correctly handle nonexistent metadata ID

Signed-off-by: Richard Ogin <rogin@users.noreply.github.com>

Author: rogin

server/src/com/mirth/connect/server/userutil/DestinationSet.java

@@ -101,9 +101,9 @@ public boolean removeAllExcept(Object metaDataIdOrConnectorName) {
         if (metaDataIds != null) {
             Integer metaDataId = convertToMetaDataId(metaDataIdOrConnectorName);
 
-            if (metaDataId != null) {
-                return metaDataIds.retainAll(Collections.singleton(metaDataId));
-            }
+            Set<Integer> set = (metaDataId != null) ? Collections.singleton(metaDataId) : Collections.emptySet();
+            
+            return metaDataIds.retainAll(set);
         }
 
         return false;

server/test/com/mirth/connect/server/userutil/DestinationSetTest.java

@@ -0,0 +1,101 @@
+package com.mirth.connect.server.userutil;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.junit.Test;
+
+import com.mirth.connect.donkey.model.message.ConnectorMessage;
+import com.mirth.connect.donkey.server.Constants;
+import com.mirth.connect.userutil.ImmutableConnectorMessage;
+
+public class DestinationSetTest {
+    private Set<Integer> createMetadataIds() {
+        Set<Integer> metaDataIds = new HashSet<>();
+        metaDataIds.add(1);
+        metaDataIds.add(3);
+        metaDataIds.add(5);
+        metaDataIds.add(7);
+        metaDataIds.add(9);
+
+        return metaDataIds;
+    }
+
+    private Map<String, Integer> createDestinationIdMap() {
+        Map<String, Integer> destinationIdMap = new HashMap<>();
+        destinationIdMap.put("One", 1);
+        destinationIdMap.put("Three", 3);
+        destinationIdMap.put("Five", 5);
+        destinationIdMap.put("Seven", 7);
+        destinationIdMap.put("Nine", 9);
+
+        return destinationIdMap;
+    }
+
+    private ImmutableConnectorMessage createMessage(Map<String, Integer> destinationIdMap, Set<Integer> metadataIds) {
+        ConnectorMessage cm = new ConnectorMessage();
+
+        if(metadataIds != null) {
+            cm.getSourceMap().put(Constants.DESTINATION_SET_KEY, metadataIds);
+        }
+
+        if(destinationIdMap != null) {
+            return new ImmutableConnectorMessage(cm,true, destinationIdMap);
+        } else {
+            return new ImmutableConnectorMessage(cm, true);
+        }
+    }
+
+    @Test
+    public void test_removeAllExceptObject_withSourceMap_removeAllForMetadataIdWhichDoesNotExist() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        assertTrue(destinationSet.removeAllExcept("I_DONT_EXIST"));
+        assertTrue(metaDataIds.isEmpty());
+    }
+
+    @Test
+    public void test_removeAllExceptObject_withSourceMap_removeForMatchingMetadataId() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        assertTrue(destinationSet.removeAllExcept(3));
+        assertTrue(metaDataIds.size() == 1);
+    }
+
+    @Test
+    public void test_removeAllExceptObject_withSourceMap_removeForMatchingConnectorName() throws Exception {
+        Set<Integer> metaDataIds = createMetadataIds();
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), metaDataIds));
+
+        assertTrue(destinationSet.removeAllExcept("Seven"));
+        assertTrue(metaDataIds.size() == 1);
+    }
+
+    @Test
+    public void test_removeAllExceptObject_noSourceMap_noRemovalForMetadataIdWhichDoesNotExist() throws Exception {
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), null));
+
+        assertFalse(destinationSet.removeAllExcept("I_DONT_EXIST"));
+    }
+
+    @Test
+    public void test_removeAllExceptObject_noSourceMap_noRemovalForMatchingMetadataId() throws Exception {
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), null));
+
+        assertFalse(destinationSet.removeAllExcept(3));
+    }
+
+    @Test
+    public void test_removeAllExceptObject_noSourceMap_noRemovalForMatchingConnectorName() throws Exception {
+        DestinationSet destinationSet = new DestinationSet(createMessage(createDestinationIdMap(), null));
+
+        assertFalse(destinationSet.removeAllExcept("Seven"));
+    }
+}