Function use

packages/platform-fastify/adapters/middie/fastify-middie.ts:64–95

(
    this: unknown,
    url:
      | string
      | null
      | MiddlewareFn<Req, Res, Ctx>
      | MiddlewareFn<Req, Res, Ctx>[],
    f?: MiddlewareFn<Req, Res, Ctx> | MiddlewareFn<Req, Res, Ctx>[],
  )

  };

  function use(
    this: unknown,
    url:
      | string
      | null
      | MiddlewareFn<Req, Res, Ctx>
      | MiddlewareFn<Req, Res, Ctx>[],
    f?: MiddlewareFn<Req, Res, Ctx> | MiddlewareFn<Req, Res, Ctx>[],
  ) {
    if (f === undefined) {
      f = url as MiddlewareFn<Req, Res, Ctx> | MiddlewareFn<Req, Res, Ctx>[];
      url = null;
    }

    let regexp: RegExp | undefined;
    if (typeof url === 'string') {
      const pathRegExp = pathToRegexp(sanitizePrefixUrl(url) as Path, {
        end: false,
      });
      regexp = pathRegExp.regexp;
    }

    if (Array.isArray(f)) {
      for (const val of f) {
        middlewares.push({ regexp, fn: val });
      }
    } else {
      middlewares.push({ regexp, fn: f });
    }

    return this;
  }

  function run(
    req: Req,