Don't register event handlers if no ApplicationService is available (#396)

Author: mofterdinger

cds-feature-attachments/src/main/java/com/sap/cds/feature/attachments/configuration/Registration.java

@@ -41,6 +41,7 @@
 import com.sap.cds.feature.attachments.service.malware.client.mapper.DefaultMalwareClientStatusMapper;
 import com.sap.cds.feature.attachments.service.malware.constants.MalwareScanConstants;
 import com.sap.cds.services.ServiceCatalog;
+import com.sap.cds.services.cds.ApplicationService;
 import com.sap.cds.services.draft.DraftService;
 import com.sap.cds.services.environment.CdsEnvironment;
 import com.sap.cds.services.environment.CdsProperties.ConnectionPool;
@@ -110,12 +111,17 @@ public void eventHandlers(CdsRuntimeConfigurer configurer) {
 		var attachmentsReader = new DefaultAttachmentsReader(new DefaultAssociationCascader(), persistenceService);
 		ThreadLocalDataStorage storage = new ThreadLocalDataStorage();
 
-		// register event handlers for application service
-		configurer.eventHandler(new CreateAttachmentsHandler(eventFactory, storage));
-		configurer.eventHandler(new UpdateAttachmentsHandler(eventFactory, attachmentsReader, outboxedAttachmentService, storage));
-		configurer.eventHandler(new DeleteAttachmentsHandler(attachmentsReader, deleteContentEvent));
-		var scanRunner = new EndTransactionMalwareScanRunner(null, null, malwareScanner, runtime);
-		configurer.eventHandler(new ReadAttachmentsHandler(attachmentService, new DefaultAttachmentStatusValidator(), scanRunner));
+		// register event handlers for application service, if at least one application service is available
+		boolean hasApplicationServices = serviceCatalog.getServices(ApplicationService.class).findFirst().isPresent();
+		if (hasApplicationServices) {
+			configurer.eventHandler(new CreateAttachmentsHandler(eventFactory, storage));
+			configurer.eventHandler(new UpdateAttachmentsHandler(eventFactory, attachmentsReader, outboxedAttachmentService, storage));
+			configurer.eventHandler(new DeleteAttachmentsHandler(attachmentsReader, deleteContentEvent));
+			var scanRunner = new EndTransactionMalwareScanRunner(null, null, malwareScanner, runtime);
+			configurer.eventHandler(new ReadAttachmentsHandler(attachmentService, new DefaultAttachmentStatusValidator(), scanRunner));
+		} else {
+			logger.debug("No application service is available. Application service event handlers will not be registered.");
+		}
 
 		// register event handlers on draft service, if at least one draft service is available
 		boolean hasDraftServices = serviceCatalog.getServices(DraftService.class).findFirst().isPresent();

cds-feature-attachments/src/test/java/com/sap/cds/feature/attachments/configuration/RegistrationTest.java

@@ -25,6 +25,7 @@
 import com.sap.cds.feature.attachments.service.handler.DefaultAttachmentsServiceHandler;
 import com.sap.cds.services.Service;
 import com.sap.cds.services.ServiceCatalog;
+import com.sap.cds.services.cds.ApplicationService;
 import com.sap.cds.services.draft.DraftService;
 import com.sap.cds.services.environment.CdsEnvironment;
 import com.sap.cds.services.handler.EventHandler;
@@ -42,6 +43,7 @@ class RegistrationTest {
 	private AttachmentService attachmentService;
 	private OutboxService outboxService;
 	private DraftService draftService;
+	private ApplicationService applicationService;
 	private ArgumentCaptor<Service> serviceArgumentCaptor;
 	private ArgumentCaptor<EventHandler> handlerArgumentCaptor;
 
@@ -61,6 +63,7 @@ void setup() {
 		attachmentService = mock(AttachmentService.class);
 		outboxService = mock(OutboxService.class);
 		draftService = mock(DraftService.class);
+		applicationService = mock(ApplicationService.class);
 		serviceArgumentCaptor = ArgumentCaptor.forClass(Service.class);
 		handlerArgumentCaptor = ArgumentCaptor.forClass(EventHandler.class);
 	}
@@ -87,6 +90,7 @@ void handlersAreRegistered() {
 		when(serviceCatalog.getService(OutboxService.class, OutboxService.PERSISTENT_UNORDERED_NAME)).thenReturn(
 				outboxService);
 		when(serviceCatalog.getServices(DraftService.class)).thenReturn(Stream.of(draftService));
+		when(serviceCatalog.getServices(ApplicationService.class)).thenReturn(Stream.of(applicationService));
 
 		cut.eventHandlers(configurer);
 
@@ -104,9 +108,40 @@ void handlersAreRegistered() {
 		isHandlerForClassIncluded(handlers, DraftActiveAttachmentsHandler.class);
 	}
 
+	@Test
+	void lessHandlersAreRegistered() {
+		when(serviceCatalog.getService(PersistenceService.class, PersistenceService.DEFAULT_NAME)).thenReturn(
+				persistenceService);
+		when(serviceCatalog.getService(AttachmentService.class, AttachmentService.DEFAULT_NAME)).thenReturn(
+				attachmentService);
+		when(serviceCatalog.getService(OutboxService.class, OutboxService.PERSISTENT_UNORDERED_NAME)).thenReturn(
+				outboxService);
+
+		cut.eventHandlers(configurer);
+
+		var handlerSize = 1;
+		verify(configurer, times(handlerSize)).eventHandler(handlerArgumentCaptor.capture());
+		var handlers = handlerArgumentCaptor.getAllValues();
+		assertThat(handlers).hasSize(handlerSize);
+		isHandlerForClassIncluded(handlers, DefaultAttachmentsServiceHandler.class);
+		// event handlers for application services are not registered
+		isHandlerForClassMissing(handlers, CreateAttachmentsHandler.class);
+		isHandlerForClassMissing(handlers, UpdateAttachmentsHandler.class);
+		isHandlerForClassMissing(handlers, DeleteAttachmentsHandler.class);
+		isHandlerForClassMissing(handlers, ReadAttachmentsHandler.class);
+		// event handlers for draft services are not registered
+		isHandlerForClassMissing(handlers, DraftPatchAttachmentsHandler.class);
+		isHandlerForClassMissing(handlers, DraftCancelAttachmentsHandler.class);
+		isHandlerForClassMissing(handlers, DraftActiveAttachmentsHandler.class);
+	}
+
 	private void isHandlerForClassIncluded(List<EventHandler> handlers, Class<? extends EventHandler> includedClass) {
 		var isHandlerIncluded = handlers.stream().anyMatch(handler -> handler.getClass() == includedClass);
 		assertThat(isHandlerIncluded).isTrue();
 	}
+	private void isHandlerForClassMissing(List<EventHandler> handlers, Class<? extends EventHandler> includedClass) {
+		var isHandlerIncluded = handlers.stream().anyMatch(handler -> handler.getClass() == includedClass);
+		assertThat(isHandlerIncluded).isFalse();
+	}
 
 }