KSP 2 support (#5727)

## Motivation: 

#5676

Also, language version 1.9 is deprecated since Kotlin 2.2.0. 

It turns out, that integration wise, it's much easier to run the symbol
processor with KSP 2 via a CLI wrapper that it is for KSP 1 as a kotlin
compiler plugin


## Details

The documentation for the CLI wrapper is
[here](https://github.com/google/ksp/blob/main/docs/ksp2cmdline.md)
albeit a bit outdated. The key component that is missing, is a reference
to the `-libraries` argument, which (as our trial and error shows)
expects the module classpath.

Micronaut had also a tricky bit, failing to resolve java sdk sources.
Passing the `-jdk-home` resolves that.

From there on, Dagger, Hilt and micronaut work without any major
adaptations from the user's api perspective as we made an effort to
consolidate `KSPModule` and `KSP2Module` input parameters

We have also retested the pokemon module outside of this repo which also
works, surprisingly without needing the `-friends` parameter

## Summary

This PR gives mill the capability to build KSP 2 with language version
and api version >= 2.0 , bringing a solution to the deprecated language
version <=1.9 needed by KSP 1.

Also, added an equivalent Micronaut example as the hello-micronaut in
javalib/web, but with full KSP, no annotation processors needed

## Credits

This PR was co-authored by @souvlakias

---------

Co-authored-by: souvlakias <[email protected]>

Author: vaslabs

example/kotlinlib/basic/7-dependency-injection/build.mill

@@ -2,39 +2,39 @@
 
 package build
 import mill.*, kotlinlib.*
-import kotlinlib.ksp.KspModule
+import kotlinlib.ksp.Ksp2Module
 
-object dagger extends KspModule {
+object dagger extends Ksp2Module {
 
-  def kotlinVersion = "2.1.0"
+  def kotlinVersion = "2.2.0"
 
-  def kspVersion = "1.0.29"
+  def kspVersion = "2.0.2"
 
-  def kotlinLanguageVersion = "1.9"
+  def kspJvmTarget = "17"
 
   def mainClass = Some("com.example.dagger.MainKt")
 
   def kotlincOptions = super.kotlincOptions() ++ Seq("-no-reflect", "-verbose")
 
-  def mvnDeps = Seq(
-    mvn"com.google.dagger:dagger-compiler:2.55"
+  def mvnDeps = super.mvnDeps() ++ Seq(
+    mvn"com.google.dagger:dagger:2.57"
   )
 
   def kotlinSymbolProcessors = Seq(
-    mvn"com.google.dagger:dagger-compiler:2.55"
+    mvn"com.google.dagger:dagger-compiler:2.57"
   )
 
-  object test extends KspTests, TestModule.Junit5 {
+  object test extends Ksp2Tests, TestModule.Junit5 {
 
     def kotlincOptions = super.kotlincOptions() ++ Seq("-no-reflect", "-verbose")
 
     def mvnDeps = super.mvnDeps() ++ Seq(
-      mvn"com.google.dagger:dagger-compiler:2.55",
+      mvn"com.google.dagger:dagger-compiler:2.57",
       mvn"io.kotest:kotest-runner-junit5:5.9.1"
     )
 
     def kotlinSymbolProcessors = Seq(
-      mvn"com.google.dagger:dagger-compiler:2.55"
+      mvn"com.google.dagger:dagger-compiler:2.57"
     )
 
   }
@@ -48,7 +48,7 @@ object dagger extends KspModule {
 
 > ./mill show dagger.compile
 
-> ls out/dagger/generatedSourcesWithKSP.dest/generated/ksp/main/java/com/example/dagger/
+> ls out/dagger/generatedSourcesWithKSP.dest/generated/java/com/example/dagger/
 DaggerNumberApp.java
 NumberService_Factory.java
 RandomNumberGenerator_Factory.java
@@ -77,7 +77,7 @@ Random number: ...
 }
 ...
 
-> ls out/dagger/test/generatedSourcesWithKSP.dest/generated/ksp/main/java/com/example/dagger/
+> ls out/dagger/test/generatedSourcesWithKSP.dest/generated/java/com/example/dagger/
 ConstantNumberGenerator_Factory.java
 DaggerDemoComponent.java
 DaggerTestApp.java

example/kotlinlib/web/8-hello-micronaut/build.mill

@@ -0,0 +1,106 @@
+package build
+
+import coursier.{MavenRepository, Repository}
+
+import mill.*
+import kotlinlib.*
+import kotlinlib.ksp.Ksp2Module
+
+object micronaut extends MicronautModule {
+
+  def mvnDeps: Task.Simple[Seq[Dep]] = Seq(
+    mvn"io.micronaut:micronaut-http-server-netty",
+    mvn"io.micronaut.serde:micronaut-serde-jackson",
+    mvn"io.micronaut:micronaut-jackson-databind",
+    mvn"io.micronaut:micronaut-http-validation",
+    mvn"ch.qos.logback:logback-classic",
+    mvn"io.micronaut.kotlin:micronaut-kotlin-runtime",
+    mvn"io.micronaut.data:micronaut-data-processor"
+  )
+
+  object test extends MicronautTests, TestModule.Junit5 {
+
+    def mvnDeps = super.mvnDeps() ++ Seq(
+      mvn"io.micronaut:micronaut-http-client",
+      mvn"io.micronaut.test:micronaut-test-junit5"
+    )
+
+  }
+
+}
+
+trait MicronautModule extends Ksp2Module { outer =>
+  def kspVersion: T[String] = "2.0.2"
+  def kotlinVersion = "2.2.0"
+  def kspJvmTarget: T[String] = "11"
+
+  def bomMvnDeps: T[Seq[Dep]] = Seq(
+    mvn"io.micronaut.platform:micronaut-platform:4.9.2"
+  )
+
+  def kotlinSymbolProcessors = Seq(
+    mvn"io.micronaut:micronaut-inject-kotlin:4.9.9"
+  )
+
+  override def kspProcessorOptions: T[Map[String, String]] = Task {
+    super.kspProcessorOptions() ++ Map(
+      "micronaut.processing.module" -> moduleSegments.render,
+      "micronaut.processing.incremental" -> "true"
+    )
+  }
+
+  override def resources: T[Seq[PathRef]] = Task {
+    super.resources() ++ Seq(generatedSourcesWithKSP().resources)
+  }
+
+  override def runClasspath: T[Seq[PathRef]] = Task {
+    super.runClasspath() ++ Seq(generatedSourcesWithKSP().classes)
+  }
+
+  trait MicronautTests extends MicronautModule, Ksp2Tests {
+
+    override def resources: T[Seq[PathRef]] = Task {
+      super[Ksp2Tests].resources() ++ Seq(generatedSourcesWithKSP().resources)
+    }
+
+    def kotlinSymbolProcessors = Seq(
+      mvn"io.micronaut:micronaut-inject-kotlin-test:4.9.9"
+    )
+
+    override def runClasspath: T[Seq[PathRef]] = Task {
+      super.runClasspath() ++ Seq(
+        generatedSourcesWithKSP().classes,
+        outer.generatedSourcesWithKSP().classes
+      )
+    }
+
+  }
+
+}
+
+/** Usage
+
+> ./mill show micronaut.test
+...
+{
+  "msg": " ",
+  "results": [
+    {
+      "fullyQualifiedName": "example.micronaut.HelloControllerTest",
+      "selector": "testHello()",
+      "duration": ...,
+      "status": "Success"
+    },
+    {
+      "fullyQualifiedName": "example.micronaut.FnrSearchServiceTest",
+      "selector": "testItWorks()",
+      "duration": ...,
+      "status": "Success"
+    }
+  ]
+}
+...
+
+> ./mill show clean
+
+*/

example/kotlinlib/web/8-hello-micronaut/micronaut/resources/application.properties

@@ -0,0 +1,2 @@
+micronaut.application.name=default
+micronaut.server.port=9099

example/kotlinlib/web/8-hello-micronaut/micronaut/resources/logback.xml

@@ -0,0 +1,14 @@
+<configuration>
+
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <!-- encoders are assigned the type
+             ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
+        <encoder>
+            <pattern>%cyan(%d{HH:mm:ss.SSS}) %gray([%thread]) %highlight(%-5level) %magenta(%logger{36}) - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <root level="info">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

example/kotlinlib/web/8-hello-micronaut/micronaut/src/HelloController.kt

@@ -0,0 +1,13 @@
+package example.micronaut
+
+import io.micronaut.http.MediaType
+import io.micronaut.http.annotation.Controller
+import io.micronaut.http.annotation.Get
+import io.micronaut.http.annotation.Produces
+
+@Controller("/hello") // <1>
+class HelloController {
+    @Get // <2>
+    @Produces(MediaType.TEXT_PLAIN) // <3>
+    fun index(): String = "Hello World" // <4>
+}

example/kotlinlib/web/8-hello-micronaut/micronaut/src/Micronaut.kt

@@ -0,0 +1,6 @@
+package example.micronaut
+
+import io.micronaut.runtime.Micronaut.run
+fun main(args: Array<String>) {
+    run(*args)
+}

example/kotlinlib/web/8-hello-micronaut/micronaut/test/resources/application-test.properties

@@ -0,0 +1 @@
+micronaut.server.port=-1

example/kotlinlib/web/8-hello-micronaut/micronaut/test/src/FnrSearchServiceTest.kt

@@ -0,0 +1,19 @@
+package example.micronaut
+
+import io.micronaut.runtime.EmbeddedApplication
+import io.micronaut.test.extensions.junit5.annotation.MicronautTest
+import jakarta.inject.Inject
+import org.junit.jupiter.api.Assertions
+import org.junit.jupiter.api.Test
+
+@MicronautTest
+class FnrSearchServiceTest {
+
+    @Inject
+    lateinit var application: EmbeddedApplication<*>
+
+    @Test
+    fun testItWorks() {
+        Assertions.assertTrue(application.isRunning)
+    }
+}

example/kotlinlib/web/8-hello-micronaut/micronaut/test/src/HelloControllerTest.kt

@@ -0,0 +1,28 @@
+package example.micronaut
+
+import io.micronaut.http.HttpRequest
+import io.micronaut.http.MediaType
+import io.micronaut.http.client.HttpClient
+import io.micronaut.http.client.annotation.Client
+import io.micronaut.test.extensions.junit5.annotation.MicronautTest
+import jakarta.inject.Inject
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertNotNull
+import org.junit.jupiter.api.Test
+
+@MicronautTest // <1>
+class HelloControllerTest {
+
+    @Inject
+    @field:Client("/") // <2>
+    lateinit var client: HttpClient
+
+    @Test
+    fun testHello() {
+        val request = HttpRequest.GET<Any>("/hello").accept(MediaType.TEXT_PLAIN) // <3>
+        val body = client.toBlocking().retrieve(request)
+
+        assertNotNull(body)
+        assertEquals("Hello World", body)
+    }
+}