RNSW 2

config.js

import { configure } from '@storybook/react';

configure(require.context('../src', true, /\.stories\.js?$/), module);

preview-head.html

<meta
  name="viewport"
  content="minimum-scale=1, initial-scale=1, width=device-width, shrink-to-fit=no"
/>
<link
  rel="stylesheet"
  href="https://fonts.googleapis.com/css?family=Roboto:300,400,500"
/>
<style>
  html,
  body {
    padding: 0;
    margin: 0;
  }
  #root {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
  }
</style>

webpack.config.js

const path = require('path');

module.exports = ({ config }) => {
  config.module.rules.push({
    test: /\.js?$/,
    include: [
      path.resolve(__dirname, '../node_modules/react-native'),
    ],
    use: [
      {
        loader: 'babel-loader',
        options: {
          presets: [
            'module:metro-react-native-babel-preset',
          ],
          plugins: [
            ['react-native-web', { commonjs: true }],
          ],
        },
      },
    ],
  });

  config.resolve.alias['react-native$'] = 'react-native-web';

  config.resolve.extensions = ['.web.js', '.js', '.jsx'];

  return config;
};