react-router.config.js

import * as fs from 'node:fs';
import * as path from 'node:path';

/**
 * @type {import('@react-router/dev/config').Config}
 */
export default {
  basename: process.env.PUBLIC_BASE_PATH ?? '/',
  buildEnd({ viteConfig }) {
    if (!viteConfig.isProduction) {
      return;
    }

    /**
     * When deploying to GitHub Pages, if you navigate from / to another
     * route and refresh the tab, it will show the default GH Pages 404
     * page. This happens because GH Pages is not configured to send all
     * traffic to the index.html where we can load our client-side JS.
     * To fix this, we can create a 404.html file that contains the same
     * content as index.html. This way, when the user refreshes the page,
     * GH Pages will serve our 404.html and everything will work as expected.
     */
    const buildPath = viteConfig.build.outDir;

    fs.copyFileSync(path.join(buildPath, 'index.html'), path.join(buildPath, '404.html'));
  },
  ssr: false,
};