react-native-bundle-visualizer/src/haul.config.extend.js

See what's inside your react-native bundle

import Visualizer from 'webpack-visualizer-plugin';
import originalConfig from '../../../haul.config.js';

export default {
  webpack: env => {
  	const config = originalConfig.webpack(env);
    config.plugins.push(new Visualizer());
    return config;
  }
};