完成以下练习题，要求如下：

1. 在/router/index.ts中添加全局守卫
2. 并在守卫中获取meta元信息，完成权限判定
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   参考答案：

//  /router/index.ts
{
    path: '/',
    element: React.createElement(BeforeEach, null, React.createElement(App)),
    meta: { auth: true },
    children: [
      {
        path: 'index',
        element: React.createElement(Index),
        meta: { auth: true }
      },
      {
        path: 'login',
        element: React.createElement(Login),
        meta: { auth: false }
      }
    ]
}

//  /component/BeforeEach/BeforEach.tsx
import React from 'react'
import { useLocation, matchRoutes, Navigate } from 'react-router-dom'
import { routes } from '../../router';
interface BeforeEachProps {
  children: React.ReactNode
}

export default function BeforeEach(props: BeforeEachProps) {
  const location = useLocation();
  const matchs = matchRoutes(routes, location)
  if(Array.isArray(matchs)){
    const meta = matchs[matchs.length-1].route.meta
    if(meta?.auth){
      return <Navigate to="/login" />
    }
  }
  return <div>{ props.children }</div>; 
}