Consuming Shared Dependencies
Master how to share common libraries and dependencies efficiently between federated applications.
Consuming Shared Dependencies is a free Micro Frontends Architecture with Module Federation lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Micro Frontends Architecture with Module Federation learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Why Share Dependencies?
In Micro Frontends, different parts of your application might use the same libraries, like React, Vue, or Lodash. Without careful management, each Micro Frontend could bundle its own copy of these libraries.
This means users would download the same code multiple times, increasing load times and wasting bandwidth. Sharing dependencies solves this problem!
The Problem: Duplicate Bundles
Imagine your main 'Host' application uses React, and a 'Remote' Micro Frontend also uses React. If both bundle React independently, your user's browser ends up downloading React twice.
- Host Bundle: Includes React
- Remote Bundle: Includes React (again!)
This leads to larger overall application sizes and slower performance.
Module Federation's Solution
Webpack's Module Federation offers a powerful solution: the shared configuration. It allows you to declare common libraries that should be shared across your federated applications.
Module Federation then ensures these libraries are loaded only once, even if multiple Micro Frontends depend on them.
Configuring `shared`
You define shared dependencies within the ModuleFederationPlugin in your webpack.config.js file. The shared property is an object where each key is the name of a module you want to share.
Here's a basic look at how it's structured:
new ModuleFederationPlugin({
// ... other configs
shared: {
// 'module-name': { options }
'react': { /* ... */ },
'react-dom': { /* ... */ }
}
})Sharing with `requiredVersion`
The requiredVersion option is crucial for compatibility. It specifies the acceptable version range for a shared dependency using semantic versioning (e.g., ^18.0.0).
Module Federation will try to use a compatible version already loaded; if none exists or it's incompatible, it will load a new one.
shared: {
react: {
requiredVersion: '^18.0.0',
// other options like singleton: true
},
'react-dom': {
requiredVersion: '^18.0.0'
}
}The `eager` Property Explained
Normally, shared modules are loaded asynchronously, on demand. However, sometimes a shared module is needed immediately at startup, before any remote modules are even requested.
For such cases, you can use the eager: true option. Be cautious, as this can impact initial load performance by forcing the module to load upfront.
shared: {
'my-critical-lib': {
requiredVersion: '^1.0.0',
eager: true // Load this module immediately
}
}Host & Remote `shared` Configs
Both your host and remote applications should typically define the same common libraries as shared. This tells Module Federation that these dependencies are part of the shared pool.
Module Federation then orchestrates which application actually loads the dependency and makes it available to others, ensuring only one copy exists in the browser.
Practical Use of Shared Deps
When react and react-dom are configured as shared, your application code can simply import them as usual. Module Federation handles the underlying logic to ensure they are loaded efficiently and only once.
This minimal React entry point demonstrates how standard imports leverage shared dependencies:
import React from 'react';
import ReactDOM from 'react-dom/client';
// This is a minimal React app entry point.
// If 'react' and 'react-dom' are shared in Module Federation,
// these imports will efficiently use a single instance.
function App() {
return (
<div>
<h1>Shared Dependencies Demo</h1>
<p>This app uses React, which can be shared!</p>
</div>
);
}
const rootElement = document.getElementById('root');
if (rootElement) {
const root = ReactDOM.createRoot(rootElement);
root.render(
<React.StrictMode>
<App />
</React.StrictMode>
);
} else {
console.error("Root element not found!");
}Benefits of Sharing Libraries
- Smaller Bundle Sizes: Prevents common libraries from being duplicated across different Micro Frontends, directly reducing the total amount of code users download.
- Improved Performance: Less code to download, parse, and execute means faster initial page load times and a more responsive user experience.
- Consistent Versions: Helps ensure all parts of your federated application use the same version of a library, reducing potential conflicts and unexpected behavior.
Shared Dependencies Check
Module Federation's shared configuration is crucial for efficient Micro Frontends. Which option correctly describes a key benefit of using shared dependencies?
Recap & Next Steps
We've learned how Module Federation's shared configuration is vital for optimizing Micro Frontends. By defining common libraries as shared, you prevent them from being bundled multiple times.
This leads to smaller initial load times, better performance, and more consistent dependency versions across your federated applications.
Next, we'll dive deeper into managing Singleton Modules & Versioning to ensure robust shared dependency handling.
Frequently asked questions
Is the “Consuming Shared Dependencies” lesson free?
Yes — the full text of “Consuming Shared Dependencies” is free to read here on the web, and the Micro Frontends Architecture with Module Federation course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Micro Frontends Architecture with Module Federation course, upgrade to CoddyKit PRO.
What will I learn in “Consuming Shared Dependencies”?
Master how to share common libraries and dependencies efficiently between federated applications. You practise Micro Frontends Architecture with Module Federation with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Micro Frontends Architecture with Module Federation?
No prior experience is required. Micro Frontends Architecture with Module Federation on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Consuming Shared Dependencies” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Micro Frontends Architecture with Module Federation lesson?
Yes. Every Micro Frontends Architecture with Module Federation lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Consuming Shared Dependencies
- Singleton Modules & Versioning
- Dynamic Module Loading
- Sharing State and Utilities Across Remotes