fix double prepend

resolvers/inbox/chats.py

@@ -63,12 +63,14 @@ async def create_chat(_, info, title="", members=[]):
     cids = await redis.execute("SMEMBERS", f"chats_by_user/{user.slug}")
     for cid in cids:
         c = await redis.execute("GET", F"chats/{cid.decode('utf-8')}")
-        isc = [x for x in c["users"] if x not in chat["users"]]
-        if isc == [] and chat["title"] == c["title"]:
-            return {
-                "error": "chat was created before",
-                "chat": chat
-            }
+        if c:
+            c = json.loads(c)
+            isc = [x for x in c["users"] if x not in chat["users"]]
+            if isc == [] and chat["title"] == c["title"]:
+                return {
+                    "error": "chat was created before",
+                    "chat": chat
+                }
 
     for m in members:
         await redis.execute("SADD", f"chats_by_user/{m}", chat_id)

resolvers/zine/topics.py

@@ -98,11 +98,12 @@ async def topic_follow(user, slug):
 async def topic_unfollow(user, slug):
     with local_session() as session:
         sub = (
-            session.query(TopicFollower)
-                .filter(
-                and_(TopicFollower.follower == user.slug, TopicFollower.topic == slug)
-            )
-                .first()
+            session.query(TopicFollower).filter(
+                and_(
+                    TopicFollower.follower == user.slug,
+                    TopicFollower.topic == slug
+                )
+            ).first()
         )
         if not sub:
             raise Exception("[resolvers.topics] follower not exist")