Support for ZIO as return type in Rest Resources

README.md

@@ -16,6 +16,7 @@
     - [Configuring Scala Jackson and the addon-on "Enum" module for JSON support](#configuring-scala-jackson-and-the-addon-on-enum-module-for-json-support)
     - [Scala DSL for rest-assured (similar to Kotlin DSL)](#scala-dsl-for-rest-assured-similar-to-kotlin-dsl)
     - [Functional HTTP routes (Vert.x handlers)](#functional-http-routes-vertx-handlers)
+- [Quarkus - Scala3 - ZIO](#quarkus---scala3---zio)
 
 ## Introduction 
 
@@ -462,3 +463,61 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
 <!-- ALL-CONTRIBUTORS-LIST:END -->
 
 This project follows the [all-contributors](https://github.com/all-contributors/all-contributors) specification. Contributions of any kind welcome!
+
+# Quarkus - Scala3 - ZIO
+Add these dependencies to your `pom.xml` (respectively gradle):
+
+```xml
+    <dependency>
+      <groupId>io.quarkiverse.scala</groupId>
+      <artifactId>quarkus-scala3-zio</artifactId>
+      <version>999-SNAPSHOT</version>
+    </dependency>
+    <dependency>
+      <groupId>io.quarkiverse.scala</groupId>
+      <artifactId>quarkus-scala3-zio-deployment</artifactId>
+      <version>999-SNAPSHOT</version>
+    </dependency>
+```
+
+Now you're able to use a `ZIO[Any, E <: Throwable, A]` in your REST-Resources, e.g.
+
+```scala
+    final case class AsyncGreetingResponse(message: String, ip: String, time: Long)
+
+    @GET
+    @Path("/greet/async")
+    @Produces(Array(APPLICATION_JSON))
+    def asyncGreeting(): Task[AsyncGreetingResponse] =
+        val numsAmount = 10
+        Log.debug(s"Generating $numsAmount numbers asynchronously...")
+        val startTime = System.currentTimeMillis()
+        // Get the IP address asynchronously
+        val IPFuture = ZIO.fromFuture(_ => getOwnIP().map(_.body).recover:
+            case e: Exception =>
+                Log.error("Failed to get the IP address.")
+                Left("Failed to get IP"))
+
+        val futureSum = ZIO.foreachPar((1 to numsAmount)){i => generateNum()}.map(_.sum)
+        for
+            sumF <- futureSum.fork
+            ipF  <- IPFuture.map(_.merge).fork
+            result <- sumF.join zip ipF.join
+            (sum, ip) = result
+        yield
+            val endTime = System.currentTimeMillis() - startTime
+            Log.debug(s"My IP is: $ip")
+            Log.debug(s"Generated $numsAmount numbers asynchronously in ${endTime}ms")
+
+            AsyncGreetingResponse(
+              s"The sum of the $numsAmount generated numbers is $sum. Was generated asynchronously in ${endTime}ms.\nYour IP is: $ip.",
+              ip,
+            endTime)
+
+    end asyncGreeting
+
+```
+
+Please note that we currently don't support anything in the Environment `R`, as we don't have a way
+to transfer this information from Java to Scala. Also, your error type needs to be either Nothing
+or a (subtype of) Throwable.

pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <groupId>io.quarkiverse</groupId>
     <artifactId>quarkiverse-parent</artifactId>
-    <version>15</version>
+    <version>16</version>
   </parent>
   <groupId>io.quarkiverse.scala</groupId>
   <artifactId>quarkus-scala3-parent</artifactId>
@@ -14,6 +14,7 @@
   <modules>
     <module>deployment</module>
     <module>runtime</module>
+    <module>zio</module>
   </modules>
   <scm>
     <connection>:git:[email protected]:quarkiverse/quarkus-scala3.git</connection>

zio/TODO.md

@@ -0,0 +1,10 @@
+# ZIO TODOs / IDEAs
+
+- ZIO-Config: Create implementation of ZIO ConfigProvider that is backed by the microprofile Config and
+  inject that into the environment / make it usable with ZIO.Config(..) [See ZIO-Configuration](https://zio.dev/reference/configuration/)
+- ZIO-Logging: Bridge ZIO-Logging to Quarkus-Logger?
+- Fill the environment with commonly required dependencies.
+- Fill the environment with dependencies specified in the `R` type (we need to figure out how to parse that, as we loose type info in Java)
+- Allow using `ZStream` where `Multi` is allowed atm (e.g. Kafka, SSE, etc.)
+- Register the ZIO Runtime using a Provider, so it could be injected.
+- ...

zio/deployment/pom.xml

@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>io.quarkiverse.scala</groupId>
+        <artifactId>quarkus-scala3-zio-parent</artifactId>
+        <version>999-SNAPSHOT</version>
+    </parent>
+    <artifactId>quarkus-scala3-zio-deployment</artifactId>
+    <name>Quarkus Scala3 Zio - Deployment</name>
+
+
+    <dependencies>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-arc-deployment</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkiverse.scala</groupId>
+            <artifactId>quarkus-scala3-zio</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-junit5-internal</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-rest-spi-deployment</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus.resteasy.reactive</groupId>
+            <artifactId>resteasy-reactive-processor</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-rest-server-spi-deployment</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.scala-lang</groupId>
+            <artifactId>scala3-library_3</artifactId>
+            <scope>compile</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>dev.zio</groupId>
+            <artifactId>zio_3</artifactId>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <sourceDirectory>src/main/scala</sourceDirectory>
+        <testSourceDirectory>src/test/scala</testSourceDirectory>
+        <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <annotationProcessorPaths>
+                        <path>
+                            <groupId>io.quarkus</groupId>
+                            <artifactId>quarkus-extension-processor</artifactId>
+                            <version>${quarkus.version}</version>
+                        </path>
+                    </annotationProcessorPaths>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>net.alchim31.maven</groupId>
+                <artifactId>scala-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+</project>

zio/deployment/src/main/scala/io/quarkiverse/scala/scala3/zio/deployment/Scala3ZIOJavaProcessor.java

@@ -0,0 +1,18 @@
+package io.quarkiverse.scala.scala3.zio.deployment;
+
+import io.quarkus.deployment.annotations.BuildStep;
+import io.quarkus.deployment.builditem.FeatureBuildItem;
+import io.quarkus.resteasy.reactive.server.spi.MethodScannerBuildItem;
+
+public class Scala3ZIOJavaProcessor {
+
+    @BuildStep
+    public FeatureBuildItem feature() {
+        return new FeatureBuildItem("scala3-zio");
+    }
+
+    @BuildStep
+    public MethodScannerBuildItem registerZIORestReturnTypes() {
+        return new MethodScannerBuildItem(new Scala3ZIOReturnTypeMethodScanner());
+    }
+}

zio/deployment/src/main/scala/io/quarkiverse/scala/scala3/zio/deployment/Scala3ZIOResponseHandler.scala

@@ -0,0 +1,44 @@
+package io.quarkiverse.scala.scala3.zio.deployment
+
+import org.jboss.resteasy.reactive.server.core.ResteasyReactiveRequestContext
+import org.jboss.resteasy.reactive.server.spi.ServerRestHandler
+import zio.ZIO
+
+import scala.jdk.CollectionConverters.*
+
+class Scala3ZIOResponseHandler() extends ServerRestHandler {
+
+  override def handle(requestContext: ResteasyReactiveRequestContext): Unit = {
+    val result = requestContext.getResult
+
+    /*
+      TODO if we're able to read the environment from the effect, we might be able to hook into
+      Quarkus dependency injection mechanism to fill it here. For now, we can only assume its any.
+     */
+    type R = Any
+
+    /* fixing the error type to Throwable. We can be sure its this type, as we've checked
+       it before in io.quarkiverse.scala.scala3.zio.deployment.Scala3ZIOReturnTypeMethodScanner.scan
+       There it can only be Nothing, or Throwable or subtypes of Throwable, so either way, we're
+       safe to assume it's Throwable here.
+     */
+    type E = Throwable
+
+    /*  We assume any as return type, as quarkus also accepts any object as return type. 
+     */
+    type A = Any
+
+    requestContext.suspend()
+    val r = result.asInstanceOf[ZIO[R, E, A]]
+
+    val r1 = r.fold(e => {
+      requestContext.handleException(e)
+      requestContext.resume()
+    }, a => {
+        requestContext.setResult(a)
+        requestContext.resume()
+    })
+
+    zio.Unsafe.unsafe(u => zio.Runtime.default.unsafe.runToFuture(r1)(zio.Trace.empty, u))
+  }
+}

zio/deployment/src/main/scala/io/quarkiverse/scala/scala3/zio/deployment/Scala3ZIOReturnTypeMethodScanner.scala

@@ -0,0 +1,62 @@
+package io.quarkiverse.scala.scala3.zio.deployment
+
+import org.jboss.jandex.ClassInfo
+import org.jboss.jandex.DotName
+import org.jboss.jandex.MethodInfo
+import org.jboss.jandex.Type
+import org.jboss.resteasy.reactive.server.model.FixedHandlerChainCustomizer
+import org.jboss.resteasy.reactive.server.model.HandlerChainCustomizer
+import org.jboss.resteasy.reactive.server.processor.scanning.MethodScanner
+
+import java.util
+import java.util.List as JList
+import java.util.Collections as JCollections
+
+class Scala3ZIOReturnTypeMethodScanner extends MethodScanner {
+  private val ZIO = DotName.createSimple("zio.ZIO")
+  private val nothing$ = DotName.createSimple("scala.Nothing$")
+  private val throwable = DotName.createSimple("java.lang.Throwable")
+
+
+  override def scan(method: MethodInfo,
+                    actualEndpointClass: ClassInfo,
+                    methodContext: util.Map[String, AnyRef]
+                   ): JList[HandlerChainCustomizer] = {
+    if(isMethodSignatureAsync(method)) {
+      ensuringFailureTypeIsNothingOrAThrowable(method)
+      JCollections.singletonList(
+        new FixedHandlerChainCustomizer(
+          new Scala3ZIOResponseHandler(),
+          HandlerChainCustomizer.Phase.AFTER_METHOD_INVOKE
+        )
+      )
+    } else {
+      JCollections.emptyList()
+    }
+  }
+
+  private def ensuringFailureTypeIsNothingOrAThrowable(info: MethodInfo): Unit = {
+    import scala.jdk.CollectionConverters._
+    val returnType = info.returnType()
+    val typeArguments: JList[Type] = returnType.asParameterizedType().arguments()
+    if (typeArguments.size() != 3) {
+      throw new RuntimeException("ZIO must have three type arguments")
+    }
+    val errorType = typeArguments.get(1)
+
+    if !(errorType.name() == nothing$) && !(errorType.name() == throwable) then
+      val realClazz = Class.forName(errorType.name().toString(), false, Thread.currentThread().getContextClassLoader)
+      if (!classOf[Throwable].isAssignableFrom(realClazz)) {
+        val returnType = info.returnType().toString.replaceAll("<","[").replaceAll(">","]")
+        val parameters = info.parameters().asScala.map(v => s"${v.name()}:${v.`type`().toString}").mkString(",")
+        val signature = s"${info.name()}(${parameters}):${returnType}"
+
+        throw new RuntimeException(s"The error type of def ${signature} in ${info.declaringClass()} needs to be either Nothing, a Throwable or subclass of Throwable")
+      }
+  }
+
+
+  override def isMethodSignatureAsync(info: MethodInfo): Boolean = {
+      info.returnType().name() == ZIO
+  }
+}

zio/deployment/src/test/scala/io/quarkiverse/scala/scala3/zio/test/Scala3ZioDevModeTest.scala

@@ -0,0 +1,23 @@
+package io.quarkiverse.scala.scala3.zio.test;
+
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusDevModeTest;
+
+class Scala3ZioDevModeTest {
+
+    // Start hot reload (DevMode) test with your extension loaded
+    @RegisterExtension
+    val devModeTest: QuarkusDevModeTest = new QuarkusDevModeTest()
+            .setArchiveProducer(() => ShrinkWrap.create(classOf[JavaArchive]))
+
+    @Test
+    def writeYourOwnDevModeTest(): Unit = {
+        // Write your dev mode tests here - see the testing extension guide https://quarkus.io/guides/writing-extensions#testing-hot-reload for more information
+        Assertions.assertTrue(true, "Add dev mode assertions to " + getClass().getName());
+    }
+}

zio/deployment/src/test/scala/io/quarkiverse/scala/scala3/zio/test/Scala3ZioTest.scala

@@ -0,0 +1,23 @@
+package io.quarkiverse.scala.scala3.zio.test;
+
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusUnitTest;
+
+class Scala3ZioTest {
+
+    // Start unit test with your extension loaded
+    @RegisterExtension
+    def unitTest: QuarkusUnitTest = new QuarkusUnitTest()
+            .setArchiveProducer(() => ShrinkWrap.create(classOf[JavaArchive]))
+
+    @Test
+    def writeYourOwnUnitTest(): Unit = {
+        // Write your unit tests here - see the testing extension guide https://quarkus.io/guides/writing-extensions#testing-extensions for more information
+        Assertions.assertTrue(true, "Add some assertions to " + getClass().getName());
+    }
+}