Files
Joshua Valderrama 35b4dd2824 fix: session context drifting — messages leaking between chats (#135) (#267)
* docs: add implementation plan for fixing chat context drifting (#135)

* fix: make Session.history immutable + fix {}.history crash

- Session.history now exposes a COPY of the internal _history list
- add_message() replaces history with a fresh copy each time
- get_context_messages() derives from _history directly
- replace_messages() updates both _history and history
- truncate_messages() updates both _history and history
- _persist_message() line 207: fixed {}.history fallback crash
- Added 11 tests for session isolation and edge cases

Addresses #135 root cause #1: shared mutable references

* fix: task scheduler uses SessionManager methods instead of overwriting sessions

- Added ensure_task_session() to SessionManager (checks cache first)
- Task scheduler now uses ensure_task_session() instead of direct dict assignment
- Task scheduler now uses SessionManager.add_message() for message persistence
- Removed direct sess_obj.history.append() that was silently losing data

Addresses #135 root causes #2 and #3

* fix: add age guard to cleanup_empty_sessions — don't delete sessions <1h old

Prevents the cleanup task from deleting sessions that were just created
and haven't received any messages yet (message_count == 0).

Addresses #135 root cause #5

* test: comprehensive session isolation tests (10/10 passing)

* refactor: consolidate _session_manager into singleton pattern

- Added set_session_manager_instance / get_session_manager_instance to core/models
- kept backward-compat aliases (set_session_manager, get_session_manager)
- session_manager.py re-exports the singleton functions
- ai_interaction.set_session_manager now syncs with the core singleton
- context_compactor uses get_session_manager_instance() instead of getattr hack
- app.py initializes the singleton once

Addresses #135 root cause #4: fragile global wiring

* test: add concurrent session isolation integration tests

Verifies:
- Concurrent add_message to different sessions doesn't cross-contaminate
- Rapid parallel writes maintain isolation
- Read-write concurrent access is safe

All 3 async tests pass, proving the immutable history fix works under concurrency

* fix: pre-import core.models in conftest to prevent test pollution

test_agent_loop.py stubs sys.modules['core.models'] = MagicMock() at
module level during collection. Any test collected after it imports
Session as a MagicMock. Pre-importing core.models in conftest.py
before test_agent_loop.py's module-level code runs prevents this.

* fix: make .history authoritative mutable list, address PR review

Per review feedback: keep .history as the authoritative mutable list so
existing code doing .history.pop(), .history = [...], etc. still works.
Fix the cross-contamination bug by ensuring __post_init__() gives each
Session its OWN unique history list (never shared).

Changes:
- core/models.py: .history IS the authoritative list. _history aliases it.
  Each Session gets its own list in __post_init__.
- core/session_manager.py: add_message() delegates to Session.add_message()
  instead of appending directly — no double-append, single source of truth.
- tests/test_session_manager.py: updated test to reflect that .history
  references see new messages (same list, not a snapshot).
- docs/plans/2026-06-01-fix-chat-context-drifting.md: removed (not for
  shipping — useful design context but too much process/doc to ship).

All 272 tests pass (3 pre-existing failures unrelated).

* Fix session manager message persistence

* Fix session history alias regressions

* Fix session history aliasing and task delivery
2026-06-09 14:12:52 +01:00

132 lines
4.1 KiB
Python

# core/models.py
"""
Pure data models — no database logic, no side effects.
These are simple datacontainers. All persistence is handled by SessionManager.
"""
from dataclasses import dataclass
from typing import Dict, List, Any, Optional, TYPE_CHECKING
if TYPE_CHECKING:
from .session_manager import SessionManager
# Module-level session manager singleton (single source of truth)
_SESSION_MANAGER_INSTANCE: Optional["SessionManager"] = None
def set_session_manager_instance(manager: "SessionManager"):
"""Set the global SessionManager singleton."""
global _SESSION_MANAGER_INSTANCE
_SESSION_MANAGER_INSTANCE = manager
def get_session_manager_instance() -> Optional["SessionManager"]:
"""Get the global SessionManager singleton."""
return _SESSION_MANAGER_INSTANCE
# Keep legacy name for backward compatibility
set_session_manager = set_session_manager_instance
get_session_manager = get_session_manager_instance
@dataclass
class ChatMessage:
"""A single chat message."""
role: str
content: str
metadata: Optional[Dict[str, Any]] = None
def to_dict(self) -> Dict[str, Any]:
"""Convert to dict for API responses."""
result = {"role": self.role, "content": self.content}
if self.metadata:
result["metadata"] = self.metadata
return result
def get(self, key: str, default=None):
"""Dict-like access for compatibility."""
return getattr(self, key, default)
@dataclass
class Session:
"""A chat session — pure data container.
``.history`` is the authoritative mutable message list. Callers may
read, append, pop, or reassign it directly — these changes take
effect immediately. ``_history`` remains a compatibility alias that
always resolves to the authoritative ``history`` list.
Each session gets its own unique history list at construction time
(the dataclass default is never shared between instances).
"""
id: str
name: str
endpoint_url: str
model: str
rag: bool = False
archived: bool = False
headers: Optional[Dict[str, str]] = None
history: List[ChatMessage] = None
owner: Optional[str] = None
is_important: bool = False
message_count: int = 0
def __post_init__(self):
if self.headers is None:
self.headers = {}
# Ensure each session gets its OWN list (not the shared dataclass default)
if self.history is None:
self.history = []
@property
def _history(self) -> List[ChatMessage]:
"""Compatibility alias for callers that still reference ``_history``."""
return self.history
@_history.setter
def _history(self, messages: List[ChatMessage]):
self.history = messages
def add_message(self, message: ChatMessage):
"""
Add a message to this session.
Appends to the authoritative history list and increments
message_count. Delegates to SessionManager for persistence
if available.
"""
self.history.append(message)
self.message_count = len(self.history)
# Delegate to session manager for persistence
if _SESSION_MANAGER_INSTANCE:
_SESSION_MANAGER_INSTANCE._persist_message(self.id, message)
def get_context_messages(self) -> List[Dict[str, Any]]:
"""Get messages in format for LLM API.
Slash-command / setup replies are persisted to history so they render
in the transcript, but they are UI chatter (e.g. ``/setup ...`` and its
status lines) the user never meant as conversation. They carry
``metadata.source == "slash"``; exclude them here so they never reach
the model. Display/history-load paths use the raw ``history`` and are
unaffected.
"""
return [
msg.to_dict()
for msg in self.history
if (msg.metadata or {}).get("source") != "slash"
]
def get(self, key: str, default=None):
"""Dict-like access for compatibility."""
return getattr(self, key, default)
def __getitem__(self, key: str):
"""Allow session['field'] syntax."""
return getattr(self, key)