Recursively boxing Kotlin nested value classes

This commit is a follow-up to spring-projects#34592. It introduces recursive boxing of
Kotlin nested value classes in CoroutinesUtils.

Signed-off-by: Dmitry Sulman <[email protected]>

Author: dmitrysulman

spring-core/src/main/java/org/springframework/core/CoroutinesUtils.java

@@ -19,6 +19,7 @@
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.Map;
+import java.util.Objects;
 
 import kotlin.Unit;
 import kotlin.coroutines.CoroutineContext;
@@ -131,11 +132,7 @@ public static Publisher<?> invokeSuspendingFunction(
 									if (!(type.isMarkedNullable() && arg == null) &&
 											type.getClassifier() instanceof KClass<?> kClass &&
 											KotlinDetector.isInlineClass(JvmClassMappingKt.getJavaClass(kClass))) {
-										KFunction<?> constructor = KClasses.getPrimaryConstructor(kClass);
-										if (!KCallablesJvm.isAccessible(constructor)) {
-											KCallablesJvm.setAccessible(constructor, true);
-										}
-										arg = constructor.call(arg);
+										arg = box(kClass, arg);
 									}
 									argMap.put(parameter, arg);
 								}
@@ -161,6 +158,20 @@ public static Publisher<?> invokeSuspendingFunction(
 		return mono;
 	}
 
+	private static Object box(KClass<?> kClass, @Nullable Object arg) {
+		KFunction<?> constructor = Objects.requireNonNull(KClasses.getPrimaryConstructor(kClass));
+		KType type = constructor.getParameters().get(0).getType();
+		if (!(type.isMarkedNullable() && arg == null) &&
+				type.getClassifier() instanceof KClass<?> parameterClass &&
+				KotlinDetector.isInlineClass(JvmClassMappingKt.getJavaClass(parameterClass))) {
+			arg = box(parameterClass, arg);
+		}
+		if (!KCallablesJvm.isAccessible(constructor)) {
+			KCallablesJvm.setAccessible(constructor, true);
+		}
+		return constructor.call(arg);
+	}
+
 	private static Flux<?> asFlux(Object flow) {
 		return ReactorFlowKt.asFlux(((Flow<?>) flow));
 	}

spring-core/src/test/kotlin/org/springframework/core/CoroutinesUtilsTests.kt

@@ -199,6 +199,15 @@ class CoroutinesUtilsTests {
 		}
 	}
 
+	@Test
+	fun invokeSuspendingFunctionWithNestedValueClassParameter() {
+		val method = CoroutinesUtilsTests::class.java.declaredMethods.first { it.name.startsWith("suspendingFunctionWithNestedValueClassParameter") }
+		val mono = CoroutinesUtils.invokeSuspendingFunction(method, this, "foo", null) as Mono
+		runBlocking {
+			Assertions.assertThat(mono.awaitSingle()).isEqualTo("foo")
+		}
+	}
+
 	@Test
 	fun invokeSuspendingFunctionWithValueClassReturnValue() {
 		val method = CoroutinesUtilsTests::class.java.declaredMethods.first { it.name.startsWith("suspendingFunctionWithValueClassReturnValue") }
@@ -328,6 +337,11 @@ class CoroutinesUtilsTests {
 		return value.value
 	}
 
+	suspend fun suspendingFunctionWithNestedValueClassParameter(value: NestedValueClass): String {
+		delay(1)
+		return value.value.value
+	}
+
 	suspend fun suspendingFunctionWithValueClassReturnValue(): ValueClass {
 		delay(1)
 		return ValueClass("foo")
@@ -382,6 +396,9 @@ class CoroutinesUtilsTests {
 	@JvmInline
 	value class ValueClass(val value: String)
 
+	@JvmInline
+	value class NestedValueClass(val value: ValueClass)
+
 	@JvmInline
 	value class ValueClassWithInit(val value: String) {
 		 init {