ES6 Modules

More than you want to know...

Kent C. Dodds

Utah

1 wife, 3 kids

PayPal, Inc.

@kentcdodds

Please Stand...

Origin Story

What this talk is

  • Brief history about JavaScript modules
  • Exploration of the ES6 modules standard & syntax
  • More than you probably care to know/will use
  • Lots of code :-)

What this talk is not

  • 100% practical (probably only 90%)

Let's
Get
STARTED!

What is a module?

It's like a chapter in a book.

  • Can have dependencies
  • Can have dependants
  • Encapsulates a topic/logic

A brief history

// globals: please load the add script first 🙏
;(function(global) {
  global.subtract = (a, b) => global.add(a, -b)
})(this)
// AMD: I explicitly depend on './add' 👍
define(['./add'], function(add) {
  return (a, b) => add(a, -b)
});
// CommonJS: I can't do async, but you can bundle me 😀
var add = require('./add')
module.exports = (a, b) => add(a, -b)

ES6 Modules are HERE!!

Sorta...

We can write them

But not load them...

ES6 Modules Spec Goals

  • Default exports are favored
  • Static module structure
  • Support for both synchronous and asynchronous loading
  • Support for cyclic dependencies between modules

Transpilers to the rescue!

Warning!!!

You're about to see transpiled code

I accept the risks...

kcd.im/es6-modules-repo

export default

named export

multiple named exports

named exports + default

named exports as list

named exports as list

with aliases

named export as default

basic import

"run this code"

import default

import named exports

alias imports

import {default}...?

import default as alias

default & named imports

import *

(import all the things)

export *

(export all the things from this other thing)

export {default, foo, bar}

interop require

(thing babel does to make it work with CommonJS modules)

Changes

import {baz} from './foo'
// foo.js
const foo = {baz: 42, bar: false}
export default foo

Babel v5

Babel v6

import foo from './foo'
const {baz} = foo

Resources

Thank you!

More than you want to know about ES6 Modules

By Kent C. Dodds

More than you want to know about ES6 Modules

ES6 Modules have been standardized and many have already started using them. They have a lot of benefits over CommonJS, AMD, and Globals. Unfortunately, there are many ways to deal with modules with this new syntax and it can be a bit confusing. In this talk, we'll explore the different ways you can use the new syntax and when you'd use the different methods. We'll also investigate what's going on at a high level. Buckle up for a firehose of ES6 information .

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