how to debugger js

[Jetsly]

when vue file is:

<template>
    <div class="list-page">
    </div>
</template>
<script src="./listpage.js"></script>
<style src="./listpage.scss" lang="scss"></style>

sourcemap is

<template>
    <div class="list-page">
    </div>
</template>
<script src="./listpage.js"></script>
<style src="./listpage.scss" lang="scss"></style>

how to debugger js

[thgh]

I tried building a sourcemap, but I don't yet understand how it's supposed to be done. Maybe you can help if you can figure out https://github.com/Rich-Harris/magic-string