NPM设置代理：

npm config set proxy="<http_proxy>"
npm config set https-proxy="<https_proxy>"

NPM删除代理：

npm config delete proxy 
npm config delete https-proxy

YARN设置代理:

yarn config set proxy <http_proxy>
yarn config set https-proxy <https_proxy>

YARN删除代理:

yarn config delete proxy  
yarn config delete https-proxy

另外，设置registry如下

npm config set registry https://registry.npmmirror.com
//npm config set registry https://registry.npm.taobao.org/
npm config set registry https://registry.npmjs.org/
yarn config set registry https://registry.npm.taobao.org/
yarn config set registry https://registry.npmjs.org/