{
  "env": {
    "test": {
      "presets": [
        "es2015"
      ]
    },
    "development": {
      "presets": [
        "es2015"
      ]
    },
    "production": {
      "presets": [
        [
          "es2015", 
          { "modules": false }]
      ],
      "plugins": [
        "external-helpers"
      ]
    }
  }
}