.babelrc.js

// https://babeljs.io/docs/en/configuration
const presets = ["@babel/preset-react"];
if (process.env["BABEL_ENV"] === "es") {
  presets.unshift(["@babel/preset-env", { modules: false }]);
} else {
  presets.unshift("@babel/preset-env");
}

const plugins = [
  "@babel/plugin-proposal-export-default-from",
  "@babel/plugin-proposal-class-properties",
  "@babel/plugin-proposal-logical-assignment-operators",
  ["@babel/plugin-proposal-optional-chaining", { loose: false }],
  ["@babel/plugin-proposal-pipeline-operator", { proposal: "minimal" }],
  ["@babel/plugin-proposal-nullish-coalescing-operator", { loose: false }],
  "@babel/plugin-proposal-do-expressions",
  "add-module-exports"
];

module.exports = {
  presets,
  plugins,
  env: {
    test: {
      presets,
      plugins: [
        ...plugins,
        "@babel/plugin-transform-runtime",
        "dynamic-import-node"
      ]
    }
  }
};