monaco-editor/docs/integrate-esm.md

Integrating the ESM version of the Monaco Editor

• Webpack
  • Option 1: Using the Monaco Editor Loader Plugin
  • Option 2: Using plain webpack
• Parcel
• Vite

Using webpack

Here is the most basic script that imports the editor using ESM with webpack.

More self-contained samples are available in the samples folder.

---

Option 1: Using the Monaco Editor WebPack Plugin

This is the easiest method, and it allows for options to be passed into the plugin in order to select only a subset of editor features or editor languages. Read more about the Monaco Editor WebPack Plugin, which is a community authored plugin.

• index.js

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

• webpack.config.js

  const MonacoWebpackPlugin = require('monaco-editor-webpack-plugin');
  const path = require('path');
  
  module.exports = {
  	entry: './index.js',
  	output: {
  		path: path.resolve(__dirname, 'dist'),
  		filename: 'app.js'
  	},
  	module: {
  		rules: [
  			{
  				test: /\.css$/,
  				use: ['style-loader', 'css-loader']
  			},
  			{
  				test: /\.ttf$/,
  				use: ['file-loader']
  			}
  		]
  	},
  	plugins: [new MonacoWebpackPlugin()]
  };
  

---

Option 2: Using plain webpack

Full working samples are available at https://github.com/microsoft/monaco-editor/tree/main/samples/browser-esm-webpack or https://github.com/microsoft/monaco-editor/tree/main/samples/browser-esm-webpack-small

• index.js

  import * as monaco from 'monaco-editor';
  
  // Since packaging is done by you, you need
  // to instruct the editor how you named the
  // bundles that contain the web workers.
  self.MonacoEnvironment = {
  	getWorkerUrl: function (moduleId, label) {
  		if (label === 'json') {
  			return './json.worker.bundle.js';
  		}
  		if (label === 'css' || label === 'scss' || label === 'less') {
  			return './css.worker.bundle.js';
  		}
  		if (label === 'html' || label === 'handlebars' || label === 'razor') {
  			return './html.worker.bundle.js';
  		}
  		if (label === 'typescript' || label === 'javascript') {
  			return './ts.worker.bundle.js';
  		}
  		return './editor.worker.bundle.js';
  	}
  };
  
  monaco.editor.create(document.getElementById('container'), {
  	value: ['function x() {', '\tconsole.log("Hello world!");', '}'].join('\n'),
  	language: 'javascript'
  });
  

• webpack.config.js:

  const path = require('path');
  
  module.exports = {
  	entry: {
  		app: './index.js',
  		// Package each language's worker and give these filenames in `getWorkerUrl`
  		'editor.worker': 'monaco-editor/esm/vs/editor/editor.worker.js',
  		'json.worker': 'monaco-editor/esm/vs/language/json/json.worker',
  		'css.worker': 'monaco-editor/esm/vs/language/css/css.worker',
  		'html.worker': 'monaco-editor/esm/vs/language/html/html.worker',
  		'ts.worker': 'monaco-editor/esm/vs/language/typescript/ts.worker'
  	},
  	output: {
  		globalObject: 'self',
  		filename: '[name].bundle.js',
  		path: path.resolve(__dirname, 'dist')
  	},
  	module: {
  		rules: [
  			{
  				test: /\.css$/,
  				use: ['style-loader', 'css-loader']
  			},
  			{
  				test: /\.ttf$/,
  				use: ['file-loader']
  			}
  		]
  	}
  };
  

---

Using parcel

A full working sample is available at https://github.com/microsoft/monaco-editor/tree/main/samples/browser-esm-parcel

When using parcel, we need to use the getWorkerUrl function and build the workers seperately from our main source. To simplify things, we can write a tiny bash script to build the workers for us.

• index.js

  import * as monaco from 'monaco-editor';
  
  self.MonacoEnvironment = {
  	getWorkerUrl: function (moduleId, label) {
  		if (label === 'json') {
  			return './json.worker.js';
  		}
  		if (label === 'css' || label === 'scss' || label === 'less') {
  			return './css.worker.js';
  		}
  		if (label === 'html' || label === 'handlebars' || label === 'razor') {
  			return './html.worker.js';
  		}
  		if (label === 'typescript' || label === 'javascript') {
  			return './ts.worker.js';
  		}
  		return './editor.worker.js';
  	}
  };
  
  monaco.editor.create(document.getElementById('container'), {
  	value: ['function x() {', '\tconsole.log("Hello world!");', '}'].join('\n'),
  	language: 'javascript'
  });
  

• build_workers.sh

  ROOT=$PWD/node_modules/monaco-editor/esm/vs
  OPTS="--no-source-maps --log-level 1"        # Parcel options - See: https://parceljs.org/cli.html
  
  parcel build $ROOT/language/json/json.worker.js $OPTS
  parcel build $ROOT/language/css/css.worker.js $OPTS
  parcel build $ROOT/language/html/html.worker.js $OPTS
  parcel build $ROOT/language/typescript/ts.worker.js $OPTS
  parcel build $ROOT/editor/editor.worker.js $OPTS
  

Then, simply run sh ./build_workers.sh && parcel index.html. This builds the workers into the same directory as your main bundle (usually ./dist). If you want to change the --out-dir of the workers, you must change the paths in index.js to reflect their new location.

note - the getWorkerUrl paths are relative to the build directory of your src bundle

---

Using Vite

Adding monaco editor to Vite is simple since it has built-in support for web workers. You only need to implement the getWorker function (NOT the getWorkerUrl) to use Vite's output (Source):

import * as monaco from 'monaco-editor';
import editorWorker from 'monaco-editor/esm/vs/editor/editor.worker?worker';
import jsonWorker from 'monaco-editor/esm/vs/language/json/json.worker?worker';
import cssWorker from 'monaco-editor/esm/vs/language/css/css.worker?worker';
import htmlWorker from 'monaco-editor/esm/vs/language/html/html.worker?worker';
import tsWorker from 'monaco-editor/esm/vs/language/typescript/ts.worker?worker';

self.MonacoEnvironment = {
	getWorker(_, label) {
		if (label === 'json') {
			return new jsonWorker();
		}
		if (label === 'css' || label === 'scss' || label === 'less') {
			return new cssWorker();
		}
		if (label === 'html' || label === 'handlebars' || label === 'razor') {
			return new htmlWorker();
		}
		if (label === 'typescript' || label === 'javascript') {
			return new tsWorker();
		}
		return new editorWorker();
	}
};

monaco.editor.create(document.getElementById('container'), {
	value: "function hello() {\n\talert('Hello world!');\n}",
	language: 'javascript'
});