Add check that the editor's ESM JS files can be loaded in a browser

test/monaco/esm-check/esm-check.js

@@ -0,0 +1,96 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+//@ts-check
+
+const fs = require('fs');
+const path = require('path');
+const util = require('../../../build/lib/util');
+const playwright = require('playwright');
+const yaserver = require('yaserver');
+const http = require('http');
+
+const DEBUG_TESTS = true;
+const SRC_DIR = path.join(__dirname, '../../../out-monaco-editor-core/esm');
+const DST_DIR = path.join(__dirname, './out');
+const PORT = 8562;
+
+run();
+
+async function run() {
+	await extractSourcesWithoutCSS();
+	const server = await startServer();
+
+	const browser = await playwright['chromium'].launch({
+		headless: !DEBUG_TESTS,
+		devtools: DEBUG_TESTS
+		// slowMo: DEBUG_TESTS ? 2000 : 0
+	});
+
+	const page = await browser.newPage({
+		viewport: {
+			width: 800,
+			height: 600
+		}
+	});
+	page.on('pageerror', (e) => {
+		console.error(`[esm-check] A page error occurred:`);
+		console.error(e);
+		process.exit(1);
+	});
+
+	const URL = `http://127.0.0.1:${PORT}/index.html`;
+	console.log(`[esm-check] Navigating to ${URL}`);
+	const response = await page.goto(URL);
+	if (!response) {
+		console.error(`[esm-check] Missing response.`);
+		process.exit(1);
+	}
+	if (response.status() !== 200) {
+		console.error(`[esm-check] Response status ${response.status()} is not 200 .`);
+		process.exit(1);
+	}
+	console.log(`[esm-check] All appears good.`)
+
+	await page.close();
+	await browser.close();
+
+	server.close();
+}
+
+/**
+ * @returns {Promise<http.Server>}
+ */
+async function startServer() {
+	const staticServer = await yaserver.createServer({ rootDir: __dirname });
+	return new Promise((resolve, reject) => {
+		const server = http.createServer((request, response) => {
+			return staticServer.handle(request, response);
+		});
+		server.listen(PORT, '127.0.0.1', () => {
+			resolve(server);
+		});
+	});
+}
+
+async function extractSourcesWithoutCSS() {
+	await util.rimraf(DST_DIR);
+
+	const files = util.rreddir(SRC_DIR);
+	for (const file of files) {
+		const srcFilename = path.join(SRC_DIR, file);
+		if (!/\.js$/.test(srcFilename)) {
+			continue;
+		}
+
+		const dstFilename = path.join(DST_DIR, file);
+
+		let contents = fs.readFileSync(srcFilename).toString();
+		contents = contents.replace(/import '[^']+\.css';/g, '');
+
+		util.ensureDir(path.dirname(dstFilename));
+		fs.writeFileSync(dstFilename, contents);
+	}
+}