jest-resolver.js

module.exports = (path, options) => {
  // Call the defaultResolver, so we leverage its cache, error handling, etc.
  return options.defaultResolver(path, {
    ...options,
    // Use packageFilter to process parsed `package.json` before the resolution (see https://www.npmjs.com/package/resolve#resolveid-opts-cb)
    packageFilter: (pkg) => {
      // see https://github.com/microsoft/accessibility-insights-web/pull/5421#issuecomment-1109168149
      // see https://github.com/uuidjs/uuid/pull/616
      //
      // jest-environment-jsdom 28+ tries to use browser exports instead of default exports,
      // but uuid/react-colorful only offers an ESM browser export and not a CommonJS one. Jest does not yet
      // support ESM modules natively, so this causes a Jest error related to trying to parse
      // "export" syntax.
      //
      // This workaround prevents Jest from considering uuid's module-based exports at all;
      // it falls back to uuid's CommonJS+node "main" property.
      //
      // Once we're able to migrate our Jest config to ESM and a browser crypto
      // implementation is available for the browser+ESM version of uuid to use (eg, via
      // https://github.com/jsdom/jsdom/pull/3352 or a similar polyfill), this can go away.
      //
      // How to test if this is needed anymore:
      // - comment it out
      // - run `yarn test`
      // - if all the tests pass, it means the workaround is no longer needed
      if (pkg.name === 'uuid') {
        delete pkg['exports'];
        delete pkg['module'];
      }
      return pkg;
    },
  });
};