This repository contains a minimal example of how to do code splitting in Kotlin/JS.

To build: ./gradlew build

To run in the Node.js repl:

node

const mainModule = await import(
    "./build/kotlin-webpack/js/productionExecutable/codesplitting.js"
)
mainModule.main()

Main.kt asynchronously imports fun chair from Chair.kt. Code splitting is taking placing: there are two JavaScript files.

Main.kt directly imports fun kofi from Kofi.kt. No code splitting takes place, the code ends up in the same JavaScript file.

Essential elements needed to make this work:

// build.gradle.kts
kotlin {
    compilerOptions {
        // Compile each .kt file to a separate .mjs file
        compilerOptions.freeCompilerArgs.add("-Xir-per-file")
    }
}

// Chair.kt
@JsExport
fun chair() {
    /* ... */
}

// Main.kt
importAsync<ChairModule>("./Chair.export.mjs")
    .then { it.chair() }

// webpack.config.d/codesplitting.js
config.entry = {
    main: require('path').resolve(
        __dirname, 
        "kotlin/codesplitting/com/zenmo/Main.export.mjs"
    )
}