monaco-editor/samples/browser-esm-parcel/src/index.js

import JSONWorker from 'url:monaco-editor/esm/vs/language/json/json.worker.js';
import CSSWorker from 'url:monaco-editor/esm/vs/language/css/css.worker.js';
import HTMLWorker from 'url:monaco-editor/esm/vs/language/html/html.worker.js';
import TSWorker from 'url:monaco-editor/esm/vs/language/typescript/ts.worker.js';
import EditorWorker from 'url:monaco-editor/esm/vs/editor/editor.worker.js';
import * as monaco from 'monaco-editor/esm/vs/editor/editor.main.js';

self.MonacoEnvironment = {
	getWorkerUrl: function (moduleId, label) {
		if (label === 'json') {
			return JSONWorker;
		}
		if (label === 'css' || label === 'scss' || label === 'less') {
			return CSSWorker;
		}
		if (label === 'html' || label === 'handlebars' || label === 'razor') {
			return HTMLWorker;
		}
		if (label === 'typescript' || label === 'javascript') {
			return TSWorker;
		}
		return EditorWorker;
	}
};

monaco.editor.create(document.getElementById('container'), {
	value: ['function x() {', '\tconsole.log("Hello world!");', '}'].join('\n'),
	language: 'javascript'
});