babel.config.js

module.exports = (api) => {
  const isTest = api.env("test");
  return {
    presets: [
      "@babel/preset-react", // optional: react: this resolves react-files (jsx, tsx)
      "@babel/preset-typescript", // allows to use TypeScript
      [
        "@babel/preset-env", // allows you to use the latest JavaScript
        isTest
          ? {
              targets: {
                node: "current",
              },
            }
          : {},
      ],
    ],
    plugins: [
      "@babel/plugin-proposal-class-properties", // transforms static class properties as well as properties declared with the property initializer syntax
      "@babel/plugin-proposal-private-methods",
      "jsx-classnames-advanced", // optional: react: this resolves className={object}
      [
        "prismjs",
        {
          languages: ["css", "javascript", "html"], // example: https://hackernoon.com/using-prismjs-as-a-syntax-highlighter-in-react
          theme: "default",
          css: true,
        },
      ],
    ],
  };
};