add a test for lambda capturing

integration-tests/main/src/main/java/io/quarkus/it/rest/ReflectionResource.java

@@ -17,4 +17,17 @@ public String getSimpleClassName(@QueryParam("className") String className) {
             return "FAILED";
         }
     }
+
+    @GET
+    @Path("/lambda")
+    public String getLambdaClassName() {
+        try {
+            ResourceLambda lambda = new ResourceLambda();
+            Class<?> clazz = lambda.getLambdaFuncClass(5);
+            return clazz.getSimpleName();
+        } catch (Exception e) {
+            return e.toString();
+        }
+    }
+
 }

integration-tests/main/src/main/java/io/quarkus/it/rest/ResourceLambda.java

@@ -0,0 +1,40 @@
+package io.quarkus.it.rest;
+
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.lang.invoke.SerializedLambda;
+import java.util.Comparator;
+
+import io.quarkus.runtime.annotations.RegisterForReflection;
+
+/**
+ * This class is registering itself for lambda capturing
+ */
+@RegisterForReflection(lambdaCapturingTypes = "java.util.Comparator", targets = {
+        SerializedLambda.class, SerializableDoubleFunction.class }, serialization = true)
+public class ResourceLambda {
+    private static final String file = "target/serialized.txt";
+
+    public Class<?> getLambdaFuncClass(Integer n) throws IOException, ClassNotFoundException {
+        SerializableDoubleFunction func = new SerializableDoubleFunction(n);
+        Comparator<Integer> comp = Comparator.comparingDouble(func);
+        serializeObject(comp);
+        return deserializeObject().getClass();
+    }
+
+    private void serializeObject(Object o) throws IOException {
+        FileOutputStream out = new FileOutputStream(file);
+        ObjectOutputStream objectOutputStream = new ObjectOutputStream(out);
+        objectOutputStream.writeObject(o);
+        objectOutputStream.close();
+    }
+
+    private Object deserializeObject() throws IOException, ClassNotFoundException {
+        FileInputStream in = new FileInputStream(file);
+        ObjectInputStream objectInputStream = new ObjectInputStream(in);
+        return objectInputStream.readObject();
+    }
+}

integration-tests/main/src/main/java/io/quarkus/it/rest/SerializableDoubleFunction.java

@@ -0,0 +1,17 @@
+package io.quarkus.it.rest;
+
+import java.io.Serializable;
+import java.util.function.ToDoubleFunction;
+
+class SerializableDoubleFunction implements Serializable, ToDoubleFunction<Integer> {
+    private final double value;
+
+    public SerializableDoubleFunction(double inputValue) {
+        value = inputValue;
+    }
+
+    @Override
+    public double applyAsDouble(Integer o) {
+        return value;
+    }
+}

integration-tests/main/src/main/resources/application.properties

@@ -52,6 +52,7 @@ quarkus.native.resources.excludes = **/unwanted.*
 
 quarkus.log.metrics.enabled=true
 
+#quarkus.native.additional-build-args =-H:ReflectionConfigurationFiles=reflection-config.json,-H:SerializationConfigurationResources=serialization-config.json
 quarkus.native.additional-build-args =-H:ReflectionConfigurationFiles=reflection-config.json
 quarkus.class-loading.removed-resources."io.quarkus\:quarkus-integration-test-shared-library"=io/quarkus/it/shared/RemovedResource.class
 quarkus.class-loading.removed-resources."io.quarkus\:quarkus-integration-test-main"=io/quarkus/it/rest/RemovedJaxRsApplication.class

integration-tests/main/src/main/resources/serialization-config.json

@@ -0,0 +1,9 @@
+{
+   "types":[
+              {"name":"io.quarkus.it.rest.SerializableDoubleFunction"},
+              {"name":"java.lang.invoke.SerializedLambda"}
+           ],
+   "lambdaCapturingTypes":[
+              {"name":"java.util.Comparator"}
+           ]
+}

integration-tests/main/src/test/java/io/quarkus/it/main/RegisterForReflectionITCase.java

@@ -1,6 +1,7 @@
 package io.quarkus.it.main;
 
 import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.startsWith;
 
 import org.junit.jupiter.api.Test;
 
@@ -68,6 +69,16 @@ public void testTargetWithoutNested() {
         assertRegistration("FAILED", resourceD + "$StaticClassOfD$OtherAccessibleClassOfD");
     }
 
+    @Test
+    @DisableIfBuiltWithGraalVMOlderThan(GraalVMVersion.GRAALVM_22_1)
+    public void testLambdaCapturing() {
+        final String resourceLambda = BASE_PKG + ".ResourceLambda";
+
+        // Starting with GraalVM 22.1 support Lambda functions serialization
+        // (see https://github.com/oracle/graal/issues/3756)
+        RestAssured.given().when().get("/reflection/lambda").then().body(startsWith("Comparator$$Lambda$"));
+    }
+
     private void assertRegistration(String expected, String queryParam) {
         RestAssured.given().queryParam("className", queryParam).when().get(ENDPOINT).then().body(is(expected));
     }

integration-tests/main/src/test/java/io/quarkus/it/main/RegisterForReflectionTestCase.java

@@ -1,6 +1,7 @@
 package io.quarkus.it.main;
 
 import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.startsWith;
 
 import org.junit.jupiter.api.Test;
 
@@ -51,6 +52,14 @@ public void testTargetWithoutNested() {
         assertRegistration("OtherAccessibleClassOfD", resourceD + "$StaticClassOfD$OtherAccessibleClassOfD");
     }
 
+    @Test
+    public void testLambdaCapturing() {
+        final String resourceLambda = BASE_PKG + ".ResourceLambda";
+
+        assertRegistration("ResourceLambda", resourceLambda);
+        RestAssured.given().when().get("/reflection/lambda").then().body(startsWith("Comparator$$Lambda$"));
+    }
+
     private void assertRegistration(String expected, String queryParam) {
         RestAssured.given().queryParam("className", queryParam).when().get(ENDPOINT).then().body(is(expected));
     }