Purge nodes without subscriptions as described by PR #274

broker/src/test/java/io/moquette/spi/impl/ProtocolProcessorTest.java

@@ -284,8 +284,9 @@ public class ProtocolProcessorTest {
         assertEquals(0, subscriptions.size());
 
         m_processor.processSubscribe(m_channel, msg);
-
-        // Exercise
+        assertEquals(1, subscriptions.size());
+                
+        //Exercise
         m_processor.processSubscribe(m_channel, msg);
 
         // Verify

broker/src/test/java/io/moquette/spi/impl/subscriptions/TreeNodeTest.java

@@ -0,0 +1,60 @@
+package io.moquette.spi.impl.subscriptions;
+
+import io.moquette.spi.ISessionsStore;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by andrea on 03/03/17.
+ */
+public class TreeNodeTest {
+
+    @Test
+    public void testRemoveTreeNodesAfterEmptySubscriptions() {
+        TreeNode root = new TreeNode();
+        TreeNode subNode1 = new TreeNode();
+
+        subNode1.addSubscription(new ISessionsStore.ClientTopicCouple("Client1", new Topic("/topic1")));
+        root.addChild(subNode1);
+
+        TreeNode updatedRoot = root.removeClientSubscriptions("Client1");
+
+        assertTrue("Empty subscriptions node should be removed", updatedRoot.m_children.isEmpty());
+    }
+
+    @Test
+    public void testRemoveTreeNodesAfterEmptySubscriptions_multiLayer() {
+        TreeNode root = new TreeNode();
+        TreeNode intermediateEmptyNode = new TreeNode();
+        TreeNode subNode1 = new TreeNode();
+
+        subNode1.addSubscription(new ISessionsStore.ClientTopicCouple("Client1", new Topic("/sub/topic1")));
+        intermediateEmptyNode.addChild(subNode1);
+        root.addChild(intermediateEmptyNode);
+
+        TreeNode updatedRoot = root.removeClientSubscriptions("Client1");
+
+        assertTrue("Empty subscriptions node should be removed", updatedRoot.m_children.isEmpty());
+    }
+
+    @Test
+    public void testRemoveTreeNodesAfterEmptySubscriptions_multiLayer_doesntRemoveIntermediateNodes() {
+        TreeNode root = new TreeNode();
+        TreeNode intermediateEmptyNode = new TreeNode();
+
+        TreeNode subNode1 = new TreeNode();
+        subNode1.addSubscription(new ISessionsStore.ClientTopicCouple("Client1", new Topic("/sub/topic1")));
+        intermediateEmptyNode.addChild(subNode1);
+
+        TreeNode subNode2 = new TreeNode();
+        subNode2.addSubscription(new ISessionsStore.ClientTopicCouple("Client2", new Topic("/sub/topic2")));
+        intermediateEmptyNode.addChild(subNode2);
+        root.addChild(intermediateEmptyNode);
+
+        TreeNode updatedRoot = root.removeClientSubscriptions("Client1");
+
+        assertFalse("Remove a subscription shouldn't remove intermediate empty nodes", updatedRoot.m_children.isEmpty());
+    }
+
+}