Hey guys, i am a bit new to multiplatform projects, i have a project for jvm and js backend targets ...

# javascript

[Hanno]

Hey guys, i am a bit new to multiplatform projects, i have a project for jvm and js backend targets and i can't get the simplest setup for js to work. Did everything like official docs state but when i add kotlin test-js dependency, compileTestKotlinJs fails saying "Module kotlin is defined in more than one file". I am trying to run tests with mocha as soon as it works and the only dependency i currently have is ktor client. Any ideas anyone?

[Ivan Kubyshkin [JetBrains]]

Can you attach a link to your project or gradle file?

[Hanno]

Sadly No :( do you know of a working minimal example with enabled javascript tests?

[Hanno]

I could somewhen later maybe extract a minimal example and share that

[Ilya Goncharov [JB]]

Maybe this can help
https://github.com/ilgonmic/kotlinjs-multi-module

[Hanno]

Not sure, i am having a multiplatform project, which seems to be configured quite different from a js only

[Ilya Goncharov [JB]]

You can check full stack demo. It is multiplatform
https://github.com/Kotlin/kotlin-full-stack-application-demo

[Hanno]

Thx for the hint, sadly the shared subproject, which is such a multiplatform project, doesn't contain any Javascript tests :(

[Robert Jaros]

@Hanno I've just added a simple test to template-fullstack-ktor kvision example (https://github.com/rjaros/kvision-examples/tree/master/template-fullstack-ktor). It works without problems for me.

[Hanno]

Thx all for your help!

@Robert Jaros your example is a bit different than my project but i will take a look at why yours works and mine doesn't.

All in all, i am a bit frustrated by the amount of configuration that seems to be necessary to get my simple example to work. I think jvm js multiplat project with working tests and corresponding reports would be super nice as a starter template, linked to from the official docs as a starting point. Going to see if i could deliver that as soon as i can, i will keep you updated.

[Hanno]

Btw my use case is an api client that we need for backends and frontends

[Robert Jaros]

Do you have a link to your project?

[Robert Jaros]

Kotlin/JS and Kotlin MMP are still experimental and
right now they are undergoing major changes

[Robert Jaros]

that's why its so hard to find up to date examples

[Hanno]

No :( company stuff i cannot share that easily.

Yap that's okay for us. Alternatively introducing another language for frontend Client and writing the thing twice is a worse Option :) yea that's true, it's difficult, i would whish there was just a single opinionated official example using mocha and done xD

[Hanno]

But hey guys, you are super nice, thanks for your help already

[Hanno]

I tried to extract a mininal example project, can be found here https://github.com/hannespernpeintner/kotlin-minimal-jvm-js would be super nice If someone could tell me why i can't call Test compile for js :)

[Robert Jaros]

With some small changes I can run your test, but with a failure

[Robert Jaros]

I think you want to have a test service running

[Robert Jaros]

But I'm not sure how do you try to run this service

[Robert Jaros]

Ok, I run your test successfully

[Robert Jaros]

with some garbage on the screen 😉 but with a checkmark :-)

[Robert Jaros]

the problem is you create a service in gradle and want to pass its port to mocha test runner

[Robert Jaros]

that forces you to bypass normal kotlin/js testing mechanism and create your own by installing and execution mocha by hand

[Robert Jaros]

but it still can work - you just have to fix some directories:

val nodeModulesParentFolder = File(buildDir, "js")
// ...
setArgs(listOf(buildDir.resolve("js/packages/kotlin-minimal-jvm-js-test/kotlin").absolutePath, "--${::testServerPort.name}=$testServerPort"))

[Robert Jaros]

instead of installMocha task I've added:

js() {
        nodejs {
            testTask {
                useMocha {
                }
            }
        }
    }

[Robert Jaros]

And last but not least - remove allWarningsAsErrors = true option. Node installation task complains about two version of node with two kotlin versions. And that warning, which is absolutely not important, is treated as an error with this option.

[Robert Jaros]

with these changes I can run your test - but it is executed twice. By the standard kotlin/js testing - and finishes with a failure because the port is not known. And by additional runMocha task, which ends with a success.

[Hanno]

You are a true hero, i try to parse all your input. The server stuff is stripped out from prod Code. The manual mocha stuff is taken from countless examples i found accepted as a working answer, desperatly trying to get it to work, i never wanted to do it that way :D going to do it with useMocha, why did i overlook that in the future official example, that's exactly what i want... What sense does it make to leave that bit out of the documentation with the hint "do it yourself your way". More harm than good.

Can't thank you enough.

[Hanno]

Hmmm.. how does one pass values from the build into the test via useMocha?

[Robert Jaros]

I'm afraid I don't know. I've been trying to look through the sources, but without luck.

[Robert Jaros]

I was thinking you could run a service inside the test, using some node API, but it's a totally different thing.

[Robert Jaros]

It just seems strange to me, to pass data into the test from the build file. External dependencies should be mocked using some mock tools :-)

[Robert Jaros]

I've been playing and I got this:
1. removed all external mocha code from build.gradle.kts (only useMocha { } is left)
2. added some deps to jstest sourceset:

js().compilations["test"].defaultSourceSet {
            dependencies {
                implementation(npm("http"))
                implementation(npm("node-fetch"))
                implementation(npm("abort-controller"))
                implementation(kotlin("test-js"))
            }
        }

3. modified the test code:

external fun require(name: String): dynamic
   // ...
    @Test
    fun testClientGet() {
        val randomPort = Random.nextInt(8000, 9000)
        val http = require("http")
        val server = http.createServer { _, res ->
            res.end()
        }.listen(randomPort)

        val config = Config(BaseUrl("<http://localhost>:$randomPort"), defaultApiKey)
        val client = ApiClient(config)
        GlobalScope.launch {
            assertEquals(ConnectionCheckResult.Success, client.checkConnection())
            server.close()
        }
    }

4. jsTest task works perfectly, without a single warning and successful test report is generated without problems

[Robert Jaros]

Hope this will be of any use :-)

[Hanno]

Thx so much for your help! But i am afraid thats Not sufficient. I have to use an external service that is started and stopped in the build with a corresponding gradle plugin. This is the way we test against real apis and it works damn good btw :) we own the service but it's a seperate repository, hence the requirement. The service is also not easy to mock somehow, that's one of the reasons we want to build a client for it. Must be possible to pass a value into the task somehow Oo i will take a look at the sources somewhen

[Hanno]

I didn't find a way, i think i will use Code Generation to pass in values from the build into the tests Oo updated my example project, should work now as a template