make pass through error code configurable [#2817 state:resolved]

Signed-off-by: NJoshua Peek <josh@joshpeek.com>

railties/lib/rails/rack/metal.rb

@@ -11,6 +11,9 @@ class Metal
       cattr_accessor :metal_paths
       self.metal_paths = ["#{Rails.root}/app/metal"]
       cattr_accessor :requested_metals
+      
+      cattr_accessor :pass_through_on
+      self.pass_through_on = 404
 
       def self.metals
         matcher = /#{Regexp.escape('/app/metal/')}(.*)\.rb\Z/
@@ -36,6 +39,9 @@ def self.metals
 
       def initialize(app)
         @app = app
+        @pass_through_on = {}
+        [*self.class.pass_through_on].each { |status| @pass_through_on[status] = true }
+        
         @metals = ActiveSupport::OrderedHash.new
         self.class.metals.each { |app| @metals[app] = true }
         freeze
@@ -44,7 +50,7 @@ def initialize(app)
       def call(env)
         @metals.keys.each do |app|
           result = app.call(env)
-          return result unless result[0].to_i == 404
+          return result unless @pass_through_on.include?(result[0].to_i)
         end
         @app.call(env)
       end

railties/test/fixtures/metal/multiplemetals/app/metal/metal_a.rb

-class MetalA < Rails::Rack::Metal
+class MetalA
   def self.call(env)
-    [200, { "Content-Type" => "text/html"}, ["Hi"]]
+    [404, { "Content-Type" => "text/html"}, ["Metal A"]]
   end
 end

railties/test/fixtures/metal/multiplemetals/app/metal/metal_b.rb

-class MetalB < Rails::Rack::Metal
+class MetalB
   def self.call(env)
-    [200, { "Content-Type" => "text/html"}, ["Hi"]]
+    [200, { "Content-Type" => "text/html"}, ["Metal B"]]
   end
 end

railties/test/metal_test.rb

@@ -55,8 +55,38 @@ def test_metal_finding_should_work_with_multiple_metal_paths_in_185_and_below
       assert_equal(["FooMetal", "EngineMetal"], found_metals_as_string_array)
     end
   end
+  
+  def test_metal_default_pass_through_on_404
+    use_appdir("multiplemetals") do
+      result = Rails::Rack::Metal.new(app).call({})
+      assert_equal 200, result.first
+      assert_equal ["Metal B"], result.last
+    end
+  end
+  
+  def test_metal_pass_through_on_417
+    use_appdir("multiplemetals") do
+      Rails::Rack::Metal.pass_through_on = 417
+      result = Rails::Rack::Metal.new(app).call({})
+      assert_equal 404, result.first
+      assert_equal ["Metal A"], result.last
+    end
+  end
+  
+  def test_metal_pass_through_on_404_and_200
+    use_appdir("multiplemetals") do
+      Rails::Rack::Metal.pass_through_on = [404, 200]
+      result = Rails::Rack::Metal.new(app).call({})
+      assert_equal 402, result.first
+      assert_equal ["End of the Line"], result.last
+    end
+  end
 
   private
+  
+  def app
+    lambda{[402,{},["End of the Line"]]}
+  end
 
   def use_appdir(root)
     dir = "#{File.dirname(__FILE__)}/fixtures/metal/#{root}"