Spring-boot project, using Gradle, coded in Kotlin, auto-generate OpenAPI kotlin classes - spring-boot

Question

Problem: Generated sources are not picked up by gradle as part of the sources, thus importing the generated interfaces fails.
Question: how to add the generated sources so that gradle(with goovy dsl and kotlin plugin) picks them up?
setup:
spring-boot -> kotlin programming language
gradle -> groovy
I can generate the kotlin classes with OpenAPI Generator Gradle Plugin with no problems.
I am using the option "interfaceOnly", so it only creates interfaces. That means I do need to implement those.
I am using the typical gradle project setup. Now I have no idea where to place the generated files so that gradle(and intellj) pick them up.
openAPI.yaml:
openapi: 3.0.1
info:
version: 0.1.0
title: Villagechatter Calendar
description: Villagechatter calendar microservice
tags:
- name: external
description: external API
- name: internal
description: Internal API for other microservices
paths:
/hello:
get:
responses:
200:
description: Ok
content:
text/plain:
schema:
type: string
description: demo
example: Hello World!
build.gradle:
id("org.springframework.boot") version "2.3.1.RELEASE"
id("io.spring.dependency-management") version "1.0.9.RELEASE"
id "org.jetbrains.kotlin.jvm" version "1.3.72"
id "org.openapi.generator" version "4.3.1"
}
apply plugin: 'kotlin'
group = "com.example"
version = "0.0.1-SNAPSHOT"
repositories {
mavenCentral()
}
compileKotlin {
kotlinOptions {
freeCompilerArgs = ["-Xjsr305=strict"]
jvmTarget = "1.8"
}
}
openApiGenerate {
inputSpec = "$rootDir/specs/openApi.yaml"
generatorName = "kotlin-spring"
//setting package names and interface only with a configFile, should not matter for the problem
outputDir = "$buildDir/generated-src"
}
dependencies {
implementation("org.springframework.boot:spring-boot-starter-oauth2-client")
implementation("org.springframework.boot:spring-boot-starter-web")
implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
implementation("org.jetbrains.kotlin:kotlin-reflect")
implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
testImplementation("org.springframework.boot:spring-boot-starter-test") {
exclude group : "org.junit.vintage"
exclude module : "junit-vintage-engine"
}
}
what I have tried:
sourceSets {
main {
kotlin.srcDirs += "PATH-TO-GENERATED-FILES"
}
}
Also tried creating a new sourceSet and adding it to the compileKotlin task
The google results I found were all about gradle and the kotlin dsl, sorry if this is a duplicate, I have not found the solution.

Answer 1

Are you trying to auto generate them and put use them as sources in the project? Why not generate them into the project directory directly?
outputDir = "$projectDir"

Answer 2

I managed to solve like this:
sourceSets {
main {
java {
srcDir("$buildDir/generated-src")
}
}
}