.babelrc

{
  "presets": [
    [
      "babel-preset-gatsby",
      {
        "targets": {
          "browsers": [
            ">0.5%",
            "not ie 11",
            "not op_mini all",
            "not samsung 4"
          ]
        }
      }
    ],
    [
      "@babel/preset-env",
      {
        "targets": {
          "esmodules": true
        }
      }
    ]
  ],
  "plugins": [
    ["prismjs", {
        "languages": ["javascript", "css", "markup", "g4"],
        "plugins": ["line-numbers"],
        "theme": "okaidia"
    }],
    ["@babel/plugin-proposal-private-property-in-object", {
      "loose": true 
    }],
    ["@babel/plugin-proposal-class-properties", {
      "loose": true 
    }],
    ["@babel/plugin-proposal-private-methods", {
      "loose": true
    }]
  ]
}