fix(CORE-001D): close boundary review gaps

app/services/price_feed.py

@@ -52,38 +52,44 @@ class PriceFeed:
         self._cache = get_cache()
 
     @staticmethod
-    def _normalize_cached_price_payload(payload: object, *, expected_symbol: str) -> PriceData:
+    def _required_payload_value(payload: Mapping[str, object], key: str, *, context: str) -> object:
+        if key not in payload:
+            raise TypeError(f"{context} is missing required field: {key}")
+        return payload[key]
+
+    @classmethod
+    def _normalize_cached_price_payload(cls, payload: object, *, expected_symbol: str) -> PriceData:
         if not isinstance(payload, Mapping):
             raise TypeError("cached price payload must be an object")
         payload_symbol = str(payload.get("symbol", expected_symbol)).strip().upper()
         normalized_symbol = expected_symbol.strip().upper()
         if payload_symbol != normalized_symbol:
             raise ValueError(f"cached symbol mismatch: {payload_symbol} != {normalized_symbol}")
-        timestamp = payload.get("timestamp")
+        timestamp = cls._required_payload_value(payload, "timestamp", context="cached price payload")
         if not isinstance(timestamp, str) or not timestamp.strip():
             raise TypeError("cached timestamp must be a non-empty ISO string")
         return PriceData(
             symbol=payload_symbol,
-            price=float(payload["price"]),
+            price=float(cls._required_payload_value(payload, "price", context="cached price payload")),
             currency=str(payload.get("currency", "USD")),
             timestamp=datetime.fromisoformat(timestamp),
             source=str(payload.get("source", "yfinance")),
         )
 
-    @staticmethod
-    def _normalize_provider_price_payload(payload: object, *, expected_symbol: str) -> PriceData:
+    @classmethod
+    def _normalize_provider_price_payload(cls, payload: object, *, expected_symbol: str) -> PriceData:
         if not isinstance(payload, Mapping):
             raise TypeError("provider price payload must be an object")
         payload_symbol = str(payload.get("symbol", expected_symbol)).strip().upper()
         normalized_symbol = expected_symbol.strip().upper()
         if payload_symbol != normalized_symbol:
             raise ValueError(f"provider symbol mismatch: {payload_symbol} != {normalized_symbol}")
-        timestamp = payload.get("timestamp")
+        timestamp = cls._required_payload_value(payload, "timestamp", context="provider price payload")
         if not isinstance(timestamp, datetime):
             raise TypeError("provider timestamp must be a datetime")
         return PriceData(
             symbol=payload_symbol,
-            price=float(payload["price"]),
+            price=float(cls._required_payload_value(payload, "price", context="provider price payload")),
             currency=str(payload.get("currency", "USD")),
             timestamp=timestamp,
             source=str(payload.get("source", "yfinance")),