What does consolidate library do?

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What does consolidate library do

The consolidate library is a JavaScript utility that allows you to consolidate multiple modules into a single module. It is commonly used with module bundlers like Webpack and Browserify to bundle multiple JavaScript files into a single file for deployment. The key benefits of using consolidate are:

Reduce HTTP Requests

When you have multiple JavaScript files, each file requires a separate HTTP request to download it. This can slow down page load times. Consolidate allows bundling these files together into one request. For example, instead of:


<script src="file1.js"></script>
<script src="file2.js"></script> 
<script src="file3.js"></script>

You can bundle them into one file:


<script src="bundle.js"></script>

This requires only one HTTP request instead of three separate requests.

Avoid Globals Collisions

When you have multiple JavaScript files, they could define global variables and functions with the same name. This causes collisions. Consolidate wraps each module in an immediately invoked function expression (IIFE) to avoid polluting the global namespace:


// file1.js
var myVar = "Hello";

// file2.js 
var myVar = "World";

// Without consolidate
// myVar will be "World" from file2.js

// With consolidate
(function() {
  var myVar = "Hello";
})();

(function() {
  var myVar = "World"; 
})();

// No collision

Dead Code Elimination

Consolidate analyzes code statically to determine what exports are used and removes any unused code. For example:


// file1.js
export function unusedFunc() {}
export const usedVar = "hello";

// file2.js
import {usedVar} from './file1.js';

// When bundled with consolidate:

// unusedFunc is removed
const usedVar = "hello";

This results in smaller bundle sizes by removing code that is not used.

Minification

Consolidate typically works together with minifiers like UglifyJS or Terser to minify code. Minification reduces file size by:

  • Removing whitespace, comments and newlines
  • Shortening variable and function names
  • Converting code to equivalent shorter forms

For example:


// Before
function sum(a, b) {
  return a + b;
}

// After
function s(a,b){return a+b}

This significantly reduces bundle size and improves load times.

Source Maps

Minified and bundled code can be difficult to debug. Consolidate generates source maps during bundling. Source maps map the bundled code back to the original source code. This allows debuggers and error stack traces to display the original source code instead of the transformed bundle code.

Tree Shaking

Tree shaking removes unused exports that are imported but never used. For example:


// file1.js
export const A = 1;
export const B = 2;

// file2.js
import {A} from './file1.js';

// Only A is imported and used. 
// So B will be removed from the bundle.

This further reduces bundle size by eliminating unused code.

Code Splitting

Consolidate allows splitting your code into multiple bundles that can be loaded on demand. For example, splitting vendor code from application code. The vendor libraries can be loaded initially, and the application bundle loaded after. This improves initial load time.

Code splitting can also load bundles on-demand as required. For example, loading the code for a specific page only when the user visits that page.

Hot Module Replacement

Hot Module Replacement (HMR) allows updating modules in a running application without needing a whole page refresh. This improves developer experience when iterating on code changes.

For example, you can update CSS/JS in a bundled file, and it will automatically reflect on page without needing a manual refresh.

Easy to Use

Consolidate provides a simple API for bundling modules. For example:


const consolidated = require('consolidate');

consolidated('entry.js')
  .bundle()
  .pipe(output);

It handles all the complexities of bundling behind this simple API.

Cross-Platform

Consolidate works across different environments including client-side browsers, Node.js, React Native, etc. It provides a consistent bundling experience across platforms.

Plugin System

Consolidate provides a rich plugin system to customize the bundling process. For example, plugins exist for:

  • Minification
  • Source maps
  • CSS extraction
  • Image handling
  • Cache busting

You can choose plugins as per your needs to optimize bundling.

Evergreen Browser Support

Consolidate allows you to bundle modern JavaScript while providing fallbacks for older browsers automatically. For example, it can transpiles ES6 code to ES5, auto-polyfill features, etc.

This allows using the latest language features while supporting older browsers.

Conclusion

In summary, consolidate is a invaluable tool in modern JavaScript development. It solves many challenges like reducing HTTP requests, avoiding globals collisions, minimizing code, enabling code splitting, and providing cross-platform support. The simple API and plugin system make it flexible and easy to customize.

Most large web and mobile apps leverage consolidate or similar bundlers to optimize delivery of JavaScript code. It seamlessly integrates with modern tooling like Webpack, Rollup, Parcel and Gulp. Consolidate streamlines the asset pipeline so developers can focus on writing code rather than plumbing.

If you are building a complex JavaScript application, consolidate is a must-have tool to optimize performance and development experience. The benefits far outweigh the minimal integration required to set it up. Consolidate unlocks the true potential of JavaScript on the web and beyond.

Benefit Description
Reduce HTTP Requests Bundle multiple modules into single file to reduce requests
Avoid Globals Collisions Wrap modules in IIFEs to avoid namespace collisions
Dead Code Elimination Remove unused exported bindings statically
Minification Shorten variable names, remove whitespace etc to reduce size
Source Maps Map bundled code to original source
Tree Shaking Remove unused imports
Code Splitting Split bundle into smaller pieces loaded on-demand
Hot Module Replacement Update modules in running app without refreshing
Easy to Use Simple consolidation API
Cross-Platform Works across client, Node.js, React Native etc
Plugin System Customize bundling via plugins
Evergreen Browser Support Transpile and polyfill to support older browsers

When to use consolidate

Here are some good cases to use consolidate library:

  • You have an application with multiple JavaScript files
  • You want to optimize HTTP requests and load times
  • You are worried about namespace collisions
  • You want to leverage code splitting and dynamic loading
  • You need wider browser compatibility for modern JavaScript
  • You want a build process to minify and optimize your code
  • You want to share common vendor libraries between pages
  • You want hot module replacement during development

When not to use consolidate

Here are some cases where you may not need consolidate:

  • You have a simple application with only a few scripts
  • Your app needs to work without any build process
  • You don’t need wider browser support
  • Your modules are already optimized and minified
  • You don’t need hot module replacement
  • Your modules don’t have globals collisions
  • You are not concerned about load performance

How to use consolidate

To use consolidate, you first need to install it:


npm install consolidate

Then create a build script to bundle your files:


// bundle.js
const consolidate = require('consolidate');

consolidate('src/index.js')
  .bundle()
  .pipe(fs.createWriteStream('dist/bundle.js'));

Run this script to produce the optimized bundle:


node bundle.js

Then reference the bundled file in your HTML:


<script src="dist/bundle.js"></script>

That’s it! Consolidate will take care of bundling your modules optimally.

You can configure consolidate with plugins and presets to customize the bundling. See the consolidate documentation for more advanced usage.

Conclusion

Consolidate is an essential tool for bundling and optimizing JavaScript code for production. It provides a wide range of performance and development benefits out of the box. Consolidate integrates seamlessly into modern web development workflows. Using consolidate will improve your user experience and developer productivity.

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