hermes-agent/tests/agent/test_memory_session_switch.py
Nicolò Boschi c38dac742b fix(hindsight): flush buffered turns and drop stale prefetch on session switch
Two data-loss / leak gaps in HindsightMemoryProvider.on_session_switch
introduced by #17409.

1. Buffered turns silently lost when retain_every_n_turns > 1.
   on_session_switch unconditionally cleared _session_turns without
   flushing. Users who batched every N>1 turns and switched mid-batch
   (/reset, /new, /resume, /branch, or context compression) had those
   buffered turns disappear. Same data-loss class as the shutdown race,
   different lifecycle event.

   Note commit_memory_session() -> on_session_end() runs *before*
   on_session_switch on /reset, but Hindsight doesn't implement
   on_session_end so the buffer survives that step and dies at clear
   time. /resume, /branch, and compression skip commit_memory_session
   entirely so an on_session_end impl wouldn't help them anyway.

   Fix: snapshot the old _session_id, _document_id, _parent_session_id,
   _turn_index, and _session_turns; spawn one final retain that lands
   under the OLD document_id; then rotate state. Metadata is built
   synchronously against the old self._* so session_id / lineage tags
   on the flushed item all reference the prior session consistently.

2. Stale _prefetch_result leaks across switch.
   If queue_prefetch ran in the old session and the result hadn't been
   consumed by prefetch() yet, on_session_switch left the cached recall
   text in place. The next session's first prefetch() call would return
   text mined from the prior session's bank/query.

   Fix: join any in-flight _prefetch_thread (3s bounded — matches
   shutdown()), then clear _prefetch_result under _prefetch_lock before
   rotating session_id.

Tests
-----
- tests/plugins/memory/test_hindsight_provider.py (TestSessionSwitchBufferFlush):
    - buffered turns flushed under OLD document_id with OLD lineage tags
    - empty buffer => no spurious retain
    - _prefetch_result cleared on switch
    - in-flight prefetch thread is awaited before clear (no race)
- tests/agent/test_memory_session_switch.py: factory extended to seed the
  attrs the new flush path reads (_retain_source, _platform, _bank_id,
  prefetch state, etc.) and stub _run_hindsight_operation so existing
  switch-state assertions keep passing without network setup.
2026-04-29 08:09:03 -07:00

310 lines
11 KiB
Python

"""Tests for the on_session_switch hook and session_id propagation.
Covers #6672: memory providers must be notified when AIAgent.session_id
rotates mid-process (via /resume, /branch, /reset, /new, or context
compression). Without the notification, providers that cache per-session
state in initialize() (Hindsight, and any plugin that stores session_id
for scoped writes) keep writing into the old session's record.
"""
import json
import pytest
from agent.memory_manager import MemoryManager
from agent.memory_provider import MemoryProvider
class _RecordingProvider(MemoryProvider):
"""Provider that records every lifecycle call for assertion."""
def __init__(self, name="rec"):
self._name = name
self.switch_calls: list[dict] = []
self.sync_calls: list[dict] = []
self.queue_calls: list[dict] = []
self.initialize_calls: list[dict] = []
@property
def name(self) -> str:
return self._name
def is_available(self) -> bool: # pragma: no cover - unused
return True
def initialize(self, session_id, **kwargs):
self.initialize_calls.append({"session_id": session_id, **kwargs})
def get_tool_schemas(self):
return []
def sync_turn(self, user_content, assistant_content, *, session_id=""):
self.sync_calls.append(
{"user": user_content, "asst": assistant_content, "session_id": session_id}
)
def queue_prefetch(self, query, *, session_id=""):
self.queue_calls.append({"query": query, "session_id": session_id})
def on_session_switch(
self,
new_session_id,
*,
parent_session_id="",
reset=False,
**kwargs,
):
self.switch_calls.append(
{
"new": new_session_id,
"parent": parent_session_id,
"reset": reset,
"extra": kwargs,
}
)
# ---------------------------------------------------------------------------
# MemoryProvider ABC — default on_session_switch is a no-op
# ---------------------------------------------------------------------------
class _MinimalProvider(MemoryProvider):
"""Provider that does NOT override on_session_switch — ABC default must no-op."""
@property
def name(self) -> str:
return "minimal"
def is_available(self) -> bool:
return True
def initialize(self, session_id, **kwargs): # pragma: no cover - unused
pass
def get_tool_schemas(self):
return []
def test_abc_default_on_session_switch_is_noop():
"""Providers that don't override the hook must not raise."""
p = _MinimalProvider()
# All three call styles must be accepted without raising
p.on_session_switch("new-id")
p.on_session_switch("new-id", parent_session_id="old-id")
p.on_session_switch("new-id", parent_session_id="old-id", reset=True)
p.on_session_switch("new-id", parent_session_id="old-id", reset=True, reason="new_session")
# ---------------------------------------------------------------------------
# MemoryManager.on_session_switch — fan-out
# ---------------------------------------------------------------------------
def test_manager_fans_out_to_all_providers():
mm = MemoryManager()
# Only one external provider is allowed; use the builtin slot for p1.
p1 = _RecordingProvider(name="builtin")
p2 = _RecordingProvider(name="hindsight")
mm.add_provider(p1)
mm.add_provider(p2)
mm.on_session_switch("new-sid", parent_session_id="old-sid", reset=False, reason="resume")
assert len(p1.switch_calls) == 1
assert len(p2.switch_calls) == 1
for call in (p1.switch_calls[0], p2.switch_calls[0]):
assert call["new"] == "new-sid"
assert call["parent"] == "old-sid"
assert call["reset"] is False
assert call["extra"] == {"reason": "resume"}
def test_manager_ignores_empty_session_id():
"""Empty string session_id must not trigger provider hooks.
Prevents accidental fires during shutdown when self.session_id may be
cleared. Providers expect a meaningful id to switch TO.
"""
mm = MemoryManager()
p = _RecordingProvider()
mm.add_provider(p)
mm.on_session_switch("")
mm.on_session_switch(None) # type: ignore[arg-type]
assert p.switch_calls == []
def test_manager_isolates_provider_failures():
"""A provider that raises must not block other providers."""
class _Broken(_RecordingProvider):
def on_session_switch(self, *args, **kwargs): # type: ignore[override]
raise RuntimeError("boom")
mm = MemoryManager()
# MemoryManager rejects a second external provider, so pair broken
# (builtin slot) with a good external one.
broken = _Broken(name="builtin")
good = _RecordingProvider(name="good")
mm.add_provider(broken)
mm.add_provider(good)
# Must not raise — exceptions in one provider are swallowed + logged
mm.on_session_switch("new-sid", parent_session_id="old-sid")
assert len(good.switch_calls) == 1
assert good.switch_calls[0]["new"] == "new-sid"
def test_manager_reset_flag_preserved():
mm = MemoryManager()
p = _RecordingProvider()
mm.add_provider(p)
mm.on_session_switch("new-sid", reset=True, reason="new_session")
assert p.switch_calls[0]["reset"] is True
assert p.switch_calls[0]["extra"] == {"reason": "new_session"}
# ---------------------------------------------------------------------------
# MemoryManager.sync_all / queue_prefetch_all — session_id propagation
# ---------------------------------------------------------------------------
def test_sync_all_propagates_session_id_to_providers():
"""run_agent.py's sync_all call must pass session_id through to providers.
Without this, a provider that updates _session_id defensively in
sync_turn (as Hindsight does at hindsight/__init__.py:1199) never
sees the new id and keeps writing under the old one.
"""
mm = MemoryManager()
p = _RecordingProvider()
mm.add_provider(p)
mm.sync_all("hello", "world", session_id="sess-42")
assert p.sync_calls == [
{"user": "hello", "asst": "world", "session_id": "sess-42"}
]
def test_queue_prefetch_all_propagates_session_id_to_providers():
mm = MemoryManager()
p = _RecordingProvider()
mm.add_provider(p)
mm.queue_prefetch_all("next query", session_id="sess-42")
assert p.queue_calls == [{"query": "next query", "session_id": "sess-42"}]
# ---------------------------------------------------------------------------
# Hindsight reference implementation — state-flush semantics
# ---------------------------------------------------------------------------
def _make_hindsight_provider():
"""Build a bare HindsightMemoryProvider that skips network setup.
We instantiate without importing optional deps at class-level by
bypassing __init__ and seeding the attributes on_session_switch
reads/writes. This keeps the test hermetic.
"""
import threading
hindsight_mod = pytest.importorskip("plugins.memory.hindsight")
provider = object.__new__(hindsight_mod.HindsightMemoryProvider)
provider._session_id = "old-sid"
provider._parent_session_id = ""
provider._document_id = "old-sid-20260101_000000_000000"
provider._session_turns = ["turn-1", "turn-2"]
provider._turn_counter = 2
provider._turn_index = 2
# Attrs read by _build_metadata / _build_retain_kwargs when the
# buffer-flush path on session switch fires. Empty strings keep the
# metadata minimal but well-formed.
provider._retain_source = ""
provider._platform = ""
provider._user_id = ""
provider._user_name = ""
provider._chat_id = ""
provider._chat_name = ""
provider._chat_type = ""
provider._thread_id = ""
provider._agent_identity = ""
provider._agent_workspace = ""
provider._retain_tags = []
provider._retain_context = "test-context"
provider._retain_async = False
provider._bank_id = "test-bank"
# Prefetch state the switch path drains/clears.
provider._prefetch_thread = None
provider._prefetch_lock = threading.Lock()
provider._prefetch_result = ""
# Sync thread tracking — flush spawn target.
provider._sync_thread = None
# Stub the network-touching helper so the spawned flush thread is a
# no-op in unit tests. Real plugin behavior is covered by the
# mock-client tests in tests/plugins/memory/test_hindsight_provider.py.
provider._run_hindsight_operation = lambda _op: None
return provider
def test_hindsight_on_session_switch_updates_session_id_and_mints_fresh_doc():
provider = _make_hindsight_provider()
old_doc = provider._document_id
provider.on_session_switch(
"new-sid", parent_session_id="old-sid", reset=False, reason="resume"
)
assert provider._session_id == "new-sid"
assert provider._parent_session_id == "old-sid"
# Document id MUST be fresh — else next retain overwrites old session doc
assert provider._document_id != old_doc
assert provider._document_id.startswith("new-sid-")
def test_hindsight_on_session_switch_clears_turn_buffers():
"""Accumulated _session_turns must not leak into the next session.
Hindsight batches turns under a single _document_id. If the buffer
isn't cleared on switch, the next retain under the new _document_id
flushes turns that belong to the previous session.
"""
provider = _make_hindsight_provider()
provider.on_session_switch("new-sid", parent_session_id="old-sid")
assert provider._session_turns == []
assert provider._turn_counter == 0
assert provider._turn_index == 0
def test_hindsight_on_session_switch_clears_on_reset_true():
"""reset=True (from /new, /reset) must also flush buffers."""
provider = _make_hindsight_provider()
provider.on_session_switch("new-sid", reset=True, reason="new_session")
assert provider._session_id == "new-sid"
assert provider._session_turns == []
assert provider._turn_counter == 0
def test_hindsight_on_session_switch_ignores_empty_id():
"""Empty new_session_id must be a no-op to avoid corrupting state."""
provider = _make_hindsight_provider()
before = (
provider._session_id,
provider._document_id,
list(provider._session_turns),
provider._turn_counter,
)
provider.on_session_switch("")
provider.on_session_switch(None) # type: ignore[arg-type]
after = (
provider._session_id,
provider._document_id,
list(provider._session_turns),
provider._turn_counter,
)
assert before == after
def test_hindsight_preserves_parent_across_empty_parent_arg():
"""Omitting parent_session_id must NOT overwrite an existing one."""
provider = _make_hindsight_provider()
provider._parent_session_id = "original-parent"
provider.on_session_switch("new-sid") # no parent passed
assert provider._parent_session_id == "original-parent"