Future[T] and Promise[T] as Controller ReturnTypes

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 - Futures](#quarkus---scala3---futures)
 
 ## Introduction 
 
@@ -133,7 +134,7 @@ In your `pom.xml` file, add:
 <dependency>
     <groupId>io.quarkiverse.scala</groupId>
     <artifactId>quarkus-scala3</artifactId>
-    <version>0.0.1<version>
+    <version>1.0.0<version>
 </dependency>
 ```
 
@@ -440,6 +441,50 @@ def mkRoutes(router: Router) =
     })
 ```
 
+# Quarkus - Scala3 - Futures
+
+# `Future[T]` and `Promise[T]` support in REST endpoints
+
+The `quarkus-scala3-futures` extension allows you to return `Future[T]` and `Promise[T]` from your REST endpoints.
+
+```scala
+
+@Path("/")
+class GreetingResource
+
+    @GET
+    @Path("/greet/future")
+    @Produces(Array(TEXT_PLAIN))
+    def futureGreeting(): Future[String] =
+       Future.successful("Hello from the future")
+    end futureGreeting
+
+    @GET
+    @Path("/greet/promise")
+    def promiseGreeting(): Promise[String] =
+      Promise.successful("Hello from the promise")
+    end promiseGreeting
+
+end GreetingResource
+```    
+
+If the `Future[T]` or `Promise[T]` fails, the normal exception handling is invoked.
+
+Make sure to have the following dependency in your `pom.xml` to make it work:
+
+```xml
+    <dependency>
+      <groupId>io.quarkus</groupId>
+      <artifactId>quarkus-rest</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>io.quarkiverse.scala</groupId>
+      <artifactId>quarkus-scala3-futures</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+```
+
+
 ## Contributors ✨
 
 Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/docs/en/emoji-key)):
@@ -462,3 +507,7 @@ 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!
+
+## TODOs
+ - correctly generate OpenAPI Spec for methods returning Future[T] or Promise[T], e.g. similar to [Quarkus #8499](https://github.com/quarkusio/quarkus/issues/8499)
+ - ArC (Quarkus' CDI implementation) has special handling for CompletionStage[T], maybe we should add similar handling for Future[T] and Promise[T], see [ActiveRequestContextInterceptor](https://github.com/quarkusio/quarkus/blob/24d3e5262d20fdaa8c056d59f012f8c7b5b1c5c8/independent-projects/arc/runtime/src/main/java/io/quarkus/arc/impl/ActivateRequestContextInterceptor.java) ?

futures/deployment/pom.xml

@@ -0,0 +1,68 @@
+<?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-futures-parent</artifactId>
+        <version>999-SNAPSHOT</version>
+    </parent>
+    <artifactId>quarkus-scala3-futures-deployment</artifactId>
+    <name>Quarkus Scala3 futures - Deployment</name>
+
+
+    <dependencies>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-arc-deployment</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>quarkus-scala3-futures</artifactId>
+            <version>${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>
+
+
+    </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>

futures/deployment/src/main/scala/io/quarkiverse/scala/scala3/futures/deployment/Scala3FuturesJavaProcessor.java

@@ -0,0 +1,19 @@
+package io.quarkiverse.scala.scala3.futures.deployment;
+
+import io.quarkiverse.scala.scala3.futures.runtime.Scala3FutureReturnTypeMethodScanner;
+import io.quarkus.deployment.annotations.BuildStep;
+import io.quarkus.deployment.builditem.FeatureBuildItem;
+import io.quarkus.resteasy.reactive.server.spi.MethodScannerBuildItem;
+
+public class Scala3FuturesJavaProcessor {
+
+    @BuildStep
+    public FeatureBuildItem feature() {
+        return new FeatureBuildItem("scala3-futures");
+    }
+
+    @BuildStep
+    public MethodScannerBuildItem registerFuturesRestReturnTypes() {
+        return new MethodScannerBuildItem(new Scala3FutureReturnTypeMethodScanner());
+    }
+}

futures/deployment/src/test/scala/io/quarkiverse/scala/scala3/futures/test/Scala3FuturesDevModeTest.scala

@@ -0,0 +1,23 @@
+package io.quarkiverse.scala.scala3.futures.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 Scala3FuturesDevModeTest {
+
+    // 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());
+    }
+}

futures/deployment/src/test/scala/io/quarkiverse/scala/scala3/futures/test/Scala3FuturesTest.scala

@@ -0,0 +1,23 @@
+package io.quarkiverse.scala.scala3.futures.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 Scala3FuturesTest {
+
+    // 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());
+    }
+}

futures/integration-tests/pom.xml

@@ -0,0 +1,127 @@
+<?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-futures-parent</artifactId>
+        <version>999-SNAPSHOT</version>
+    </parent>
+    <artifactId>quarkus-scala3-futures-integration-tests</artifactId>
+    <name>Quarkus Scala3 futures - Integration Tests</name>
+
+    <properties>
+        <skipITs>false</skipITs>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-rest</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkiverse.scala</groupId>
+            <artifactId>quarkus-scala3-futures</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+<!--        <dependency>-->
+<!--            <groupId>io.quarkiverse.scala</groupId>-->
+<!--            <artifactId>quarkus-scala3-futures-deployment</artifactId>-->
+<!--            <version>${project.version}</version>-->
+<!--        </dependency>-->
+        <dependency>
+            <groupId>org.scala-lang</groupId>
+            <artifactId>scala3-compiler_3</artifactId>
+            <version>${scala.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.scala-lang</groupId>
+            <artifactId>scala3-library_3</artifactId>
+            <version>${scala.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-junit5</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-junit5-internal</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.rest-assured</groupId>
+            <artifactId>rest-assured</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <sourceDirectory>src/main/scala</sourceDirectory>
+        <testSourceDirectory>src/test/scala</testSourceDirectory>
+
+        <plugins>
+            <plugin>
+                <groupId>io.quarkus</groupId>
+                <artifactId>quarkus-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>build</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <artifactId>maven-failsafe-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>integration-test</goal>
+                            <goal>verify</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <systemPropertyVariables>
+                        <native.image.path>${project.build.directory}/${project.build.finalName}-runner</native.image.path>
+                        <java.util.logging.manager>org.jboss.logmanager.LogManager</java.util.logging.manager>
+                        <maven.home>${maven.home}</maven.home>
+                    </systemPropertyVariables>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>net.alchim31.maven</groupId>
+                <artifactId>scala-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+    <profiles>
+        <profile>
+            <id>native-image</id>
+            <activation>
+                <property>
+                    <name>native</name>
+                </property>
+            </activation>
+            <build>
+                <plugins>
+                    <plugin>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <configuration>
+                            <skipTests>${native.surefire.skip}</skipTests>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
+            <properties>
+                <skipITs>false</skipITs>
+                <quarkus.native.enabled>true</quarkus.native.enabled>
+            </properties>
+        </profile>
+    </profiles>
+</project>

futures/integration-tests/src/main/scala/io/quarkiverse/scala/scala3/futures/it/Scala3FuturesResource.scala

@@ -0,0 +1,38 @@
+package io.quarkiverse.scala.scala3.futures.it
+
+import jakarta.ws.rs.GET
+import jakarta.ws.rs.Path
+import jakarta.ws.rs.Produces
+import jakarta.ws.rs.core.MediaType.TEXT_PLAIN
+
+import scala.concurrent.Future
+import scala.concurrent.Promise
+import scala.concurrent.ExecutionContext.Implicits.global
+
+@Path("")
+class Scala3FuturesResource {
+
+  @GET
+  @Path("/hello")
+  def hello(): String = "Hello from Scala 3.4.1"
+
+  @GET
+  @Path("/simple-future")
+  @Produces(Array(TEXT_PLAIN))
+  def simpleFuture: Future[String] = for {
+    _ <- Future { Thread.sleep(2000L) }
+    s <- Future.successful("Hello from a Future in Scala 3.4.1")
+  } yield s
+
+  @GET
+  @Path("simple-promise")
+  @Produces(Array(TEXT_PLAIN))
+  def simplePromise: Promise[String] = Promise.successful("Promise returned")
+
+
+  @GET
+  @Path("future-failure")
+  @Produces(Array(TEXT_PLAIN))
+  def futureFailure: Future[String] = Future.failed(new RuntimeException("Future failed"))
+
+}