Major bottleneck for me right now with kotlin/js i...

# javascript

[Alex Styl]

Major bottleneck for me right now with kotlin/js is the compilation speed. It slows down the dev loop dramatically vs just using javascript. This is while building backends on nodejs

Everything else is fantastic

[Edoardo Luppi]

What I've seen takes most of the time are:
• Gradle starting up
• The kotlinNpmInstall task
Apart from that the rest is only slightly slower than the JVM counterpart.
But yeah, if we compare it to TS there is still a significant gap.

[gildor]

Gradle starting up slow? Strange, you mean an actual gradle app?

[Alex Styl]

Gradle starting up

that is not really an issue for me. I am not using gradle to start my app but only for compilation (running it continous)

[Alex Styl]

in order words, my issue is the time it takes to go from saving changes to a kt file to having output js

[Artem Kobzar]

Thank you for sharing your pain-point.
We have plans for the next year to change a bit the compilation process, so in theory (we want to check it), it should speed up the compilation

[Alex Styl]

btw @Artem Kobzar just so you are aware why this is important to me

For backend stuff, working with kotlin is fantastic. I use tests to iterate blazing fast so that is not really an issue. I am very productive with the language, so even if my server takes a while to load I don't mind, because Im pretty confident I don't need to iterate a lot. If I do need to iterate many times, I switch to JVM (write tests) and the dev loop is ultra quick.

For iterating on websites though, I need to be able to see changes ASAP. In the perfect world, I would save my kotlin file and I would see the changes on the browser immediately. The way I work is very iterative, and the final design touches are always done in code (responsive, making sure the design is pixel perfect, etc). I might be doing hundreds of iterations on a design, so any delay there is multiplied probably hundreds of times.

[gildor]

This is why it's so nice to work with the compose preview 🥹

Just curious, what do you use for UI?

[Alex Styl]

kotlinx html

[Alex Styl]

I am not talking about compose here

I have 0 issues with the dev cycle of building compose apps.

this is about static content (landing pages, blogs, doc sites, etc)

[gildor]

yes, I understand

[gildor]

I never really liked html DSLs for this reason, from old not-good times of first versions of Jade for node.js

[Alex Styl]

I am all in with kotlin because it removes any context switch from coding work in my business. I am a solo founder, so this is fantastic for me.

so yeah, even if the compilation is slow, the removal of the context switch is a huge boost for me

[gildor]

I really don't think that Kotlin would be fast enough for it, unlike just use raw html and maybe convert it to some template when UI work is done

[gildor]

I mean, comparing to just immedeate rendering

[Alex Styl]

I am already aware of the alternatives. Not interesting of switching

[gildor]

Maybe something like compose preview could be done for kotlin.html, after all, compile function, return html is very doable, but considering that it not supported much, I wouldn't bet on it

[Alex Styl]

Again, im not interested in alternatives. i don't use compose preview because it doesn't make sense to my workflow and in fact slows me down. not because it takes a while to load, but because it is now how I work

hot reload on the other hand is spot on how I work

[gildor]

I'm just thinking out loud.
Having Kotlin with good html support is a wide spread use case, but again, I don't really see how it can be done efficiently for UI development

[Alex Styl]

feel free to suggest ways for better html support, but kindly do it in a different thread.

it is getting out of topic in terms of kotlin/js performance

[Alex Styl]

@Artem Kobzar just a thought: maybe (project) compilation is not the issue. But individual files (compiling modified files), given I rely on continuous mode (-t)

Not sure if that changes anything for you, but I believe it's worth mentioning.