GH-320 - Explicitly drop non-bootstrapped module beans during test run.

We now explicitly drop all beans resulting in a type that's contained in an application module *not* included in the current test bootstrap.

spring-modulith-test/src/main/java/org/springframework/modulith/test/ModuleContextCustomizerFactory.java

@@ -24,13 +24,19 @@ import java.util.stream.Stream;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.modulith.core.ApplicationModule;
+import org.springframework.modulith.core.JavaPackage;
 import org.springframework.test.context.ContextConfigurationAttributes;
 import org.springframework.test.context.ContextCustomizer;
 import org.springframework.test.context.ContextCustomizerFactory;
 import org.springframework.test.context.MergedContextConfiguration;
 import org.springframework.test.context.TestContextAnnotationUtils;
+import org.springframework.util.Assert;
 
 /**
  * @author Oliver Drotbohm
@@ -53,7 +59,6 @@ class ModuleContextCustomizerFactory implements ContextCustomizerFactory {
 	static class ModuleContextCustomizer implements ContextCustomizer {
 
 		private static final Logger LOGGER = LoggerFactory.getLogger(ModuleContextCustomizer.class);
-		private static final String BEAN_NAME = ModuleTestExecution.class.getName();
 
 		private final Supplier<ModuleTestExecution> execution;
 
@@ -73,7 +78,9 @@ class ModuleContextCustomizerFactory implements ContextCustomizerFactory {
 			logModules(testExecution);
 
 			var beanFactory = context.getBeanFactory();
-			beanFactory.registerSingleton(BEAN_NAME, testExecution);
+			beanFactory.registerSingleton(ModuleTestExecution.class.getName(), testExecution);
+			beanFactory.registerSingleton(ModuleTestExecutionBeanDefinitionSelector.class.getName(),
+					new ModuleTestExecutionBeanDefinitionSelector(testExecution));
 
 			var events = new DefaultPublishedEvents();
 			beanFactory.registerSingleton(events.getClass().getName(), events);
@@ -173,4 +180,78 @@ class ModuleContextCustomizerFactory implements ContextCustomizerFactory {
 			return Objects.hash(execution);
 		}
 	}
+
+	/**
+	 * A {@link BeanDefinitionRegistryPostProcessor} that selects
+	 * {@link org.springframework.beans.factory.config.BeanDefinition}s that are either non-module beans (i.e.
+	 * infrastructure) or beans living inside an {@link ApplicationModule} being part of the current
+	 * {@link ModuleTestExecution}.
+	 *
+	 * @author Oliver Drotbohm
+	 * @since 1.1
+	 */
+	private static class ModuleTestExecutionBeanDefinitionSelector implements BeanDefinitionRegistryPostProcessor {
+		
+		private static final Logger LOGGER = LoggerFactory.getLogger(ModuleTestExecutionBeanDefinitionSelector.class);
+
+		private final ModuleTestExecution execution;
+
+		/**
+		 * Creates a new {@link ModuleTestExecutionBeanDefinitionSelector} for the given {@link ModuleTestExecution}.
+		 * 
+		 * @param execution must not be {@literal null}.
+		 */
+		private ModuleTestExecutionBeanDefinitionSelector(ModuleTestExecution execution) {
+
+			Assert.notNull(execution, "ModuleTestExecution must not be null!");
+
+			this.execution = execution;
+		}
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor#postProcessBeanDefinitionRegistry(org.springframework.beans.factory.support.BeanDefinitionRegistry)
+		 */
+		@Override
+		public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
+
+			if (!(registry instanceof ConfigurableListableBeanFactory factory)) {
+				return;
+			}
+
+			var modules = execution.getModules();
+
+			for (String name : registry.getBeanDefinitionNames()) {
+
+				var type = factory.getType(name, false);
+				var module = modules.getModuleByType(type);
+
+				// Not a module type -> pass
+				if (module.isEmpty()) {
+					continue;
+				}
+
+				var packagesIncludedInTestRun = execution.getBasePackages().toList();
+
+				// A type of a module bootstrapped -> pass
+				if (module.map(ApplicationModule::getBasePackage)
+						.map(JavaPackage::getName)
+						.filter(packagesIncludedInTestRun::contains).isPresent()) {
+					continue;
+				}
+				
+				LOGGER.trace("Dropping bean definition {} for type {} as it is not included in an application module to be bootstrapped!", name, type.getName());
+
+				// Remove bean definition from bootstrap
+				registry.removeBeanDefinition(name);
+			}
+		}
+
+		/* 
+		 * (non-Javadoc)
+		 * @see org.springframework.beans.factory.config.BeanFactoryPostProcessor#postProcessBeanFactory(org.springframework.beans.factory.config.ConfigurableListableBeanFactory)
+		 */
+		@Override
+		public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {}
+	}
 }

spring-modulith-test/src/main/java/org/springframework/modulith/test/ModuleTestExecution.java

@@ -21,6 +21,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.stream.Stream;
 
 import org.slf4j.Logger;
@@ -227,7 +228,7 @@ public class ModuleTestExecution implements Iterable<ApplicationModule> {
 
 		return Arrays.stream(annotation.extraIncludes()) //
 				.map(modules::getModuleByName) //
-				.flatMap(it -> it.map(Stream::of).orElseGet(Stream::empty));
+				.flatMap(Optional::stream);
 	}
 
 	private static record Key(String moduleBasePackage, ApplicationModuleTest annotation) {}