iai-mcp-opencode/tests/test_store_read_consistency.py

"""F-05 regression: MemoryStore reader must see cross-connection writes.

Symptom that prompted this test:
    The sleep daemon ticks every 30 s and calls ``_store_is_empty(store)``
    against a connection it opened at process start. When short-lived MCP
    tool calls (e.g. ``memory_capture``) wrote new rows through a
    DIFFERENT connection to the same LanceDB directory, the daemon kept
    reporting ``last_tick_skipped_reason: empty_store`` forever — it had
    pinned the manifest snapshot at boot and LanceDB's default
    ``read_consistency_interval=None`` meant the handle never
    auto-refreshed.

Fix shape:
    ``MemoryStore`` gained a ``read_consistency_interval: timedelta | None``
    kwarg that is passed through to ``lancedb.connect``. Long-lived
    readers (the daemon) opt into ``timedelta(seconds=0)`` — strong
    consistency — so every read re-checks the latest committed
    version. Short-lived MCP callers keep the default ``None`` because
    they create a fresh connection per call and exit before staleness
    matters.

These tests pin both sides of the contract:
 1. With strong consistency the reader sees a writer's insert even
    when the reader opened first.
 2. With the default interval the reader's handle stays pinned to the
    snapshot it opened against (documents the knob the daemon now
    overrides, and guards against an accidental default change).
"""
from __future__ import annotations

from datetime import datetime, timedelta, timezone
from uuid import uuid4

import pytest


def _make_record(store):
    """Construct a minimal MemoryRecord sized to the store's embed dim."""
    from iai_mcp.types import MemoryRecord

    now = datetime.now(timezone.utc)
    return MemoryRecord(
        id=uuid4(),
        tier="semantic",
        literal_surface="f-05 regression probe",
        aaak_index="",
        embedding=[0.0] * store.embed_dim,
        community_id=None,
        centrality=0.0,
        detail_level=1,
        pinned=False,
        stability=0.0,
        difficulty=0.0,
        last_reviewed=None,
        never_decay=False,
        never_merge=False,
        provenance=[],
        created_at=now,
        updated_at=now,
        language="en",
    )


@pytest.fixture
def tmp_store_env(tmp_path, monkeypatch):
    monkeypatch.setenv("IAI_MCP_STORE", str(tmp_path / "iai"))
    monkeypatch.setenv("IAI_MCP_EMBED_DIM", "384")
    return tmp_path


def test_reader_with_strong_consistency_sees_writer_insert(tmp_store_env):
    """F-05 core regression: daemon-style reader (opened first, long-lived)
    must observe records written by a separate connection."""
    from iai_mcp.daemon import _store_is_empty
    from iai_mcp.store import MemoryStore

    # Reader opens first while store is empty — this is the daemon at boot.
    reader = MemoryStore(read_consistency_interval=timedelta(seconds=0))
    assert _store_is_empty(reader) is True  # baseline: nothing written yet

    # Writer is a distinct connection to the same directory — this is the
    # MCP tool call (memory_capture) running in a short-lived process.
    writer = MemoryStore()
    writer.insert(_make_record(writer))

    # With strong consistency the reader sees the commit on the next read.
    # Before the fix this stayed True forever.
    assert _store_is_empty(reader) is False


def test_default_connection_is_snapshot_pinned(tmp_store_env):
    """Documents the non-default behaviour: a reader opened with the
    default ``read_consistency_interval=None`` pins its view of the
    ``records`` table to the version present at ``open_table`` time.

    This is the semantics short-lived MCP callers rely on (they finish
    and exit before staleness matters). Guards against an accidental
    default change that would regress MCP latency. The test also proves
    ``checkout_latest()`` is the manual escape hatch, matching the
    LanceDB consistency contract.
    """
    from iai_mcp.store import MemoryStore

    reader = MemoryStore()  # no consistency kwarg — default None
    records_tbl = reader.db.open_table("records")
    assert records_tbl.count_rows() == 0

    writer = MemoryStore()
    writer.insert(_make_record(writer))

    # Same table handle, reader did not ask for strong consistency:
    # the pinned snapshot still shows zero.
    assert records_tbl.count_rows() == 0

    # Manual refresh restores visibility — this is the second blessed
    # pattern (strong consistency being the first).
    records_tbl.checkout_latest()
    assert records_tbl.count_rows() == 1


def test_kwarg_is_persisted_for_introspection(tmp_store_env):
    """Callers (ops tooling, tests) can read the interval back."""
    from iai_mcp.store import MemoryStore

    default_store = MemoryStore()
    assert default_store._read_consistency_interval is None

    strong_store = MemoryStore(read_consistency_interval=timedelta(seconds=0))
    assert strong_store._read_consistency_interval == timedelta(seconds=0)

    eventual_store = MemoryStore(read_consistency_interval=timedelta(seconds=30))
    assert eventual_store._read_consistency_interval == timedelta(seconds=30)