Method use

packages/router/src/index.ts:263–287

* Push middleware to the stack

(...args: UseMethodParams<Req, Res, App>)

   * Push middleware to the stack
   */
  use(...args: UseMethodParams<Req, Res, App>) {
    const base = args[0]

    const handlers = args.slice(1).flat()

    if (typeof base === 'string') {
      pushMiddleware(this.middleware)({
        path: base,
        handler: handlers[0] as Handler,
        handlers: handlers.slice(1) as Handler[],
        type: 'mw'
      })
    } else {
      pushMiddleware(this.middleware)({
        path: '/',
        handler: Array.isArray(base) ? base[0] : (base as Handler),
        handlers: Array.isArray(base)
          ? [...(base.slice(1) as Handler[]), ...(handlers as Handler[])]
          : (handlers as Handler[]),
        type: 'mw'
      })
    }

    return this
  }
}