Ensure metals and initializers in plugins are loaded.

1 files changed, 22 insertions, 7 deletions

diff --git a/railties/lib/rails/rack/metal.rb b/railties/lib/rails/rack/metal.rb
index 565f95d7c4..732936da32 100644
--- a/railties/lib/rails/rack/metal.rb
+++ b/railties/lib/rails/rack/metal.rb
@@ -3,14 +3,29 @@ require 'action_dispatch'
 module Rails
   module Rack
     class Metal
-      def initialize(metal_roots, metals=nil)
-        load_list = metals || Dir["{#{metal_roots.join(",")}}/**/*.rb"]
+      def self.paths
+        @paths ||= []
+      end
+
+      def initialize(list=nil)
+        metals = []
+        list   = Array(list || :all).map(&:to_sym)
+
+        self.class.paths.each do |path|
+          matcher = /\A#{Regexp.escape(path)}\/(.*)\.rb\Z/
+          Dir.glob("#{path}/**/*.rb").sort.each do |metal_path|
+            metal = metal_path.sub(matcher, '\1').to_sym
+            next unless list.include?(metal) || list.include?(:all)
+            require_dependency metal
+            metals << metal
+          end
+        end
+
+        metals = metals.sort_by do |m|
+          [list.index(m) || list.index(:all), m.to_s]
+        end
 
-        @metals = load_list.map { |metal|
-          metal = File.basename(metal, '.rb')
-          require_dependency metal
-          metal.camelize.constantize
-        }.compact
+        @metals = metals.map { |m| m.to_s.camelize.constantize }
       end
 
       def new(app)