test_wrap_tool_call_access_state() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/core/test_wrap_tool_call.py lines 152–187

def test_wrap_tool_call_access_state() -> None:
    """Test accessing agent state from wrap_tool_call decorator."""
    state_data = []

    @wrap_tool_call
    def access_state(
        request: ToolCallRequest, handler: Callable[[ToolCallRequest], ToolMessage | Command[Any]]
    ) -> ToolMessage | Command[Any]:
        # Access state from request
        if request.state is not None:
            messages = request.state.get("messages", [])
            state_data.append(len(messages))
        return handler(request)

    model = FakeToolCallingModel(
        tool_calls=[
            [ToolCall(name="search", args={"query": "test"}, id="1")],
            [],
        ]
    )

    agent = create_agent(
        model=model,
        tools=[search],
        middleware=[access_state],
        checkpointer=InMemorySaver(),
    )

    agent.invoke(
        {"messages": [HumanMessage("Search")]},
        {"configurable": {"thread_id": "test"}},
    )

    # Middleware should have accessed state
    assert len(state_data) >= 1
    assert state_data[0] > 0  # Should have at least the initial message