Method use

packages/socket.io/lib/index.ts:864–872

* Registers a middleware, which is a function that gets executed for every incoming {@link Socket}. * * @example * io.use((socket, next) => { * // ... * next(); * }); * * @param fn - the middleware function

(
    fn: (
      socket: Socket<ListenEvents, EmitEvents, ServerSideEvents, SocketData>,
      next: (err?: ExtendedError) => void,
    ) => void,
  )

   * @param fn - the middleware function
   */
  public use(
    fn: (
      socket: Socket<ListenEvents, EmitEvents, ServerSideEvents, SocketData>,
      next: (err?: ExtendedError) => void,
    ) => void,
  ): this {
    this.sockets.use(fn);
    return this;
  }

  /**
   * Targets a room when emitting.