test_create_agent_sync_invoke_with_mixed_middleware() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/core/test_framework.py lines 503–543

def test_create_agent_sync_invoke_with_mixed_middleware() -> None:
    """Test that sync invoke works with mixed sync/async middleware when sync versions exist."""
    calls = []

    class MixedMiddleware(AgentMiddleware):
        def before_model(self, state: AgentState[Any], runtime: Runtime) -> None:
            calls.append("MixedMiddleware.before_model")

        async def abefore_model(self, state: AgentState[Any], runtime: Runtime) -> None:
            calls.append("MixedMiddleware.abefore_model")

        def wrap_model_call(
            self,
            request: ModelRequest,
            handler: Callable[[ModelRequest], ModelResponse],
        ) -> ModelCallResult:
            calls.append("MixedMiddleware.wrap_model_call")
            return handler(request)

        async def awrap_model_call(
            self,
            request: ModelRequest,
            handler: Callable[[ModelRequest], Awaitable[ModelResponse]],
        ) -> ModelCallResult:
            calls.append("MixedMiddleware.awrap_model_call")
            return await handler(request)

    agent = create_agent(
        model=FakeToolCallingModel(),
        tools=[],
        system_prompt="You are a helpful assistant.",
        middleware=[MixedMiddleware()],
    )

    agent.invoke({"messages": [HumanMessage("hello")]})

    # In sync mode, only sync methods should be called
    assert calls == [
        "MixedMiddleware.before_model",
        "MixedMiddleware.wrap_model_call",
    ]