Angular 2 offline support with sw-precache library

sw-precache-script.js

const fs = require('fs');
const swPrecache = require('sw-precache');

function getFiles(path, regExpArray) {
	//Returns an erray of fileNames that respect the RegExp

	return new Promise((resolve, reject) => {
		fs.readdir(path, (err, items) => {
			resolve(items.filter(item => regExpArray.some(regExp => regExp.test(item))).map(item => `${path}/${item}`));
		});
	});
}

getFiles('dist', [new RegExp('vendor.(.+).js')]).then(items => {
	const options = {
		"clientsClaim ": false,
		"skipWaiting": false,
		"staticFileGlobs": [
			"dist/**.css",
			...items
  		],
		"stripPrefix": "dist",
		"runtimeCaching": [{
			"urlPattern": "(.+).chunk.js",
			"handler": "cacheFirst"
  		}],
		"verbose": true
	}
	swPrecache.write('./dist/service-worker.js', options, (err) => {
		if (err) {
			console.error(err);
		}
	});
});