Reorganize autoloads:

  * A new module (ActiveSupport::Autoload) is provide that extends
    autoloading with new behavior.
  * All autoloads in modules that have extended ActiveSupport::Autoload
    will be eagerly required in threadsafe environments
  * Autoloads can optionally leave off the path if the path is the same
    as full_constant_name.underscore
  * It is possible to specify that a group of autoloads live under an
    additional path. For instance, all of ActionDispatch's middlewares
    are ActionDispatch::MiddlewareName, but they live under 
    "action_dispatch/middlewares/middleware_name"
  * It is possible to specify that a group of autoloads are all found
    at the same path. For instance, a number of exceptions might all
    be declared there.
  * One consequence of this is that testing-related constants are not
    autoloaded. To get the testing helpers for a given component,
    require "component_name/test_case". For instance, "action_controller/test_case".
  * test_help.rb, which is automatically required by a Rails application's
    test helper, requires the test_case.rb for all active components, so
    this change will not be disruptive in existing or new applications.

27 files changed, 343 insertions, 301 deletions

diff --git a/actionpack/lib/abstract_controller.rb b/actionpack/lib/abstract_controller.rb
index 1a6c4278c9..688a2fe31c 100644
--- a/actionpack/lib/abstract_controller.rb
+++ b/actionpack/lib/abstract_controller.rb
@@ -2,15 +2,20 @@ require "active_support/core_ext/module/attr_internal"
 require "active_support/core_ext/module/delegation"
 
 module AbstractController
-  autoload :Base,                "abstract_controller/base"
-  autoload :Callbacks,           "abstract_controller/callbacks"
-  autoload :Helpers,             "abstract_controller/helpers"
-  autoload :Layouts,             "abstract_controller/layouts"
-  autoload :LocalizedCache,      "abstract_controller/localized_cache"
-  autoload :Logger,              "abstract_controller/logger"
-  autoload :RenderingController, "abstract_controller/rendering_controller"
+  extend ActiveSupport::Autoload
+
+  autoload :Base
+  autoload :Callbacks
+  autoload :Helpers
+  autoload :Layouts
+  autoload :LocalizedCache
+  autoload :Logger
+  autoload :RenderingController
+
   # === Exceptions
-  autoload :ActionNotFound,      "abstract_controller/exceptions"
-  autoload :DoubleRenderError,   "abstract_controller/exceptions"
-  autoload :Error,               "abstract_controller/exceptions"
+  autoload_at "abstract_controller/exceptions" do
+    autoload :ActionNotFound
+    autoload :DoubleRenderError
+    autoload :Error
+  end
 end
diff --git a/actionpack/lib/abstract_controller/rendering_controller.rb b/actionpack/lib/abstract_controller/rendering_controller.rb
index 7054b9cf26..777e515d60 100644
--- a/actionpack/lib/abstract_controller/rendering_controller.rb
+++ b/actionpack/lib/abstract_controller/rendering_controller.rb
@@ -115,7 +115,7 @@ module AbstractController
     # _partial<TrueClass, FalseClass>:: Whether or not the file to look up is a partial
     def _determine_template(options)
       if options.key?(:text)
-        options[:_template] = ActionView::TextTemplate.new(options[:text], format_for_text)
+        options[:_template] = ActionView::Template::Text.new(options[:text], format_for_text)
       elsif options.key?(:inline)
         handler = ActionView::Template.handler_class_for_extension(options[:type] || "erb")
         template = ActionView::Template.new(options[:inline], "inline #{options[:inline].inspect}", handler, {})
diff --git a/actionpack/lib/action_controller.rb b/actionpack/lib/action_controller.rb
index 03a40e4fce..f830223058 100644
--- a/actionpack/lib/action_controller.rb
+++ b/actionpack/lib/action_controller.rb
@@ -1,66 +1,72 @@
+require "active_support"
+
 module ActionController
-  autoload :Base,                 "action_controller/base"
-  autoload :Benchmarking,         "action_controller/metal/benchmarking"
-  autoload :ConditionalGet,       "action_controller/metal/conditional_get"
-  autoload :Configuration,        "action_controller/metal/configuration"
-  autoload :Head,                 "action_controller/metal/head"
-  autoload :Helpers,              "action_controller/metal/helpers"
-  autoload :HideActions,          "action_controller/metal/hide_actions"
-  autoload :Layouts,              "action_controller/metal/layouts"
-  autoload :Metal,                "action_controller/metal"
-  autoload :Middleware,           "action_controller/middleware"
-  autoload :RackConvenience,      "action_controller/metal/rack_convenience"
-  autoload :Rails2Compatibility,  "action_controller/metal/compatibility"
-  autoload :Redirector,           "action_controller/metal/redirector"
-  autoload :RenderingController,  "action_controller/metal/rendering_controller"
-  autoload :RenderOptions,        "action_controller/metal/render_options"
-  autoload :Rescue,               "action_controller/metal/rescuable"
-  autoload :Responder,            "action_controller/metal/responder"
-  autoload :Session,              "action_controller/metal/session"
-  autoload :Testing,              "action_controller/metal/testing"
-  autoload :UrlFor,               "action_controller/metal/url_for"
+  extend ActiveSupport::Autoload
 
-  autoload :Caching,           'action_controller/caching'
-  autoload :Dispatcher,        'action_controller/dispatch/dispatcher'
-  autoload :Integration,       'action_controller/deprecated/integration_test'
-  autoload :IntegrationTest,   'action_controller/deprecated/integration_test'
-  autoload :MimeResponds,      'action_controller/metal/mime_responds'
-  autoload :PerformanceTest,   'action_controller/deprecated/performance_test'
-  autoload :PolymorphicRoutes, 'action_controller/polymorphic_routes'
-  autoload :RecordIdentifier,  'action_controller/record_identifier'
-  autoload :Routing,           'action_controller/deprecated'
-  autoload :SessionManagement, 'action_controller/metal/session_management'
-  autoload :TestCase,          'action_controller/testing/test_case'
-  autoload :TestProcess,       'action_controller/testing/process'
-  autoload :UrlRewriter,       'action_controller/url_rewriter'
-  autoload :UrlWriter,         'action_controller/url_rewriter'
+  autoload :Base
+  autoload :Caching
+  autoload :PolymorphicRoutes
+  autoload :RecordIdentifier
+  autoload :UrlRewriter
+  autoload :Translation
+  autoload :Metal
+  autoload :Middleware
 
-  autoload :Verification,             'action_controller/metal/verification'
-  autoload :Flash,                    'action_controller/metal/flash'
-  autoload :RequestForgeryProtection, 'action_controller/metal/request_forgery_protection'
-  autoload :Streaming,                'action_controller/metal/streaming'
-  autoload :HttpAuthentication,       'action_controller/metal/http_authentication'
-  autoload :FilterParameterLogging,   'action_controller/metal/filter_parameter_logging'
-  autoload :Translation,              'action_controller/translation'
-  autoload :Cookies,                  'action_controller/metal/cookies'
+  autoload_under "metal" do
+    autoload :Benchmarking
+    autoload :ConditionalGet
+    autoload :Configuration
+    autoload :Head
+    autoload :Helpers
+    autoload :HideActions
+    autoload :Layouts
+    autoload :MimeResponds
+    autoload :RackConvenience
+    autoload :Compatibility
+    autoload :Redirector
+    autoload :RenderingController
+    autoload :RenderOptions
+    autoload :Rescue
+    autoload :Responder
+    autoload :Session
+    autoload :SessionManagement
+    autoload :UrlFor
+    autoload :Verification
+    autoload :Flash
+    autoload :RequestForgeryProtection
+    autoload :Streaming
+    autoload :HttpAuthentication
+    autoload :FilterParameterLogging
+    autoload :Cookies
+  end
 
-  autoload :ActionControllerError,    'action_controller/metal/exceptions'
-  autoload :RenderError,              'action_controller/metal/exceptions'
-  autoload :RoutingError,             'action_controller/metal/exceptions'
-  autoload :MethodNotAllowed,         'action_controller/metal/exceptions'
-  autoload :NotImplemented,           'action_controller/metal/exceptions'
-  autoload :UnknownController,        'action_controller/metal/exceptions'
-  autoload :MissingFile,              'action_controller/metal/exceptions'
-  autoload :RenderError,              'action_controller/metal/exceptions'
-  autoload :SessionOverflowError,     'action_controller/metal/exceptions'
-  autoload :UnknownHttpMethod,        'action_controller/metal/exceptions'
-end
+  autoload :Dispatcher,               'action_controller/dispatch/dispatcher'
+  autoload :PerformanceTest,          'action_controller/deprecated/performance_test'
+  autoload :Routing,                  'action_controller/deprecated'
+  autoload :Integration,              'action_controller/deprecated/integration_test'
+  autoload :IntegrationTest,          'action_controller/deprecated/integration_test'
 
-autoload :HTML, 'action_controller/vendor/html-scanner'
-autoload :AbstractController, 'abstract_controller'
+  autoload :UrlWriter,                'action_controller/url_rewriter'
+
+  autoload_at "action_controller/metal/exceptions" do
+    autoload :ActionControllerError
+    autoload :RenderError
+    autoload :RoutingError
+    autoload :MethodNotAllowed
+    autoload :NotImplemented
+    autoload :UnknownController
+    autoload :MissingFile
+    autoload :RenderError
+    autoload :SessionOverflowError
+    autoload :UnknownHttpMethod
+  end
+end
 
+# All of these simply register additional autoloads
+require 'abstract_controller'
 require 'action_dispatch'
 require 'action_view'
+require 'action_controller/vendor/html-scanner'
 
 # Common ActiveSupport usage in ActionController
 require "active_support/concern"
diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index 4c026fe5f7..ed3984c9d4 100644
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -24,7 +24,7 @@ module ActionController
     include ActionController::MimeResponds
 
     # Rails 2.x compatibility
-    include ActionController::Rails2Compatibility
+    include ActionController::Compatibility
 
     include ActionController::Cookies
     include ActionController::Session
diff --git a/actionpack/lib/action_controller/caching.rb b/actionpack/lib/action_controller/caching.rb
index 3caf759032..ad357cceda 100644
--- a/actionpack/lib/action_controller/caching.rb
+++ b/actionpack/lib/action_controller/caching.rb
@@ -30,10 +30,11 @@ module ActionController #:nodoc:
   #   config.action_controller.cache_store = MyOwnStore.new("parameter")
   module Caching
     extend ActiveSupport::Concern
+    extend ActiveSupport::Autoload
 
-    autoload :Actions, 'action_controller/caching/actions'
-    autoload :Fragments, 'action_controller/caching/fragments'
-    autoload :Pages, 'action_controller/caching/pages'
+    autoload :Actions
+    autoload :Fragments
+    autoload :Pages
     autoload :Sweeper, 'action_controller/caching/sweeping'
     autoload :Sweeping, 'action_controller/caching/sweeping'
 
diff --git a/actionpack/lib/action_controller/deprecated/integration_test.rb b/actionpack/lib/action_controller/deprecated/integration_test.rb
index 86336b6bc4..05c8c0f156 100644
--- a/actionpack/lib/action_controller/deprecated/integration_test.rb
+++ b/actionpack/lib/action_controller/deprecated/integration_test.rb
@@ -1,2 +1,4 @@
+require "action_dispatch/testing/integration"
+
 ActionController::Integration = ActionDispatch::Integration
 ActionController::IntegrationTest = ActionDispatch::IntegrationTest
diff --git a/actionpack/lib/action_controller/metal/compatibility.rb b/actionpack/lib/action_controller/metal/compatibility.rb
index 0c264fcd09..a90f798cd5 100644
--- a/actionpack/lib/action_controller/metal/compatibility.rb
+++ b/actionpack/lib/action_controller/metal/compatibility.rb
@@ -1,5 +1,5 @@
 module ActionController
-  module Rails2Compatibility
+  module Compatibility
     extend ActiveSupport::Concern
 
     class ::ActionController::ActionControllerError < StandardError #:nodoc:
diff --git a/actionpack/lib/action_controller/metal/helpers.rb b/actionpack/lib/action_controller/metal/helpers.rb
index b4325e24ad..d0402e5bad 100644
--- a/actionpack/lib/action_controller/metal/helpers.rb
+++ b/actionpack/lib/action_controller/metal/helpers.rb
@@ -52,7 +52,7 @@ module ActionController
     included do
       # Set the default directory for helpers
       extlib_inheritable_accessor(:helpers_dir) do
-        defined?(Rails) ? "#{Rails.root}/app/helpers" : "app/helpers"
+        defined?(Rails.root) ? "#{Rails.root}/app/helpers" : "app/helpers"
       end
     end
 
diff --git a/actionpack/lib/action_controller/metal/rescuable.rb b/actionpack/lib/action_controller/metal/rescue.rb
index bbca1b2179..bbca1b2179 100644
--- a/actionpack/lib/action_controller/metal/rescuable.rb
+++ b/actionpack/lib/action_controller/metal/rescue.rb
diff --git a/actionpack/lib/action_controller/testing/test_case.rb b/actionpack/lib/action_controller/test_case.rb
index 01a55fe930..7533a22299 100644
--- a/actionpack/lib/action_controller/testing/test_case.rb
+++ b/actionpack/lib/action_controller/test_case.rb
@@ -1,5 +1,8 @@
 require 'active_support/test_case'
 require 'rack/session/abstract/id'
+require 'action_controller/metal/testing'
+require 'action_controller/testing/process'
+require 'action_dispatch/test_case'
 
 module ActionController
   class TestRequest < ActionDispatch::TestRequest #:nodoc:
diff --git a/actionpack/lib/action_controller/vendor/html-scanner.rb b/actionpack/lib/action_controller/vendor/html-scanner.rb
index f622d195ee..2cb20ddd05 100644
--- a/actionpack/lib/action_controller/vendor/html-scanner.rb
+++ b/actionpack/lib/action_controller/vendor/html-scanner.rb
@@ -1,6 +1,8 @@
 $LOAD_PATH << "#{File.dirname(__FILE__)}/html-scanner"
 
 module HTML
+  extend ActiveSupport::Autoload
+
   autoload :CDATA, 'html/node'
   autoload :Document, 'html/document'
   autoload :FullSanitizer, 'html/sanitizer'
diff --git a/actionpack/lib/action_dispatch.rb b/actionpack/lib/action_dispatch.rb
index 259814a322..e21dbc59cc 100644
--- a/actionpack/lib/action_dispatch.rb
+++ b/actionpack/lib/action_dispatch.rb
@@ -28,37 +28,38 @@ module Rack
 end
 
 module ActionDispatch
-  autoload :Request, 'action_dispatch/http/request'
-  autoload :Response, 'action_dispatch/http/response'
-  autoload :StatusCodes, 'action_dispatch/http/status_codes'
-  autoload :Utils, 'action_dispatch/http/utils'
+  extend ActiveSupport::Autoload
 
-  autoload :Callbacks, 'action_dispatch/middleware/callbacks'
-  autoload :MiddlewareStack, 'action_dispatch/middleware/stack'
-  autoload :ParamsParser, 'action_dispatch/middleware/params_parser'
-  autoload :Rescue, 'action_dispatch/middleware/rescue'
-  autoload :ShowExceptions, 'action_dispatch/middleware/show_exceptions'
-  autoload :Static, 'action_dispatch/middleware/static'
-  autoload :StringCoercion, 'action_dispatch/middleware/string_coercion'
+  autoload_under "http" do
+    autoload :Request
+    autoload :Response
+    autoload :StatusCodes
+    autoload :Utils
+  end
 
-  autoload :Routing, 'action_dispatch/routing'
+  autoload_under "middleware" do
+    autoload :Callbacks
+    autoload :ParamsParser
+    autoload :Rescue
+    autoload :ShowExceptions
+    autoload :Static
+    autoload :StringCoercion
+  end
 
-  autoload :Assertions, 'action_dispatch/testing/assertions'
-  autoload :Integration, 'action_dispatch/testing/integration'
-  autoload :IntegrationTest, 'action_dispatch/testing/integration'
-  autoload :PerformanceTest, 'action_dispatch/testing/performance_test'
-  autoload :TestRequest, 'action_dispatch/testing/test_request'
-  autoload :TestResponse, 'action_dispatch/testing/test_response'
+  autoload :MiddlewareStack, 'action_dispatch/middleware/stack'
+  autoload :Routing
 
   autoload :HTML, 'action_controller/vendor/html-scanner'
 
   module Http
-    autoload :Headers, 'action_dispatch/http/headers'
+    extend ActiveSupport::Autoload
+
+    autoload :Headers
   end
 
   module Session
     autoload :AbstractStore, 'action_dispatch/middleware/session/abstract_store'
-    autoload :CookieStore, 'action_dispatch/middleware/session/cookie_store'
+    autoload :CookieStore,   'action_dispatch/middleware/session/cookie_store'
     autoload :MemCacheStore, 'action_dispatch/middleware/session/mem_cache_store'
   end
 end
diff --git a/actionpack/lib/action_dispatch/middleware/show_exceptions.rb b/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
index 036deec6d2..67c70a0418 100644
--- a/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
@@ -29,7 +29,7 @@ module ActionDispatch
       'ActionView::MissingTemplate'         => 'missing_template',
       'ActionController::RoutingError'      => 'routing_error',
       ActionController::UnknownAction.name  => 'unknown_action',
-      'ActionView::TemplateError'           => 'template_error'
+      'ActionView::Template::Error'         => 'template_error'
     })
 
     FAILSAFE_RESPONSE = [500, {'Content-Type' => 'text/html'},
@@ -119,7 +119,7 @@ module ActionDispatch
         return unless logger
 
         ActiveSupport::Deprecation.silence do
-          if ActionView::TemplateError === exception
+          if ActionView::Template::Error === exception
             logger.fatal(exception.to_s)
           else
             logger.fatal(
diff --git a/actionpack/lib/action_dispatch/test_case.rb b/actionpack/lib/action_dispatch/test_case.rb
new file mode 100644
index 0000000000..afd708f06f
--- /dev/null
+++ b/actionpack/lib/action_dispatch/test_case.rb
@@ -0,0 +1,6 @@
+require "action_dispatch/testing/assertions"
+require "action_dispatch/testing/integration"
+require "action_dispatch/testing/performance_test"
+require "action_dispatch/testing/test_request"
+require "action_dispatch/testing/test_response"
+require "action_dispatch/testing/integration"
\ No newline at end of file
diff --git a/actionpack/lib/action_view.rb b/actionpack/lib/action_view.rb
index f6f7ec0c8c..81ee19d996 100644
--- a/actionpack/lib/action_view.rb
+++ b/actionpack/lib/action_view.rb
@@ -24,27 +24,25 @@
 require File.join(File.dirname(__FILE__), "action_pack")
 
 module ActionView
-  def self.load_all!
-    [Context, Base, TemplateError]
+  extend ActiveSupport::Autoload
+
+  autoload :Base
+  autoload :Context
+  autoload :Template
+  autoload :Helpers
+  autoload :SafeBuffer
+
+
+  autoload_under "render" do
+    autoload :Partials
+    autoload :Rendering
   end
 
-  autoload :Base,              'action_view/base'
-  autoload :Context,           'action_view/context'
-  autoload :Helpers,           'action_view/helpers'
   autoload :MissingTemplate,   'action_view/base'
-  autoload :Partials,          'action_view/render/partials'
   autoload :Resolver,          'action_view/template/resolver'
   autoload :PathResolver,      'action_view/template/resolver'
   autoload :PathSet,           'action_view/paths'
-  autoload :Rendering,         'action_view/render/rendering'
-  autoload :Template,          'action_view/template/template'
-  autoload :TemplateError,     'action_view/template/error'
-  autoload :TemplateHandler,   'action_view/template/handler'
-  autoload :TemplateHandlers,  'action_view/template/handlers'
-  autoload :TextTemplate,      'action_view/template/text'
-  autoload :Helpers,           'action_view/helpers'
   autoload :FileSystemResolverWithFallback, 'action_view/template/resolver'
-  autoload :SafeBuffer,        'action_view/safe_buffer'
 end
 
 require 'action_view/erb/util'
diff --git a/actionpack/lib/action_view/base.rb b/actionpack/lib/action_view/base.rb
index c33695770f..d69e5109fa 100644
--- a/actionpack/lib/action_view/base.rb
+++ b/actionpack/lib/action_view/base.rb
@@ -196,7 +196,7 @@ module ActionView #:nodoc:
     end
 
     class << self
-      delegate :erb_trim_mode=, :to => 'ActionView::TemplateHandlers::ERB'
+      delegate :erb_trim_mode=, :to => 'ActionView::Template::Handlers::ERB'
       delegate :logger, :to => 'ActionController::Base', :allow_nil => true
     end
 
diff --git a/actionpack/lib/action_view/paths.rb b/actionpack/lib/action_view/paths.rb
index 23bde61f9c..0059b79e5f 100644
--- a/actionpack/lib/action_view/paths.rb
+++ b/actionpack/lib/action_view/paths.rb
@@ -4,7 +4,7 @@ module ActionView #:nodoc:
       # TODO: Clean this up
       if obj.is_a?(String)
         if cache.nil?
-          cache = !defined?(Rails) || Rails.application.config.cache_classes
+          cache = !defined?(Rails.application) || Rails.application.config.cache_classes
         end
         FileSystemResolverWithFallback.new(obj, :cache => cache)
       else
diff --git a/actionpack/lib/action_view/template/template.rb b/actionpack/lib/action_view/template.rb
index d1970ca3c7..210ad508f5 100644
--- a/actionpack/lib/action_view/template/template.rb
+++ b/actionpack/lib/action_view/template.rb
@@ -6,7 +6,14 @@ require "action_view/template/resolver"
 
 module ActionView
   class Template
-    extend TemplateHandlers
+    extend ActiveSupport::Autoload
+    
+    autoload :Error
+    autoload :Handler
+    autoload :Handlers
+    autoload :Text
+    
+    extend Template::Handlers
     attr_reader :source, :identifier, :handler, :mime_type, :formats, :details
 
     def initialize(source, identifier, handler, details)
@@ -32,11 +39,11 @@ module ActionView
         view.send(method_name, locals, &block)
       end
     rescue Exception => e
-      if e.is_a?(TemplateError)
+      if e.is_a?(Template::Error)
         e.sub_template_of(self)
         raise e
       else
-        raise TemplateError.new(self, view.assigns, e)
+        raise Template::Error.new(self, view.assigns, e)
       end
     end
 
@@ -103,7 +110,7 @@ module ActionView
             logger.debug "Backtrace: #{e.backtrace.join("\n")}"
           end
 
-          raise ActionView::TemplateError.new(self, {}, e)
+          raise ActionView::Template::Error.new(self, {}, e)
         end
       end
 
diff --git a/actionpack/lib/action_view/template/error.rb b/actionpack/lib/action_view/template/error.rb
index aa21606f76..a136d4333b 100644
--- a/actionpack/lib/action_view/template/error.rb
+++ b/actionpack/lib/action_view/template/error.rb
@@ -1,101 +1,103 @@
 require "active_support/core_ext/enumerable"
 
 module ActionView
-  # The TemplateError exception is raised when the compilation of the template fails. This exception then gathers a
-  # bunch of intimate details and uses it to report a very precise exception message.
-  class TemplateError < ActionViewError #:nodoc:
-    SOURCE_CODE_RADIUS = 3
+  class Template
+    # The Template::Error exception is raised when the compilation of the template fails. This exception then gathers a
+    # bunch of intimate details and uses it to report a very precise exception message.
+    class Error < ActionViewError #:nodoc:
+      SOURCE_CODE_RADIUS = 3
 
-    attr_reader :original_exception
+      attr_reader :original_exception
 
-    def initialize(template, assigns, original_exception)
-      @template, @assigns, @original_exception = template, assigns.dup, original_exception
-      @backtrace = compute_backtrace
-    end
+      def initialize(template, assigns, original_exception)
+        @template, @assigns, @original_exception = template, assigns.dup, original_exception
+        @backtrace = compute_backtrace
+      end
 
-    def file_name
-      @template.identifier
-    end
+      def file_name
+        @template.identifier
+      end
 
-    def message
-      ActiveSupport::Deprecation.silence { original_exception.message }
-    end
+      def message
+        ActiveSupport::Deprecation.silence { original_exception.message }
+      end
 
-    def clean_backtrace
-      if defined?(Rails) && Rails.respond_to?(:backtrace_cleaner)
-        Rails.backtrace_cleaner.clean(original_exception.backtrace)
-      else
-        original_exception.backtrace
+      def clean_backtrace
+        if defined?(Rails) && Rails.respond_to?(:backtrace_cleaner)
+          Rails.backtrace_cleaner.clean(original_exception.backtrace)
+        else
+          original_exception.backtrace
+        end
       end
-    end
 
-    def sub_template_message
-      if @sub_templates
-        "Trace of template inclusion: " +
-        @sub_templates.collect { |template| template.inspect }.join(", ")
-      else
-        ""
+      def sub_template_message
+        if @sub_templates
+          "Trace of template inclusion: " +
+          @sub_templates.collect { |template| template.inspect }.join(", ")
+        else
+          ""
+        end
       end
-    end
 
-    def source_extract(indentation = 0)
-      return unless num = line_number
-      num = num.to_i
+      def source_extract(indentation = 0)
+        return unless num = line_number
+        num = num.to_i
 
-      source_code = @template.source.split("\n")
+        source_code = @template.source.split("\n")
 
-      start_on_line = [ num - SOURCE_CODE_RADIUS - 1, 0 ].max
-      end_on_line   = [ num + SOURCE_CODE_RADIUS - 1, source_code.length].min
+        start_on_line = [ num - SOURCE_CODE_RADIUS - 1, 0 ].max
+        end_on_line   = [ num + SOURCE_CODE_RADIUS - 1, source_code.length].min
 
-      indent = ' ' * indentation
-      line_counter = start_on_line
-      return unless source_code = source_code[start_on_line..end_on_line]
+        indent = ' ' * indentation
+        line_counter = start_on_line
+        return unless source_code = source_code[start_on_line..end_on_line]
 
-      source_code.sum do |line|
-        line_counter += 1
-        "#{indent}#{line_counter}: #{line}\n"
+        source_code.sum do |line|
+          line_counter += 1
+          "#{indent}#{line_counter}: #{line}\n"
+        end
       end
-    end
 
-    def sub_template_of(template_path)
-      @sub_templates ||= []
-      @sub_templates << template_path
-    end
-
-    def line_number
-      @line_number ||=
-        if file_name
-          regexp = /#{Regexp.escape File.basename(file_name)}:(\d+)/
-
-          $1 if message =~ regexp or clean_backtrace.find { |line| line =~ regexp }
-        end
-    end
+      def sub_template_of(template_path)
+        @sub_templates ||= []
+        @sub_templates << template_path
+      end
 
-    def to_s
-      "\n#{self.class} (#{message}) #{source_location}:\n" + 
-      "#{source_extract}\n    #{clean_backtrace.join("\n    ")}\n\n"
-    end
+      def line_number
+        @line_number ||=
+          if file_name
+            regexp = /#{Regexp.escape File.basename(file_name)}:(\d+)/
 
-    # don't do anything nontrivial here. Any raised exception from here becomes fatal 
-    # (and can't be rescued).
-    def backtrace
-      @backtrace
-    end
+            $1 if message =~ regexp or clean_backtrace.find { |line| line =~ regexp }
+          end
+      end
 
-    private
-      def compute_backtrace
-        [
-          "#{source_location.capitalize}\n\n#{source_extract(4)}\n    " +
-          clean_backtrace.join("\n    ")
-        ]
+      def to_s
+        "\n#{self.class} (#{message}) #{source_location}:\n" + 
+        "#{source_extract}\n    #{clean_backtrace.join("\n    ")}\n\n"
       end
 
-      def source_location
-        if line_number
-          "on line ##{line_number} of "
-        else
-          'in '
-        end + file_name
+      # don't do anything nontrivial here. Any raised exception from here becomes fatal 
+      # (and can't be rescued).
+      def backtrace
+        @backtrace
       end
+
+      private
+        def compute_backtrace
+          [
+            "#{source_location.capitalize}\n\n#{source_extract(4)}\n    " +
+            clean_backtrace.join("\n    ")
+          ]
+        end
+
+        def source_location
+          if line_number
+            "on line ##{line_number} of "
+          else
+            'in '
+          end + file_name
+        end
+    end
   end
 end
\ No newline at end of file
diff --git a/actionpack/lib/action_view/template/handler.rb b/actionpack/lib/action_view/template/handler.rb
index 4bf58b9fa8..5a46a27893 100644
--- a/actionpack/lib/action_view/template/handler.rb
+++ b/actionpack/lib/action_view/template/handler.rb
@@ -3,34 +3,39 @@ require "action_dispatch/http/mime_type"
 
 # Legacy TemplateHandler stub
 module ActionView
-  module TemplateHandlers #:nodoc:
-    module Compilable
-      def self.included(base)
-        base.extend(ClassMethods)
-      end
+  class Template
+    module Handlers #:nodoc:
+      module Compilable
+        def self.included(base)
+          base.extend(ClassMethods)
+        end
 
-      module ClassMethods
-        def call(template)
-          new.compile(template)
+        module ClassMethods
+          def call(template)
+            new.compile(template)
+          end
         end
-      end
 
-      def compile(template)
-         raise "Need to implement #{self.class.name}#compile(template)"
-       end
+        def compile(template)
+           raise "Need to implement #{self.class.name}#compile(template)"
+         end
+      end
     end
-  end
 
-  class TemplateHandler
-    extlib_inheritable_accessor :default_format
-    self.default_format = Mime::HTML
+    class Template::Handler
+      extlib_inheritable_accessor :default_format
+      self.default_format = Mime::HTML
 
-    def self.call(template)
-      raise "Need to implement #{self.class.name}#call(template)"
-    end
+      def self.call(template)
+        raise "Need to implement #{self.class.name}#call(template)"
+      end
 
-    def render(template, local_assigns)
-      raise "Need to implement #{self.class.name}#render(template, local_assigns)"
+      def render(template, local_assigns)
+        raise "Need to implement #{self.class.name}#render(template, local_assigns)"
+      end
     end
   end
+  
+  TemplateHandlers = Template::Handlers
+  TemplateHandler = Template::Handler
 end
diff --git a/actionpack/lib/action_view/template/handlers.rb b/actionpack/lib/action_view/template/handlers.rb
index faf54b9fe5..35488c0391 100644
--- a/actionpack/lib/action_view/template/handlers.rb
+++ b/actionpack/lib/action_view/template/handlers.rb
@@ -1,52 +1,54 @@
 module ActionView #:nodoc:
-  module TemplateHandlers #:nodoc:
-    autoload :ERB, 'action_view/template/handlers/erb'
-    autoload :RJS, 'action_view/template/handlers/rjs'
-    autoload :Builder, 'action_view/template/handlers/builder'
-
-    def self.extended(base)
-      base.register_default_template_handler :erb, TemplateHandlers::ERB
-      base.register_template_handler :rjs, TemplateHandlers::RJS
-      base.register_template_handler :builder, TemplateHandlers::Builder
-
-      # TODO: Depreciate old template extensions
-      base.register_template_handler :rhtml, TemplateHandlers::ERB
-      base.register_template_handler :rxml, TemplateHandlers::Builder
-    end
-
-    @@template_handlers = {}
-    @@default_template_handlers = nil
+  class Template
+    module Handlers #:nodoc:
+      autoload :ERB, 'action_view/template/handlers/erb'
+      autoload :RJS, 'action_view/template/handlers/rjs'
+      autoload :Builder, 'action_view/template/handlers/builder'
+
+      def self.extended(base)
+        base.register_default_template_handler :erb, ERB
+        base.register_template_handler :rjs, RJS
+        base.register_template_handler :builder, Builder
+
+        # TODO: Depreciate old template extensions
+        base.register_template_handler :rhtml, ERB
+        base.register_template_handler :rxml, Builder
+      end
+
+      @@template_handlers = {}
+      @@default_template_handlers = nil
     
-    def self.extensions
-      @@template_handlers.keys
-    end
-
-    # Register a class that knows how to handle template files with the given
-    # extension. This can be used to implement new template types.
-    # The constructor for the class must take the ActiveView::Base instance
-    # as a parameter, and the class must implement a +render+ method that
-    # takes the contents of the template to render as well as the Hash of
-    # local assigns available to the template. The +render+ method ought to
-    # return the rendered template as a string.
-    def register_template_handler(extension, klass)
-      @@template_handlers[extension.to_sym] = klass
-    end
-
-    def template_handler_extensions
-      @@template_handlers.keys.map {|key| key.to_s }.sort
-    end
-
-    def registered_template_handler(extension)
-      extension && @@template_handlers[extension.to_sym]
-    end
-
-    def register_default_template_handler(extension, klass)
-      register_template_handler(extension, klass)
-      @@default_template_handlers = klass
-    end
-
-    def handler_class_for_extension(extension)
-      (extension && registered_template_handler(extension.to_sym)) || @@default_template_handlers
+      def self.extensions
+        @@template_handlers.keys
+      end
+
+      # Register a class that knows how to handle template files with the given
+      # extension. This can be used to implement new template types.
+      # The constructor for the class must take the ActiveView::Base instance
+      # as a parameter, and the class must implement a +render+ method that
+      # takes the contents of the template to render as well as the Hash of
+      # local assigns available to the template. The +render+ method ought to
+      # return the rendered template as a string.
+      def register_template_handler(extension, klass)
+        @@template_handlers[extension.to_sym] = klass
+      end
+
+      def template_handler_extensions
+        @@template_handlers.keys.map {|key| key.to_s }.sort
+      end
+
+      def registered_template_handler(extension)
+        extension && @@template_handlers[extension.to_sym]
+      end
+
+      def register_default_template_handler(extension, klass)
+        register_template_handler(extension, klass)
+        @@default_template_handlers = klass
+      end
+
+      def handler_class_for_extension(extension)
+        (extension && registered_template_handler(extension.to_sym)) || @@default_template_handlers
+      end
     end
   end
 end
diff --git a/actionpack/lib/action_view/template/handlers/builder.rb b/actionpack/lib/action_view/template/handlers/builder.rb
index 5f381f7bf0..a93cfca8aa 100644
--- a/actionpack/lib/action_view/template/handlers/builder.rb
+++ b/actionpack/lib/action_view/template/handlers/builder.rb
@@ -1,6 +1,6 @@
 module ActionView
-  module TemplateHandlers
-    class Builder < TemplateHandler
+  module Template::Handlers
+    class Builder < Template::Handler
       include Compilable
 
       self.default_format = Mime::XML
diff --git a/actionpack/lib/action_view/template/handlers/erb.rb b/actionpack/lib/action_view/template/handlers/erb.rb
index 88aeb4b053..f8e6376589 100644
--- a/actionpack/lib/action_view/template/handlers/erb.rb
+++ b/actionpack/lib/action_view/template/handlers/erb.rb
@@ -3,7 +3,7 @@ require 'active_support/core_ext/string/output_safety'
 require 'erubis'
 
 module ActionView
-  module TemplateHandlers
+  module Template::Handlers
     class Erubis < ::Erubis::Eruby
       def add_preamble(src)
         src << "@output_buffer = ActionView::SafeBuffer.new;"
@@ -26,7 +26,7 @@ module ActionView
       end
     end
 
-    class ERB < TemplateHandler
+    class ERB < Template::Handler
       include Compilable
 
       ##
diff --git a/actionpack/lib/action_view/template/handlers/rjs.rb b/actionpack/lib/action_view/template/handlers/rjs.rb
index b1d15dc209..63e7dc0902 100644
--- a/actionpack/lib/action_view/template/handlers/rjs.rb
+++ b/actionpack/lib/action_view/template/handlers/rjs.rb
@@ -1,6 +1,6 @@
 module ActionView
-  module TemplateHandlers
-    class RJS < TemplateHandler
+  module Template::Handlers
+    class RJS < Template::Handler
       include Compilable
 
       self.default_format = Mime::JS
diff --git a/actionpack/lib/action_view/template/resolver.rb b/actionpack/lib/action_view/template/resolver.rb
index 7336114e1b..a2f4ab2ef5 100644
--- a/actionpack/lib/action_view/template/resolver.rb
+++ b/actionpack/lib/action_view/template/resolver.rb
@@ -1,6 +1,6 @@
 require "pathname"
 require "active_support/core_ext/class"
-require "action_view/template/template"
+require "action_view/template"
 
 module ActionView
   # Abstract superclass
@@ -20,7 +20,7 @@ module ActionView
     register_detail(:locale)  { [I18n.locale] }
     register_detail(:formats) { Mime::SET.symbols }
     register_detail(:handlers, :allow_nil => false) do
-      TemplateHandlers.extensions
+      Template::Handlers.extensions
     end
 
     def initialize(options = {})
@@ -65,7 +65,7 @@ module ActionView
     # as well as incorrectly putting part of the path in the template
     # name instead of the prefix.
     def normalize_name(name, prefix)
-      handlers = TemplateHandlers.extensions.join('|')
+      handlers = Template::Handlers.extensions.join('|')
       name = name.to_s.gsub(/\.(?:#{handlers})$/, '')
 
       parts = name.split('/')
diff --git a/actionpack/lib/action_view/template/text.rb b/actionpack/lib/action_view/template/text.rb
index f6e011a5ab..67e086d8bd 100644
--- a/actionpack/lib/action_view/template/text.rb
+++ b/actionpack/lib/action_view/template/text.rb
@@ -1,38 +1,40 @@
 module ActionView #:nodoc:
-  class TextTemplate < String #:nodoc:
-    HTML = Mime[:html]
-
-    def initialize(string, content_type = HTML)
-      super(string.to_s)
-      @content_type = Mime[content_type] || content_type
-    end
-
-    def details
-      {:formats => [@content_type.to_sym]}
-    end
-
-    def identifier
-      self
-    end
-
-    def inspect
-      'text template'
-    end
-
-    def render(*args)
-      to_s
-    end
-
-    def mime_type
-      @content_type
-    end
-
-    def formats
-      [mime_type]
-    end
-
-    def partial?
-      false
+  class Template
+    class Text < String #:nodoc:
+      HTML = Mime[:html]
+
+      def initialize(string, content_type = HTML)
+        super(string.to_s)
+        @content_type = Mime[content_type] || content_type
+      end
+
+      def details
+        {:formats => [@content_type.to_sym]}
+      end
+
+      def identifier
+        self
+      end
+
+      def inspect
+        'text template'
+      end
+
+      def render(*args)
+        to_s
+      end
+
+      def mime_type
+        @content_type
+      end
+
+      def formats
+        [mime_type]
+      end
+
+      def partial?
+        false
+      end
     end
   end
 end
diff --git a/actionpack/lib/action_view/test_case.rb b/actionpack/lib/action_view/test_case.rb
index 86bbad822d..ab5bc49cf9 100644
--- a/actionpack/lib/action_view/test_case.rb
+++ b/actionpack/lib/action_view/test_case.rb
@@ -1,5 +1,5 @@
 require 'active_support/test_case'
-require 'action_controller/testing/test_case'
+require 'action_controller/test_case'
 
 module ActionView
   class Base