关于打包es6 使用 useBuiltIns 报错

Question

先上配置
{
test: /.js$/,
exclude: /node_modules/,
loader: “babel-loader”
}

{
“presets”: [
[
"@babel/preset-env",
{
“useBuiltIns”: “usage”
}
]
]
}

结果打包的时候报错

ERROR in ./src/js/Director.js
Module not found: Error: Can’t resolve ‘core-js/modules/es6.array.for-each’ in ‘/Users/szh/Documents/study/game/flybirdWebpack/src/js’
@ ./src/js/Director.js 2:0-44
@ ./src/main.js

ERROR in ./src/js/base/ResourcesLoader.js
Module not found: Error: Can’t resolve ‘core-js/modules/es6.array.is-array’ in ‘/Users/szh/Documents/study/game/flybirdWebpack/src/js/base’
@ ./src/js/base/ResourcesLoader.js 1:0-44
@ ./src/main.js

请问老师 这是什么问题 我还去babel官网去看了 没找到解决

Answer 1

提问者 昨夜星辰璀璨 2019-04-01 22:11:10

老师我下载这个  core-js 解决了  我看老师讲的时候 不需要下载这个啊 

• Dell #1

  升级了，当时是不需要的

• 提问者 昨夜星辰璀璨 回复 Dell #2

  WARNING: We noticed you're using the `useBuiltIns` option without declaring a core-js version. Currently, we assume version 2.x when no version is passed. Since this default version will likely change in future versions of Babel, we recommend explicitly setting the core-js version you are using via the `corejs` option.
  
  You should also be sure that the version you pass to the `corejs` option matches the version specified in your `package.json`'s `dependencies` section. If it doesn't, you need to run one of the following commands:
  这是警告 他说我没有制定js核心模块， 意思是"@babel/polyfill": "^7.4.0",移除了js核心模块吗？  英文不太好，看的有点蒙

• Dell 回复 提问者 昨夜星辰璀璨 #3

  大概是这个意思的