Make coroutines with custom AOP aspects work with @Transactional

Previous to this change, the transactional aspect would supersed the
user-defined AspectJ aspect, shortcircuiting to calling the original
Kotlin suspending function.

This change simplifies the TransactionAspectSupport way of dealing with
transactional coroutines, thanks to the fact that lower level support
for AOP has been introduced in c8169e5c.

Closes gh-33095

integration-tests/src/test/kotlin/org/springframework/aop/framework/autoproxy/AspectJAutoProxyInterceptorKotlinIntegrationTests.kt

@@ -20,6 +20,9 @@ import kotlinx.coroutines.delay
 import kotlinx.coroutines.runBlocking
 import org.aopalliance.intercept.MethodInterceptor
 import org.aopalliance.intercept.MethodInvocation
+import org.aspectj.lang.ProceedingJoinPoint
+import org.aspectj.lang.annotation.Around
+import org.aspectj.lang.annotation.Aspect
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 import org.springframework.aop.framework.autoproxy.AspectJAutoProxyInterceptorKotlinIntegrationTests.InterceptorConfig
@@ -28,10 +31,18 @@ import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.context.annotation.Bean
 import org.springframework.context.annotation.Configuration
 import org.springframework.context.annotation.EnableAspectJAutoProxy
+import org.springframework.stereotype.Component
 import org.springframework.test.annotation.DirtiesContext
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig
+import org.springframework.transaction.annotation.EnableTransactionManagement
+import org.springframework.transaction.annotation.Transactional
+import org.springframework.transaction.testfixture.ReactiveCallCountingTransactionManager
 import reactor.core.publisher.Mono
 import java.lang.reflect.Method
+import kotlin.annotation.AnnotationTarget.ANNOTATION_CLASS
+import kotlin.annotation.AnnotationTarget.CLASS
+import kotlin.annotation.AnnotationTarget.FUNCTION
+import kotlin.annotation.AnnotationTarget.TYPE
 
 
 /**
@@ -43,7 +54,9 @@ import java.lang.reflect.Method
 class AspectJAutoProxyInterceptorKotlinIntegrationTests(
     @Autowired val echo: Echo,
     @Autowired val firstAdvisor: TestPointcutAdvisor,
-    @Autowired val secondAdvisor: TestPointcutAdvisor) {
+    @Autowired val secondAdvisor: TestPointcutAdvisor,
+    @Autowired val countingAspect: CountingAspect,
+    @Autowired val reactiveTransactionManager: ReactiveCallCountingTransactionManager) {
 
     @Test
     fun `Multiple interceptors with regular function`() {
@@ -67,8 +80,22 @@ class AspectJAutoProxyInterceptorKotlinIntegrationTests(
 		assertThat(secondAdvisor.interceptor.invocations).singleElement().matches { Mono::class.java.isAssignableFrom(it) }
     }
 
+	@Test // gh-33095
+	fun `Aspect and reactive transactional with suspending function`() {
+		assertThat(countingAspect.counter).isZero()
+		assertThat(reactiveTransactionManager.commits).isZero()
+		val value = "Hello!"
+		runBlocking {
+			assertThat(echo.suspendingTransactionalEcho(value)).isEqualTo(value)
+		}
+		assertThat(countingAspect.counter).`as`("aspect applied").isOne()
+		assertThat(reactiveTransactionManager.begun).isOne()
+		assertThat(reactiveTransactionManager.commits).`as`("transactional applied").isOne()
+	}
+
     @Configuration
     @EnableAspectJAutoProxy
+    @EnableTransactionManagement
     open class InterceptorConfig {
 
         @Bean
@@ -77,6 +104,13 @@ class AspectJAutoProxyInterceptorKotlinIntegrationTests(
         @Bean
         open fun secondAdvisor() = TestPointcutAdvisor().apply { order = 1 }
 
+		@Bean
+		open fun countingAspect() = CountingAspect()
+
+		@Bean
+		open fun transactionManager(): ReactiveCallCountingTransactionManager {
+			return ReactiveCallCountingTransactionManager()
+		}
 
         @Bean
         open fun echo(): Echo {
@@ -107,6 +141,24 @@ class AspectJAutoProxyInterceptorKotlinIntegrationTests(
         }
     }
 
+	@Target(CLASS, FUNCTION, ANNOTATION_CLASS, TYPE)
+	@Retention(AnnotationRetention.RUNTIME)
+	annotation class Counting()
+
+	@Aspect
+	@Component
+	class CountingAspect {
+
+		var counter: Long = 0
+
+		@Around("@annotation(org.springframework.aop.framework.autoproxy.AspectJAutoProxyInterceptorKotlinIntegrationTests.Counting)")
+		fun logging(joinPoint: ProceedingJoinPoint): Any {
+			return (joinPoint.proceed(joinPoint.args) as Mono<*>).doOnTerminate {
+				counter++
+			}
+		}
+	}
+
     open class Echo {
 
         open fun echo(value: String): String {
@@ -118,6 +170,13 @@ class AspectJAutoProxyInterceptorKotlinIntegrationTests(
             return value
         }
 
+		@Transactional
+		@Counting
+		open suspend fun suspendingTransactionalEcho(value: String): String {
+			delay(1)
+			return value
+		}
+
     }
 
 }