.babelrc

{
  "presets": [
    [
      "@babel/preset-env",
      {
        "modules": false,
        "targets": {
          "browsers": [
            "last 3 versions",
            "safari >= 7"
          ]
        }
      }
    ],
    "@babel/preset-react",
    "@babel/preset-flow"
  ],
  "plugins": [
    "universal-import",
    "@babel/plugin-syntax-dynamic-import",
    "@babel/plugin-syntax-import-meta",
    "@babel/plugin-proposal-class-properties",
    "@babel/plugin-proposal-json-strings",
    [
      "@babel/plugin-proposal-decorators",
      {
        "legacy": true
      }
    ],
    "@babel/plugin-proposal-function-sent",
    "@babel/plugin-proposal-export-namespace-from",
    "@babel/plugin-proposal-numeric-separator",
    "@babel/plugin-proposal-throw-expressions"
  ],
  "env": {
    "production": {
      "only": [
        "src"
      ],
      "plugins": [
        "@babel/plugin-transform-react-constant-elements",
        "@babel/plugin-transform-react-inline-elements"
      ]
    },
    "development": {
      "plugins": [
        "react-hot-loader/babel"
      ]
    }
  }
}