little cubes

Death to Default Exports!

Zach Olivare --

Why you should go right now and delete every "default" from your codebase

I am continuously surprised at how commonly I see developers using default exports as their “default” strategy for exporting JavaScript modules from files. I will make the case in this post that you should prefer named exports for every module exported from every one of your JS files.

If you get to the end of this article and still have something to say in defense of default exports, please let me know!

1. The sole advantage is in fact a disadvantage

The only advantage of default exports is that you can import them with a different name than they had when they were exported. But why would you ever intentionally do that? To make it harder to do a global project search for the name of the component? To make your code less readable? To hasten the heat death of the universe?

You would never do intentionally do that, but with default exports doing so accidentally is only one typo away.

2. You can’t export default const (or let, or var)

You can’t default export a variable at the same time you declare it, so instead it becomes a more awkward two step process. This is especially annoying if you’re the type of person who likes to declare your functions with const:

const myFunction = () => {
  // A
  // whole
  // bunch
  // of
  // code
  // that
  // you
  // have
  // to
  // scroll
  // past
}

export default myFunction

When reading this file you now have to scroll down to the bottom of the function to know if it’s exported or not, AND IF SO BY WHAT NAME.

It’s so much nicer with a named export

export const myFunction = () => {}

3. Default exports can’t be re-exported from barrel files

I love barrel files, because I love clean imports. Being able to do:

import {Thing1, Thing2, Thing3} from '~/components'

and not have to worry about exactly which file each of those components lives and not have a long complicated import path for every module in is a huge win for developer experience in my book.

But if you export default Thing1, then in the barrel file the star export export * from './thing1' isn’t going to work because Thing1 doesn’t have a module name! So instead you’re forced to give it one, similarly to how you would if you were trying to import the module:

export {default as Thing1} from './thing1'
export * from './thing1' // Still necessary if there are other named exports

Just another opportunity for a typo.

4. Mixing default imports with named imports creates inconsistency

Because each file can only have a single default export, you’re always going to have some named exports even if you’re intentionally trying to avoid them.

And now all of a sudden you’ve got both kinds scattered about your codebase and you can’t be certain how to import the module you need without opening the file and checking.

5. Mixing default imports with named imports is awkward

Not to mention that it’s just so awkward to import both a default and named export from the same module:

import MyComponent, {type MyComponentProps} from './my-component'

6. It’s just less typing

If I still haven’t convinced you to drop the default, can I persuade you with silly character count argument?

// Default Export: 91 characters
const colors = ['red', 'green', 'blue']
export default colors
import colors from './colors'
// Named Export: 78 characters
export const colors = ['red', 'green', 'blue']
import {colors} from './colors'