Code for my blog post: https://kentcdodds.com/blog/super-simple-start-to-es-modules-in-the-browser

append-div.js

function appendDiv(message) {
  const div = document.createElement('div')
  div.textContent = message
  document.body.appendChild(div)
}

export {appendDiv}

async-script.js

import {appendDiv} from './append-div.js'

function go() {
  appendDiv('Hello from async script')
}

export {go}

index.html

<script type="module">
  import {appendDiv} from './append-div.js'
  appendDiv('Hello from inline script')
</script>
<script type="module" src="./script-src.js"></script>

script-src.js

import {appendDiv} from './append-div.js'

appendDiv('Hello from external script')

import('./async-script.js').then(
  moduleExports => {
    moduleExports.go()
  },
  error => {
    console.error('there was an error loading the script')
    throw error
  },
)