from __future__ import annotations

import importlib.util

import pytest

from graph.langgraph_runtime import LangGraphRuntime


def test_langgraph_runtime_reports_missing_dependency() -> None:
    if importlib.util.find_spec("langgraph") is not None:
        pytest.skip("langgraph is installed; adapter execution is covered by integration parity tests")

    runtime = LangGraphRuntime()

    with pytest.raises(RuntimeError, match="langgraph package|NodeHandlerRegistry"):
        runtime.run_until_terminal_or_paused(None)  # type: ignore[arg-type]