config-overrides.js

const rewireWebpackBundleAnalyzer = require('react-app-rewire-webpack-bundle-analyzer');

module.exports = function override(config, env) {
  switch (env) {
    case 'production':
      config = rewireWebpackBundleAnalyzer(config, env, {
        analyzerMode: 'static',
        reportFilename: 'report.html'
      });
      break;
    default:
  }

  return config;
}