babel.config.js

const BABEL_ENV = process.env.BABEL_ENV;
const IS_TEST = BABEL_ENV === "test"
const ignore = IS_TEST ? [] : ['test/**/*.js']
const targets = IS_TEST ? { node: "current" } : { browsers: "defaults" }

module.exports = {
  presets: [
    [
      "@babel/preset-env",
      {
        modules: ["cjs", "test"].includes(BABEL_ENV) ? "commonjs" : false,
        targets
      },
    ],
    "@babel/preset-react"
  ],
  plugins: [
    "@babel/plugin-proposal-class-properties",
    "@babel/plugin-proposal-optional-chaining"
  ],
  ignore,
};