ES6 promise前端ajax请求

let request=(method,url,data)=>{
        let request=new XMLHttpRequest()
        return new Promise((resolve,reject)=>{
            request.onreadystatechange==function(){
                if(request.readyState==4){
                    resolve(request.responseText);
                }else{
                    reject(request.status)
                    console.log(111)
                }
            }
            request.open(method,url)
            request.send(data)
        })
    }

let Object=function(){};

url = '/pro/v1/api/contract/list'

Object.prototype={
    getData:function(){
        request("get",url,"").then((result)=>{
                console.log(JSON.parse(result))   
        }).catch((err)=>{
                console.log(err)
        })
    }
}

let obj=new Object();
obj.getData();