fix: 合并 Langfuse OpenAI tool_calls

Author: XavierWangHX

src/services/langfuse/__tests__/langfuse.test.ts

@@ -228,6 +228,54 @@ describe('Langfuse integration', () => {
         { role: 'tool', content: 'tool output', tool_call_id: 'call_1' },
       ])
     })
+
+    test('merges assistant tool calls from OpenAI-style array content', async () => {
+      const { convertMessagesToLangfuse } = await import('../convert.js')
+      const result = convertMessagesToLangfuse([
+        {
+          role: 'assistant',
+          content: [
+            {
+              type: 'text',
+              text: 'calling a tool',
+              tool_calls: [
+                {
+                  id: 'call_from_part',
+                  type: 'function',
+                  function: { name: 'part_tool', arguments: '{}' },
+                },
+              ],
+            },
+          ],
+          tool_calls: [
+            {
+              id: 'call_from_message',
+              type: 'function',
+              function: { name: 'message_tool', arguments: '{"ok":true}' },
+            },
+          ],
+        },
+      ])
+
+      expect(result).toEqual([
+        {
+          role: 'assistant',
+          content: 'calling a tool',
+          tool_calls: [
+            {
+              id: 'call_from_message',
+              type: 'function',
+              function: { name: 'message_tool', arguments: '{"ok":true}' },
+            },
+            {
+              id: 'call_from_part',
+              type: 'function',
+              function: { name: 'part_tool', arguments: '{}' },
+            },
+          ],
+        },
+      ])
+    })
   })
 
   // ── client tests ────────────────────────────────────────────────────────────

src/services/langfuse/convert.ts

@@ -47,6 +47,43 @@ type LangfuseInputMessage =
   | AssistantMessage
   | LangfuseChatMessage
 
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return value !== null && typeof value === 'object' && !Array.isArray(value)
+}
+
+function isLangfuseToolCall(value: unknown): value is LangfuseToolCall {
+  if (!isRecord(value)) return false
+  const fn = value.function
+  return (
+    typeof value.id === 'string' &&
+    value.type === 'function' &&
+    isRecord(fn) &&
+    typeof fn.name === 'string' &&
+    typeof fn.arguments === 'string'
+  )
+}
+
+function getToolCalls(value: unknown): LangfuseToolCall[] {
+  return Array.isArray(value) ? value.filter(isLangfuseToolCall) : []
+}
+
+function getContentToolCalls(content: unknown[]): LangfuseToolCall[] {
+  return content.flatMap(block =>
+    isRecord(block) ? getToolCalls(block.tool_calls) : [],
+  )
+}
+
+function mergeToolCalls(
+  ...groups: readonly LangfuseToolCall[][]
+): LangfuseToolCall[] {
+  const merged = new Map<string, LangfuseToolCall>()
+  for (const toolCall of groups.flat()) {
+    const key = toolCall.id || `${toolCall.function.name}:${toolCall.function.arguments}`
+    if (!merged.has(key)) merged.set(key, toolCall)
+  }
+  return [...merged.values()]
+}
+
 /** Normalize a content block into a LangfuseContentPart (non-tool_use, non-tool_result) */
 function toContentPart(block: Record<string, unknown>): LangfuseContentPart | null {
   const type = block.type as string | undefined
@@ -163,30 +200,34 @@ export function convertMessagesToLangfuse(
       isLangfuseRole(inner.role) ? inner.role : isWrappedMessage ? toRole(msg) : 'user'
     const rawContent = inner.content
     if (typeof rawContent === 'string' || !Array.isArray(rawContent)) {
+      const toolCalls = getToolCalls(inner.tool_calls)
       result.push({
         role,
         content: String(rawContent ?? ''),
         ...('tool_call_id' in inner && typeof inner.tool_call_id === 'string'
           ? { tool_call_id: inner.tool_call_id }
           : {}),
-        ...('tool_calls' in inner && Array.isArray(inner.tool_calls)
-          ? { tool_calls: inner.tool_calls as LangfuseToolCall[] }
-          : {}),
+        ...(toolCalls.length > 0 ? { tool_calls: toolCalls } : {}),
       })
       continue
     }
 
     if (role === 'assistant') {
       // Extract tool_use → tool_calls at message level
       const { tool_calls, rest } = extractToolCalls(rawContent)
+      const allToolCalls = mergeToolCalls(
+        tool_calls,
+        getToolCalls(inner.tool_calls),
+        getContentToolCalls(rest),
+      )
       const parts = rest
         .filter((b): b is Record<string, unknown> => b != null && typeof b === 'object')
         .map(b => toContentPart(b))
         .filter((p): p is LangfuseContentPart => p !== null)
       result.push({
         role: 'assistant',
         content: collapseContent(parts),
-        ...(tool_calls.length > 0 && { tool_calls }),
+        ...(allToolCalls.length > 0 && { tool_calls: allToolCalls }),
       })
     } else {
       // User messages: extract tool_result → separate tool messages
@@ -196,15 +237,17 @@ export function convertMessagesToLangfuse(
         .map(b => toContentPart(b))
         .filter((p): p is LangfuseContentPart => p !== null)
       if (parts.length > 0 || toolMessages.length === 0) {
+        const toolCalls = mergeToolCalls(
+          getToolCalls(inner.tool_calls),
+          getContentToolCalls(rest),
+        )
         result.push({
           role,
           content: collapseContent(parts),
           ...('tool_call_id' in inner && typeof inner.tool_call_id === 'string'
             ? { tool_call_id: inner.tool_call_id }
             : {}),
-          ...('tool_calls' in inner && Array.isArray(inner.tool_calls)
-            ? { tool_calls: inner.tool_calls as LangfuseToolCall[] }
-            : {}),
+          ...(toolCalls.length > 0 ? { tool_calls: toolCalls } : {}),
         })
       }
       result.push(...toolMessages)