Scope js to it's own IIFE

public/assets/enhancements.js

@@ -1,3 +1,5 @@
+(function() {
+
   // Check if DOM has already loaded as we're loading async
   ['interactive', 'complete'].indexOf(document.readyState) >= 0
     ? init()
@@ -6,3 +8,5 @@
   // When DOM is ready
   function init() {
   }
+
+})();