环境搭建基本配置
package.json
{
"name": "09-babel-demo",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "",
"license": "ISC",
"devDependencies": {
"@babel/cli": "^7.7.5",
"@babel/core": "^7.7.5",
"@babel/plugin-transform-runtime": "^7.7.5",
"@babel/preset-env": "^7.7.5"
},
"dependencies": {
"@babel/polyfill": "^7.7.0",
"@babel/runtime": "^7.7.5"
}
}
.babelrc
{
"presets": [
[
"@babel/preset-env",
{
"useBuiltIns": "usage",
"corejs": 3
}
]
],
"plugins": [
[
"@babel/plugin-transform-runtime",
{
"absoluteRuntime": false,
"corejs": 3,
"helpers": true,
"regenerator": true,
"useESModules": false
}
]
]
}
babal-polyfill
babal-polyfill => core-js + regenerator
babal7.4之后弃用babel-polyfill，直接使用core-js + regenerator
js新语法打补丁，使低版本浏览器支持新语法
babel-runtime
不污染全集环境，名字前加"_" _promise
