// import the monaco module
import monacoModule from '@theia/monaco/lib/browser/monaco-frontend-module';
// adding into the container
container.load(monacoModule);

ERROR in ./node_modules/onigasm/lib/onigasm.wasm
WebAssembly module is included in initial chunk.
This is not allowed, because WebAssembly download and compilation must happen asynchronous.
Add an async splitpoint (i. e. import()) somewhere between your entrypoint and the WebAssembly module:
* multi (webpack)-dev-server/client?http://localhost:8080 ./src --> ./src/index.ts --> ./src/app.ts --> ./node_modules/@theia/monaco/lib/browser/monaco-frontend-module.js --> ./node_modules/@theia/monaco/lib/browser/textmate/monaco-textmate-frontend-bindings.js --> ./node_modules/onigasm/lib/onigasm.wasm

// index.ts
import { runApplicationNew } from "./app";
const element = document.getElementById("react-container");
if (element != null) {
  runApplicationNew(element);
}
//app.ts
import 'reflect-metadata';
import { FrontendApplication } from '@theia/core/lib/browser';
import { Container, ContainerModule } from 'inversify';
import { FrontendApplicationConfigProvider } from '@theia/core/lib/browser/frontend-application-config-provider';
import { frontendApplicationModule } from '@theia/core/lib/browser/frontend-application-module';
import { messagingFrontendModule } from '@theia/core/lib/browser/messaging/messaging-frontend-module';
import { loggerFrontendModule } from '@theia/core/lib/browser/logger-frontend-module';
import browserMenuModule from '@theia/core/lib/browser/menu/browser-menu-module';
import { ThemeService } from '@theia/core/lib/browser/theming';
import "./index.css";
const getFrontendModule = (host: HTMLElement) => new ContainerModule((_bind, _unbind, _isBound, rebind) => {
  class MyFrontendApplication extends FrontendApplication {
    protected getHost(): Promise<HTMLElement> {
      return Promise.resolve(host);
    }
  }
  rebind(FrontendApplication).to(MyFrontendApplication).inSingletonScope();
});
export const runApplicationNew = (appElement: HTMLElement) => {
  FrontendApplicationConfigProvider.set({
    applicationName: "Theia"
  });
  const container = new Container();
  container.load(frontendApplicationModule);
  container.load(messagingFrontendModule);
  container.load(loggerFrontendModule);
  container.load(getFrontendModule(appElement));
  function load(raw: { default: any; }) {
    return Promise.resolve(raw.default).then(module =>
        container.load(module)
    )
  }
  function start() {
    const themeService = ThemeService.get();
    themeService.loadUserTheme();
    const application = container.get(FrontendApplication);
    application.start();
  }
  Promise.resolve()
  .then(function () { return import('@theia/core/lib/browser/menu/browser-menu-module').then(load) })
  .then(function () { return import('@theia/core/lib/browser/window/browser-window-module').then(load) })
  .then(function () { return import('@theia/core/lib/browser/keyboard/browser-keyboard-module').then(load) })
  .then(function () { return import('@theia/output/lib/browser/output-frontend-module').then(load) })
  .then(function () { return import('@theia/filesystem/lib/browser/filesystem-frontend-module').then(load) })
  .then(function () { return import('@theia/filesystem/lib/browser/download/file-download-frontend-module').then(load) })
  .then(function () { return import('@theia/filesystem/lib/browser/file-dialog/file-dialog-module').then(load) })
  .then(function () { return import('@theia/variable-resolver/lib/browser/variable-resolver-frontend-module').then(load) })
  .then(function () { return import('@theia/workspace/lib/browser/workspace-frontend-module').then(load) })
  .then(function () { return import('@theia/languages/lib/browser/languages-frontend-module').then(load) })
  .then(function () { return import('@theia/editor/lib/browser/editor-frontend-module').then(load) })
  .then(function () { return import('@theia/navigator/lib/browser/navigator-frontend-module').then(load) })
  .then(function () { return import('@theia/markers/lib/browser/problem/problem-frontend-module').then(load) })
  .then(function () { return import('@theia/outline-view/lib/browser/outline-view-frontend-module').then(load) })
  .then(function () { return import('@theia/monaco/lib/browser/monaco-browser-module').then(load) })
  // .then(function () { return import('@theia/callhierarchy/lib/browser/callhierarchy-frontend-module').then(load) })
  .then(function () { return import('@theia/console/lib/browser/console-frontend-module').then(load) })
  .then(function () { return import('@theia/json/lib/browser/json-frontend-module').then(load) })
  .then(function () { return import('@theia/userstorage/lib/browser/user-storage-frontend-module').then(load) })
  .then(function () { return import('@theia/preferences/lib/browser/preference-frontend-module').then(load) })
  .then(function () { return import('@theia/terminal/lib/browser/terminal-frontend-module').then(load) })
  .then(function () { return import('@theia/task/lib/browser/task-frontend-module').then(load) })
  // .then(function () { return import('@theia/cpp/lib/browser/cpp-frontend-module').then(load) })
  .then(function () { return import('@theia/debug/lib/browser/debug-frontend-module').then(load) })
  // .then(function () { return import('@theia/editor-preview/lib/browser/editor-preview-frontend-module').then(load) })
  // .then(function () { return import('@theia/editorconfig/lib/browser/editorconfig-frontend-module').then(load) })
  .then(function () { return import('@theia/file-search/lib/browser/file-search-frontend-module').then(load) })
  .then(function () { return import('@theia/keymaps/lib/browser/keymaps-frontend-module').then(load) })
  .then(function () { return import('@theia/getting-started/lib/browser/getting-started-frontend-module').then(load) })
  .then(function () { return import('@theia/scm/lib/browser/scm-frontend-module').then(load) })
  // .then(function () { return import('@theia/git/lib/browser/git-frontend-module').then(load) })
  // .then(function () { return import('@theia/git/lib/browser/prompt/git-prompt-module').then(load) })
  // .then(function () { return import('@theia/java/lib/browser/java-frontend-module').then(load) })
  // .then(function () { return import('@theia/java-debug/lib/browser/java-debug-frontend-module').then(load) })
  // .then(function () { return import('@theia/merge-conflicts/lib/browser/merge-conflicts-frontend-module').then(load) })
  .then(function () { return import('@theia/messages/lib/browser/messages-frontend-module').then(load) })
  .then(function () { return import('@theia/mini-browser/lib/browser/mini-browser-frontend-module').then(load) })
  .then(function () { return import('@theia/search-in-workspace/lib/browser/search-in-workspace-frontend-module').then(load) })
  // .then(function () { return import('@theia/plugin-ext/lib/plugin-ext-frontend-module').then(load) })
  // .then(function () { return import('@theia/plugin-dev/lib/browser/plugin-dev-frontend-module').then(load) })
  // .then(function () { return import('@theia/plugin-ext-vscode/lib/browser/plugin-vscode-frontend-module').then(load) })
  // .then(function () { return import('@theia/preview/lib/browser/preview-frontend-module').then(load) })
  // .then(function () { return import('@theia/python/lib/browser/python-frontend-module').then(load) })
  .then(function () { return import('@theia/textmate-grammars/lib/browser/textmate-grammars-frontend-module').then(load) })
  // .then(function () { return import('@theia/typehierarchy/lib/browser/typehierarchy-frontend-module').then(load) })
  // .then(function () { return import('@theia/typescript/lib/browser/typescript-frontend-module').then(load) })
    .then(start).catch(reason => {
        console.error('Failed to start the frontend application.');
        if (reason) {
            console.error(reason);
        }
    });
}
//webpack.config.js
const HtmlWebPackPlugin = require("html-webpack-plugin");
const path = require('path');
const CopyWebpackPlugin = require('copy-webpack-plugin');
const outputPath = path.resolve(__dirname, 'dist');
const monacoEditorCorePath = '/home/satya/ide/theia-embedded-demo/node_modules/@typefox/monaco-editor-core/min/vs';
const monacoCssLanguagePath = '/home/satya/ide/theia-embedded-demo/node_modules/monaco-css/release/min';
const monacoHtmlLanguagePath = '/home/satya/ide/theia-embedded-demo/node_modules/monaco-html/release/min';
module.exports = {
  node: {
    net: "mock",
  },
  module: {
    rules: [
      {
        test: /\.tsx?$/,
        use: 'ts-loader',
        exclude: /node_modules/
      },
      {
        test: /\.html$/,
        use: [
          {
            loader: "html-loader"
          }
        ]
      },
      {
        test: /\.css$/,
        exclude: /\.useable\.css$/,
        use: ['style-loader', 'css-loader']
      },
      {
        test: /\.useable\.css$/,
        use: [
          {
            loader: 'style-loader/useable',
            options: {
              singleton: true,
              attrs: { id: 'theia-theme' },
            }
          },
          'css-loader'
        ]
      },
      {
        test: /\.(ttf|eot|svg)(\?v=\d+\.\d+\.\d+)?$/,
        loader: 'url-loader?limit=10000&mimetype=image/svg+xml'
      },
      {
        test: /\.(jpg|png|gif)$/,
        loader: 'file-loader',
        options: {
            name: '[path][name].[hash].[ext]',
        }
      },
      {
        test: /\.woff(2)?(\?v=[0-9]\.[0-9]\.[0-9])?$/,
        loader: "url-loader?limit=10000&mimetype=application/font-woff"
      },
      {
        test: /node_modules[\\|/](vscode-languageserver-types|vscode-uri|jsonc-parser)/,
        use: { loader: 'umd-compat-loader' }
      },
      {
          test: /\.wasm$/,
          loader: "file-loader",
          type: "javascript/auto",
      },
      {
          test: /\.plist$/,
          loader: "file-loader",
      },
    ]
  },
  resolve: {
    extensions: [ '.tsx', '.ts', '.js' ],
    alias: {
      'vs': path.resolve(outputPath, monacoEditorCorePath),
      'vscode': require.resolve('monaco-languageclient/lib/vscode-compatibility')
    }
  },
  plugins: [
    new HtmlWebPackPlugin({
      template: "./src/index.html",
      filename: "./index.html"
    }),
    new CopyWebpackPlugin([
      {
          from: monacoEditorCorePath,
          to: 'vs'
      },
      {
          from: monacoCssLanguagePath,
          to: 'vs/language/css'
      },
      {
          from: monacoHtmlLanguagePath,
          to: 'vs/language/html'
      }
    ]),
  ]
};
I do `webpack --mode production` and try to serve through nodejs( same as the backend folder contains in the theia examples