⚡ Bolt: Cache JSON parsing for Pokemon types

.jules/bolt.md

@@ -0,0 +1,3 @@
+## 2026-05-25 - Cached JSON Parsing in Pydantic Schema Validators
+**Learning:** In Pydantic v2 schemas configured with `from_attributes=True` that map ORM strings to lists (e.g. JSON strings), using a pre-validator that directly calls `json.loads()` becomes a bottleneck when loading thousands of records from the database.
+**Action:** Extract the JSON parsing into a private helper function, cache it with `@functools.lru_cache(maxsize=1024)` to return an immutable `tuple`, and have the public validator return `list(cached_tuple)` to maintain type safety and avoid cache pollution.

src/app/schemas/pokemon.py

@@ -1,10 +1,28 @@
 """Pokemon module."""
 
+import functools
 import json
+import logging
 from typing import Any
 
 from pydantic import BaseModel, ConfigDict, field_validator
 
+logger = logging.getLogger(__name__)
+
+
+@functools.lru_cache(maxsize=1024)
+def _parse_types_json(value: str) -> tuple[str, ...]:
+    """Private helper to parse and cache JSON strings into immutable tuples."""
+    try:
+        parsed = json.loads(value)
+        if not isinstance(parsed, list):
+            logger.error("invalid types format")
+            raise ValueError("invalid types format")
+        return tuple(parsed)
+    except json.JSONDecodeError as e:
+        logger.error("malformed types JSON")
+        raise ValueError("malformed types JSON") from e
+
 
 def parse_pokemon_types(value: Any) -> Any:
     """Helper function to parse the types JSON string.
@@ -19,13 +37,7 @@ def parse_pokemon_types(value: Any) -> Any:
         ValueError: If the string is not valid JSON or not a list.
     """
     if isinstance(value, str):
-        try:
-            parsed = json.loads(value)
-            if not isinstance(parsed, list):
-                raise ValueError("invalid types format")
-            return parsed
-        except json.JSONDecodeError as e:
-            raise ValueError("malformed types JSON") from e
+        return list(_parse_types_json(value))
     return value