Auth middleware for socket

SocketManager.ts

class SocketManager {
  io: SocketIO.Server;
  pubClient: redis.RedisClient;
  sessionStore: RedisSessionStore;
  serverConfig: IServerConfig;
  redisEnabled: boolean;
  dynamoEnabled: boolean;

  constructor(server: http.Server, config: IServerConfig) {
    this.configureMiddleware();
  }

  configureMiddleware = () => {
    this.io.use(async (socket: ICustomSocket, next) => {
      const sessionId = socket.handshake.auth.sessionId;

      if (sessionId && this.redisEnabled) {
        const session = await this.sessionStore.findSession(sessionId);

        if (session) {
          socket.sessionId = sessionId;
          socket.username = session.username;

          return next();
        }
      }
      const username = socket.handshake.auth.username;
      if (!username) {
        return next(new Error("invalid username"));
      }

      socket.sessionId = v4();
      socket.username = username;

      next();
    });
  };
}