Handle merging multiple tool results into a single assistant message (#1829)

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Fixes OPS-3386

Author: rSnapkoOpenOps

packages/server/api/src/app/ai/chat/utils.ts

@@ -14,28 +14,11 @@ export function mergeToolResultsIntoMessages(
   },
 ): Array<Omit<UIMessage, 'id'>> {
   const uiMessages: Array<Omit<UIMessage, 'id'>> = [];
-  const toolResultsToMerge: Array<{
-    toolResult: ToolResultPart;
-    messageIndex: number;
-  }> = [];
-
-  for (let i = 0; i < messages.length; i++) {
-    const msg = messages[i];
+  const toolResultsToMerge: ToolResultPart[] = [];
 
+  for (const msg of messages) {
     if (isToolMessage(msg)) {
-      if (Array.isArray(msg.content) && msg.content.length > 0) {
-        const toolResult = msg.content[0];
-        if (
-          toolResult &&
-          typeof toolResult === 'object' &&
-          'toolCallId' in toolResult
-        ) {
-          toolResultsToMerge.push({
-            toolResult: toolResult as ToolResultPart,
-            messageIndex: i,
-          });
-        }
-      }
+      toolResultsToMerge.push(...extractToolResults(msg));
       continue;
     }
 
@@ -45,13 +28,29 @@ export function mergeToolResultsIntoMessages(
     }
   }
 
-  for (const { toolResult } of toolResultsToMerge) {
+  for (const toolResult of toolResultsToMerge) {
     mergeToolResultIntoUIMessage(toolResult, uiMessages);
   }
 
   return uiMessages;
 }
 
+function extractToolResults(msg: ModelMessage): ToolResultPart[] {
+  const toolResults: ToolResultPart[] = [];
+  if (Array.isArray(msg.content)) {
+    for (const part of msg.content) {
+      if (isToolResultPart(part)) {
+        toolResults.push(part);
+      }
+    }
+  }
+  return toolResults;
+}
+
+function isToolResultPart(part: any): part is ToolResultPart {
+  return part && typeof part === 'object' && 'toolCallId' in part;
+}
+
 /**
  * Sanitize chat history for secondary tasks like naming/summarization.
  * - keeps only 'user' and 'assistant' roles

packages/server/api/test/unit/ai/utils.test.ts

@@ -802,6 +802,66 @@ describe('mergeToolResultsIntoMessages', () => {
         input: { userId: '123' },
       });
     });
+
+    it('should handle multiple tool results in a single tool message', () => {
+      const messages: ModelMessage[] = [
+        {
+          role: 'assistant',
+          content: [
+            {
+              type: 'tool-call',
+              toolCallId: 'call_1',
+              toolName: 'tool_1',
+              input: { arg: 1 },
+            },
+            {
+              type: 'tool-call',
+              toolCallId: 'call_2',
+              toolName: 'tool_2',
+              input: { arg: 2 },
+            },
+          ],
+        },
+        {
+          role: 'tool',
+          content: [
+            {
+              type: 'tool-result',
+              toolCallId: 'call_1',
+              toolName: 'tool_1',
+              output: {
+                type: 'text',
+                value: 'result_1',
+              } as any,
+            },
+            {
+              type: 'tool-result',
+              toolCallId: 'call_2',
+              toolName: 'tool_2',
+              output: {
+                type: 'text',
+                value: 'result_2',
+              } as any,
+            },
+          ],
+        },
+      ];
+
+      const result = mergeToolResultsIntoMessages(messages);
+      expect(result).toHaveLength(1);
+      expect(result[0].parts).toHaveLength(2);
+
+      expect(result[0].parts[0]).toMatchObject({
+        toolCallId: 'call_1',
+        state: 'output-available',
+        output: 'result_1',
+      });
+      expect(result[0].parts[1]).toMatchObject({
+        toolCallId: 'call_2',
+        state: 'output-available',
+        output: 'result_2',
+      });
+    });
   });
 });