fix: fix linter and encoding of MemorystoreChatMessageHistory class.

src/langchain_google_memorystore_redis/__init__.py

@@ -11,7 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from langchain_google_memorystore_redis.chat_message_history import MemorystoreChatMessageHistory
+from .chat_message_history import MemorystoreChatMessageHistory
 from .vector_store import FLATConfig, HNSWConfig, RedisVectorStore
 
 __all__ = ["MemorystoreChatMessageHistory"]

src/langchain_google_memorystore_redis/chat_message_history.py

@@ -13,15 +13,11 @@
 # limitations under the License.
 
 import json
-import redis
 from typing import List, Optional
 
+import redis
 from langchain_core.chat_history import BaseChatMessageHistory
-from langchain_core.messages import (
-    BaseMessage,
-    message_to_dict,
-    messages_from_dict,
-)
+from langchain_core.messages import BaseMessage, message_to_dict, messages_from_dict
 
 
 class MemorystoreChatMessageHistory(BaseChatMessageHistory):
@@ -46,13 +42,16 @@ def __init__(
         self._redis = client
         self._key = session_id
         self._ttl = ttl
+        self._encoder = client.connection_pool.get_encoder()
 
     @property
-    def messages(self) -> List[BaseMessage]:
+    def messages(self) -> List[BaseMessage]:  # type: ignore
         """Retrieve all messages chronologically stored in this session."""
         all_elements = self._redis.lrange(self._key, 0, -1)
+
+        assert isinstance(all_elements, list)
         messages = messages_from_dict(
-            [json.loads(e.decode("utf-8")) for e in all_elements]
+            [json.loads(self._encoder.decode(e)) for e in all_elements]
         )
         return messages
 

src/langchain_google_memorystore_redis/vector_store.py

@@ -227,7 +227,6 @@ def __init__(
 
 
 class RedisVectorStore(VectorStore):
-
     DEFAULT_CONTENT_FIELD = "page_content"
     DEFAULT_VECTOR_FIELD = "vector"
     DEFAULT_DATA_TYPE = "float32"
@@ -503,7 +502,6 @@ def delete(self, ids: Optional[List[str]] = None, **kwargs: Any) -> Optional[boo
     def _similarity_search_by_vector_with_score_and_embeddings(
         self, query_embedding: List[float], k: int = 4, **kwargs: Any
     ) -> List[Tuple[Document, float, List[float]]]:
-
         distance_threshold = kwargs.get(
             "distance_threshold", kwargs.get("score_threshold")
         )

tests/test_chat_message_history.py

@@ -15,15 +15,15 @@
 
 import os
 import uuid
+
+import redis
 from langchain_core.messages import AIMessage, BaseMessage, HumanMessage
+
 from langchain_google_memorystore_redis import MemorystoreChatMessageHistory
-import redis
 
 
 def test_redis_multiple_sessions() -> None:
-    client = redis.from_url(
-        get_env_var("REDIS_URL", "URL of the Redis instance")
-    )
+    client = redis.from_url(get_env_var("REDIS_URL", "URL of the Redis instance"))
 
     session_id1 = uuid.uuid4().hex
     history1 = MemorystoreChatMessageHistory(