Method use

lib/index.ts:776–784

* Registers a middleware, which is a function that gets executed for every incoming 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.