【Promise】Promise实现请求超时处理（加强版）

　　昨天闲来无事，于是把之前写过的promise优化了一下，代码如下：

/*写文件、追加写、读文件*/
var fs = require('fs');

function wrapper(fn,context) {
    var args = Array.prototype.slice.call(arguments,2);
    return new Promise((resolve,reject) => {
        args.push((err,data) => {
            err ? reject(err) : resolve(data);
        });
        fn.apply(context,args);
    });
}

wrapper(fs.writeFile,fs,'message.txt','word')
    .then(() => wrapper(fs.appendFile,fs,'message.txt','word'))
    .then(() => wrapper(fs.readFile,fs,'message.txt','word'))
    .then(data => console.log(data))
    .catch(err => console.log(err));


/*获取员工id、并发获取两个接口信息、读信息*/
var http = require('http');
var url = require('url');

function delayPromise(ms) {
    return new Promise((resolve,reject) => {
        setTimeout(reject, ms);
    });
}

function get(url,ms) {  
    return new Promise.race([
        delayPromise(ms),
        wrapper(request,null,url).then(data => {
            return JSON.parse(data);
        })
    ]);
    
}

get('http://demos.so/result/homework.promise.userInfo')
    .then( data => {
        return Promise.all([get('http://demos.so/result/userid=' + args['_id']), get('http://demos.so/result/student=' + args['_id'])])
    }
    .then( data => console.log(data))
    .catch( err => console.log(args));