lib/sprockets.rb in sprockets-4.0.0.beta2 vs lib/sprockets.rb in sprockets-4.0.0.beta3

@@ -1,6 +1,8 @@
 # encoding: utf-8
+# frozen_string_literal: true
+
 require 'sprockets/version'
 require 'sprockets/cache'
 require 'sprockets/environment'
 require 'sprockets/errors'
 require 'sprockets/manifest'
@@ -119,11 +121,11 @@
 
   require 'sprockets/bundle'
   register_bundle_processor 'application/javascript', Bundle
   register_bundle_processor 'text/css', Bundle
 
-  register_bundle_metadata_reducer '*/*', :data, proc { "" }, :concat
-  register_bundle_metadata_reducer 'application/javascript', :data, proc { "" }, Utils.method(:concat_javascript_sources)
+  register_bundle_metadata_reducer '*/*', :data, proc { String.new("") }, :concat
+  register_bundle_metadata_reducer 'application/javascript', :data, proc { String.new("") }, Utils.method(:concat_javascript_sources)
   register_bundle_metadata_reducer '*/*', :links, :+
   register_bundle_metadata_reducer '*/*', :map, SourceMapUtils.method(:concat_source_maps)
 
   require 'sprockets/closure_compressor'
   require 'sprockets/sass_compressor'