refactor(api): tighten phase 1 shared type contracts (#33453)

api/configs/middleware/cache/redis_pubsub_config.py

@@ -1,4 +1,4 @@
-from typing import Literal, Protocol
+from typing import Literal, Protocol, cast
 from urllib.parse import quote_plus, urlunparse
 
 from pydantic import AliasChoices, Field
@@ -12,16 +12,13 @@ class RedisConfigDefaults(Protocol):
     REDIS_PASSWORD: str | None
     REDIS_DB: int
     REDIS_USE_SSL: bool
-    REDIS_USE_SENTINEL: bool | None
-    REDIS_USE_CLUSTERS: bool
 
 
-class RedisConfigDefaultsMixin:
-    def _redis_defaults(self: RedisConfigDefaults) -> RedisConfigDefaults:
-        return self
+def _redis_defaults(config: object) -> RedisConfigDefaults:
+    return cast(RedisConfigDefaults, config)
 
 
-class RedisPubSubConfig(BaseSettings, RedisConfigDefaultsMixin):
+class RedisPubSubConfig(BaseSettings):
     """
     Configuration settings for event transport between API and workers.
 
@@ -74,7 +71,7 @@ class RedisPubSubConfig(BaseSettings, RedisConfigDefaultsMixin):
     )
 
     def _build_default_pubsub_url(self) -> str:
-        defaults = self._redis_defaults()
+        defaults = _redis_defaults(self)
         if not defaults.REDIS_HOST or not defaults.REDIS_PORT:
             raise ValueError("PUBSUB_REDIS_URL must be set when default Redis URL cannot be constructed")
 
@@ -91,11 +88,9 @@ class RedisPubSubConfig(BaseSettings, RedisConfigDefaultsMixin):
         if userinfo:
             userinfo = f"{userinfo}@"
 
-        host = defaults.REDIS_HOST
-        port = defaults.REDIS_PORT
         db = defaults.REDIS_DB
 
-        netloc = f"{userinfo}{host}:{port}"
+        netloc = f"{userinfo}{defaults.REDIS_HOST}:{defaults.REDIS_PORT}"
         return urlunparse((scheme, netloc, f"/{db}", "", "", ""))
 
     @property