I'm creating a Kotlin/JS library which is Compose ...

# compose-web

[David Herman]

I'm creating a Kotlin/JS library which is Compose aware. By default (using the skeleton from the tutorials), I was defining it as a multiplatform module, but code only lives under the "jsMain" folder. This library generates two maven artifacts (the main one and the "-js" one), and it works.

Now, I was hoping to clean this up by converting the module into a JS module and publishing just a single maven artifact instead, but I'm getting a dreaded Compose assertion when I try to compile my project using the new version of the artifact: java.lang.AssertionError: No such value argument slot in IrCallImpl: 4 (total=4).

So my question: Am I just publishing my library wrong? (Because with multiplatform, maven-publish just worked, but with Kotlin/JS, I'm setting it up myself). Or is this a fundamental requirement of all Compose library artifacts that they need to be multiplatform modules, for technical reasons behind the scenes that require a common artifact AND a JS artifact be created?

[David Herman]

I can link to build scripts if necessary, but in general, my setup went from this:

plugins {
  kotlin("multiplatform")
  ...
}

kotlin {
    js(IR) {
        browser()
        binaries.executable()
    }
    sourceSets {
        val jsMain by getting {
            dependencies {
                implementation(compose.web.core)
                implementation(compose.runtime)
                implementation(project("..."))
            }
        }
    }
}

to this:

plugins {
  kotlin("js")
  ...
}

kotlin {
    js(IR) {
        browser()
        binaries.executable()
    }
}

dependencies {
    implementation(compose.web.core)
    implementation(compose.runtime)
    implementation(project("..."))
}

[David Herman]

and my publishing step went from letting the multiplatform plugin define my MavenPublication, to me doing essentially this:

val kotlinComponent = project.components.findByName("kotlin")
val kotlinSourcesJar = project.tasks.named("kotlinSourcesJar")

if (kotlinComponent != null) {
    publications.create("maven", MavenPublication::class.java) {
        groupId = project.group.toString()
        this.artifactId = artifactId
        version = project.version.toString()

        from(kotlinComponent)
        artifact(kotlinSourcesJar)
    }
}

[rnett]

Pretty sure I saw in the docs somewhere that Compose only works w/ the multiplatform plugin, I'll see if I can find it

[rnett]

I don't see it anywhere explicit, but the tutorial use the multiplatform plugin, so I'm guessing it's still a thing

[David Herman]

Yeah not sure if it's required or just the easy path (thanks to logic in the multiplatform plugin)

[David Herman]

I was hoping it would be a quick cleanup but since it's looking trickier than I thought, and since it sounds like this might actually be by design, I'll back out of it for now

[shikasd]

From the dreaded assertion, it seems like the compiler plugin is not applied to one of the libraries, probably you could fix this by adding kotlinCompilerPluginClasspath to project dependencies

[David Herman]

Oh?

[David Herman]

I can try that

[David Herman]

I was assuming it was up to the project that called the libraries to apply the compose plugin?

[David Herman]

Let me paste the shape of my build script for the project that's consuming my libraries

[shikasd]

If you call composables, you have to apply it too :)

[David Herman]

OK, makes sense!

[David Herman]

I guess it transforms the code before it's published to maven?

[shikasd]

Yes, exactly

[David Herman]

I'll look into kotlinCompilerPluginClasspath then. Any example scripts you can link to? (Otherwise, I'll dig)

[David Herman]

So far this seemed like the most promising lead: https://github.com/sampingantech/jetpack-compose-animation-playground/blob/84ebd1540aa012684c64f7ac96161b121d336e82/app/build.gradle.kts#L48

[David Herman]

But now (as far as I can tell) handling this myself puts me into an uncomfortable position of making sure my JB Kotlin versions and Androidx compiler versions need to be kept in sync?

[David Herman]

which I assume is something the multiplatform plugin is doing for me (just a guess)

[David Herman]

I feel like all signs are pointing to "Don't shave this yak, just use the multiplatform plugin" 🙂

[shikasd]

Yeah, I think this would be the best decision from that point of view :)
I am just used to managing things from before multiplatform supported compose, but it is quite manual, I agree

[David Herman]

Thanks for shedding light onto my situation, Andrei

[David Herman]

Just to close the loop on this, what I ended up doing is I still use the multiplatform plugin but have disabled the "publishKotlinMultiplatformPublication..." tasks for my modules. This seems to work - I'm not filling up my maven repository with extra "common" bits that I don't need, while still allowing the multiplatform plugin to pre-process my JS artifacts with the Compose compiler plugin.