unleash.unleash/frontend/.babelrc

{
  "presets": ["@babel/preset-env", "@babel/preset-react"],
  "plugins": [
    ["@babel/plugin-proposal-decorators", { "legacy": true }],
    "@babel/plugin-proposal-class-properties"
  ],
  "env": {
    "test": {
      "plugins": ["@babel/plugin-transform-modules-commonjs"]
    }
  }
}