.babelrc

{
  "presets": [
    ["env", {
      "modules": false
    }],
    "stage-2"
  ],
  "plugins": [
    "transform-runtime",["component",[{
      "libraryName": "element-ui",
      "styleLibraryName": "theme-default"
    }]]
  ],
  "comments": false,
  "env": {
    "test": {
      "presets": ["env", "stage-2"],
      "plugins": ["istanbul"]
    }
  }
}