That was an interesting watch. And the

Long

issue is now pretty much resolved with

bigint

. Tho @Arkadii Ivanov I'm curious to understand why you guys think annotating declaration isn't ideal. Which kind of solution would you prefer? Gradle-based to mass export?

I'm getting an error when

:kotlinWasmNpmInstall

and

:kotlinNpmInstall

run at the same time. https://scans.gradle.com/s/clmy5234k76zi Is this a known issue? Or is there anything I can do about it?

Sorry for the noob question, but what Node.js version should I use? The KMP curated version is quite old, v22.0.0 and without patches. Is it just the oldest version KMP supports, or a preferable one? I am using NodeJS just for builds, so security is less of a concern.

Powerful optimization of the first KMP 3D Globe engine WorldWind Kotlin v1.8.2 released https://github.com/WorldWindEarth/WorldWindKotlin/releases/tag/v1.8.2

In Kotlin/JS, how can I initialize a JavaScript Integer? I'm creating typings for a library (Discord Embedded App SDK) and to set an activity they have a

Timestamps

object that expects two integers: A

start

and

end

timestamps. These timestamps are Epoch millis. The library expects integers for these timestamps: https://discord.com/developers/docs/events/gateway-events#activity-object-activity-timestamps But that's where the issue lies: I can't figure out a way to initialize a JavaScript Integer! • A Kotlin Int doesn't work because converting a epoch millis to a Kotlin Int causes it to overflow and go into the negatives • A Kotlin Long doesn't work due to the way Kotlin Long works in Kotlin/JS • A Kotlin BigInt doesn't work because the backend (in this case, Discord's RPC protocol) complains that it isn't a number • A Kotlin String doesn't work because the backend complains that it isn't a number The only way I found to make it work is by initializing the number via

js

, but I wonder if there's a better way to do this?

discordSDK.commands.setActivity(
                        SetActivityRequest(
                            activity = Activity(
                                0, // Changes the top of the activity title in the profile
                                "PixelBloom",
                                "Placing pixels at ${cursor.value?.x}, ${cursor.value?.y}",
                                timestamps = Timestamps(
                                    start = js("new Date().getTime()")
                                )
                            ).also {
                                console.log("Generated Activity: ", it)
                            }
                        )
                    )

I cannot see the green arrows anymore in a kotlin js test file to run tests from intellij. Also right click on test folder does not show any run test actions. Kotlin 2.2.0, multiplatfor gradle plugin, karma test. Running the gradle task is the only way to do it for me. I remember in the past this was working 🤔

Running

./gradlew jsBrowserDevelopmentRun -t

always refreshes my browser page twice. On save on on compile. Is it possible to configure some debounce here?

I've noticed that production executable js file (generated by jsBrowserDistribution task) is not obfuscated (has original class/function/variable names) and contains embedded source map (sourceMappingURL=data:application/json;...) Is it a bug or i should configure Gradle build somehow? I'm using Kotlin 2.2.20-RC

Anyone else is experiencing webpack production task not being executed? Even after clean build the

jsBrowserProductionWebpack

task is somehow skipped.

Vite for Kotlin 0.6.0 is out! This version adds the options

server.host

,

server.port

,

server.strictPort

and

server.proxy

. The documentation is now available at https://vite-kotlin.opensavvy.dev

I am working on upgrading our kotlin version from

2.1.20

->

2.2.10

. Previously, we used

KtMap.getInstance().fromJsMap()

to convert a JS Map to a Kotlin map so that the client can send some data back to KM. However, in

2.2.10

getInstance()

is not available anymore. Is there a more preferred way to do these sorts of operators for objects like

KtMap

or

KtList

?

When generating Javascript binaries in dist/js folder i see *.mjs files that are never used/downloaded when browsing app. Why are they needed? Is it safe to remove them from distribution? Kotlin 2.2.20-Beta2 Compose 1.9.0-rc01

Anyone using

2.2.20-Beta2+

please check: https://kotlinlang.slack.com/archives/C0KLZSCHF/p1756626364165389

In a Cloudflare Worker I want to verify a JWT token. I saw that the awesome

kotlin-wrappers

project has already wrappers for that, but I lack sample code how to use it. I find it hard to use it without docs & samples. This is the original JavaScript I want to translate:

async function verifyJwt(token, publicKeyBase64Der) {

    const parts = token.split('.');

    if (parts.length !== 3)
        throw new Error("JWT malformed");

    const [headerBase64, payloadBase64, signatureBase64] = parts;

    const signature = base64urlToUint8Array(signatureBase64);
    const data = new TextEncoder().encode(headerBase64 + '.' + payloadBase64);
    const headerJson = JSON.parse(utf8Decode(base64urlToUint8Array(headerBase64)));

    if (headerJson.alg !== "ES256")
        throw new Error("Unsupported Algorithm: " + headerJson.alg);

    const keyData = base64ToUint8Array(publicKeyBase64Der);

    const cryptoKey = await crypto.subtle.importKey(
        "spki",
        keyData,
        {
            name: "ECDSA",
            namedCurve: "P-256",
        },
        false,
        ["verify"]
    );

    const verified = await crypto.subtle.verify(
        {name: "ECDSA", hash: "SHA-256"},
        cryptoKey,
        signature,
        data
    );

    if (!verified)
        throw new Error("Invalid signature");

    return JSON.parse(utf8Decode(base64urlToUint8Array(payloadBase64)));
}

Did someone ever used a Cloudflare R2 bucket from a Cloudflare worker in Kotlin/JS? I wonder how that is defined.

anyone aware of any examples like this using ktor instead of spring https://github.com/Kotlin/kmp-spring-petclinic/?

I'd like people with a good Cloudflare and Kotlin/JS understanding to review (or contribute to) my new project: https://github.com/StefanOltmann/cloudflare-steam-name-update-service I think a lot can be improved here. Especially how I pass in the environment - didn’t find a better way. And I don't like all the

js()

interop, too. I like this to be Kotlin/WASM, but the sample (a fork from the original hello world) I found was outdated and didn't work for me. So I appeciate if you drop me hints how to improve or helpful ressources (like sample code) how to properly work with Kotlin/JS (or even better Kotlin/WASM) on Cloudflare Workers. 🙂

As far as I recall, there was some talk about un-deprecating the

@EagerInitialization

annotation. If that is the case: 1. could it be also applicable to top-level functions? This would be useful for code that has to run when the JS module is initialized. The current workaround is a property that calls a function. 2. could we instead move to an annotation that starts with

@Js*

to streamline the naming? For example

@JsEager

or

@JsImmediate

.

Trying to upgrade Kotlin from 2.2.0 -> 2.2.10 and started getting this error:

Execution failed for task ':kotlinNpmInstall'.
>                 Process 'Resolving NPM dependencies using yarn' returns 1
                  Unknown Syntax Error: Unsupported option name ("--network-concurrency").

Any workaround?

What would be the correct way to add a dependency if the user has configured a specific feature? For example, I need a specific dependency if the user has defined

useCommonJs()

. To detect that, I'm using:

val moduleKind = project.objects.property<JsModuleKind>()
	project.tasks.withType<org.jetbrains.kotlin.gradle.targets.js.ir.KotlinJsIrLink> {
		moduleKind.set(compilerOptions.moduleKind)
	}

but by the time

moduleKind

is set, it's not allowed to add a

implementation(npm("foo", "1.0.0"))

anymore. I've also tried having a

: RequiresNpmDependencies

task with a dependency set that changes once

moduleKind

is known, and that works without the configuration cache, but with it I get a serialization crash within the configuration cache itself.

How can I achieve lazy loading to reduce initialize time of any kotlin js browser app?

Hello, I have a library that targets both Android and Js. It uses Metro for DI. I compile with

jsBrowserProductionLibraryDistribution

js {
        moduleName = project.name
        useEsModules()
        binaries.library()
    }

I have the following code

@Inject
internal class InvocationHandler(
    private val exposedFunctions: Map<String, Provider<ExposedFunction>>,
) {
    operator fun invoke(
        onInvocations: SharedFlow<Invocation>,
    ): Flow<Invocation> {
        return onInvocations
            .onEach {
                val exposedFunction = exposedFunctions[it.location] ?: return@onEach

                it.handle {
                    val fn = exposedFunction()
                    fn(it.parameters) // This throws an error on JS
                }
            }
    }
}

// ...

@Inject
@ContributesIntoMap(AppScope::class)
@ExposedAtLocation(ExposedFunctionLocation.IS_FILE_CACHED)
internal class IsFileCached(private val cacheRepository: CacheRepository) : ExposedFunction {
    override suspend fun invoke(args: List<Any>): Any {
        val fileUrl = args[0] as? String ?: return false
        return cacheRepository.isCached(fileUrl)
    }
}

For the code above, I will get

TypeError: fn is not a function

And if I print with

fn.toString

function (_this__u8e3s4, $completion) {
    return i.v8b(_this__u8e3s4, $completion);
  }

Do you know what could cause this issue?

I'm getting this weird import in the generated

kotlin-kotlin-stdlib.js

const DYNAMIC_MODULES_ID = '\0commonjs-dynamic-modules';
const HELPERS_ID = '\0commonjsHelpers.js';

Note the

\0

. Has anyone seen this before?

Im getting an error

Could not locate the bindings file

when I am installing

sqlite3

as a npm() dependnecy in build.gradle.kts:

implementation(npm("sqlite3",  "5.1.7"))

I think it has something to do with native bindings (C ?) . The library is this one Any pointers on how to use it in kotlin /js ?

running into

e: org.jetbrains.kotlin.util.FileAnalysisException: Somewhere in file /Users/casvanluijtelaar/Projects/***/deals/DealsOfferKey.kt: java.lang.NullPointerException: null cannot be cast to non-null type org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
	at org.jetbrains.kotlin.util.AnalysisExceptionsKt.wrapIntoFileAnalysisExceptionIfNeeded(AnalysisExceptions.kt:62)
	at org.jetbrains.kotlin.fir.FirCliExceptionHandler.handleExceptionOnFileAnalysis(Utils.kt:251)
	at org.jetbrains.kotlin.fir.resolve.transformers.FirSupertypeResolverTransformer.transformFile(FirSupertypesResolution.kt:892)
	at org.jetbrains.kotlin.fir.declarations.FirFile.transform(FirFile.kt:46)
	at org.jetbrains.kotlin.fir.resolve.transformers.FirTransformerBasedResolveProcessor.processFile(FirResolveProcessor.kt:48)
	at org.jetbrains.kotlin.fir.resolve.transformers.FirTotalResolveProcessor.process(FirTotalResolveProcessor.kt:36)
	at org.jetbrains.kotlin.fir.pipeline.AnalyseKt.runResolution(analyse.kt:24)
	at org.jetbrains.kotlin.fir.pipeline.FirUtilsKt.resolveAndCheckFir(firUtils.kt:76)

when I try to build

jsBrowserDevelopmentLibraryDistribution

seems to throw on any file with kotlinx-serializable imported. e.g. this file only contains:

import kotlinx.serialization.Serializable

@Serializable
data class DealsOfferKey(
    val offerId: Int,
    val offerInstanceUniqueId: String?,
)

removing the annotation and the import fixes the issue. but then errors on one of a million other files with serializable included. Anyone seen this before?

2.2.20 is out, and there are a lot of improvements for JS. https://github.com/JetBrains/kotlin/releases/tag/v2.2.20

Just an observation now that I've compiled with 2.2.20. The new

String.substring

approach is better because it directly calls JS'

substring

, however it now produces:

substring(response, startIndex, endIndex);

Where

substring

is:

function substring(_this__u8e3s4, startIndex, endIndex) {
  _init_properties_stringJs_kt__bg7zye();
  // Inline function 'kotlin.js.asDynamic' call
  return _this__u8e3s4.substring(startIndex, endIndex);
}

If instead you bring back

inline

for those two functions https://github.com/JetBrains/kotlin/blob/400e1ecadbef70744b6ee7eb6234a0a6ea8bbda8/libraries/stdlib/js/src/kotlin/text/stringJs.kt#L274-L276 you won't have to pass by the lazy initialization of the file-level properties. A similar situation is valid for

Long

too as far as I can see. Alternatively properties could be marked with

EagerInitialization

.

Is it possible to use

@JsName

on properties declared on a

@JsPlainObject

? I wanted to change some

snake_case

variables into

camelCase

, to make it look "better" in Kotlin I tried searching for it, but the only result of someone trying to do this was this conversation: https://kotlinlang.slack.com/archives/C0B8L3U69/p1728428182216839 However after testing it, it doesn't seem to work on Kotlin 2.2.0 😞

Are unsigned types fully supported on JS? I was trying to use them but I ran into a strange error:

fun main() {
    ubyteArrayOf(
        *listOf(ubyteArrayOf())[0]
    )
}

results in:

Unhandled JavaScript exception: listOf(...).get_c1px32_k$(...).slice is not a function

https://pl.kotl.in/nEyBqjkBZ The same code works just fine when replacing

ubyteArrayOf

with

byteArrayOf

or running it on JVM instead.

Worried about bundle size? Here are two options that can help decrease it: • Using ESM modules • Using ES2015 language features Both of these articles give examples of how the options affect the generated code.