wip

Author: mme

typescript-sdk/packages/client/src/agent/__tests__/subscriber.test.ts

@@ -628,12 +628,12 @@ describe("RunAgentSubscriber", () => {
       expect(specificSubscriber.onTextMessageContentEvent).toHaveBeenCalledWith(
         expect.objectContaining({
           event: textContentEvent,
-          textMessageBuffer: "Hello",
-          messages: [
-            { content: "Hello", id: "msg-1", role: "user" },
-            { content: "", id: "test-msg", role: "assistant" },
-          ], // Pre-mutation state (before current delta is applied to messages)
-          state: { counter: 0 }, // Pre-mutation state
+          textMessageBuffer: "", // Empty - buffer before current delta is applied
+          messages: expect.arrayContaining([
+            expect.objectContaining({ content: "Hello", id: "msg-1", role: "user" }),
+            expect.objectContaining({ content: "", id: "test-msg", role: "assistant" }), // Message before delta applied
+          ]),
+          state: { counter: 0 },
           agent,
         }),
       );
@@ -777,23 +777,23 @@ describe("RunAgentSubscriber", () => {
       // Check buffer accumulation
       expect(mockSubscriber.onToolCallArgsEvent).toHaveBeenCalledTimes(2);
 
-      // First call should have partial buffer
+      // First call should have empty buffer (before first delta applied)
       expect(mockSubscriber.onToolCallArgsEvent).toHaveBeenNthCalledWith(
         1,
         expect.objectContaining({
-          toolCallBuffer: '{"query": "te',
+          toolCallBuffer: "",
           toolCallName: "search",
-          partialToolCallArgs: '{"query": "te"}', // Partial JSON from untruncateJson
+          partialToolCallArgs: "", // Empty string when buffer is empty
         }),
       );
 
-      // Second call should have complete buffer
+      // Second call should have partial buffer (before second delta applied)
       expect(mockSubscriber.onToolCallArgsEvent).toHaveBeenNthCalledWith(
         2,
         expect.objectContaining({
-          toolCallBuffer: '{"query": "test"}',
+          toolCallBuffer: '{"query": "te',
           toolCallName: "search",
-          partialToolCallArgs: '{"query": "test"}', // Complete JSON from untruncateJson
+          partialToolCallArgs: '{"query": "te"}', // untruncateJson returns truncated JSON string
         }),
       );
 

typescript-sdk/packages/client/src/apply/default.ts

@@ -116,10 +116,6 @@ export const defaultApplyEvents = (
         }
 
         case EventType.TEXT_MESSAGE_CONTENT: {
-          const { delta } = event as TextMessageContentEvent;
-          const currentContent = messages[messages.length - 1].content ?? "";
-          const newTextMessageBuffer = currentContent + delta;
-
           const mutation = await runSubscribersWithMutation(
             subscribers,
             messages,
@@ -131,15 +127,17 @@ export const defaultApplyEvents = (
                 state,
                 agent,
                 input,
-                textMessageBuffer: newTextMessageBuffer,
+                textMessageBuffer: messages[messages.length - 1].content ?? "",
               }),
           );
           applyMutation(mutation);
 
           if (mutation.stopPropagation !== true) {
+            const { delta } = event as TextMessageContentEvent;
+
             // Get the last message and append the content
             const lastMessage = messages[messages.length - 1];
-            lastMessage.content = newTextMessageBuffer;
+            lastMessage.content = lastMessage.content! + delta;
             applyMutation({ messages });
           }
 
@@ -235,31 +233,30 @@ export const defaultApplyEvents = (
         }
 
         case EventType.TOOL_CALL_ARGS: {
-          const { delta } = event as ToolCallArgsEvent;
-          const toolCalls = (messages[messages.length - 1] as AssistantMessage)?.toolCalls ?? [];
-          const currentToolCallBuffer =
-            toolCalls.length > 0 ? toolCalls[toolCalls.length - 1].function.arguments : "";
-          const newToolCallBuffer = currentToolCallBuffer + delta;
-          const toolCallName =
-            toolCalls.length > 0 ? toolCalls[toolCalls.length - 1].function.name : "";
-
-          let partialToolCallArgs = {};
-          try {
-            partialToolCallArgs = untruncateJson(newToolCallBuffer);
-          } catch (error) {}
-
           const mutation = await runSubscribersWithMutation(
             subscribers,
             messages,
             state,
             (subscriber, messages, state) => {
+              const toolCalls =
+                (messages[messages.length - 1] as AssistantMessage)?.toolCalls ?? [];
+              const toolCallBuffer =
+                toolCalls.length > 0 ? toolCalls[toolCalls.length - 1].function.arguments : "";
+              const toolCallName =
+                toolCalls.length > 0 ? toolCalls[toolCalls.length - 1].function.name : "";
+              let partialToolCallArgs = {};
+              try {
+                // Parse from toolCallBuffer only (before current delta is applied)
+                partialToolCallArgs = untruncateJson(toolCallBuffer);
+              } catch (error) {}
+
               return subscriber.onToolCallArgsEvent?.({
                 event: event as ToolCallArgsEvent,
                 messages,
                 state,
                 agent,
                 input,
-                toolCallBuffer: newToolCallBuffer,
+                toolCallBuffer,
                 toolCallName,
                 partialToolCallArgs,
               });
@@ -268,14 +265,16 @@ export const defaultApplyEvents = (
           applyMutation(mutation);
 
           if (mutation.stopPropagation !== true) {
+            const { delta } = event as ToolCallArgsEvent;
+
             // Get the last message
             const lastMessage = messages[messages.length - 1];
 
             // Get the last tool call
             const lastToolCall = lastMessage.toolCalls[lastMessage.toolCalls.length - 1];
 
-            // Set the complete new arguments
-            lastToolCall.function.arguments = newToolCallBuffer;
+            // Append the arguments
+            lastToolCall.function.arguments += delta;
 
             applyMutation({ messages });
           }