fix(temporal): Use robust argument binding and remove unused variable

Author: marcusmotill

src/google/adk/integrations/temporal.py

@@ -15,6 +15,7 @@
 """Temporal integration helpers for ADK."""
 
 import functools
+import inspect
 from typing import Any, AsyncGenerator, Callable, Optional, List
 
 from temporalio import workflow, activity
@@ -39,17 +40,21 @@ def activity_as_tool(
 
     # We create a wrapper that delegates to workflow.execute_activity
     async def tool_wrapper(*args, **kwargs) -> Any:
-        # Note: ADK tools usually pass args/kwargs strictly matched to signature.
-        # Activities expect positional args in a list if 'args' is used.
-        # If the tool signature matches the activity signature, we can pass args.
-        # It's safer if activity takes Pydantic models or simple types.
-        
-        # We assume strict positional argument mapping for now, or simplistic kwargs handling if supported.
-        # Temporal Python SDK typically invokes activities with `args=[...]`.
-        
+        # Bind arguments to the activity signature to ensure correct order/mapping.
+        try:
+            sig = inspect.signature(activity_def)
+            bound_args = sig.bind(*args, **kwargs)
+            bound_args.apply_defaults()
+            activity_args = [bound_args.arguments[p] for p in sig.parameters]
+        except (TypeError, ValueError):
+            # Fallback for built-ins or other complex callables where binding may fail
+            # or if arguments don't match signature (e.g. simpler invocation).
+            # Temporal Python SDK typically invokes activities with `args=[...]`.
+            activity_args = list(args) + list(kwargs.values()) if kwargs else list(args)
+
         return await workflow.execute_activity(
             activity_def,
-            args=list(args) + list(kwargs.values()) if kwargs else list(args),
+            args=activity_args,
             **activity_options
         )
 
@@ -64,7 +69,6 @@ async def tool_wrapper(*args, **kwargs) -> Any:
 
     # CRITICAL: Copy signature so FunctionTool can generate correct parameters schema
     try:
-        import inspect
         tool_wrapper.__signature__ = inspect.signature(activity_def)
     except Exception:
         pass  # Fallback if signature copy fails (e.g. builtins)

tests/integration/manual_test_temporal_integration.py

@@ -221,15 +221,13 @@ async def run(self, prompt: str) -> str:
         # Turn 2: Trigger Handoff
         logger.info("--- Turn 2: Trigger Handoff ---")
         handoff_response_text = ""
-        last_author = ""
         async with Aclosing(runner.run_async(
             user_id=session.user_id,
             session_id=session.id,
             new_message=types.Content(role='user', parts=[types.Part(text="Please switch me to the specialist.")])
         )) as agen:
             async for event in agen:
                 logger.info(f"Event Author: {event.author} | Actions: {event.actions}")
-                last_author = event.author
                 if event.content and event.content.parts:
                     for part in event.content.parts:
                         if part.text: handoff_response_text += part.text