babel

环境搭建和基本配置

• 环境搭建

babel-polyfill

• core-js和regenerator的集合

//配置按需引入
"presets": [
    [
        "@babel/preset-env",
        {
        "useBuiltIns": "usage",
        "corejs": 3
        }
    ]
],

//缺点： 污染全局

babel-runtime

//.babelrc
"plugins": [
    [
        "@babel/plugin-transform-runtime",
        {
        "absoluteRuntime": false,
        "corejs": 3,
        "helpers": true,
        "regenerator": true,
        "useESModules": false
        }
    ]
]