webpack.config.js

const createExpoWebpackConfigAsync = require('@expo/webpack-config');
const path = require("path");
const WorkboxWebpackPlugin = require("workbox-webpack-plugin");


module.exports = async function (env, argv) {
	// Set by expo-cli during `expo build:web`
	const isEnvProduction = env.mode === "production";

	// Create the default config
	const config = await createExpoWebpackConfigAsync(env, argv);

	/*
	  resolve victory-native as victory for the Web app
	  https://formidable.com/open-source/victory/docs/faq/#expo-web-apps-that-use-victory-native
	*/
	config.resolve.alias['victory-native'] = 'victory';

	// https://github.com/expo/examples/blob/master/with-workbox/webpack.config.js
	if (isEnvProduction) {
		config.plugins.push(
			// Generate a service worker script that will precache, and keep up to date,
			// the HTML & assets that are part of the webpack build.
			new WorkboxWebpackPlugin.InjectManifest({
				swSrc: path.resolve(__dirname, "src/service-worker.js"),
				dontCacheBustURLsMatching: /\.[0-9a-f]{8}\./,
				exclude: [
					/\.map$/,
					/asset-manifest\.json$/,
					/LICENSE/,
					/\.js\.gz$/,
					// Exclude all apple touch and chrome images because they're cached locally after the PWA is added.
					/(apple-touch-startup-image|chrome-icon|apple-touch-icon).*\.png$/,
				],
				// Bump up the default maximum size (2mb) that's precached,
				// to make lazy-loading failure scenarios less likely.
				// See https://github.com/cra-template/pwa/issues/13#issuecomment-722667270
				maximumFileSizeToCacheInBytes: 5 * 1024 * 1024,
			})
		);
	}	

	return config;
};