.babelrc

{
  "presets": ["env"],
  "plugins": [
    "transform-class-properties",
    "transform-object-rest-spread",
    [
      "transform-runtime",
      {
        "polyfill": false,
        "regenerator": true
      }
    ]
  ],
  "sourceMaps": true,
  "retainLines": true,
  "env": {
    "test": {
      "plugins": [["istanbul"]]
    }
  }
}