Module Federation Best Practices

Best Practices Overview

At its core, best practices is about doing one thing well inside your Module Federation project. Once you understand the pattern, you can apply it consistently across features and teams.

Good best practices pays off across the whole codebase: fewer surprises, easier testing, and smoother onboarding. The snippet below is a solid starting point.

const { ModuleFederationPlugin } = require('webpack').container;

module.exports = {
  plugins: [
    new ModuleFederationPlugin({
      name: 'shell',
      remotes: { catalog: 'catalog@http://localhost:3001/remoteEntry.js' },
      exposes: {},
      shared: { react: { singleton: true }, 'react-dom': { singleton: true } },
    }),
  ],
};

ModuleFederationPlugin configures which modules an app exposes, consumes, and shares.

Best Practices Example

new ModuleFederationPlugin({
  name: 'app',
  filename: 'remoteEntry.js',
  exposes: { './Widget': './src/Widget' },
  remotes: { other: 'other@http://host/remoteEntry.js' },
  shared: { react: { singleton: true } },
});

• Start from a minimal Best Practices example and grow it only as needed.
• Keep configuration explicit so Best Practices behaves the same in every environment.
• Name things clearly so teammates understand your Best Practices at a glance.
• Add tests around Best Practices early to lock in expected behaviour.

Module Federation Cheatsheet

Key Module Federation settings related to best practices.

How Best Practices Works in Module Federation

Best Practices builds on Module Federation's ability to load code from another independently built and deployed application at runtime. Each app can be a host, a remote, or both.

ModuleFederationPlugin configures which modules an app exposes, consumes, and shares.

• Remotes expose modules through a remoteEntry.js manifest.
• Hosts declare remotes and import exposed modules dynamically.
• Shared dependencies are deduplicated, ideally as singletons.
• Each micro frontend builds and deploys on its own schedule.

Practical Guidance for Best Practices

In production, best practices needs careful version management and graceful failure handling. Align shared dependency versions and always render a fallback when a remote cannot load.

Common Mistakes

• Skipping error handling and edge cases when wiring up best practices.
• Leaving best practices untested, so regressions slip into production.
• Over-engineering best practices before you actually need the extra flexibility.
• Ignoring documentation, which makes best practices hard for the next developer to change.

Key Takeaways

• Best Practices is a core part of working effectively with Module Federation.
• Start small and keep best practices focused on a single responsibility.
• Apply consistent patterns so best practices scales across your project.
• Test and document best practices to keep it maintainable over time.