GH-1139 - Detect @NamedInterface on composed annotations.

Author: odrotbohm

spring-modulith-core/src/main/java/org/springframework/modulith/core/NamedInterfaces.java

@@ -291,7 +291,7 @@ private static List<NamedInterface> ofAnnotatedTypes(Classes classes) {
 				.filter(it -> !JavaPackage.isPackageInfoType(it)) //
 				.forEach(it -> {
 
-					if (!it.isAnnotatedWith(org.springframework.modulith.NamedInterface.class)) {
+					if (!it.isMetaAnnotatedWith(org.springframework.modulith.NamedInterface.class)) {
 						return;
 					}
 

spring-modulith-core/src/test/java/example/metani/Exposed.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2025 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 example.metani;
+
+/**
+ * @author Oliver Drotbohm
+ */
+@ModuleApi
+public class Exposed {}

spring-modulith-core/src/test/java/example/metani/ModuleApi.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2025 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 example.metani;
+
+import static java.lang.annotation.ElementType.*;
+import static java.lang.annotation.RetentionPolicy.*;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import org.springframework.modulith.NamedInterface;
+
+/**
+ * @author Oliver Drotbohm
+ */
+@Retention(RUNTIME)
+@Target({ TYPE })
+@NamedInterface("api")
+public @interface ModuleApi {}

spring-modulith-core/src/test/java/org/springframework/modulith/core/ApplicationModulesUnitTests.java

@@ -37,6 +37,7 @@ void discoversComplexModuleArrangement() {
 				.containsExactlyInAnyOrder(
 						"invalid",
 						"customId",
+						"metani",
 						"ni",
 						"ni.nested",
 						"ni.nested.b.first",

spring-modulith-core/src/test/java/org/springframework/modulith/core/NamedInterfacesUnitTests.java

@@ -142,6 +142,18 @@ void doesNotExcludeAnyPackagesByDefault() {
 		assertThat(interfaces).hasSizeGreaterThan(1);
 	}
 
+	@Test // GH-1139
+	void discoveredNamedInterfaceOnComposedAnnotation() {
+
+		var pkg = TestUtils.getPackage(example.metani.Exposed.class);
+
+		var result = NamedInterfaces.discoverNamedInterfaces(pkg);
+
+		assertThat(result).hasSize(2)
+				.extracting(NamedInterface::getName)
+				.containsExactlyInAnyOrder(NamedInterface.UNNAMED_NAME, "api");
+	}
+
 	private static void assertInterfaceContains(NamedInterfaces interfaces, String name, Class<?>... types) {
 
 		var classNames = Arrays.stream(types).map(Class::getName).toArray(String[]::new);