Simple server exception manager, for anticore. Try it with https://github.com/Lcfvs/anticore-default-project

assets\js\dev\exception.md.js

// create this file
import { anticore } from 'anticore'
import { one } from 'anticore/dom/query/one'
import { replace } from 'anticore/dom/tree/replace'

anticore.on('main.exception', function (element, next, loaded) {
  loaded && replace(element, one('body > main'))
  next()
})

assets\js\dev\index.js

// add the following line into your index.js, BEFORE the `anticore.defaults().populate()`
import './exception.md'

fragments\404.html

<!-- create this file -->
<main class="exception">
    <h1>Page not found</h1>
    <a href="">Restart</a>
</main>

index.html

<!-- add the following line into your index.html file -->
<a href="./fragments/404.html">Load the 404</a>