fix #1750 better error message when passing AgentHooks to Runner (#1752)

This pull request resolves #1750

Author: seratch

src/agents/run.py

@@ -53,7 +53,7 @@
     ToolCallItemTypes,
     TResponseInputItem,
 )
-from .lifecycle import RunHooks
+from .lifecycle import AgentHooksBase, RunHooks, RunHooksBase
 from .logger import logger
 from .memory import Session, SessionInputCallback
 from .model_settings import ModelSettings
@@ -461,13 +461,11 @@ async def run(
     ) -> RunResult:
         context = kwargs.get("context")
         max_turns = kwargs.get("max_turns", DEFAULT_MAX_TURNS)
-        hooks = kwargs.get("hooks")
+        hooks = cast(RunHooks[TContext], self._validate_run_hooks(kwargs.get("hooks")))
         run_config = kwargs.get("run_config")
         previous_response_id = kwargs.get("previous_response_id")
         conversation_id = kwargs.get("conversation_id")
         session = kwargs.get("session")
-        if hooks is None:
-            hooks = RunHooks[Any]()
         if run_config is None:
             run_config = RunConfig()
 
@@ -668,14 +666,12 @@ def run_streamed(
     ) -> RunResultStreaming:
         context = kwargs.get("context")
         max_turns = kwargs.get("max_turns", DEFAULT_MAX_TURNS)
-        hooks = kwargs.get("hooks")
+        hooks = cast(RunHooks[TContext], self._validate_run_hooks(kwargs.get("hooks")))
         run_config = kwargs.get("run_config")
         previous_response_id = kwargs.get("previous_response_id")
         conversation_id = kwargs.get("conversation_id")
         session = kwargs.get("session")
 
-        if hooks is None:
-            hooks = RunHooks[Any]()
         if run_config is None:
             run_config = RunConfig()
 
@@ -732,6 +728,23 @@ def run_streamed(
         )
         return streamed_result
 
+    @staticmethod
+    def _validate_run_hooks(
+        hooks: RunHooksBase[Any, Agent[Any]] | AgentHooksBase[Any, Agent[Any]] | Any | None,
+    ) -> RunHooks[Any]:
+        if hooks is None:
+            return RunHooks[Any]()
+        input_hook_type = type(hooks).__name__
+        if isinstance(hooks, AgentHooksBase):
+            raise TypeError(
+                "Run hooks must be instances of RunHooks. "
+                f"Received agent-scoped hooks ({input_hook_type}). "
+                "Attach AgentHooks to an Agent via Agent(..., hooks=...)."
+            )
+        if not isinstance(hooks, RunHooksBase):
+            raise TypeError(f"Run hooks must be instances of RunHooks. Received {input_hook_type}.")
+        return hooks
+
     @classmethod
     async def _maybe_filter_model_input(
         cls,

tests/test_run_hooks.py

@@ -1,11 +1,11 @@
 from collections import defaultdict
-from typing import Any, Optional
+from typing import Any, Optional, cast
 
 import pytest
 
 from agents.agent import Agent
 from agents.items import ItemHelpers, ModelResponse, TResponseInputItem
-from agents.lifecycle import RunHooks
+from agents.lifecycle import AgentHooks, RunHooks
 from agents.models.interface import Model
 from agents.run import Runner
 from agents.run_context import RunContextWrapper, TContext
@@ -191,6 +191,29 @@ async def boom(*args, **kwargs):
     assert hooks.events["on_agent_end"] == 0
 
 
+class DummyAgentHooks(AgentHooks):
+    """Agent-scoped hooks used to verify runtime validation."""
+
+
+@pytest.mark.asyncio
+async def test_runner_run_rejects_agent_hooks():
+    model = FakeModel()
+    agent = Agent(name="A", model=model)
+    hooks = cast(RunHooks, DummyAgentHooks())
+
+    with pytest.raises(TypeError, match="Run hooks must be instances of RunHooks"):
+        await Runner.run(agent, input="hello", hooks=hooks)
+
+
+def test_runner_run_streamed_rejects_agent_hooks():
+    model = FakeModel()
+    agent = Agent(name="A", model=model)
+    hooks = cast(RunHooks, DummyAgentHooks())
+
+    with pytest.raises(TypeError, match="Run hooks must be instances of RunHooks"):
+        Runner.run_streamed(agent, input="hello", hooks=hooks)
+
+
 class BoomModel(Model):
     async def get_response(self, *a, **k):
         raise AssertionError("get_response should not be called in streaming test")