Cannot read property 'add' of undefined

vue打包时报这个错误,但是我代码中没有写add, 调试只知道问题点应该在post请求下面用到了cooike,但是cookie单独写在外面就不会报错 . 错误: Module build failed: TypeError: E:/dev/src/pages/Login/Login.vue: Cannot read property 'add' of undefined

Cookie拿不到，要不放外面，要不换localStorage吧