Create A Module Federation Monorepo React Project Using Nx CLI With Electron App

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In the realm of modern web and desktop application development, the concept of monorepos has gained significant traction. A monorepo, a single repository housing multiple projects, offers numerous advantages, including streamlined code sharing, simplified dependency management, and enhanced collaboration. When combined with Module Federation, a cutting-edge Webpack feature, monorepos can unlock even greater potential, enabling the creation of highly modular, scalable, and maintainable applications. This article delves into the intricacies of building a Module Federation monorepo using the Nx CLI, focusing on React projects integrated with Electron for desktop deployments. We will walk through the process step-by-step, from setting up the monorepo to configuring Module Federation and integrating Electron, providing a comprehensive guide for developers seeking to leverage these powerful technologies.

Understanding the Fundamentals: Monorepos, Module Federation, and Nx CLI

Before diving into the practical implementation, let's establish a solid understanding of the core concepts involved. A monorepo, as the name suggests, is a single repository that houses multiple projects, libraries, and applications. This approach contrasts with the traditional polyrepo architecture, where each project resides in its own separate repository. Monorepos offer several key benefits:

  • Code Sharing and Reusability: Monorepos facilitate seamless code sharing between projects, reducing code duplication and promoting consistency across the application ecosystem.
  • Dependency Management: Managing dependencies in a monorepo is simplified, as all projects share a common node_modules directory, eliminating version conflicts and streamlining updates.
  • Collaboration and Visibility: Monorepos enhance collaboration by providing a central location for all code, improving visibility and fostering a sense of shared ownership.
  • Simplified Build and Deployment: Monorepos enable unified build and deployment processes, making it easier to manage and deploy multiple projects simultaneously.

Module Federation, a groundbreaking feature of Webpack 5, takes modularity to the next level. It allows different applications or parts of an application to be built and deployed independently, and then dynamically loaded at runtime. This approach enables the creation of highly decoupled and scalable systems, where individual modules can be updated and deployed without affecting the entire application. Module Federation offers several key advantages:

  • Independent Deployments: Modules can be deployed independently, reducing the risk of breaking the entire application during updates.
  • Code Sharing Across Applications: Modules can be shared across different applications, promoting code reuse and consistency.
  • Scalability and Maintainability: Module Federation enables the creation of highly scalable and maintainable applications, as individual modules can be updated and maintained independently.
  • Improved Development Velocity: Teams can work on different modules concurrently, accelerating the development process.

Nx CLI is a powerful command-line tool that simplifies the creation and management of monorepos. It provides a rich set of features, including code generation, dependency management, build and deployment tools, and more. Nx CLI is particularly well-suited for building large-scale applications with complex architectures. It offers several key advantages:

  • Code Generation: Nx CLI provides generators for creating various types of projects, libraries, and components, streamlining the development process.
  • Dependency Management: Nx CLI automatically manages dependencies between projects, ensuring that the correct versions are used and preventing conflicts.
  • Build and Deployment Tools: Nx CLI provides built-in tools for building and deploying applications, simplifying the release process.
  • Extensibility: Nx CLI is highly extensible, allowing developers to create custom plugins and generators to tailor the tool to their specific needs.

Setting Up the Monorepo: Nx CLI to the Rescue

Now that we have a grasp of the fundamental concepts, let's dive into the practical steps of creating a Module Federation monorepo using the Nx CLI. First, ensure that you have Node.js and npm (or yarn) installed on your system. Then, install the Nx CLI globally using the following command:

npm install -g nx

Once Nx CLI is installed, you can create a new monorepo using the create-nx-workspace command:

npx create-nx-workspace my-monorepo --preset=react --integrated

This command will create a new monorepo named my-monorepo with a React application as the initial project. The --preset=react flag specifies that we want to use the React preset, which includes pre-configured settings for React development. The --integrated flag indicates that we want to use an integrated monorepo, where all projects share a single node_modules directory.

After the monorepo is created, navigate into the project directory:

cd my-monorepo

Generating React Applications: Laying the Foundation for Module Federation

With the monorepo set up, we can now generate the React applications that will participate in the Module Federation. In this example, let's create three applications: erp, hr, pm, and crm. The erp application will serve as the host, while the others will be remotes.

Use the following Nx CLI command to generate the applications:

npx nx g @nx/react:host erp --remotes=hr,pm,crm

This command utilizes the @nx/react:host generator to create a new React application named erp. The --remotes flag specifies the remote applications that will be federated with the host. In this case, we are federating hr, pm, and crm with erp. Nx CLI will automatically configure Module Federation for these applications.

Installing Electron: Bridging the Gap to Desktop

To integrate Electron into our monorepo, we need to install the nx-electron plugin. This plugin provides generators and executors for building Electron applications within an Nx workspace.

Install the nx-electron plugin using the following command:

npm install --save-dev @nx/electron

Once the plugin is installed, you can generate an Electron application using the nx g @nx/electron:app command. Let's create an Electron application named desktop:

nx g @nx/electron:app desktop

This command will generate an Electron application within the apps directory of your monorepo. You can then configure this application to host the federated React modules.

Configuring Module Federation: Connecting the Pieces

Nx CLI simplifies the configuration of Module Federation by automatically generating the necessary Webpack configuration files. However, it's crucial to understand how these files work to customize the federation behavior.

Each application in the monorepo will have a webpack.config.js file in its project directory. This file contains the Webpack configuration for the application, including the Module Federation settings. Let's examine the webpack.config.js file for the host application (erp):

const { withModuleFederation } = require('@nx/react/module-federation');
const moduleFederationConfig = require('./module-federation.config');
module.exports = withModuleFederation(moduleFederationConfig);

This file imports the withModuleFederation function from @nx/react/module-federation and passes the moduleFederationConfig object to it. The withModuleFederation function automatically configures Webpack for Module Federation.

The moduleFederationConfig object, defined in module-federation.config.js, contains the core Module Federation settings:

module.exports = {
  name: 'erp',
  remotes: ['hr', 'pm', 'crm'],
  shared: (libraryName, config) => {
    if (['react', 'react-dom'].includes(libraryName)) {
      return {
        ...config,
        singleton: true,
        strictVersion: false,
      };
    }
    return false;
  },
};

Here's a breakdown of the key settings:

  • name: The name of the application, which is used to identify it in the federation.
  • remotes: An array of remote applications that this application will federate with.
  • shared: A function that determines which dependencies should be shared between applications. In this case, we are sharing react and react-dom as singletons, ensuring that only one instance of each library is loaded.

The webpack.config.js files for the remote applications (hr, pm, crm) will have similar configurations, but with different name and remotes values. They will also define the modules that they expose to the host application.

Integrating with Electron: Hosting Federated Modules in a Desktop Application

To integrate the federated React modules into the Electron application, we need to modify the Electron application's main process file (apps/desktop/src/main.ts).

First, install the @module-federation/runtime package:

npm install @module-federation/runtime

This package provides the necessary runtime support for Module Federation in Electron.

Then, in apps/desktop/src/main.ts, import the loadRemoteModule function from @module-federation/runtime and use it to load the federated modules:

import { app, BrowserWindow } from 'electron';
import { loadRemoteModule } from '@module-federation/runtime';

function createWindow() {
  const mainWindow = new BrowserWindow({
    width: 800,
    height: 600,
    webPreferences: {
      nodeIntegration: true,
      contextIsolation: false,
    },
  });

  loadRemoteModule({
    url: 'http://localhost:4200',
    scope: 'erp',
    module: './Module',
  })
    .then((module) => {
      mainWindow.loadURL(module.render());
    })
    .catch((err) => {
      console.error('Failed to load remote module', err);
      mainWindow.loadURL('<h1>Error loading remote module</h1>');
    });
}

app.whenReady().then(createWindow);

In this example, we are loading the erp application's Module from http://localhost:4200. The loadRemoteModule function returns a promise that resolves with the loaded module. We then use the module's render function to render it in the Electron window.

Running the Applications: Witnessing Module Federation in Action

To run the applications, you need to start the host and remote applications in development mode. Use the following Nx CLI commands:

nx serve erp
nx serve hr
nx serve pm
nx serve crm
nx serve desktop

These commands will start the applications on different ports. The erp application will be running on port 4200, the hr application on port 4201, and so on. The desktop application will launch an Electron window that displays the federated modules.

Addressing Console Errors: Troubleshooting Common Issues

During the development process, you may encounter console errors related to Module Federation. These errors can be caused by various factors, such as incorrect configuration, missing dependencies, or version mismatches.

One common error is the "Shared module is not available for eager consumption" error. This error occurs when a shared module is required before it is loaded. To resolve this error, you can try adjusting the shared configuration in the module-federation.config.js file or using dynamic imports.

Another common error is the "Cannot find module" error. This error occurs when a module is not found at the specified URL. To resolve this error, you can verify that the module is being served correctly and that the URL is correct.

Conclusion: Empowering Scalable and Modular Applications with Module Federation and Nx CLI

In conclusion, Module Federation, combined with the power of Nx CLI, provides a robust foundation for building highly modular, scalable, and maintainable applications. By leveraging the monorepo architecture and the dynamic module loading capabilities of Module Federation, developers can create systems that are easier to develop, deploy, and maintain. This article has provided a comprehensive guide to setting up a Module Federation monorepo with React and Electron using Nx CLI, equipping you with the knowledge and tools to embark on your own Module Federation journey. By embracing these technologies, you can unlock new levels of productivity and innovation in your development workflows.

How to create a Module Federation monorepo React project using Nx CLI with an Electron app? And how to solve console errors?

Create a Module Federation Monorepo with React, Electron, and Nx CLI