fix: normalize snapshot read failures to unavailable in slots RPC path

Co-authored-by: genichin <4282227+genichin@users.noreply.github.com>

tests/application/test_account_snapshot.py

@@ -36,6 +36,11 @@ class FakeAccountBroker:
         return self.cash
 
 
+class BrokenLoadStore(InMemoryAccountSnapshotStore):
+    def load(self, account_hash: str) -> AccountSnapshot | None:
+        raise RuntimeError("db read failed")
+
+
 def _wire():
     now = [datetime(2026, 7, 29, tzinfo=UTC)]
     broker = FakeAccountBroker()
@@ -177,3 +182,19 @@ def test_slots_rpc_uses_snapshot_only_with_sell_ttl_freshness():
     with pytest.raises(AccountSnapshotUnavailable) as raised:
         service.holdings_for_slots_rpc()
     assert raised.value.code == "expired"
+
+
+def test_slots_rpc_normalizes_snapshot_store_read_failure():
+    broker = FakeAccountBroker()
+    service = AccountSnapshotService(
+        broker=broker,
+        store=BrokenLoadStore(),
+        buy_max_age_sec=600,
+        sell_max_age_sec=3600,
+        clock=lambda: datetime(2026, 7, 29, tzinfo=UTC),
+        rng=lambda: 0.5,
+    )
+
+    with pytest.raises(AccountSnapshotUnavailable) as raised:
+        service.holdings_for_slots_rpc()
+    assert raised.value.code == "read_failed"

tests/application/test_slots_handler_broker_quantity.py

@@ -2,8 +2,14 @@
 from __future__ import annotations
 
 from datetime import UTC, datetime
+from typing import Protocol
 
-from trex_core.application.account_snapshot import AccountSnapshotUnavailable
+from trex_core.application.account_snapshot import (
+    AccountSnapshot,
+    AccountSnapshotService,
+    AccountSnapshotUnavailable,
+    InMemoryAccountSnapshotStore,
+)
 from trex_core.application.broker_port import BalanceItem
 from trex_core.application.messaging import RpcRequest
 from trex_core.application.messaging_handlers import make_slots_rpc_handler
@@ -32,9 +38,29 @@ class _Reader:
         return list(self._holdings), self._captured_at
 
 
+class _SlotsReader(Protocol):
+    def holdings_for_slots_rpc(self) -> tuple[list[BalanceItem], datetime]: ...
+
+
+class _BrokenLoadStore(InMemoryAccountSnapshotStore):
+    def load(self, account_hash: str) -> AccountSnapshot | None:
+        raise RuntimeError("db read failed")
+
+
+class _Broker:
+    def account_scope_hash(self) -> str:
+        return "a" * 64
+
+    def get_balance(self) -> list[BalanceItem]:
+        return []
+
+    def get_available_cash(self, *, price_check_code: str = "005930") -> int:
+        return 0
+
+
 def _holding_handler(
     *,
-    broker_reader: _Reader,
+    broker_reader: _SlotsReader,
     instance_key: str = "default",
     portfolio_id: str = "pf-A",
     symbol: str = "104620",
@@ -131,6 +157,24 @@ def test_holding_qty_stale_snapshot_is_unavailable():
     assert row["broker_quantity_available"] is False
 
 
+def test_holding_qty_store_read_failure_is_unavailable():
+    _, handler = _holding_handler(
+        broker_reader=AccountSnapshotService(
+            broker=_Broker(),
+            store=_BrokenLoadStore(),
+            buy_max_age_sec=600,
+            sell_max_age_sec=3600,
+            clock=lambda: datetime(2026, 8, 24, 12, 0, tzinfo=UTC),
+            rng=lambda: 0.5,
+        ),
+    )
+    row = handler(_req_holding()).payload["slots"][0]
+    assert row["qty"] is None
+    assert row["qty_source"] == "unavailable"
+    assert row["broker_quantity_available"] is False
+    assert row["broker_quantity_captured_at"] is None
+
+
 def test_broker_quantity_reader_is_instance_bound_per_handler():
     repo = InMemorySlotRepository()
     svc = SlotService(repo)

trex_core/application/account_snapshot.py

@@ -49,6 +49,7 @@ class AccountSnapshotUnavailable(RuntimeError):
         "account_mismatch",
         "expired",
         "live_read_failed",
+        "read_failed",
     })
 
     def __init__(self, code: str) -> None:
@@ -189,7 +190,15 @@ class AccountSnapshotService:
         account_hash = self._broker.account_scope_hash()
         if not account_hash:
             raise AccountSnapshotUnavailable("account_mismatch")
-        snapshot = self._store.load(account_hash)
+        try:
+            snapshot = self._store.load(account_hash)
+        except Exception as exc:
+            _log.warning(
+                "account snapshot load failed: account_hash=%s",
+                account_hash,
+                exc_info=True,
+            )
+            raise AccountSnapshotUnavailable("read_failed") from exc
         if snapshot is None or snapshot.account_hash != account_hash:
             raise AccountSnapshotUnavailable("account_mismatch")
         return snapshot