.babelrc

{
  "presets": ["@babel/preset-env", "@babel/preset-react"],
  "plugins": [["@babel/plugin-proposal-class-properties"]],
  "env": {
    "test": {
      "presets": ["@babel/preset-env", "@babel/preset-react"],
      "plugins": ["istanbul", ["@babel/plugin-transform-runtime"]]
    }
  }
}