_browser.mjs

import puppeteer from 'puppeteer';
import http from 'http';
import { promises as fsp } from 'fs';
import test from 'node:test';
import process from 'node:process';

const requestListener = async function (req, res) {

	const parsedUrl = new URL(req.url, 'http://localhost:8080');
	const pathname = parsedUrl.pathname;

	switch (pathname) {
		case '':
		case '/':
			res.setHeader('Content-type', 'text/html');
			res.writeHead(200);
			res.end(await fsp.readFile('test/_browser.html', 'utf8'));
			break;
		case '/test/browser.expect.css':
			res.writeHead(200);
			res.end(await fsp.readFile('test/browser.expect.css', 'utf8'));
			break;
		default:
			res.setHeader('Content-type', 'text/plain');
			res.writeHead(404);
			res.end('Not found');
			break;
	}
};

function startServers() {
	const server = http.createServer(requestListener);
	server.listen(8080);

	return () => {
		server.close();
	};
}

if (!process.env.DEBUG) {
	test('browser', { skip: process.env.GITHUB_ACTIONS && !process.env.BROWSER_TESTS }, async () => {
		const cleanup = startServers();

		const browser = await puppeteer.launch({
			headless: 'new',
		});

		const page = await browser.newPage();
		page.on('pageerror', (msg) => {
			throw msg;
		});
		await page.goto('http://localhost:8080');
		const result = await page.evaluate(async () => {
			// eslint-disable-next-line no-undef
			return await window.runTest();
		});
		if (!result) {
			throw new Error('Test failed, expected "window.runTest()" to return true');
		}

		await browser.close();

		await cleanup();
	});
} else {
	startServers();

	console.log('visit : http://localhost:8080');
}