockImplementation(() => ({
+    DELIMITER: '\n',
+    end: jest.fn(),
+    push: mockPush,
+    responseWithHeaders: {
+      body: mockStream,
+      headers: {
+        'X-Accel-Buffering': 'no',
+        'X-Content-Type-Options': 'nosniff',
+        'Cache-Control': 'no-cache',
+        Connection: 'keep-alive',
+        'Transfer-Encoding': 'chunked',
+      },
+    },
+  })),
+}));
 
 const mockConnectorId = 'mock-connector-id';
 
@@ -209,5 +228,55 @@ describe('callAgentExecutor', () => {
         false
       );
     });
+
+    it('does not streams token after handleStreamEnd has been called', async () => {
+      const mockInvokeWithChainCallback = jest.fn().mockImplementation((a, b, c, d, e, f, g) => {
+        b.callbacks[0].handleLLMNewToken('hi', {}, '123', '456');
+        b.callbacks[0].handleChainEnd({ output: 'hello' }, '123');
+        b.callbacks[0].handleLLMNewToken('hey', {}, '678', '456');
+        return Promise.resolve();
+      });
+      (initializeAgentExecutorWithOptions as jest.Mock).mockImplementation(
+        (_a, _b, { agentType }) => ({
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          call: (props: any, more: any) => mockCall({ ...props, agentType }, more),
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          invoke: (props: any, more: any) =>
+            mockInvokeWithChainCallback({ ...props, agentType }, more),
+        })
+      );
+      const onLlmResponse = jest.fn();
+      await callAgentExecutor({ ...defaultProps, onLlmResponse, isStream: true });
+
+      expect(mockPush).toHaveBeenCalledWith({ payload: 'hi', type: 'content' });
+      expect(mockPush).not.toHaveBeenCalledWith({ payload: 'hey', type: 'content' });
+    });
+
+    it('only streams tokens with length from the root parentRunId', async () => {
+      const mockInvokeWithChainCallback = jest.fn().mockImplementation((a, b, c, d, e, f, g) => {
+        b.callbacks[0].handleLLMNewToken('', {}, '123', '456');
+
+        b.callbacks[0].handleLLMNewToken('hi', {}, '123', '456');
+        b.callbacks[0].handleLLMNewToken('hello', {}, '555', '666');
+        b.callbacks[0].handleLLMNewToken('hey', {}, '678', '456');
+        return Promise.resolve();
+      });
+      (initializeAgentExecutorWithOptions as jest.Mock).mockImplementation(
+        (_a, _b, { agentType }) => ({
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          call: (props: any, more: any) => mockCall({ ...props, agentType }, more),
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          invoke: (props: any, more: any) =>
+            mockInvokeWithChainCallback({ ...props, agentType }, more),
+        })
+      );
+      const onLlmResponse = jest.fn();
+      await callAgentExecutor({ ...defaultProps, onLlmResponse, isStream: true });
+
+      expect(mockPush).toHaveBeenCalledWith({ payload: 'hi', type: 'content' });
+      expect(mockPush).toHaveBeenCalledWith({ payload: 'hey', type: 'content' });
+      expect(mockPush).not.toHaveBeenCalledWith({ payload: 'hello', type: 'content' });
+      expect(mockPush).not.toHaveBeenCalledWith({ payload: '', type: 'content' });
+    });
   });
 });

x-pack/plugins/elastic_assistant/server/lib/langchain/execute_custom_llm_chain/index.ts

@@ -164,6 +164,7 @@ export const callAgentExecutor: AgentExecutor<true | false> = async ({
     };
 
     let message = '';
+    let tokenParentRunId = '';
 
     executor
       .invoke(
@@ -175,8 +176,14 @@ export const callAgentExecutor: AgentExecutor<true | false> = async ({
         {
           callbacks: [
             {
-              handleLLMNewToken(payload) {
-                if (payload.length && !didEnd) {
+              handleLLMNewToken(payload, _idx, _runId, parentRunId) {
+                if (tokenParentRunId.length === 0 && !!parentRunId) {
+                  // set the parent run id as the parentRunId of the first token
+                  // this is used to ensure that all tokens in the stream are from the same run
+                  // filtering out runs that are inside e.g. tool calls
+                  tokenParentRunId = parentRunId;
+                }
+                if (payload.length && !didEnd && tokenParentRunId === parentRunId) {
                   push({ payload, type: 'content' });
                   // store message in case of error
                   message += payload;