Kotlin Multiplatform serve ktor as backend jvm module

Question

I'm working on my multiplatform project and added ktor based backend module as part of it as i wanted to share my common code with this backend module i've added it to dependencies

implementation(project(":shared"))

But there seems to be an issue with sharing code for jvm target(which ktor backend is) I've found a workaround to have my project got this dependency resolved by marking this backend submodule as a multiplatform itself, but now as I build it and start to run I'm getting this error

Error: Could not find or load main class com.owlsoft.backend.ServerKt

My whole backend ktor build.gradle.kts

plugins {
    application
    kotlin("multiplatform")
    id("kotlinx-serialization")
}


kotlin {
    jvm {
        withJava()
    }
}

application {
    @Suppress("DEPRECATION")
    mainClassName.set("com.owlsoft.backend.ServerKt")
}


dependencies {
    implementation(Libs.Coroutines.core)

    implementation(Libs.KtorServer.core)
    implementation(Libs.KtorServer.netty)
    implementation(Libs.KtorServer.serialization)
    implementation(Libs.KtorServer.websockets)

    implementation(Libs.kotlinSerialization) // JVM dependency

    implementation("ch.qos.logback:logback-classic:1.2.3")
    implementation(project(":shared"))
    testImplementation(Libs.KtorServer.test)
}

tasks.register("stage") {
    dependsOn("installDist")
}

I'm mostly trying to share some models and business logic I've only made backend module with ktor in it multiplatform to fix issue with it's not being able to pick up shared module changes.

Answer 1

I faced the same problem in the same scenario. I fixed this way:

1. Open your project in Intellij IDEA. Right click on the project name in the Project window
2. Select Open Module Settings
3. Check if backend module is inside your project, not as a separate module above. Remove the separate module if exists (code will remain the same).
4. Check if you have this folder structure in backend: src - jvmMain - kotlin - Server.kt

I think the root cause is that I added backend module with Android Studio and the project structure was broken somehow.