Support Kotlin Context Parameters

spring-core/spring-core.gradle

@@ -127,6 +127,12 @@ jar {
 	}
 }
 
+kotlin {
+    compilerOptions {
+        freeCompilerArgs.addAll("-Xcontext-parameters")
+    }
+}
+
 test {
 	// Make sure the classes dir is used on the test classpath (required by ResourceTests).
 	// When test fixtures are involved, the JAR is used by default.

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

@@ -125,7 +125,7 @@ public static Publisher<?> invokeSuspendingFunction(
 					for (KParameter parameter : function.getParameters()) {
 						switch (parameter.getKind()) {
 							case INSTANCE -> argMap.put(parameter, target);
-							case VALUE, EXTENSION_RECEIVER -> {
+							case VALUE, EXTENSION_RECEIVER, CONTEXT -> {
 								Object arg = args[index];
 								if (!(parameter.isOptional() && arg == null)) {
 									KType type = parameter.getType();

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

@@ -275,6 +275,26 @@ class CoroutinesUtilsTests {
 		}
 	}
 
+	@Test
+	fun invokeSuspendingFunctionWithContextParameter() {
+		val method = CoroutinesUtilsTests::class.java.getDeclaredMethod("suspendingFunctionWithContextParameter",
+			CustomException::class.java, Continuation::class.java)
+		val mono = CoroutinesUtils.invokeSuspendingFunction(method, this, CustomException("foo")) as Mono
+		runBlocking {
+			Assertions.assertThat(mono.awaitSingleOrNull()).isEqualTo("foo")
+		}
+	}
+
+	@Test
+	fun invokeSuspendingFunctionWithContextParameterAndParameter() {
+		val method = CoroutinesUtilsTests::class.java.getDeclaredMethod("suspendingFunctionWithContextParameterAndParameter",
+			CustomException::class.java, Int::class.java, Continuation::class.java)
+		val mono = CoroutinesUtils.invokeSuspendingFunction(method, this, CustomException("foo"), 20) as Mono
+		runBlocking {
+			Assertions.assertThat(mono.awaitSingleOrNull()).isEqualTo("foo-20")
+		}
+	}
+
 	@Test
 	fun invokeSuspendingFunctionWithGenericParameter() {
 		val method = GenericController::class.java.declaredMethods.first { it.name.startsWith("handle") }
@@ -377,6 +397,18 @@ class CoroutinesUtilsTests {
 		return "${this.message}-$limit"
 	}
 
+	context(value: CustomException)
+	suspend fun suspendingFunctionWithContextParameter(): String {
+		delay(1)
+		return "${value.message}"
+	}
+
+	context(value: CustomException)
+	suspend fun suspendingFunctionWithContextParameterAndParameter(limit: Int): String {
+		delay(1)
+		return "${value.message}-$limit"
+	}
+
 	interface Named {
 		val name: String
 	}

spring-web/spring-web.gradle

@@ -102,3 +102,9 @@ dependencies {
 	testRuntimeOnly("org.glassfish:jakarta.el")
 	testRuntimeOnly("org.hibernate.validator:hibernate-validator")
 }
+
+kotlin {
+    compilerOptions {
+        freeCompilerArgs.addAll("-Xcontext-parameters")
+    }
+}

spring-web/src/main/java/org/springframework/web/method/support/InvocableHandlerMethod.java

@@ -316,7 +316,7 @@ private static class KotlinDelegate {
 			for (KParameter parameter : function.getParameters()) {
 				switch (parameter.getKind()) {
 					case INSTANCE -> argMap.put(parameter, target);
-					case VALUE, EXTENSION_RECEIVER -> {
+					case VALUE, EXTENSION_RECEIVER, CONTEXT -> {
 						Object arg = args[index];
 						if (!(parameter.isOptional() && arg == null)) {
 							KType type = parameter.getType();

spring-web/src/test/kotlin/org/springframework/web/method/support/InvocableHandlerMethodKotlinTests.kt

@@ -238,6 +238,22 @@ class InvocableHandlerMethodKotlinTests {
 		Assertions.assertThat(value).isEqualTo("foo-20")
 	}
 
+	@Test
+	fun contextParameter() {
+		composite.addResolver(StubArgumentResolver(CustomException::class.java, CustomException("foo")))
+		val value = getInvocable(ReflectionUtils.findMethod(ContextParameterHandler::class.java, "handle", CustomException::class.java)!!).invokeForRequest(request, null)
+		Assertions.assertThat(value).isEqualTo("foo")
+	}
+
+	@Test
+	fun contextParameterWithParameter() {
+		composite.addResolver(StubArgumentResolver(CustomException::class.java, CustomException("foo")))
+		composite.addResolver(StubArgumentResolver(Int::class.java, 20))
+		val value = getInvocable(ReflectionUtils.findMethod(ContextParameterHandler::class.java, "handleWithParameter", CustomException::class.java, Int::class.java)!!)
+			.invokeForRequest(request, null)
+		Assertions.assertThat(value).isEqualTo("foo-20")
+	}
+
 	@Test
 	fun genericParameter() {
 		val horse = Animal("horse")
@@ -359,6 +375,19 @@ class InvocableHandlerMethodKotlinTests {
 		}
 	}
 
+	private class ContextParameterHandler {
+
+		context(exception: CustomException)
+		fun handle(): String {
+			return "${exception.message}"
+		}
+
+		context(exception: CustomException)
+		fun handleWithParameter(limit: Int): String {
+			return "${exception.message}-$limit"
+		}
+	}
+
 	private abstract class GenericHandler<T : Named> {
 
 		fun handle(named: T) = named.name