deer-flow/backend/tests/test_dynamic_context_middleware.py

337 lines
14 KiB
Python

"""Tests for DynamicContextMiddleware.
Verifies that memory and current date are injected as a <system-reminder> into
the first HumanMessage exactly once per session (frozen-snapshot pattern).
"""
from types import SimpleNamespace
from unittest import mock
from langchain_core.messages import AIMessage, HumanMessage
from deerflow.agents.middlewares.dynamic_context_middleware import (
_DYNAMIC_CONTEXT_REMINDER_KEY,
DynamicContextMiddleware,
)
_SYSTEM_REMINDER_TAG = "<system-reminder>"
def _make_middleware(**kwargs) -> DynamicContextMiddleware:
return DynamicContextMiddleware(**kwargs)
def _fake_runtime():
return SimpleNamespace(context={})
def _reminder_msg(content: str, msg_id: str) -> HumanMessage:
"""Build a reminder HumanMessage the way the middleware would produce it."""
return HumanMessage(
content=content,
id=msg_id,
additional_kwargs={"hide_from_ui": True, _DYNAMIC_CONTEXT_REMINDER_KEY: True},
)
# ---------------------------------------------------------------------------
# Basic injection
# ---------------------------------------------------------------------------
def test_injects_system_reminder_into_first_human_message():
mw = _make_middleware()
state = {"messages": [HumanMessage(content="Hello", id="msg-1")]}
with mock.patch("deerflow.agents.lead_agent.prompt._get_memory_context", return_value=""), mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt:
mock_dt.now.return_value.strftime.return_value = "2026-05-08, Friday"
result = mw.before_agent(state, _fake_runtime())
assert result is not None
updated_msgs = result["messages"]
assert len(updated_msgs) == 2
reminder_msg = updated_msgs[0]
assert isinstance(reminder_msg, HumanMessage)
assert reminder_msg.id == "msg-1" # takes the original ID (position swap)
assert reminder_msg.additional_kwargs.get(_DYNAMIC_CONTEXT_REMINDER_KEY) is True
assert _SYSTEM_REMINDER_TAG in reminder_msg.content
assert "<current_date>2026-05-08, Friday</current_date>" in reminder_msg.content
assert "Hello" not in reminder_msg.content # reminder only — no user text
user_msg = updated_msgs[1]
assert isinstance(user_msg, HumanMessage)
assert user_msg.id == "msg-1__user" # derived ID
assert user_msg.content == "Hello"
def test_memory_included_when_present():
mw = _make_middleware()
state = {"messages": [HumanMessage(content="Hi", id="msg-1")]}
with (
mock.patch(
"deerflow.agents.lead_agent.prompt._get_memory_context",
return_value="<memory>\nUser prefers Python.\n</memory>",
),
mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt,
):
mock_dt.now.return_value.strftime.return_value = "2026-05-08, Friday"
result = mw.before_agent(state, _fake_runtime())
# Reminder is the first returned message; user query is the second
reminder_content = result["messages"][0].content
assert "User prefers Python." in reminder_content
assert "<current_date>2026-05-08, Friday</current_date>" in reminder_content
assert result["messages"][1].content == "Hi"
# ---------------------------------------------------------------------------
# Frozen-snapshot: no re-injection within a session
# ---------------------------------------------------------------------------
def test_skips_injection_if_already_present():
"""Second turn: separate reminder message already present → no update."""
mw = _make_middleware()
reminder_content = "<system-reminder>\n<current_date>2026-05-08, Friday</current_date>\n</system-reminder>"
state = {
"messages": [
_reminder_msg(reminder_content, "msg-1"),
HumanMessage(content="Hello", id="msg-1__user"),
AIMessage(content="Hi there"),
HumanMessage(content="Follow-up", id="msg-2"),
]
}
with mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt:
mock_dt.now.return_value.strftime.return_value = "2026-05-08, Friday"
result = mw.before_agent(state, _fake_runtime())
assert result is None # no update needed
def test_injects_only_into_first_human_message_not_later_ones():
"""Reminder targets the first HumanMessage; subsequent messages are not touched."""
mw = _make_middleware()
state = {
"messages": [
HumanMessage(content="First", id="msg-1"),
AIMessage(content="Reply"),
HumanMessage(content="Second", id="msg-2"),
]
}
with mock.patch("deerflow.agents.lead_agent.prompt._get_memory_context", return_value=""), mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt:
mock_dt.now.return_value.strftime.return_value = "2026-05-08, Friday"
result = mw.before_agent(state, _fake_runtime())
assert result is not None
msgs = result["messages"]
# Only the two injected messages are returned (reminder + original first query)
assert len(msgs) == 2
assert msgs[0].id == "msg-1" # reminder takes first message's ID
assert msgs[0].additional_kwargs.get(_DYNAMIC_CONTEXT_REMINDER_KEY) is True
assert _SYSTEM_REMINDER_TAG in msgs[0].content
assert msgs[1].id == "msg-1__user" # original content with derived ID
assert msgs[1].content == "First"
# "Second" (msg-2) is not in the returned update — it is left unchanged
assert all(m.id != "msg-2" for m in msgs)
def test_summary_human_message_is_not_used_as_injection_target():
"""After summarization, the synthetic summary HumanMessage is not a user turn."""
mw = _make_middleware()
state = {
"messages": [
HumanMessage(content="Here is a summary of the conversation to date:\n\n...", id="summary-1", name="summary"),
AIMessage(content="Earlier reply"),
HumanMessage(content="Follow-up", id="msg-2"),
]
}
with mock.patch("deerflow.agents.lead_agent.prompt._get_memory_context", return_value=""), mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt:
mock_dt.now.return_value.strftime.return_value = "2026-05-08, Friday"
result = mw.before_agent(state, _fake_runtime())
assert result is not None
msgs = result["messages"]
assert len(msgs) == 2
assert msgs[0].id == "msg-2"
assert msgs[0].additional_kwargs.get(_DYNAMIC_CONTEXT_REMINDER_KEY) is True
assert msgs[1].id == "msg-2__user"
assert msgs[1].content == "Follow-up"
# ---------------------------------------------------------------------------
# Edge cases
# ---------------------------------------------------------------------------
def test_no_messages_returns_none():
mw = _make_middleware()
result = mw.before_agent({"messages": []}, _fake_runtime())
assert result is None
def test_no_human_message_returns_none():
mw = _make_middleware()
state = {"messages": [AIMessage(content="assistant only")]}
with mock.patch("deerflow.agents.lead_agent.prompt._get_memory_context", return_value=""):
result = mw.before_agent(state, _fake_runtime())
assert result is None
def test_list_content_message_handled_as_separate_reminder():
"""List-content (e.g. multi-modal) messages remain intact; reminder is a separate message."""
mw = _make_middleware()
original_content = [{"type": "text", "text": "Hello"}]
state = {"messages": [HumanMessage(content=original_content, id="msg-1")]}
with mock.patch("deerflow.agents.lead_agent.prompt._get_memory_context", return_value=""), mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt:
mock_dt.now.return_value.strftime.return_value = "2026-05-08, Friday"
result = mw.before_agent(state, _fake_runtime())
assert result is not None
msgs = result["messages"]
assert len(msgs) == 2
# Reminder is a plain string message with the flag set
assert isinstance(msgs[0].content, str)
assert msgs[0].additional_kwargs.get(_DYNAMIC_CONTEXT_REMINDER_KEY) is True
assert _SYSTEM_REMINDER_TAG in msgs[0].content
# Original list-content message is untouched
assert msgs[1].content == original_content
def test_reminder_uses_original_id_user_message_uses_derived_id():
"""Reminder takes original ID (position swap); user message gets {id}__user."""
mw = _make_middleware()
original_id = "original-id-abc"
state = {"messages": [HumanMessage(content="Hello", id=original_id)]}
with mock.patch("deerflow.agents.lead_agent.prompt._get_memory_context", return_value=""), mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt:
mock_dt.now.return_value.strftime.return_value = "2026-05-08, Friday"
result = mw.before_agent(state, _fake_runtime())
assert result["messages"][0].id == original_id
assert result["messages"][1].id == f"{original_id}__user"
def test_message_without_id_gets_stable_uuid():
"""If the original HumanMessage has no ID, a UUID is generated and used consistently."""
mw = _make_middleware()
state = {"messages": [HumanMessage(content="Hello", id=None)]}
with mock.patch("deerflow.agents.lead_agent.prompt._get_memory_context", return_value=""), mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt:
mock_dt.now.return_value.strftime.return_value = "2026-05-08, Friday"
result = mw.before_agent(state, _fake_runtime())
assert result is not None
reminder_id = result["messages"][0].id
user_id = result["messages"][1].id
assert reminder_id is not None
assert reminder_id != "None"
assert user_id == f"{reminder_id}__user"
def test_user_message_containing_system_reminder_tag_does_not_prevent_injection():
"""A user message containing '<system-reminder>' must not be mistaken for a reminder."""
mw = _make_middleware()
state = {
"messages": [
HumanMessage(content="What is <system-reminder>?", id="msg-1"),
]
}
with mock.patch("deerflow.agents.lead_agent.prompt._get_memory_context", return_value=""), mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt:
mock_dt.now.return_value.strftime.return_value = "2026-05-08, Friday"
result = mw.before_agent(state, _fake_runtime())
# Injection must happen — the user message does NOT carry the reminder flag
assert result is not None
assert result["messages"][0].additional_kwargs.get(_DYNAMIC_CONTEXT_REMINDER_KEY) is True
# ---------------------------------------------------------------------------
# Midnight crossing
# ---------------------------------------------------------------------------
def test_midnight_crossing_injects_date_update_as_separate_message():
"""When the date has changed, a separate date-update reminder is injected before
the current turn's HumanMessage using the ID-swap technique."""
mw = _make_middleware()
reminder_content = "<system-reminder>\n<current_date>2026-05-08, Friday</current_date>\n</system-reminder>"
state = {
"messages": [
_reminder_msg(reminder_content, "msg-1"),
HumanMessage(content="Hello", id="msg-1__user"),
AIMessage(content="Response"),
HumanMessage(content="Good morning", id="msg-2"),
]
}
with mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt:
mock_dt.now.return_value.strftime.return_value = "2026-05-09, Saturday"
result = mw.before_agent(state, _fake_runtime())
assert result is not None
msgs = result["messages"]
assert len(msgs) == 2
# Date-update reminder takes the current message's ID
assert msgs[0].id == "msg-2"
assert msgs[0].additional_kwargs.get(_DYNAMIC_CONTEXT_REMINDER_KEY) is True
assert _SYSTEM_REMINDER_TAG in msgs[0].content
assert "<current_date>2026-05-09, Saturday</current_date>" in msgs[0].content
assert "Good morning" not in msgs[0].content # reminder only
# Original user text appended with derived ID
assert msgs[1].id == "msg-2__user"
assert msgs[1].content == "Good morning"
def test_midnight_crossing_id_swap():
"""Date-update reminder uses original ID; user message uses {id}__user."""
mw = _make_middleware()
reminder_content = "<system-reminder>\n<current_date>2026-05-08, Friday</current_date>\n</system-reminder>"
state = {
"messages": [
_reminder_msg(reminder_content, "msg-1"),
HumanMessage(content="Next day message", id="msg-2"),
]
}
with mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt:
mock_dt.now.return_value.strftime.return_value = "2026-05-09, Saturday"
result = mw.before_agent(state, _fake_runtime())
assert result["messages"][0].id == "msg-2"
assert result["messages"][1].id == "msg-2__user"
def test_no_second_midnight_injection_once_date_updated():
"""After a midnight update is persisted, the same-day path skips re-injection."""
mw = _make_middleware()
date_update_content = "<system-reminder>\n<current_date>2026-05-09, Saturday</current_date>\n</system-reminder>"
state = {
"messages": [
_reminder_msg(
"<system-reminder>\n<current_date>2026-05-08, Friday</current_date>\n</system-reminder>",
"msg-1",
),
HumanMessage(content="Hello", id="msg-1__user"),
AIMessage(content="Response"),
_reminder_msg(date_update_content, "msg-2"),
HumanMessage(content="Good morning", id="msg-2__user"),
AIMessage(content="Good morning!"),
HumanMessage(content="Third turn", id="msg-3"),
]
}
with mock.patch("deerflow.agents.middlewares.dynamic_context_middleware.datetime") as mock_dt:
mock_dt.now.return_value.strftime.return_value = "2026-05-09, Saturday"
result = mw.before_agent(state, _fake_runtime())
assert result is None # same day as last injected date → no update