babelpresetsenv配置项-exclude-的探究

babel-presets-env 结合一个target选项很好的控制了 编译的范围。但是有时候，不想制定这个一个不太准确的targrt,而希望更精致的配置，参考文档，就得使用 exclude了

比如，不希望编译 箭头函数，就在exclude里加上 “transform-es2015-arrow-functions”,

{

"presets": [
    [

        "env",

        {
            "modules": false,

            "useBuiltIns": false,

            "exclude": [
                "transform-es2015-arrow-functions",


                "transform-async-generator-functions"

            ]
        }
    ]
]

}

但是如果不想编译 async语法呢？

用这个吗 “transform-async-generator-functions”

报错了：
Invariant Violation: Invalid Option: The plugins/built-ins ‘transform-async-generator-functions’ passed to the ‘exclude’ option are not

valid. Please check data/[plugin-features|built-in-features].js in babel-preset-env (While processing preset: "D:\\learn\\es6\\node_modules\\babel-preset-env\\lib\\index.js")

顺着报错行找下去，法相选项只要不在validIncludesAndExcludes 的，统统报错：

var validIncludesAndExcludes = [].concat(

  Object.keys(_plugins2.default),   // "../data/plugins.json"
  

  // "./module-transformations"
  Object.keys(_moduleTransformations2.default).map(function(m) {
    return _moduleTransformations2.default[m];
  }),

  Object.keys(_builtIns2.default),  // ../data/built-ins.json


  _defaultIncludes.defaultWebIncludes  // "./default-includes"


);