GH-936 - Make sure ModuleTracingBeanPostProcessor is executed early.

We now explicitly declare an order for the MTBPP so that it gets registered for execution before the ones that create infrastructure for message listeners so that those already see the potentially proxied instance and invocations actually invoke the advice creating the traces.

spring-modulith-observability/pom.xml

@@ -99,6 +99,12 @@
 			<scope>test</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>org.springframework.amqp</groupId>
+			<artifactId>spring-rabbit</artifactId>
+			<scope>test</scope>
+		</dependency>
+
 	</dependencies>
 
 </project>

spring-modulith-observability/src/main/java/org/springframework/modulith/observability/ModuleTracingBeanPostProcessor.java

@@ -33,6 +33,7 @@
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.core.Ordered;
 import org.springframework.modulith.runtime.ApplicationModulesRuntime;
 import org.springframework.util.Assert;
 
@@ -42,7 +43,7 @@
  *
  * @author Oliver Drotbohm
  */
-public class ModuleTracingBeanPostProcessor extends ModuleTracingSupport implements BeanPostProcessor {
+public class ModuleTracingBeanPostProcessor extends ModuleTracingSupport implements BeanPostProcessor, Ordered {
 
 	public static final String MODULE_BAGGAGE_KEY = "org.springframework.modulith.module";
 
@@ -70,6 +71,15 @@ public ModuleTracingBeanPostProcessor(ApplicationModulesRuntime runtime, Supplie
 		this.factory = factory;
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.core.Ordered#getOrder()
+	 */
+	@Override
+	public int getOrder() {
+		return Ordered.LOWEST_PRECEDENCE - 50;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.beans.factory.config.BeanPostProcessor#postProcessAfterInitialization(java.lang.Object, java.lang.String)

spring-modulith-observability/src/test/java/org/springframework/modulith/observability/ModuleTracingBeanPostProcessorUnitTests.java

@@ -22,6 +22,7 @@
 import example.sample.SampleProperties;
 
 import org.junit.jupiter.api.Test;
+import org.springframework.amqp.rabbit.annotation.RabbitListenerAnnotationBeanPostProcessor;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.modulith.runtime.ApplicationModulesRuntime;
@@ -50,4 +51,15 @@ void doesNotProxyConfiguationProperties() {
 
 		assertThat(result).isSameAs(bean);
 	}
+
+	@Test // GH-936
+	void processorIsRegisteredBefore() {
+
+		var rabbitProcessor = new RabbitListenerAnnotationBeanPostProcessor();
+		var tracingProcessor = new ModuleTracingBeanPostProcessor(mock(ApplicationModulesRuntime.class), () -> null,
+				new DefaultListableBeanFactory());
+
+		assertThat(rabbitProcessor.getOrder()).isGreaterThan(tracingProcessor.getOrder());
+
+	}
 }