GH-102 - ApplicationModules now allows traversing modules in topological order.

We now optionally integrate with the JGraphT library to calculate the topological order of modules based on their dependency structure. That order is then exposed in ApplicationModules' iteration and via ….getComparator().

Renamed FormattableJavaClass to FormattableType and allow it to be created from a plain Class as well.

spring-modulith-integration-test/src/test/java/org/springframework/modulith/model/ApplicationModulesIntegrationTest.java

@@ -17,9 +17,9 @@ package org.springframework.modulith.model;
 
 import static org.assertj.core.api.Assertions.*;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
-import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 import org.junit.jupiter.api.Test;
@@ -27,13 +27,15 @@ import org.junit.jupiter.api.Test;
 import com.acme.myproject.Application;
 import com.acme.myproject.complex.internal.FirstTypeBasedPort;
 import com.acme.myproject.complex.internal.SecondTypeBasePort;
+import com.acme.myproject.moduleA.ServiceComponentA;
 import com.acme.myproject.moduleA.SomeConfigurationA.SomeAtBeanComponentA;
+import com.acme.myproject.moduleB.ServiceComponentB;
 
 /**
  * @author Oliver Drotbohm
  * @author Peter Gafert
  */
-class ModulesIntegrationTest {
+class ApplicationModulesIntegrationTest {
 
 	ApplicationModules modules = ApplicationModules.of(Application.class);
 
@@ -150,6 +152,18 @@ class ModulesIntegrationTest {
 						modules.stream().map(ApplicationModule::getName).toList());
 	}
 
+	@Test // #102
+	void ordersTypesByModuleDependencies() {
+
+		// Non-module type first, B depending on A
+		var source = new ArrayList<>(List.of(String.class, ServiceComponentB.class, ServiceComponentA.class));
+
+		source.sort(ApplicationModules.of(Application.class).getComparator());
+
+		// Expect A before B before non-module type.
+		assertThat(source).containsExactly(ServiceComponentA.class, ServiceComponentB.class, String.class);
+	}
+
 	private static void verifyNamedInterfaces(NamedInterfaces interfaces, String name, Class<?>... types) {
 
 		Stream.of(types).forEach(type -> {