@beisen/storybook-react/src/server/framework-preset-cra-styles.js

Storybook for React: Develop React Component in isolation with Hot Reloading.

import { logger } from '@storybook/node-logger';
import { applyCRAWebpackConfig, isReactScriptsInstalled } from './cra-config';

export function webpackFinal(config) {
  if (!isReactScriptsInstalled()) {
    logger.info('=> Using base config because react-scripts is not installed.');
    return config;
  }

  logger.info('=> Loading create-react-app config.');

  return applyCRAWebpackConfig(config);
}