How to compile Kotlin domain module with client module with Gradle?

Question

I have the following project structure:
- parent
- - client (written in Kotlin but compiled to JS)
- - server (written in Kotlin)
- - model (written in Kotlin)
client module has a dependency on model. So when I compile client to JS it also should compile model with it. For now I have the following Gradle configurations which are not doing the desired thing:

project/parent.gradle

group 'com.vchernogorov.tycher'
version '1.0-SNAPSHOT'

buildscript {
    ext.kotlin_version = '1.1.3-2'

    repositories {
        mavenCentral()
    }
    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

apply plugin: 'kotlin'

repositories {
    mavenCentral()
}

dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib-jre8:$kotlin_version"
    compile project(":model")
    compile project(":client")
    compile project(":server")
}

compileKotlin {
    kotlinOptions.jvmTarget = "1.8"
}
compileTestKotlin {
    kotlinOptions.jvmTarget = "1.8"
}

project/settings.gradle

rootProject.name = 'parent'
include ':model'
include ':server'
include ':client'

project/model/build.gradle

group 'com.vchernogorov.tycher'
version '1.0-SNAPSHOT'

buildscript {
    ext.kotlin_version = '1.1.3-2'

    repositories {
        mavenCentral()
    }
    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

apply plugin: 'kotlin'

repositories {
    mavenCentral()
}

dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib-jre8:$kotlin_version"
}

compileKotlin {
    kotlinOptions.jvmTarget = "1.8"
}
compileTestKotlin {
    kotlinOptions.jvmTarget = "1.8"
}

project/client/build.gradle

group 'com.vchernogorov.tycher'
version '1.0-SNAPSHOT'

buildscript {
    ext.kotlin_version = '1.1.3-2'

    repositories {
        mavenCentral()
    }
    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

apply plugin: 'kotlin2js'

repositories {
    mavenCentral()
}

dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib-js:$kotlin_version"
    compile project(":model")
}

build.doLast {
    configurations.compile.each { File file ->
        copy {
            includeEmptyDirs = false

            from zipTree(file.absolutePath)
            into "${projectDir}/web"
            include { fileTreeElement ->
                def path = fileTreeElement.path
                path.endsWith(".js") && (path.startsWith("META-INF/resources/") || !path.startsWith("META-INF/"))
            }
        }
    }
}

When I run gradle build command on client I get this message:

:model:compileKotlin
Using kotlin incremental compilation
:model:compileJava UP-TO-DATE
:model:copyMainKotlinClasses
:model:processResources UP-TO-DATE
:model:classes UP-TO-DATE
:model:jar
:client:compileJava UP-TO-DATE
:client:compileKotlin2Js
e: project/client/src/main/kotlin/HelloWorld.kt: (30, 19): Unresolved reference: Position
e: project/client/src/main/kotlin/HelloWorld.kt: (50, 5): Unresolved reference: Test
e: project/client/src/main/kotlin/SocketHandler.kt: (10, 36): Unresolved reference: User
:client:compileKotlin2Js FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':client:compileKotlin2Js'.
> Compilation error. See log for more details

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 13.891 secs

These 3 classes are defined in model.
So what should I do to successfully compile client and not changing the code?

Answer 1

I have developed the following architecture for my application: I have client,server and model modules but also I have a separate source directory with DTOs called dto (not module btw). Here's the dependency hierarchy for the build:

• client depends on dto
• server depends on model
• model depends on dto

With such hierarchy model can still use stdlib functionality and server will share all DTOs with client module. Meanwhile dto module will use the stdlib if it's compiled as module dependency and stdlib-js if it's compiled as client dependency, so it important to remember which classes you are able to use there.

In order to achieve this, you need to add

sourceSets.main.kotlin.srcDirs += '../dto/src/main/kotlin

config to both client and model build.gradle files. For Gradle Kotlin DSL:

the<JavaPluginConvention>().sourceSets {
    "main" {
        java {
            srcDirs("../dto/src/main/kotlin")
        }
    }
}