Comparing Module Federation and Single-SPA

1. Introduction

Micro frontends allow teams to develop and deploy parts of their applications independently. Two popular approaches to achieve this are Module Federation and Single-SPA. This lesson explores both frameworks, highlighting their features, advantages, and differences.

2. Module Federation

2.1 Definition

Module Federation is a feature introduced in Webpack 5 that allows JavaScript applications to dynamically load code from other applications at runtime. This capability is particularly useful for micro frontend architectures.

2.2 Key Features

Dynamic loading of shared dependencies.
Independent deployment of micro frontends.
Automatic handling of version mismatches.

2.3 Code Example

// webpack.config.js
const ModuleFederationPlugin = require("webpack").container.ModuleFederationPlugin;

module.exports = {
    plugins: [
        new ModuleFederationPlugin({
            name: "app1",
            filename: "remoteEntry.js",
            exposes: {
                './Component': './src/Component',
            },
            shared: {
                react: {
                    singleton: true,
                    eager: true,
                },
            },
        }),
    ],
};

3. Single-SPA

3.1 Definition

Single-SPA is a JavaScript framework for building micro frontend applications. It allows you to load multiple frameworks on the same page without refreshing, enabling a seamless user experience.

3.2 Key Features

Framework agnostic; supports React, Vue, Angular, etc.
Routing and lifecycle management for micro frontends.
Easy integration with existing applications.

3.3 Code Example

// root-config.js
import { registerApplication, start } from 'single-spa';

registerApplication({
    name: '@orgName/app1',
    app: () => System.import('@orgName/app1'),
    activeWhen: ['/app1'],
});

start();

4. Comparison

The following table summarizes the key differences between Module Federation and Single-SPA:

Feature	Module Federation	Single-SPA
Framework Support	Webpack-based	Framework agnostic
Dynamic Loading	Yes	Yes
Shared Libraries	Automatic version handling	Manual configuration

5. Best Practices

Evaluate the team’s expertise with the frameworks.
Consider the application's architecture and requirements.
Implement shared libraries carefully to avoid conflicts.
Use lazy loading for better performance.

6. FAQ

What is the main advantage of using Module Federation?

Module Federation allows for better dependency management and enables teams to share libraries dynamically, which enhances the development speed and reduces bundle size.

Can Single-SPA work with different frameworks?

Yes, Single-SPA is designed to be framework agnostic, allowing you to integrate React, Vue, Angular, and more in the same application.

Which approach is better for large teams?

It depends on the team's familiarity with the tools. Module Federation is often preferred for complex applications with dynamic dependencies, while Single-SPA is great for integrating various frameworks.