gross hack for https://github.com/GoogleChrome/workbox/issues/1384#issuecomment-433550967

post-build.js

// see https://github.com/GoogleChrome/workbox/issues/1384#issuecomment-433550967
function precacheManifestHack() {
	console.log(
		chalk.red(
			"Applying dirty hack for https://github.com/GoogleChrome/workbox/issues/1384#issuecomment-433550967"
		)
	);
	const globPath = path.join(
		__dirname,
		"/..",
		"dist",
		"precache-manifest.*.js"
	);
	glob(globPath, function(err, matches) {
		if (err) {
			throw err;
		}
		if (matches.length !== 1) {
			throw new Error("matches.length for " + globPath + " !== 1");
		}
		const filepath = matches[0];
		let self = {};
		eval(fs.readFileSync(filepath, "utf8"));
		let manifest = self.__precacheManifest;
		let hash = manifest.filter(route => route.url === "/index.html")[0]
			.revision;
		manifest.push({ url: "/", revision: hash });
		const outputStr = "self.__precacheManifest = " + JSON.stringify(manifest);
		fs.writeFileSync(filepath, outputStr);
	});
}