Refine Kotlin ParameterNameDiscoverer tests

Related to gh-30052, we should improve ParameterNameDiscoverer
Kotlin tests to make sure DefaultParameterNameDiscoverer behaves
as expected and is consistent with
KotlinReflectionParameterNameDiscoverer behavior.

Closes gh-30618

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

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.core
+
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.Test
+
+import org.springframework.util.ReflectionUtils
+
+/**
+ * Abstract tests for Kotlin [ParameterNameDiscoverer] aware implementations.
+ *
+ * @author Sebastien Deleuze
+ */
+@Suppress("UNUSED_PARAMETER")
+abstract class AbstractKotlinReflectionParameterNameDiscovererTests(protected val parameterNameDiscoverer: ParameterNameDiscoverer) {
+
+	@Test
+	fun getParameterNamesOnInterface() {
+		val method = ReflectionUtils.findMethod(MessageService::class.java,"sendMessage", String::class.java)!!
+		val actualParams = parameterNameDiscoverer.getParameterNames(method)
+		assertThat(actualParams).contains("message")
+	}
+
+	@Test
+	fun getParameterNamesOnClass() {
+		val constructor = ReflectionUtils.accessibleConstructor(MessageServiceImpl::class.java,String::class.java)
+		val actualConstructorParams = parameterNameDiscoverer.getParameterNames(constructor)
+		assertThat(actualConstructorParams).contains("message")
+		val method = ReflectionUtils.findMethod(MessageServiceImpl::class.java,"sendMessage", String::class.java)!!
+		val actualMethodParams = parameterNameDiscoverer.getParameterNames(method)
+		assertThat(actualMethodParams).contains("message")
+	}
+
+	@Test
+	fun getParameterNamesOnExtensionMethod() {
+		val method = ReflectionUtils.findMethod(UtilityClass::class.java, "identity", String::class.java)!!
+		val actualParams = parameterNameDiscoverer.getParameterNames(method)!!
+		assertThat(actualParams).contains("\$receiver")
+	}
+
+	interface MessageService {
+		fun sendMessage(message: String)
+	}
+
+	class MessageServiceImpl(message: String) {
+		fun sendMessage(message: String) = message
+	}
+
+	class UtilityClass {
+		fun String.identity() = this
+	}
+
+	class TestClass(name: String, age: Int) {
+		fun test(name: String, age: Int) {
+		}
+	}
+
+	interface TestInterface {
+		fun test(name: String, age: Int)
+	}
+
+}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,9 +19,13 @@ package org.springframework.core
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 
-class KotlinDefaultParameterNameDiscovererTests {
+/**
-
+ * Tests for Kotlin support in [DefaultParameterNameDiscoverer].
-	private val parameterNameDiscoverer = DefaultParameterNameDiscoverer()
+ *
+ * @author Sebastien Deleuze
+ */
+class KotlinDefaultParameterNameDiscovererTests :
+	AbstractKotlinReflectionParameterNameDiscovererTests(DefaultParameterNameDiscoverer()){
 
 	enum class MyEnum {
 		ONE, TWO
@@ -31,6 +35,7 @@ class KotlinDefaultParameterNameDiscovererTests {
 	fun getParameterNamesOnEnum() {
 		val constructor = MyEnum::class.java.declaredConstructors[0]
 		val actualParams = parameterNameDiscoverer.getParameterNames(constructor)
-		assertThat(actualParams!!.size).isEqualTo(2)
+		assertThat(actualParams).containsExactly("\$enum\$name", "\$enum\$ordinal")
 	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,48 +16,10 @@
 
 package org.springframework.core
 
-import org.assertj.core.api.Assertions.assertThat
-import org.junit.jupiter.api.Test
-
-import org.springframework.util.ReflectionUtils
-
 /**
- * Tests for KotlinReflectionParameterNameDiscoverer
+ * Tests for [KotlinReflectionParameterNameDiscoverer].
+ *
+ * @author Sebastien Deleuze
  */
-class KotlinReflectionParameterNameDiscovererTests {
+class KotlinReflectionParameterNameDiscovererTests :
-
+    AbstractKotlinReflectionParameterNameDiscovererTests(KotlinReflectionParameterNameDiscoverer())
-	private val parameterNameDiscoverer = KotlinReflectionParameterNameDiscoverer()
-
-	@Test
-	fun getParameterNamesOnInterface() {
-		val method = ReflectionUtils.findMethod(MessageService::class.java,"sendMessage", String::class.java)!!
-		val actualParams = parameterNameDiscoverer.getParameterNames(method)
-		assertThat(actualParams).contains("message")
-	}
-
-	@Test
-	fun getParameterNamesOnClass() {
-		val method = ReflectionUtils.findMethod(MessageServiceImpl::class.java,"sendMessage", String::class.java)!!
-		val actualParams = parameterNameDiscoverer.getParameterNames(method)
-		assertThat(actualParams).contains("message")
-	}
-
-	@Test
-	fun getParameterNamesOnExtensionMethod() {
-		val method = ReflectionUtils.findMethod(UtilityClass::class.java, "identity", String::class.java)!!
-		val actualParams = parameterNameDiscoverer.getParameterNames(method)!!
-		assertThat(actualParams).contains("\$receiver")
-	}
-
-	interface MessageService {
-		fun sendMessage(message: String)
-	}
-
-	class MessageServiceImpl {
-		fun sendMessage(message: String) = message
-	}
-
-	class UtilityClass {
-		fun String.identity() = this
-	}
-}