.babelrc

{
  "presets": [
    "@babel/preset-react",
    [
      "@babel/preset-env",
      {
        "targets": {
          "browsers": [
            "last 2 versions",
            "safari >= 7"
          ]
        },
        "modules": false
      }
    ]
  ],
  "plugins": [
    "@babel/plugin-syntax-object-rest-spread",
    "@babel/plugin-proposal-object-rest-spread",
    "@babel/plugin-proposal-class-properties"
  ],
  "env": {
    "test": {
      "presets": [
        "@babel/preset-react",
        [
          "@babel/preset-env",
          {
            "targets": {
              "browsers": [
                "last 2 versions",
                "safari >= 7"
              ]
            }
          }
        ]
      ],
      "plugins": [
        "@babel/plugin-syntax-object-rest-spread",
        "@babel/plugin-proposal-object-rest-spread",
        "@babel/plugin-proposal-class-properties"
      ]
    }
  }
}