Name Game: Why You Should Favor Named Exports in ES Modules

The ECMAScript (ES) modules system brought a standardized module format to the JavaScript ecosystem. But with it came a frequent developer dilemma: should we use named exports or default exports? While both have their place, there are compelling reasons to prefer named exports. In this deep dive, we’ll unpack why.

1. Transparent Functionality with Clear Exports

Named exports leave no room for ambiguity. When you open a module, you can immediately identify what functionalities are available, without trawling through the entire module. It’s like reading the contents page in a book.

// utils.js
export const add = (a, b) => a + b;
export const subtract = (a, b) => a - b;

You can immediately see that the utils.js module provides add and subtract functions.

2. Foster Consistency Across the Codebase

Named exports enforce a specific identifier for each exported entity. When various developers use the same functionality, they reference it by the same name, avoiding confusion.

// Without named exports
import MainComponent from "./Component";

// With named exports
import { MainComponent } from "./Component";

The latter ensures the imported component is always referenced as MainComponent.

3. Streamlined Refactoring

When you decide to rename a named export, modern tooling like ESLint or TypeScript can auto-update the imports in other modules. This ensures that the renamed entity reflects across all files without manual intervention.

For instance, if functionA is renamed to functionAlpha, tools can automatically make these changes:

// Before
import { functionA } from "./module";

// After
import { functionAlpha } from "./module";

4. The Power of Selective Imports

Named exports allow you to import only the functions or components you need. This is not only efficient but also makes the code’s intentions clear to any reader.

// Only importing what's needed
import { functionA, constantB } from "module-name";

5. Autocomplete: A Developer’s Best Friend

Ever forget a function’s exact name? With named exports, modern code editors provide autocompletion, helping you quickly find and use module functionalities.

Imagine having a module with dozens of exports; named exports ensure you don’t need to memorize all of them!

6. The Explicitness of Named Exports

By enforcing explicit naming, named exports ensure clarity in intent and usage. There’s no guessing about what you’re importing or its purpose.

Contrast this with default exports:

// What exactly is "Component"?
import Component from "./DetailComponent";

With named exports, the ambiguity is removed:

// Ah, it's the "DetailComponent"!
import { DetailComponent } from "./components";

7. Optimize with Ease: Tree Shaking

While modern bundlers can tree-shake both named and default exports, named exports make the process less error-prone. By removing unused code, named exports help in reducing your bundle size, making your application leaner and faster.

8. Catering to Multifunctional Modules

Modules often offer multiple functionalities. Named exports shine here, allowing multiple exports without any constraints.

export const fetchData = () => {...};
export const transformData = (data) => {...};

With a single glance, we know this module handles data fetching and transformation.

9. Putting an End to Import Confusion

Default exports offer the liberty to rename imports, which can lead to varied naming across files. Named exports standardize this:

// Developer A
import { DataComponent } from "./Component";

// Developer B
import { DataComponent } from "./Component";

Both developers are compelled to use DataComponent, ensuring consistency.

Wrapping Up

While default exports have their moments, especially for modules with a singular focus, named exports provide clarity, consistency, and enhanced tooling support. Embracing named exports can significantly elevate the clarity and maintainability of your codebase. As you structure your next JavaScript project, consider giving named exports the limelight they deserve.

Written by Zubin Khavarian