Files
deer-flow/backend/tests/test_checkpointer.py
lailoo 959b4f2b09 fix(checkpointer): return InMemorySaver instead of None when not configured (#1016) (#1019)
* fix(checkpointer): return InMemorySaver instead of None when not configured (#1016)

* fix(checkpointer): also fix get_checkpointer() to return InMemorySaver

Make all three checkpointer functions consistent:
- make_checkpointer() (async) → InMemorySaver
- checkpointer_context() (sync) → InMemorySaver
- get_checkpointer() (sync singleton) → InMemorySaver

This ensures DeerFlowClient always has a valid checkpointer.

* fix: address CI failure and Copilot review feedback

- Fix import order in test_checkpointer_none_fix.py (I001 ruff error)
- Fix type annotation: _checkpointer should be Checkpointer | None
- Update docstring: change "None if not configured" to "InMemorySaver if not configured"
- Ensure app config is loaded before checking checkpointer config to prevent incorrect InMemorySaver fallback

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
2026-03-09 15:48:27 +08:00

261 lines
10 KiB
Python

"""Unit tests for checkpointer config and singleton factory."""
import sys
from unittest.mock import MagicMock, patch
import pytest
from src.agents.checkpointer import get_checkpointer, reset_checkpointer
from src.config.checkpointer_config import (
CheckpointerConfig,
get_checkpointer_config,
load_checkpointer_config_from_dict,
set_checkpointer_config,
)
@pytest.fixture(autouse=True)
def reset_state():
"""Reset singleton state before each test."""
set_checkpointer_config(None)
reset_checkpointer()
yield
set_checkpointer_config(None)
reset_checkpointer()
# ---------------------------------------------------------------------------
# Config tests
# ---------------------------------------------------------------------------
class TestCheckpointerConfig:
def test_load_memory_config(self):
load_checkpointer_config_from_dict({"type": "memory"})
config = get_checkpointer_config()
assert config is not None
assert config.type == "memory"
assert config.connection_string is None
def test_load_sqlite_config(self):
load_checkpointer_config_from_dict({"type": "sqlite", "connection_string": "/tmp/test.db"})
config = get_checkpointer_config()
assert config is not None
assert config.type == "sqlite"
assert config.connection_string == "/tmp/test.db"
def test_load_postgres_config(self):
load_checkpointer_config_from_dict({"type": "postgres", "connection_string": "postgresql://localhost/db"})
config = get_checkpointer_config()
assert config is not None
assert config.type == "postgres"
assert config.connection_string == "postgresql://localhost/db"
def test_default_connection_string_is_none(self):
config = CheckpointerConfig(type="memory")
assert config.connection_string is None
def test_set_config_to_none(self):
load_checkpointer_config_from_dict({"type": "memory"})
set_checkpointer_config(None)
assert get_checkpointer_config() is None
def test_invalid_type_raises(self):
with pytest.raises(Exception):
load_checkpointer_config_from_dict({"type": "unknown"})
# ---------------------------------------------------------------------------
# Factory tests
# ---------------------------------------------------------------------------
class TestGetCheckpointer:
def test_returns_in_memory_saver_when_not_configured(self):
"""get_checkpointer should return InMemorySaver when not configured."""
from langgraph.checkpoint.memory import InMemorySaver
cp = get_checkpointer()
assert cp is not None
assert isinstance(cp, InMemorySaver)
def test_memory_returns_in_memory_saver(self):
load_checkpointer_config_from_dict({"type": "memory"})
from langgraph.checkpoint.memory import InMemorySaver
cp = get_checkpointer()
assert isinstance(cp, InMemorySaver)
def test_memory_singleton(self):
load_checkpointer_config_from_dict({"type": "memory"})
cp1 = get_checkpointer()
cp2 = get_checkpointer()
assert cp1 is cp2
def test_reset_clears_singleton(self):
load_checkpointer_config_from_dict({"type": "memory"})
cp1 = get_checkpointer()
reset_checkpointer()
cp2 = get_checkpointer()
assert cp1 is not cp2
def test_sqlite_raises_when_package_missing(self):
load_checkpointer_config_from_dict({"type": "sqlite", "connection_string": "/tmp/test.db"})
with patch.dict(sys.modules, {"langgraph.checkpoint.sqlite": None}):
reset_checkpointer()
with pytest.raises(ImportError, match="langgraph-checkpoint-sqlite"):
get_checkpointer()
def test_postgres_raises_when_package_missing(self):
load_checkpointer_config_from_dict({"type": "postgres", "connection_string": "postgresql://localhost/db"})
with patch.dict(sys.modules, {"langgraph.checkpoint.postgres": None}):
reset_checkpointer()
with pytest.raises(ImportError, match="langgraph-checkpoint-postgres"):
get_checkpointer()
def test_postgres_raises_when_connection_string_missing(self):
load_checkpointer_config_from_dict({"type": "postgres"})
mock_saver = MagicMock()
mock_module = MagicMock()
mock_module.PostgresSaver = mock_saver
with patch.dict(sys.modules, {"langgraph.checkpoint.postgres": mock_module}):
reset_checkpointer()
with pytest.raises(ValueError, match="connection_string is required"):
get_checkpointer()
def test_sqlite_creates_saver(self):
"""SQLite checkpointer is created when package is available."""
load_checkpointer_config_from_dict({"type": "sqlite", "connection_string": "/tmp/test.db"})
mock_saver_instance = MagicMock()
mock_cm = MagicMock()
mock_cm.__enter__ = MagicMock(return_value=mock_saver_instance)
mock_cm.__exit__ = MagicMock(return_value=False)
mock_saver_cls = MagicMock()
mock_saver_cls.from_conn_string = MagicMock(return_value=mock_cm)
mock_module = MagicMock()
mock_module.SqliteSaver = mock_saver_cls
with patch.dict(sys.modules, {"langgraph.checkpoint.sqlite": mock_module}):
reset_checkpointer()
cp = get_checkpointer()
assert cp is mock_saver_instance
mock_saver_cls.from_conn_string.assert_called_once()
mock_saver_instance.setup.assert_called_once()
def test_postgres_creates_saver(self):
"""Postgres checkpointer is created when packages are available."""
load_checkpointer_config_from_dict({"type": "postgres", "connection_string": "postgresql://localhost/db"})
mock_saver_instance = MagicMock()
mock_cm = MagicMock()
mock_cm.__enter__ = MagicMock(return_value=mock_saver_instance)
mock_cm.__exit__ = MagicMock(return_value=False)
mock_saver_cls = MagicMock()
mock_saver_cls.from_conn_string = MagicMock(return_value=mock_cm)
mock_pg_module = MagicMock()
mock_pg_module.PostgresSaver = mock_saver_cls
with patch.dict(sys.modules, {"langgraph.checkpoint.postgres": mock_pg_module}):
reset_checkpointer()
cp = get_checkpointer()
assert cp is mock_saver_instance
mock_saver_cls.from_conn_string.assert_called_once_with("postgresql://localhost/db")
mock_saver_instance.setup.assert_called_once()
# ---------------------------------------------------------------------------
# app_config.py integration
# ---------------------------------------------------------------------------
class TestAppConfigLoadsCheckpointer:
def test_load_checkpointer_section(self):
"""load_checkpointer_config_from_dict populates the global config."""
set_checkpointer_config(None)
load_checkpointer_config_from_dict({"type": "memory"})
cfg = get_checkpointer_config()
assert cfg is not None
assert cfg.type == "memory"
# ---------------------------------------------------------------------------
# DeerFlowClient falls back to config checkpointer
# ---------------------------------------------------------------------------
class TestClientCheckpointerFallback:
def test_client_uses_config_checkpointer_when_none_provided(self):
"""DeerFlowClient._ensure_agent falls back to get_checkpointer() when checkpointer=None."""
from langgraph.checkpoint.memory import InMemorySaver
from src.client import DeerFlowClient
load_checkpointer_config_from_dict({"type": "memory"})
captured_kwargs = {}
def fake_create_agent(**kwargs):
captured_kwargs.update(kwargs)
return MagicMock()
model_mock = MagicMock()
config_mock = MagicMock()
config_mock.models = [model_mock]
config_mock.get_model_config.return_value = MagicMock(supports_vision=False)
config_mock.checkpointer = None
with (
patch("src.client.get_app_config", return_value=config_mock),
patch("src.client.create_agent", side_effect=fake_create_agent),
patch("src.client.create_chat_model", return_value=MagicMock()),
patch("src.client._build_middlewares", return_value=[]),
patch("src.client.apply_prompt_template", return_value=""),
patch("src.client.DeerFlowClient._get_tools", return_value=[]),
):
client = DeerFlowClient(checkpointer=None)
config = client._get_runnable_config("test-thread")
client._ensure_agent(config)
assert "checkpointer" in captured_kwargs
assert isinstance(captured_kwargs["checkpointer"], InMemorySaver)
def test_client_explicit_checkpointer_takes_precedence(self):
"""An explicitly provided checkpointer is used even when config checkpointer is set."""
from src.client import DeerFlowClient
load_checkpointer_config_from_dict({"type": "memory"})
explicit_cp = MagicMock()
captured_kwargs = {}
def fake_create_agent(**kwargs):
captured_kwargs.update(kwargs)
return MagicMock()
model_mock = MagicMock()
config_mock = MagicMock()
config_mock.models = [model_mock]
config_mock.get_model_config.return_value = MagicMock(supports_vision=False)
config_mock.checkpointer = None
with (
patch("src.client.get_app_config", return_value=config_mock),
patch("src.client.create_agent", side_effect=fake_create_agent),
patch("src.client.create_chat_model", return_value=MagicMock()),
patch("src.client._build_middlewares", return_value=[]),
patch("src.client.apply_prompt_template", return_value=""),
patch("src.client.DeerFlowClient._get_tools", return_value=[]),
):
client = DeerFlowClient(checkpointer=explicit_cp)
config = client._get_runnable_config("test-thread")
client._ensure_agent(config)
assert captured_kwargs["checkpointer"] is explicit_cp