GH-284 - Support for open application modules.

Application modules can now be declared as open, which causes internal components being exposed for access by other modules.

spring-modulith-core/src/test/java/example/ni/internal/Internal.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2024 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.ni.internal;
+
+/**
+ * @author Oliver Drotbohm
+ */
+public interface Internal {}

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

@@ -22,6 +22,7 @@ import example.ni.RootType;
 import example.ni.api.ApiType;
 import example.ni.internal.AdditionalSpiType;
 import example.ni.internal.DefaultedNamedInterfaceType;
+import example.ni.internal.Internal;
 import example.ni.spi.SpiType;
 import example.ninvalid.InvalidDefaultNamedInterface;
 
@@ -64,6 +65,18 @@ class NamedInterfacesUnitTests {
 				.withMessageContaining(InvalidDefaultNamedInterface.class.getSimpleName());
 	}
 
+	@Test // GH-284
+	void detectsOpenNamedInterface() {
+
+		var javaPackage = TestUtils.getPackage(RootType.class);
+		var interfaces = NamedInterfaces.forOpen(javaPackage);
+
+		assertThat(interfaces).map(NamedInterface::getName)
+				.containsExactlyInAnyOrder(NamedInterface.UNNAMED_NAME, "api", "spi", "kpi", "internal");
+
+		assertInterfaceContains(interfaces, NamedInterface.UNNAMED_NAME, RootType.class, Internal.class);
+	}
+
 	private static void assertInterfaceContains(NamedInterfaces interfaces, String name, Class<?>... types) {
 
 		var classNames = Arrays.stream(types).map(Class::getName).toArray(String[]::new);