1 files changed, 38 insertions, 0 deletions
diff --git a/jstests/core/group5.js b/jstests/core/group5.js
new file mode 100644
index 00000000000..3534fe5f030
--- /dev/null
+++ b/jstests/core/group5.js
@@ -0,0 +1,38 @@
+
+t = db.group5;
+t.drop();
+
+// each group has groupnum+1 5 users
+for ( var group=0; group<10; group++ ){
+    for ( var i=0; i<5+group; i++ ){
+        t.save( { group : "group" + group , user : i } )
+    }
+}
+
+function c( group ){
+    return t.group( 
+        { 
+            key : { group : 1 } , 
+            q : { group : "group" + group } ,
+            initial : { users : {} },
+            reduce :  function(obj,prev){
+                prev.users[obj.user] = true; // add this user to the hash
+            },
+            finalize : function(x){
+                var count = 0;
+                for (var key in x.users){
+                    count++;
+                }
+
+                //replace user obj with count
+                //count add new field and keep users
+                x.users = count;
+                return x;
+            }
+        })[0]; // returns array
+}
+
+assert.eq( "group0" , c(0).group , "g0" );
+assert.eq( 5 ,        c(0).users , "g0 a" );
+assert.eq( "group5" , c(5).group , "g5" );
+assert.eq( 10 ,       c(5).users , "g5 a" );