Redirect missing Webpack assets to S3 bucket

WebpackAssetsPlugin.ts

import * as path from 'path';

import * as Boom from '@hapi/boom';
import { plugin as H2O2 } from '@hapi/h2o2';
import * as Hapi from '@hapi/hapi';

export interface WebpackAssetsPluginOptions {
  bundleStore: {
    enabled: boolean;
    uri: string;
  };
}

const WebpackAssetsPlugin: Hapi.Plugin<WebpackAssetsPluginOptions> &
  Hapi.PluginNameVersion = {
  name: 'WebpackAssetsPlugin',
  async register(server, options) {
    const routePath = '/assets/{param*}';

    server.route({
      method: 'GET',
      path: '/assets/{param*}',
      handler: {
        directory: {
          path: path.join(__dirname, '..', '..', '..', 'dist', 'assets'),
        },
      },
    });

    if (options.bundleStore.enabled) {
      server.ext('onPreResponse', (request, h) => {
        if (request.route.path !== routePath) {
          return h.continue;
        }

        if (
          Boom.isBoom(request.response) &&
          request.response.output.statusCode === 404
        ) {
          return h.proxy({
            passThrough: true,
            uri: options.bundleStore.uri,
            xforward: true,
          });
        }

        return h.continue;
      });
    }
  },
  dependencies: [H2O2.pkg.name],
};

export { WebpackAssetsPlugin };