Is there anything I can do to reduce the size of t...

# javascript

[Daniele B]

Is there anything I can do to reduce the size of the built .js file for a Kotlin/React project?
For a relatively simple project the js file is 2.7 MB. I am using the gradle build command, which I guess it’s already doing DCE (Dead Code Elimination).

[turansky]

There are 2 main blockers for webpack optimization:
1. No root export
2. No es module support
Write please Kotlin version and mode (ir or legacy).

[Daniele B]

I am not sure where I should specify the Kotlin version in Gradle. I can’t see any Kotlin version written in my JS gradle file.
I tried using both ir and legacy.
With IR, the file is 2.3MB
With legacy, the file is 2.7MB.
Can we expect an optimization any soon?

[turansky]

Votes required from our part to expect changes :)

[bashor]

@Daniele B do you use any other libraries than kotlin-react & co? E.g. kotlinx-coroutines?

[Daniele B]

@bashor in the shared code I use coroutines

[bashor]

honestly kotlinx-coroutines is heavy, we are going to address it, but not very soon

[Daniele B]

@bashor more or less than 1 year?

[Daniele B]

I am using Ktor in the shared module, which I am calling from a coroutine

[Daniele B]

Ktor’s get is a suspend function, so you need to call it from a coroutine.

[Daniele B]

Does it mean that it’s not advisable to use Ktor with JS?

[bashor]

likely we will not be able to look at it seriously until we release IR based compiler

[bashor]

To be clear it’s not about suspend, it’s only about kotlinx-coroutines library and as consequence about libraries depending on it (directly or indirectly).

[bashor]

IR compiler already works better with it, but some libraries, like Ktor, use kotlinx-coroutines a lot.

[Daniele B]

is filesize the main issue with kotlinx-coroutines on JS, or there are also other issues?

[Daniele B]

when do you expect to release the IR based compiler?

[bashor]

is filesize the main issue with kotlinx-coroutines on JS

could please clarify your question -- is it about issues in kotlinx-coroutines or about size in JS, in general?

[bashor]

when do you expect to release the IR based compiler?

hope for next major release 🤞

[Daniele B]

could please clarify your question -- is it about issues in kotlinx-coroutines or about size in JS, in general?

Ktor seems to work well in my project
I was just concerned with the JS filesize

[Daniele B]

I would expect it would be possible to minimize the JS file

[bashor]

@turansky Speaking about mentioned issues: I don’t believe that they will help much in cases like this because they firstly related to consuming JS produced by Kotlin, it’s not case here. But I think they could help to remove unused exports when consuming generated code from JS.

[turansky]

I don't believe that they will help much in cases like this because they firstly related to consuming JS produced by Kotlin, it's not case here

@bashor
1. Webpack works after Kotlin
2. React declared in this case. Only react - 200KB. And it included fully, only because Kotlin/JS doesn't support ES module format.

It looks like important unresolved problem.

[Nicodemus Ojwee]

I was facing the same problem and failed to get a solution. I had to switch from using ktor client to using javascript fetch API.
My bundle size reduced from 2.6MB to 700KB.

[turansky]

First Webpack blocker described here
https://twitter.com/vnturansky/status/1315822595493769217?s=20