Yarn和npm使用相同的 package.json 格式，而且从 npm 迁移 Yarn 可以从npm安装依赖包。
只需执行：
1 | yarn |
Yarn 将通过自己的解析算法来重新组织 node_modules 目录，这个算法和node.js 模块解析算法是兼容的。
CLI命令比较
| npm(v5) | Yarn |
|---|---|
| npm install | yarn install |
| 不适用 | yarn install –flat |
| 不适用 | yarn install –har |
| npm install –no-package-lock | yarn install –no-lockfile |
| (不适用) | yarn install –pure-lockfile |
| npm install [package] | yarn add [package] |
| npm install [package] –save-dev | yarn add [package] –dev |
| (不适用) | yarn add [package] –peer |
| npm install [package] –save-optional | yarn add [package] –optional |
| npm install [package] –save-exact | yarn add [package] –exact |
| (不适用) | yarn add [package] –tilde |
| npm install [package] –global | yarn global add [package] |
| npm update –global | yarn global upgrade |
| npm rebuild | yarn install –force |
| npm uninstall [package] | yarn remove [package] |
| npm cache clean | yarn cache clean [package] |
| rm -rf node_modules && npm install | yarn upgrade |
