Hello, has anyone here used a Kotlin/JS library in...

# javascript

[Stan van der Bend]

Hello, has anyone here used a Kotlin/JS library in Vite?

I have this KMM library that I want to export for both JVM and JS targets. I have a front end that is written using svelte.
When I export my KMM library as a web-pack package and install it using npm, it works when I import it in a javascript file and run that independently from vite, but it fails when I have it imported in some javascript code that is run through vite.
I suspect it has something to do with an unsupported module format by vite; apparently, it tries to convert umd/commonjs modules to ESM. Could this step fail?

I have tried many different ways to export the library code. But to be honest, I have no idea what I am doing most of the time. I know next to nothing about the javascript ecosystem, I mainly want to just export my KMM code and have it useable in the frontend.
If someone could point me in the right direction, that would be greatly appreciated :)

[turansky]

Possible options (not tested):

1. Commonjs
a. Use commonjs format for bundle, produced by Kotlin/JS
b. Activate commonjs for Vite, which isn’t enabled by default
2. ESM
a. Use commonjs format for bundle, produced by Kotlin/JS
b. Convert commonjs bundle to ESM via custom Gradle plugin
c. Vite configuration isn’t required

[turansky]

Do you use IR compiler?
Which Kotlin version do you use?

[Nick Williams]

@Stan van der Bend did you figure this out in the end?

[Nick Williams]

@turansky can useEsModules() help here?

[turansky]

Vite must work fine with ES modules

[Nick Williams]

Thanks, I got it all working in the end reading your comments on an issue on YouTrack!

[Nick Williams]

So much undocumented stuff in kotlin js

[turansky]

It works! :)

[Stan van der Bend]

@Nick Williams hey, I did figure it out in the end, its been a while but could spin up a repo for it.

[Stan van der Bend]

Oh nvm I just read u already figured it out :))

[Nick Williams]

I did, but thanks for getting back 👍

[apatrida]

How about the rest of us, we don't know what you figured out 🙂

[apatrida]

maybe was this:

plugins {
    kotlin("js") version "1.8.20-RC2"
}

kotlin {
    js(IR) {
        useEsModules()
        browser()
    }
}

from here
https://youtrack.jetbrains.com/issue/KT-12784/JS-generate-ES2015-compatible-modules