stack/tests/llm/test_init_lazy.py

"""#720: the notebooks container installs the workspace without the
``llm`` extra (no langchain, no sqlalchemy). ``llm.config``,
``llm.links`` and ``llm.lineage`` must import there anyway — the pool
exports are resolved lazily, and ``llm.evidence`` only touches
sqlalchemy when a pgvector query actually runs."""

from __future__ import annotations

import importlib
import subprocess
import sys

import pytest

_PROBE = """
import sys, builtins
_real = builtins.__import__
def _fake(name, *a, **k):
    if name.split('.')[0] in {'langchain_core', 'langchain_postgres', 'langchain_ollama', 'sqlalchemy'}:
        raise ModuleNotFoundError(name)
    return _real(name, *a, **k)
builtins.__import__ = _fake
import llm.config, llm.links, llm.lineage, llm.evidence  # must not need langchain/sqlalchemy
import llm
print('ok', llm.LlmConfig.__name__)
"""


def test_config_links_lineage_evidence_import_without_langchain_or_sqlalchemy():
    r = subprocess.run(
        [sys.executable, "-c", _PROBE], capture_output=True, text=True, check=False
    )
    assert r.returncode == 0, r.stderr[-800:]
    assert "ok LlmConfig" in r.stdout


def test_pool_exports_resolve_lazily():
    llm = importlib.import_module("llm")
    assert llm.HostPool.__name__ == "HostPool"
    assert llm.PoolEmbeddings.__name__ == "PoolEmbeddings"
    with pytest.raises(AttributeError):
        _ = llm.NoSuchName