Add ArchUnit

pom.xml

@@ -112,6 +112,14 @@
       <artifactId>jakarta.xml.bind-api</artifactId>
     </dependency>
 
+    <dependency>
+      <groupId>com.tngtech.archunit</groupId>
+      <artifactId>archunit</artifactId>
+      <version>1.0.1</version>
+      <scope>test</scope>
+    </dependency>
+
+
   </dependencies>
 
   <build>

src/main/java/org/springframework/samples/petclinic/application/UseCase.java

@@ -0,0 +1,5 @@
+package org.springframework.samples.petclinic.application;
+
+public class UseCase {
+
+}

src/main/java/org/springframework/samples/petclinic/domain/MyDomain.java

@@ -0,0 +1,5 @@
+package org.springframework.samples.petclinic.domain;
+
+public class MyDomain {
+
+}

src/test/java/org/springframework/samples/petclinic/LayerDependencyRulesTest.java

@@ -0,0 +1,26 @@
+package org.springframework.samples.petclinic;
+
+import static com.tngtech.archunit.lang.syntax.ArchRuleDefinition.noClasses;
+
+import com.tngtech.archunit.core.domain.JavaClasses;
+import com.tngtech.archunit.core.importer.ClassFileImporter;
+import com.tngtech.archunit.lang.ArchRule;
+import org.junit.jupiter.api.Test;
+
+class LayerDependencyRulesTest {
+
+	private final JavaClasses importedClasses = new ClassFileImporter()
+		.importPackages("org.springframework.samples.petclinic");
+
+	@Test
+	void applicationLayerShouldNotDependOnInfrastructureLayer() {
+		ArchRule rule = noClasses().that()
+			.resideInAPackage("..application..")
+			.should()
+			.dependOnClassesThat()
+			.resideInAPackage("..infrastructure..");
+
+		rule.check(importedClasses);
+	}
+
+}