Export Kotlin code to jar is recognized as Java code on the consumer project - kotlin

Question

I'm working on a multi-module repository. One module exports Kotlin library, and the other one consumes the artifact and uses it.
I've noticed that once I'm trying to use named parameters inside the consumer it tells me that I cannot do this in a non-kotlin code (e.g. from Java). When I've tried to decompile the code of the library I've seen that the code I see there is indeed Java code (however this might be related to the fact that IntelliJ decompile everything into Java?)
The entire code can be found in this following link where demo-app is the consumer and rabbit-hole is the producer
Just for complicity, I'll put the build gradle file of both here as well:
Library:
plugins {
id "java"
id "org.jetbrains.kotlin.jvm"
id "org.jetbrains.kotlin.plugin.allopen"
id "jacoco"
id "maven-publish"
id "org.springframework.boot"
id "io.spring.dependency-management"
id "com.diffplug.spotless"
}
jar {
enabled = true
}
bootJar {
enabled = false
}
dependencies {
implementation group: "org.jetbrains.kotlin", name: "kotlin-stdlib-jdk8"
implementation group: 'org.springframework.boot', name: 'spring-boot-starter-amqp'
// Tests
testImplementation("org.springframework.boot:spring-boot-starter-test") {
exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
}
testImplementation group: 'io.mockk', name: 'mockk', version: '1.12.1'
}
build {
finalizedBy spotlessApply
}
test {
useJUnitPlatform()
finalizedBy spotlessApply
finalizedBy jacocoTestReport
}
publishing {
publications {
maven(MavenPublication) {
groupId = 'com.yonatankarp'
artifactId = project.name
version = project.version
from components.java
versionMapping {
usage('java-runtime') {
fromResolutionResult()
}
}
}
}
repositories {
maven {
name = "GitHubPackages"
url = uri("https://maven.pkg.github.com/yonatankarp/rabbit-hole")
credentials {
username = project.findProperty("gpr.user") ?: System.getenv("GITHUB_ACTOR")
password = project.findProperty("gpr.key") ?: System.getenv("GITHUB_TOKEN")
}
}
}
}
allOpen {
annotation("org.springframework.context.annotation.Configuration")
}
Consumer:
plugins {
id "java"
id "org.jetbrains.kotlin.jvm"
id "org.jetbrains.kotlin.plugin.allopen"
id "jacoco"
id "org.springframework.boot"
id "io.spring.dependency-management"
id "com.diffplug.spotless"
}
group = 'com.yonatankarp'
version "${version}"
sourceCompatibility = '11'
jar {
enabled = false
}
bootJar {
enabled = true
}
repositories {
mavenLocal()
mavenCentral()
maven {
name = "Rabbit Hole"
url = uri("https://maven.pkg.github.com/yonatankarp/rabbit-hole")
credentials {
username = project.findProperty("gpr.user") ?: System.getenv("GITHUB_ACTOR")
password = project.findProperty("gpr.key") ?: System.getenv('GITHUB_TOKEN')
}
}
}
dependencies {
implementation group: "org.jetbrains.kotlin", name: "kotlin-stdlib-jdk8"
implementation 'org.springframework.boot:spring-boot-starter-web'
implementation 'org.springframework.boot:spring-boot-starter-amqp'
implementation "com.yonatankarp:rabbit-hole:+"
testImplementation("org.springframework.boot:spring-boot-starter-test") {
exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
}
}
build {
finalizedBy spotlessApply
}
test {
useJUnitPlatform()
finalizedBy spotlessApply
finalizedBy jacocoTestReport
}
allOpen {
annotation("org.springframework.context.annotation.Configuration")
}
EDIT
For clarity: Both the library and the consumer of it are written in Kotlin