@babel/preset-typescript
optimizeConstEnums
默認(rèn)值 false
如果設(shè)置為true, Babel會(huì)直接替換枚舉值為常量值豺裆，比如：
const enum Animals {
Fish
}
console.log(Animals.Fish)
會(huì)被直接轉(zhuǎn)換成
console.log(0)
如果設(shè)置為false, Babel會(huì)使用正常的enum轉(zhuǎn)換方法，比如上述例子會(huì)被解釋為：
var Animals
(function(Animals) {
Animals[Animals["Fish"] = 0] = "Fish"
})(Animals || (Animals = {}))
console.log(Animals.Fish)
