Add type hints

fixbackend/auth/rate_limiter.py

@@ -1,5 +1,6 @@
 from datetime import timedelta
 from textwrap import dedent
+from typing import List, Optional, cast, Any
 from fixbackend.types import Redis
 
 from fixcloudutils.util import utc
@@ -28,14 +29,16 @@ def _new_tokens(self, tokens: int, ttl: int) -> float:
         return min(self.limit, tokens + time_passed * self.refill_rate)
 
     async def check(self, username: str) -> bool:
-        [tokens, ttl] = await self.redis.eval(
+        result = await self.redis.eval(
             """ local ttl = redis.call('TTL', KEYS[1])
                 local tokens = redis.call('GET', KEYS[1])
                 return {tokens, ttl}
             """,
             1,
             f"rate_limit:{username}",
         )
+        result = cast(List[Optional[int]], result)
+        tokens, ttl = result
 
         if tokens is None:
             return True
@@ -45,7 +48,7 @@ async def check(self, username: str) -> bool:
         return new_tokens >= 1
 
     async def consume(self, username: str) -> bool:
-        allowed = await self.redis.eval(
+        allowed: Any = await self.redis.eval(
             dedent(
                 """
                 local bucket_key = KEYS[1]
@@ -87,5 +90,4 @@ async def consume(self, username: str) -> bool:
             utc().timestamp(),
         )
 
-        allowed = bool(allowed)
-        return allowed
+        return bool(allowed)