system-test.js

import { execFileSync } from 'child_process';
import { JSDOM } from 'jsdom';

const { Promise } = global;

const options = { resources: 'usable', runScripts: 'dangerously' };
const server = execFileSync('node', [ './dist/server/index.js' ], { cwd: process.cwd() });
const browser = { };

beforeAll(async () => {
	await new Promise(resolve => setTimeout(resolve, 2000));

	const dom = await JSDOM.fromURL('http://localhost:8080', options);
	const { window } = dom;

	Object.assign(browser, { window });

	await new Promise(resolve => window.addEventListener('load', resolve));
});

afterAll(() => {
	server.kill();
});

describe('...', () => {

	test('...', () => {
		console.log(browser.window.document.body.outerHTML);
	});
});