actually filter empty groups

Author: kritzcreek

package.json

@@ -6,6 +6,6 @@
   },
   "dependencies": {
     "pulp": "^12.2.0",
-    "purescript": "slamdata/node-purescript#0.12"
+    "purescript": "^0.12.0"
   }
 }

src/MoteRunner.purs

@@ -98,5 +98,5 @@ shouldKeep pattern = case _ of
         let
           filtered = Array.mapMaybe (shouldKeep pattern) (unPlan value)
         in
-          guard (Array.null filtered) $>
+          guard (not Array.null filtered) $>
             (Plan.Group { label, bracket, value: Plan filtered })