Fix Ruff errors

backend/app/database.py

@@ -17,7 +17,7 @@
 
 
 def get_engine() -> AsyncEngine:
-    global engine
+    global engine  # noqa: PLW0603
 
     if SQLALCHEMY_DATABASE_URL is None:
         raise ValueError("DATABASE_URL environment variable is not set")
@@ -30,8 +30,8 @@ def get_engine() -> AsyncEngine:
 async_session_maker: None | async_sessionmaker = None
 
 
-def get_session_maker():
-    global async_session_maker
+def get_session_maker() -> async_sessionmaker:
+    global async_session_maker  # noqa: PLW0603
     if async_session_maker is None:
         async_session_maker = async_sessionmaker(
             autocommit=False, autoflush=False, bind=get_engine(), expire_on_commit=False

backend/app/main.py

@@ -14,6 +14,8 @@
 
 from app.settings import APISettings
 
+MAX_CONNECTION_ATTEMPTS = 10
+
 
 @asynccontextmanager
 async def lifespan(_: FastAPI) -> AsyncGenerator[None, None]:
@@ -25,7 +27,7 @@ async def lifespan(_: FastAPI) -> AsyncGenerator[None, None]:
         except Exception as ex:
             print(ex)
             time.sleep(1)
-        if i == 9:
+        if i == MAX_CONNECTION_ATTEMPTS - 1:
             sys.exit()
 
     Path.mkdir(Path(FILE_PATH), exist_ok=True)

backend/app/settings.py

@@ -1,6 +1,6 @@
-from pydantic_settings import BaseSettings, SettingsConfigDict
+from pydantic_settings import BaseSettings
 
 
 class APISettings(BaseSettings):
-    host: str = "0.0.0.0"
+    host: str = "0.0.0.0"  # noqa: S104
     port: int = 8002