.babelrc

{
  "presets": [
    ["es2015", {"modules": false}], // webpack understands the native import syntax, and uses it for tree shaking
    "stage-2",
    // Specifies what level of language features to activate.
    // Stage 2 is "draft", 4 is finished, 0 is strawman.
    // See https://tc39.github.io/process-document/
    "flow"
  ],
  "plugins": [

  ],
  "env": {
    "production": {
      "plugins": [
        "add-module-exports"
      ]
    },
    "test": {
      "presets": ["es2015", "stage-2"]
    }
  }
}