SPR-6416, reshaping removal of hierarchical conversations and adding repository test

org.springframework.context/src/main/java/org/springframework/conversation/manager/AbstractConversationRepository.java

@@ -16,8 +16,6 @@
 
 package org.springframework.conversation.manager;
 
-import org.springframework.conversation.Conversation;
-
 /**
  * An abstract implementation for a conversation repository. Its implementation is based on the
  * {@link org.springframework.conversation.manager.DefaultConversation} and manages its initial timeout and provides
@@ -89,11 +87,16 @@ public abstract class AbstractConversationRepository implements ConversationRepo
 	 * @param conversation the conversation to be removed, including its children, if any
 	 */
 	protected final void removeConversation(MutableConversation conversation) {
-		for (Conversation child : conversation.getChildren()) {
-			// remove the child from its parent and recursively invoke this method to remove the children of the
-			// current conversation
-			conversation.removeChildConversation((MutableConversation)child);
-			removeConversation((MutableConversation)child);
+		// as recursively removing children will decrease the children list, always pick out
+		// the first child to be removed next
+		while (conversation.getChildren().size() > 0) {
+			removeConversation((MutableConversation)conversation.getChildren().get(0));
+		}
+
+		// remove the conversation from its parent, if any
+		MutableConversation parentConversation = (MutableConversation) conversation.getParent();
+		if (parentConversation != null) {
+			parentConversation.removeChildConversation(conversation);
 		}
 
 		// end the conversation (will internally clear the attributes, invoke destruction callbacks, if any, and
@@ -102,7 +105,7 @@ public abstract class AbstractConversationRepository implements ConversationRepo
 		conversation.invalidate();
 
 		// finally, remove the single object from the repository
-		removeSingleConversationObject((MutableConversation)conversation);
+		removeSingleConversationObject((MutableConversation) conversation);
 	}
 
 	/**

org.springframework.context/src/main/java/org/springframework/conversation/manager/DefaultConversation.java

@@ -176,13 +176,12 @@ public class DefaultConversation implements MutableConversation, Serializable {
 				children = null;
 			}
         }
-    }
 
-    protected void removeFromParent() {
-        if (parent != null) {
-            parent.removeChildConversation(this);
-        }
+		// remove the parent conversation from the child relationship
+		((DefaultConversation)conversation).removeParent();
+    }
 
+    protected void removeParent() {
 		parent = null;
     }
 

org.springframework.context/src/test/java/org/springframework/conversation/ConversationRepositoryTest.java

@@ -0,0 +1,182 @@
+/*
+ * Copyright 2002-2011 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
+ *
+ *      http://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 org.springframework.conversation;
+
+import java.util.List;
+
+import org.junit.Test;
+
+import org.springframework.conversation.manager.ConversationRepository;
+import org.springframework.conversation.manager.LocalTransientConversationRepository;
+import org.springframework.conversation.manager.MutableConversation;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author Micha Kiener
+ */
+public class ConversationRepositoryTest {
+
+	@Test
+	public void testConversationCreation() {
+		ConversationRepository repository = createRepository();
+		assertNotNull("repository must not be null", repository);
+
+		MutableConversation conversation = repository.createNewConversation();
+		assertNotNull("conversation object must not be null", conversation);
+		assertNull("Id must not be set after creation", conversation.getId());
+		assertNotNull("List of children must never be null", conversation.getChildren());
+		assertEquals("Children list must be empty", 0, conversation.getChildren().size());
+	}
+
+	@Test
+	public void testConversationCreationAndStorage() {
+		ConversationRepository repository = createRepository();
+
+		MutableConversation conversation = repository.createNewConversation();
+		repository.storeConversation(conversation);
+		String conversationId = conversation.getId();
+		assertNotNull("ID must not be null after storage of a conversation", conversationId);
+
+		MutableConversation conversationRequested = repository.getConversation(conversationId);
+		assertNotNull("Conversation must be available after storage", conversationRequested);
+		assertSame("Conversation objects must be the same in a transient repository", conversation,
+				conversationRequested);
+	}
+
+	@Test
+	public void testConversationCreationStorageAndRemoval() {
+		ConversationRepository repository = createRepository();
+
+		MutableConversation conversation = repository.createNewConversation();
+		repository.storeConversation(conversation);
+		String conversationId = conversation.getId();
+
+		repository.removeConversation(conversationId, true);
+		MutableConversation conversationRequested = repository.getConversation(conversationId);
+		assertNull("Conversation must no longer be available after removal", conversationRequested);
+	}
+
+	@Test
+	public void testConversationHierarchyCreation() {
+		ConversationRepository repository = createRepository();
+
+		MutableConversation conversation = repository.createNewConversation();
+		repository.storeConversation(conversation);
+		String rootConversationId = conversation.getId();
+
+		MutableConversation childConversation = repository.createNewChildConversation(conversation, false);
+		assertNotNull("child conversation must not be null", childConversation);
+		assertNotNull("parent conversation must be available", childConversation.getParent());
+		assertSame("parent conversation and root conversation must be the same", conversation,
+				childConversation.getParent());
+		assertFalse("nested conversation must not be isolated", childConversation.isIsolated());
+
+		List<? extends Conversation> children = conversation.getChildren();
+		assertNotNull("children list must never be null", children);
+		assertEquals("children size must be one", 1, children.size());
+		assertSame("child conversation must be available through the children list of the root conversation",
+				childConversation, children.get(0));
+
+		repository.storeConversation(childConversation);
+		String childConversationId = childConversation.getId();
+		assertNotNull("child conversation id must be set after storage", childConversationId);
+		assertNotSame("root and child conversation id must be different", rootConversationId, childConversationId);
+
+		assertNotNull("root conversation must be retrievable through repository",
+				repository.getConversation(rootConversationId));
+		assertNotNull("child conversation must be retrievable through repository",
+				repository.getConversation(childConversationId));
+
+		assertSame("root conversation must be the same, if getRoot is invoked", conversation, conversation.getRoot());
+		assertSame("root conversation must be the same, if getRoot is invoked", conversation,
+				childConversation.getRoot());
+	}
+
+	@Test
+	public void testConversationHierarchyCreationAndSingleRemoval() {
+		ConversationRepository repository = createRepository();
+
+		MutableConversation conversation = repository.createNewConversation();
+		repository.storeConversation(conversation);
+		String rootConversationId = conversation.getId();
+
+		MutableConversation childConversation = repository.createNewChildConversation(conversation, false);
+		repository.storeConversation(childConversation);
+		String childConversationId = childConversation.getId();
+
+		repository.removeConversation(childConversationId, false);
+
+		assertNull("parent must not be available after removal", childConversation.getParent());
+		assertEquals("list of children must be empty after removal", 0, conversation.getChildren().size());
+
+		assertNull("child conversation must not be available through the repository after removal",
+				repository.getConversation(childConversationId));
+		assertNotNull("root conversation must still be available after removal of its child conversation",
+				repository.getConversation(rootConversationId));
+	}
+
+	@Test
+	public void testConversationHierarchyCreationAndRootThroughChildRemoval() {
+		ConversationRepository repository = createRepository();
+
+		MutableConversation conversation = repository.createNewConversation();
+		repository.storeConversation(conversation);
+		String rootConversationId = conversation.getId();
+
+		MutableConversation childConversation = repository.createNewChildConversation(conversation, false);
+		repository.storeConversation(childConversation);
+		String childConversationId = childConversation.getId();
+
+		repository.removeConversation(childConversationId, true);
+
+		assertNull("parent must not be available after removal", childConversation.getParent());
+		assertEquals("list of children must be empty after removal", 0, conversation.getChildren().size());
+
+		assertNull("child conversation must not be available through the repository after removal",
+				repository.getConversation(childConversationId));
+		assertNull("root conversation must not be available after root removal",
+				repository.getConversation(rootConversationId));
+	}
+
+	@Test
+	public void testConversationHierarchyCreationAndRootThroughParentRemoval() {
+		ConversationRepository repository = createRepository();
+
+		MutableConversation conversation = repository.createNewConversation();
+		repository.storeConversation(conversation);
+		String rootConversationId = conversation.getId();
+
+		MutableConversation childConversation = repository.createNewChildConversation(conversation, false);
+		repository.storeConversation(childConversation);
+		String childConversationId = childConversation.getId();
+
+		repository.removeConversation(rootConversationId, false);
+
+		assertNull("parent must not be available after removal", childConversation.getParent());
+		assertEquals("list of children must be empty after removal", 0, conversation.getChildren().size());
+
+		assertNull("child conversation must not be available through the repository after removal",
+				repository.getConversation(childConversationId));
+		assertNull("root conversation must not be available after root removal",
+				repository.getConversation(rootConversationId));
+	}
+
+	protected ConversationRepository createRepository() {
+		return new LocalTransientConversationRepository();
+	}
+}