Merge pull request #206 from QuantStrategyLab/codex/binance-strict-bool-20260904

fix: reject non-boolean Binance buyer flags

Author: Pigbibi

application/broker_reconciliation.py

@@ -58,6 +58,12 @@ def _finite_number(value: object, *, field_name: str) -> float:
     return parsed
 
 
+def _strict_bool(value: object, *, field_name: str) -> bool:
+    if type(value) is not bool:
+        raise BinanceReconciliationReadError(f"Binance reconciliation received an invalid {field_name}.")
+    return value
+
+
 def _normalize_balance(raw: Mapping[str, object]) -> dict[str, object]:
     asset = _text(raw.get("asset")).upper()
     if not asset:
@@ -102,7 +108,7 @@ def _normalize_trade(raw: Mapping[str, object]) -> dict[str, object]:
         "commission": _finite_number(raw.get("commission"), field_name="trade commission"),
         "commission_asset": _text(raw.get("commissionAsset")).upper(),
         "time": _text(raw.get("time")),
-        "is_buyer": bool(raw.get("isBuyer")),
+        "is_buyer": _strict_bool(raw.get("isBuyer"), field_name="trade buyer flag"),
     }
 
 

tests/test_broker_reconciliation.py

@@ -109,6 +109,22 @@ def get_account(self):
         )
 
 
+@pytest.mark.parametrize("invalid_is_buyer", ["false", None, 0, 1])
+def test_invalid_trade_buyer_flag_fails_closed(invalid_is_buyer):
+    class InvalidBuyerFlag(_Client):
+        def get_my_trades(self, *, symbol, startTime, endTime, limit):
+            payload = super().get_my_trades(
+                symbol=symbol, startTime=startTime, endTime=endTime, limit=limit
+            )[0]
+            payload["isBuyer"] = invalid_is_buyer
+            return [payload]
+
+    with pytest.raises(BinanceReconciliationReadError, match="buyer flag"):
+        collect_read_only_reconciliation_observations(
+            InvalidBuyerFlag(), strategy_symbols=("BTCUSDT",), local_execution_ledger={}
+        )
+
+
 def test_recent_trades_are_partitioned_into_day_windows_and_deduplicated():
     class WindowRecordingClient(_Client):
         def __init__(self):