Claudflare added support Kotlin(/JS) for writing workers (their serverless solution) along with few other languages compiled to JS. https://blog.cloudflare.com/cloudflare-workers-announces-broad-language-support/

🛠️ In case you haven’t seen it yet: we’re happy to share a preview version of

kotlinx-nodejs

with you, which provides typesafe Node.js API bindings for Kotlin/JS! :kotlin-flag: You can find installation instructions for

kotlinx-nodejs

in the blogpost for 1.4.0-RC or on GitHub. Have fun experimenting - and don’t forget to report any encountered issues!

I’m using the react template to start an app for the 1.4.0 RC. Even the basic template runs VERY slow with webpack (I’m guessing it has something to do with the packed output being a 22 MB file). For dev, I’d like to not rely on webpack because it increases my compile times substantially. What are my options for removing webpack from the dev experience, and getting my compile times to something sane?

I'm testing react app and I have problems in render cycle with useEffect(). I added a dependency array in my useEffect for prevent render loop but ignores dependency array and render 2 times. Any hint what's going on? Code:

val (mensajes, setMensajes) = useState(emptyArray<Json>()) //{ nick, msg, type}
val (users, setUsers)       = useState(emptyArray<Json>())

useEffect(listOf(users)) {
  socket.on("loginUser") { data ->
      console.log("OnloginUser")
      val noOfUsers = data["numOfUsers"] as Int
      val item = getMsgJson("", getParticipantsMessage(noOfUsers), "log")
      val items = mensajes.plus(item)
	  
      setMensajes(items) //render 1 time
      setUsers(data["usersList"]) //render 2 time
  }
}

is jest supported as javascript testRunner? in kotlinjstest i find only

useKarma

and `useMocha`methods.

are there any plans to support typescript and javascipt source code in kotlin/js projects, for example

src/jsMain/js

and

src/jsMain/ts

(like kotlin/jvm supports java sourcecode)

Hey all. Trying very hard to get react-hot-loader working with KotlinJs. Anybody managed to do that? I am always getting error "Cannot call a class as a function" 😞

I take it non-empty constructors are no longer supported in 1.4.0-rc? This used to work fine up to 1.4-M3

@JsExport
@ExperimentalJsExport
class LoginState(
	json: String? = null,
) {

now in RC the compiler complains:

e: java.lang.IllegalStateException: Can't find name for declaration FUN SYNTHESIZED_DECLARATION name:LoginState_init_$Create$ visibility:public modality:FINAL <> (json:kotlin.String?, $mask0:<http://kotlin.Int|kotlin.Int>, $marker:kotlin.js.DefaultConstructorMarker?) returnType:com.rezproperty.modules.account.state.LoginState

and neither is adding a second constructor after removing the param from the default constructor?

@JsExport
@ExperimentalJsExport
class LoginState() {

	@JsName("LoginStateWithJson")
	constructor(json: String): this() {
        ...
	}

e: java.lang.IllegalStateException: Can't find name for declaration FUN SYNTHESIZED_DECLARATION name:LoginState_init_$Create$ visibility:public modality:FINAL <> (json:kotlin.String) returnType:com.rezproperty.modules.account.state.LoginState

In IDEA, is there a button somewhere to "view generated JS" for selected code, analogous as with Kotlin/JVM you're able to view generated bytecode? If there is, where is it? I've been locating and opening the generated JS file manually so far.

Trying to use the new ir compiler, setting

kotlin.js.compiler=ir

in

gradle.properties

, all is fine generally, but if I use

--continuous

in my the run configuration for the

run

gradle task, the first compile works, but as soon as I change a file and save, the build crashes with a file not found on the <ModuleName>.js file. Restarting the task again works fine. It seems doubtful I'm the first to try this, so I'm guessing I'm doing something wrong here. Anyone have an easy answer, or YT ?

(a) So I'm wanting to use some js stdlib classes that are incomplete, and I'm doing this to fix it (in this example, adding

join()

to `Uint16Array`:

@JsName("Uin16Array")
public external open class Uint16ArrayX : Uint16Array {
    // copy/paste constructors from Uint16Array here
    fun join(separator: String = definedExternally): String
}

This seems to work, but it also feels like I need to wash my hands now. I can use an

Uint16ArrayX

anywhere a

Uint16Array

is asked for. The only caveat is that going from X to original needs an unsafeCast, but that is mildly inconvenient at worst. I didn't find a way to patch Uint16Array directly. The compiler wont accept external extensions to an external class. Is there a better way to do this than above? Ofcourse I could just (Uint16Array).asDynamic().join(...) but that's not the point of this exercise. (b) It seems CharArray uses Uint16Array internally (IntArray to Int32Array, etc), but am I correct in my understanding that CharArray's functions are otherwise pure kotlin and not (or rarely) mapped to their Uint16Array counterparts (which aren't declared at this point anyway) ? (c) For TypedArrays (and a few other things) it seems Kotlin's definitions are a bit outdated/missing. I looked in Kotlin source GitHub to see if I might contribute at some point, but it is unclear to me what comes from where. There's idl files referenced to which the original urls no longer serve (are the kotlin files autogenerated from them .idl or hand-translated?). There are several copies of the definitions as well. Where to start here for possible (far) future pull request ?

Additionally, I found that using bare data classes (consisting only of primitive types, and nested data classes, creating quite complex structures) with javascript functions expecting objects and vice versa works perfectly well:

data class Test(val i: Int, val s: String)
var t = Test(1, "hello")
someJavascriptFunctionExpectingObject(t)
var t = js("{i: 1, s: 'hello'}").unsafeCase<Test>()

In hindsight it seems obvious that this works. But when Googling around for this I ran into all sorts of parsers and lengthy code ending up with the same thing but significantly slower. Is there something wrong with doing it this way, other than losing presence/type checks for the fields? Is this likely to break in unexpected ways (such as?) or is it fine to use in tightly controlled cases? Thank you for coming to my TED talk 🙂

does anyone here know why splitChunks in the webpack definition would cause the output to no longer go to the distributions folder? If I add the following to my webpack config

config.optimization.splitChunks = {
    minSize: <someNumber>,
    maxSize: <theSameNumber>
 };

I get nothing in my distributions folder. If I remove it, the distributions folder gets created on build. Any ideas?

In 1.4-rc, how do I change the js output filename? I don't want to change the module name, I want to append the version to the filename for cache busting reasons.

I wrote a GitHub action using TypeScript. Now I wanted to rewrite the whole thing in Kotlin/JS. I applied

kotlin("js") version "1.3.72"

I called

kotlin { target { nodejs() } }

I declared all the dependencies I had in

package.json

now with

implementation(npm("...", "..."))

Now my current problem is how do I make those dependencies properly usable using Dukat? I've read you can set the project property

kotlin.js.experimental.generateKotlinExternals = true

to enable automatic Dukat magic. But either this is wrong, or I did something wrong or not fully. When I run

gradlew build

, I get this:

> Task :generateExternals
events.js:187
      throw er; // Unhandled 'error' event
      ^

Error: write EPIPE
    at afterWriteDispatched (internal/stream_base_commons.js:150:25)
    at writeGeneric (internal/stream_base_commons.js:141:3)
    at Socket._writeGeneric (net.js:771:11)
    at Socket._write (net.js:783:8)
    at doWrite (_stream_writable.js:431:12)
    at writeOrBuffer (_stream_writable.js:415:5)
    at Socket.Writable.write (_stream_writable.js:305:11)
    at Readable.ondata (_stream_readable.js:727:22)
    at Readable.emit (events.js:210:5)
    at Readable.read (_stream_readable.js:525:10)
Emitted 'error' event on Socket instance at:
    at errorOrDestroy (internal/streams/destroy.js:108:12)
    at Socket.onerror (_stream_readable.js:759:7)
    at Socket.emit (events.js:215:7)
    at errorOrDestroy (internal/streams/destroy.js:108:12)
    at onwriteError (_stream_writable.js:446:5)
    at onwrite (_stream_writable.js:473:5)
    at internal/streams/destroy.js:50:7
    at Socket._destroy (net.js:664:5)
    at Socket.destroy (internal/streams/destroy.js:38:8)
    at afterWriteDispatched (internal/stream_base_commons.js:150:17) {
  errno: 'EPIPE',
  code: 'EPIPE',
  syscall: 'write'
}

Hi guys, Is there a way to configure the npm registry to use when building a kotlin js module?

Is there a guide somewhere to package my JS module (make it a library) and publish it to maven? First local, ultimately bintray (or does js-only go to mavenCentral) ?

After I got my

EPIPE

problem from above solved, I'm a step further, but highly confused. Maybe someone can shed some light here. • If I only have

implementation(npm("@actions/core", "1.2.4"))

as npm dependency, automatic Dukat runs fine now, producing a

core.module_@actions_core.kt

file with the external definitions, but all exported methods are in the default package, not in an npm-package specific package, is that expected or can this be changed? I imagine this could easily cause conflicts if you add more dependencies. • Also, with only

@actions/core

as dependency, it then compiled fine, but doing

./gradlew run

complains with

ReferenceError: setFailed is not defined

• Now it gets even uglier, I added the other dependencies I have (or at least had in the TS variant, some are probably superfluous now):

implementation(npm("@actions/cache", "1.0.1"))
implementation(npm("@actions/core", "1.2.4"))
implementation(npm("@actions/exec", "1.0.4"))
implementation(npm("@actions/http-client", "1.0.8"))
implementation(npm("@actions/io", "1.0.2"))
implementation(npm("@actions/tool-cache", "1.6.0"))
implementation(npm("semver", "7.3.2"))
implementation(npm("null-writable", "1.0.5"))
implementation(npm("node-filter-async", "2.0.0"))

and now while Dukat still duly does its work (and produces 316! Kotlin files o_O), the compiler is super unhappy, throwing 802 errors at me.

Hello! When building gradle multi module js project build folder in root directory is created and Intellij Idea after each build indexing it. What configuration show I add to exclude this folder from indexing? I tried to use idea gradle plugin with excluded build folder but it did not help. Please help me with advice!

Hi I'm looking for open source examples of multiplatform (jvm/js) kotlin code-bases that demonstrate how well kotlin can serve as a language to be consumed by both ecosystems. Anyone aware of some?

In running JS Browser test; it looks like the toolchain (K/JS, Karma, Chrome Headless) is also executing my JS Application and not just the Unit Tests.

I'm updating Kotlin/JS code in https://github.com/joreilly/BikeShare/blob/master/web/src/main/kotlin/App.kt to start using

kotlin-react-router-dom

wrapper ....it looks like correct property gets passed to

StationList

but

useEffectWithCleanup

block isn't being executed 2nd time I click on a link (so isn't loading the data)....anyone know what I should be doing differently here?

Is adding support to allow running node commands using the installation from the Kotlin js plugin on the roadmap? I haven’t found a supported way to do this at the moment 😢

I could use a hand; Trying to learn how to use js modules in my kotlin JS apps for browser. I'm stuck on defining this lamba part; all untested just trying to get off the ground:

@JsModule("grapesjs")
external class Grapes {
    fun init(lambda: () -> Unit): Grapes = definedExternally
}

class WebEditorViewController {
    val grapes = Grapes().init {
        val container = "#gjs"
        val fromElement = true
    }
}

And here is what the actual JS is supposed to look like, from the hello world examples

const editor = grapesjs.init({
  container: '#gjs',
  fromElement: true,
  height: '300px',
  width: 'auto',
  storageManager: false,
  panels: { defaults: [] },
});

What's up wiwth browserDevelopmentRun, is there a way to avoid webpack and dce... just trying to debug here, tired of waiting on webpack...lol, because I'm missing something obvious

How do I access the standard

Intl

functionality? I’m trying to use

Intl.Locale

.

What is

warning "workspace-aggregator-6f2c6a0d-778d-49e5-9792-0c1b7ca65d3f > setup-wsl > kotlinx-coroutines-core@1.3.8" has incorrect peer dependency "kotlin@1.3.71".

telling me? Did I do something wrong? Is there a Koltin/JS error? ...? This is displyed when I have

implementation(npm("kotlinx-coroutines-core", "1.3.8"))

and refresh in IntelliJ. Actually mainly wondering, because I'll replace that with

implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core-js:1.3.8")

as the

npm

variant does not provide navigation to definition.

And next question, how do I access things from

process

in Kotlin/JS for node.js besides using for example

private val platform = js("process.platform") as String

Aaand next question, how is one supposed to use coroutines in Kotlin/JS for node.js? You cannot do

runBlocking

as it does not exist for Kotlin/JS intentionally. Actually right now I just declared the

fun main()

as

suspend fun main()

and it seems to work properly. Just want to double-check whether this is the correct way. 🙂