这几天工作的需要，要研究下webpack,看到官网上说：

Pre-requisites
Before we begin, make sure you have a fresh version of [Node.js]
(https://nodejs.org/en/) installed. The current Long Term Support (LTS)
release is an ideal starting point. You may run into a variety of issues with
the older versions as they may be missing functionality webpack and/or its
related packages require.

于是乎就去屁颠屁颠地去升级电脑中的node.js,结果蛋疼的公司代理又一次阻止了一次伟大的....(此处省略)，反复设置代理又删除代理还是不行，报了如下错误，mac环境：

tunneling socket could not be established, cause=connect ETIMEDOUT
npm ERR! network This is most likely not a problem with npm itself
npm ERR! network and is related to network connectivity.
npm ERR! network In most cases you are behind a proxy or have bad 
network settings.

折腾了好久，回到家里心想躲过了万恶的公司代理应该没问题了，结果结果，是我错怪它了，接着到网上搜索了下相关信息，感谢stackoverflow上的答案：

Removing the proxy settings resolved the issue:

npm config rm proxy
npm config rm https-proxy

可能是之前删除代理的姿势不对,之前执行的是这个

npm config delete proxy

这个我也搞不清楚为啥不行。

啰嗦这么久，送上升级node.js版本的方法：

1.安装n模块
npm install -g n

2.升级到最新稳定版
n stable

3.也可以用n命令升级到其他版本，尽情挖掘其他功能

升级成功，后面不知道还会有什么更大的麻烦，就酱。

 linzhch:~ linzhch$ n stable
 install : node-v8.0.0
 mkdir : /usr/local/n/versions/node/8.0.0
 fetch : https://nodejs.org/dist/v8.0.0/node-v8.0.0-darwin-x64.tar.gz
######################################################################## 100.0%
   installed : v8.0.0