koa2实现拦截器进行登录前session校验

//定义允许直接访问的url
const allowpage = ['/login','/api/login']
//拦截
function localFilter(ctx) {
    let url = ctx.originalUrl
    if (allowpage.indexOf(url) > -1) {
        logger.info('当前地址可直接访问')
    }else {
        if (ctx.isAuthenticated()) {
            if(url==='/'){
                ctx.redirect('/projectList')
            }
            console.log('login status validate success')
        } else {
            console.log('login status validate fail')
            console.log(ctx.request.url)
            ctx.redirect('/login')
        }
    }
}
//session拦截
app.use(async (ctx, next) => {
    localFilter(ctx)
    await next()

})