babel入门

1.安装babel

npm install --save-dev @babel/core @babel/cli @babel/preset-env

2.编写babel配置文件 babel.config.json

{
  "plugins": [
    "@babel/plugin-transform-reserved-words"
  ]
}

3.配置脚本

{
  "scripts": {
      "build": "babel src --out-dir lib"
  }
}

4.配置源文件src/index.js

var abstract = 1;
var x = abstract + 1;