monaco-editor/docs/integrate-esm.md

Integrating the ESM version of the Monaco Editor

• Webpack
  • Option 1
  • Option 2
• Parcel

Using webpack

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

More self-contained samples are available at monaco-editor-samples.

---

Option 1: Using the Monaco Editor Loader 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 Loader 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']
    }]
  },
  plugins: [
    new MonacoWebpackPlugin()
  ]
};

---

Option 2: Using plain webpack

• 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') {
      return './css.worker.bundle.js';
    }
    if (label === 'html') {
      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']
    }]
  }
};

---

Using 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.bundle.js';
    }
    if (label === 'css') {
      return './css.worker.bundle.js';
    }
    if (label === 'html') {
      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'
});

• 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