Fix for issue #67 - ImmutableSetMultimap ordering

src/main/java/com/fasterxml/jackson/datatype/guava/GuavaDeserializers.java

@@ -197,7 +197,9 @@ public JsonDeserializer<?> findMapLikeDeserializer(MapLikeType type,
             }
 
             if (ImmutableSetMultimap.class.isAssignableFrom(raw)) {
-                // TODO
+                // [Issue#67]: Preserve order of entries
+                return new LinkedHashMultimapDeserializer(type, keyDeserializer,
+                        elementTypeDeserializer, elementDeserializer);
             }
             if (HashMultimap.class.isAssignableFrom(raw)) {
                 return new HashMultimapDeserializer(type, keyDeserializer, elementTypeDeserializer,

src/test/java/com/fasterxml/jackson/datatype/guava/TestMultimaps.java

@@ -7,6 +7,7 @@
 import com.google.common.collect.*;
 
 import java.io.IOException;
+import java.util.Iterator;
 import java.util.Map;
 
 import static com.google.common.collect.TreeMultimap.create;
@@ -235,4 +236,21 @@ private ListMultimap<String, String> listBasedHelper(TypeReference<?> type) thro
         assertTrue(map.containsEntry("second", "bar"));
         return map;
     }
-}
+
+    public void testIssue67() throws IOException
+    {
+        ImmutableSetMultimap<String, Integer> map = MAPPER.readValue(
+            "{\"d\":[1,2],\"c\":[3,4],\"b\":[5,6],\"a\":[7,8]}",
+            new TypeReference<ImmutableSetMultimap<String, Integer>>() {});
+        assertEquals(8, map.size());
+        Iterator<Map.Entry<String, Integer>> iterator = map.entries().iterator();
+        assertEquals(Maps.immutableEntry("d", 1), iterator.next());
+        assertEquals(Maps.immutableEntry("d", 2), iterator.next());
+        assertEquals(Maps.immutableEntry("c", 3), iterator.next());
+        assertEquals(Maps.immutableEntry("c", 4), iterator.next());
+        assertEquals(Maps.immutableEntry("b", 5), iterator.next());
+        assertEquals(Maps.immutableEntry("b", 6), iterator.next());
+        assertEquals(Maps.immutableEntry("a", 7), iterator.next());
+        assertEquals(Maps.immutableEntry("a", 8), iterator.next());
+    }
+}