Provide a cleaner syntax for paths configuration that does not rely on method_missing.

21 files changed, 359 insertions, 270 deletions

diff --git a/actionmailer/lib/action_mailer/railtie.rb b/actionmailer/lib/action_mailer/railtie.rb
index 86136bdafd..d67a5b6521 100644
--- a/actionmailer/lib/action_mailer/railtie.rb
+++ b/actionmailer/lib/action_mailer/railtie.rb
@@ -14,9 +14,9 @@ module ActionMailer
       paths   = app.config.paths
       options = app.config.action_mailer
 
-      options.assets_dir      ||= paths.public.to_a.first
-      options.javascripts_dir ||= paths.public.javascripts.to_a.first
-      options.stylesheets_dir ||= paths.public.stylesheets.to_a.first
+      options.assets_dir      ||= paths["public"].first
+      options.javascripts_dir ||= paths["public/javascripts"].first
+      options.stylesheets_dir ||= paths["public/stylesheets"].first
 
       # make sure readers methods get compiled
       options.asset_path           ||= nil
diff --git a/actionpack/lib/action_controller/railtie.rb b/actionpack/lib/action_controller/railtie.rb
index 0ade42ba2d..c5a661f2b0 100644
--- a/actionpack/lib/action_controller/railtie.rb
+++ b/actionpack/lib/action_controller/railtie.rb
@@ -21,10 +21,10 @@ module ActionController
       paths   = app.config.paths
       options = app.config.action_controller
 
-      options.assets_dir           ||= paths.public.to_a.first
-      options.javascripts_dir      ||= paths.public.javascripts.to_a.first
-      options.stylesheets_dir      ||= paths.public.stylesheets.to_a.first
-      options.page_cache_directory ||= paths.public.to_a.first
+      options.assets_dir           ||= paths["public"].first
+      options.javascripts_dir      ||= paths["public/javascripts"].first
+      options.stylesheets_dir      ||= paths["public/stylesheets"].first
+      options.page_cache_directory ||= paths["public"].first
 
       # make sure readers methods get compiled
       options.asset_path           ||= nil
diff --git a/actionpack/lib/action_controller/railties/paths.rb b/actionpack/lib/action_controller/railties/paths.rb
index fa71d55946..7a59d4f2f3 100644
--- a/actionpack/lib/action_controller/railties/paths.rb
+++ b/actionpack/lib/action_controller/railties/paths.rb
@@ -5,12 +5,14 @@ module ActionController
         Module.new do
           define_method(:inherited) do |klass|
             super(klass)
+
             if namespace = klass.parents.detect {|m| m.respond_to?(:_railtie) }
-              klass.helpers_path = namespace._railtie.config.paths.app.helpers.to_a
+              paths = namespace._railtie.paths["app/helpers"].existent
             else
-              klass.helpers_path = app.config.helpers_paths
+              paths = app.config.helpers_paths
             end
 
+            klass.helpers_path = paths
             klass.helper :all if klass.superclass == ActionController::Base
           end
         end
diff --git a/activerecord/lib/active_record/railties/databases.rake b/activerecord/lib/active_record/railties/databases.rake
index 58c705c8b2..4ef6c6f751 100644
--- a/activerecord/lib/active_record/railties/databases.rake
+++ b/activerecord/lib/active_record/railties/databases.rake
@@ -2,7 +2,7 @@ namespace :db do
   task :load_config => :rails_env do
     require 'active_record'
     ActiveRecord::Base.configurations = Rails.application.config.database_configuration
-    ActiveRecord::Migrator.migrations_path = Rails.application.config.paths.db.migrate.to_a.first
+    ActiveRecord::Migrator.migrations_path = Rails.application.paths["db/migrate"].first
   end
 
   task :copy_migrations => :load_config do
@@ -11,8 +11,8 @@ namespace :db do
     Rails.application.railties.all do |railtie|
       next unless to_load == :all || to_load.include?(railtie.railtie_name)
 
-      if railtie.config.respond_to?(:paths) && railtie.config.paths.db
-        railties[railtie.railtie_name] = railtie.config.paths.db.migrate.to_a.first
+      if railtie.respond_to?(:paths) && (path = railtie.paths["db/migrate"].first)
+        railties[railtie.railtie_name] = path
       end
     end
 
diff --git a/railties/lib/rails.rb b/railties/lib/rails.rb
index 3663910281..cca0891835 100644
--- a/railties/lib/rails.rb
+++ b/railties/lib/rails.rb
@@ -92,7 +92,7 @@ module Rails
     end
 
     def public_path
-      application && application.paths.public.to_a.first
+      application && application.paths["public"].first
     end
   end
 end
diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index 075e3c5692..5559f49fbd 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -72,7 +72,7 @@ module Rails
     end
 
     def require_environment! #:nodoc:
-      environment = paths.config.environment.to_a.first
+      environment = paths["config/environment"].existent.first
       require environment if environment
     end
 
diff --git a/railties/lib/rails/application/bootstrap.rb b/railties/lib/rails/application/bootstrap.rb
index e39b3bc705..213aa0768a 100644
--- a/railties/lib/rails/application/bootstrap.rb
+++ b/railties/lib/rails/application/bootstrap.rb
@@ -23,7 +23,7 @@ module Rails
       # Initialize the logger early in the stack in case we need to log some deprecation.
       initializer :initialize_logger do
         Rails.logger ||= config.logger || begin
-          path = config.paths.log.to_a.first
+          path = config.paths["log"].first
           logger = ActiveSupport::BufferedLogger.new(path)
           logger.level = ActiveSupport::BufferedLogger.const_get(config.log_level.to_s.upcase)
           logger.auto_flushing = false if Rails.env.production?
diff --git a/railties/lib/rails/application/configuration.rb b/railties/lib/rails/application/configuration.rb
index f902c3ded2..3505388479 100644
--- a/railties/lib/rails/application/configuration.rb
+++ b/railties/lib/rails/application/configuration.rb
@@ -9,7 +9,7 @@ module Rails
                     :filter_parameters,  :log_level, :logger,
                     :preload_frameworks, :reload_plugins,
                     :secret_token, :serve_static_assets, :session_options,
-                    :time_zone, :whiny_nils
+                    :time_zone, :whiny_nils, :helpers_paths
 
       def initialize(*)
         super
@@ -17,6 +17,7 @@ module Rails
         @allow_concurrency = false
         @consider_all_requests_local = false
         @filter_parameters = []
+        @helpers_paths = []
         @dependency_loading = true
         @serve_static_assets = true
         @session_store = :cookie_store
@@ -60,13 +61,12 @@ module Rails
       def paths
         @paths ||= begin
           paths = super
-          paths.config.database     "config/database.yml"
-          paths.config.environment  "config/environment.rb"
-          paths.lib.templates       "lib/templates"
-          paths.log                 "log/#{Rails.env}.log"
-          paths.tmp                 "tmp"
-          paths.tmp.cache           "tmp/cache"
-
+          paths.add "config/database",    :with => "config/database.yml"
+          paths.add "config/environment", :with => "config/environment.rb"
+          paths.add "lib/templates"
+          paths.add "log",                :with => "log/#{Rails.env}.log"
+          paths.add "tmp"
+          paths.add "tmp/cache"
           paths
         end
       end
@@ -88,7 +88,7 @@ module Rails
       # YAML::load.
       def database_configuration
         require 'erb'
-        YAML::load(ERB.new(IO.read(paths.config.database.to_a.first)).result)
+        YAML::load(ERB.new(IO.read(paths["config/database"].first)).result)
       end
 
       def cache_store
diff --git a/railties/lib/rails/application/finisher.rb b/railties/lib/rails/application/finisher.rb
index b95df467c7..e3342be7ee 100644
--- a/railties/lib/rails/application/finisher.rb
+++ b/railties/lib/rails/application/finisher.rb
@@ -4,7 +4,7 @@ module Rails
       include Initializable
 
       initializer :add_generator_templates do
-        config.generators.templates.unshift(*paths.lib.templates.to_a)
+        config.generators.templates.unshift(*paths["lib/templates"].existent)
       end
 
       initializer :ensure_autoload_once_paths_as_subset do
diff --git a/railties/lib/rails/engine.rb b/railties/lib/rails/engine.rb
index 3981e8dfd5..bd3e612153 100644
--- a/railties/lib/rails/engine.rb
+++ b/railties/lib/rails/engine.rb
@@ -90,17 +90,17 @@ module Rails
   # The available paths in an Engine are:
   #
   #   class MyEngine < Rails::Engine
-  #     paths.app                 = "app"
-  #     paths.app.controllers     = "app/controllers"
-  #     paths.app.helpers         = "app/helpers"
-  #     paths.app.models          = "app/models"
-  #     paths.app.views           = "app/views"
-  #     paths.lib                 = "lib"
-  #     paths.lib.tasks           = "lib/tasks"
-  #     paths.config              = "config"
-  #     paths.config.initializers = "config/initializers"
-  #     paths.config.locales      = "config/locales"
-  #     paths.config.routes       = "config/routes.rb"
+  #     paths["app"]                 #=> ["app"]
+  #     paths["app/controllers"]     #=> ["app/controllers"]
+  #     paths["app/helpers"]         #=> ["app/helpers"]
+  #     paths["app/models"]          #=> ["app/models"]
+  #     paths["app/views"]           #=> ["app/views"]
+  #     paths["lib"]                 #=> ["lib"]
+  #     paths["lib/tasks"]           #=> ["lib/tasks"]
+  #     paths["config"]              #=> ["config"]
+  #     paths["config/initializers"] #=> ["config/initializers"]
+  #     paths["config/locales"]      #=> ["config/locales"]
+  #     paths["config/routes"]       #=> ["config/routes.rb"]
   #   end
   #
   # Your Application class adds a couple more paths to this set. And as in your Application,
@@ -276,11 +276,11 @@ module Rails
   #     end
   #   end
   #
-  # There is also 'app' helper that gives you access to application's routes inside Engine:
+  # There is also 'main_app' helper that gives you access to application's routes inside Engine:
   #
   #   module MyEngine
   #     class BarController
-  #       app.foo_path #=> /foo
+  #       main_app.foo_path #=> /foo
   #     end
   #   end
   #
@@ -381,7 +381,7 @@ module Rails
 
     def load_tasks
       super
-      config.paths.lib.tasks.to_a.sort.each { |ext| load(ext) }
+      paths["lib/tasks"].existent.sort.each { |ext| load(ext) }
     end
 
     def eager_load!
@@ -441,7 +441,7 @@ module Rails
     #
     # Blog::Engine.load_seed
     def load_seed
-      seed_file = config.paths.db.seeds.to_a.first
+      seed_file = paths["db/seeds"].existent.first
       load(seed_file) if File.exist?(seed_file)
     end
 
@@ -469,20 +469,22 @@ module Rails
     end
 
     initializer :add_routing_paths do |app|
-      app.routes_reloader.blocks[routes] = routes_draw_block
-      paths.config.routes.to_a.each do |route|
-        app.routes_reloader.paths.unshift(route) if File.exists?(route)
+      paths = self.paths["config/routes"].existent
+
+      if routes? || paths.any?
+        app.routes_reloader.blocks[routes] = routes_draw_block
+        app.routes_reloader.paths.unshift(*paths)
       end
     end
 
     # I18n load paths are a special case since the ones added
     # later have higher priority.
     initializer :add_locales do
-      config.i18n.railties_load_path.concat(paths.config.locales.to_a)
+      config.i18n.railties_load_path.concat(paths["config/locales"].existent)
     end
 
     initializer :add_view_paths do
-      views = paths.app.views.to_a
+      views = paths["app/views"].existent
       unless views.empty?
         ActiveSupport.on_load(:action_controller){ prepend_view_path(views) }
         ActiveSupport.on_load(:action_mailer){ prepend_view_path(views) }
@@ -490,28 +492,27 @@ module Rails
     end
 
     initializer :load_environment_config, :before => :load_environment_hook do
-      environment = config.paths.config.environments.to_a.first
+      environment = paths["config/environments"].existent.first
       require environment if environment
     end
 
     initializer :append_asset_paths do
       config.asset_path ||= "/#{engine_name}%s"
 
-      public_path = config.paths.public.to_a.first
+      public_path = paths["public"].first
       if config.compiled_asset_path && File.exist?(public_path)
         config.static_asset_paths[config.compiled_asset_path] = public_path
       end
     end
 
-    initializer :prepend_helpers_path do
-      unless namespaced?
-        config.helpers_paths = [] unless config.respond_to?(:helpers_paths)
-        config.helpers_paths = config.paths.app.helpers.to_a + config.helpers_paths
+    initializer :prepend_helpers_path do |app|
+      if !namespaced? || (app == self)
+        app.config.helpers_paths.unshift(*paths["app/helpers"].existent)
       end
     end
 
     initializer :load_config_initializers do
-      paths.config.initializers.to_a.sort.each do |initializer|
+      config.paths["config/initializers"].existent.sort.each do |initializer|
         load(initializer)
       end
     end
@@ -524,6 +525,10 @@ module Rails
   protected
     attr_accessor :routes_draw_block
 
+    def routes?
+      defined?(@routes)
+    end
+
     def find_root_with_flag(flag, default=nil)
       root_path = self.class.called_from
 
diff --git a/railties/lib/rails/engine/configuration.rb b/railties/lib/rails/engine/configuration.rb
index b69c0e1c53..7a07dcad7d 100644
--- a/railties/lib/rails/engine/configuration.rb
+++ b/railties/lib/rails/engine/configuration.rb
@@ -10,7 +10,6 @@ module Rails
       def initialize(root=nil)
         super()
         @root = root
-        @helpers_paths = []
       end
 
       # Returns the middleware stack for the engine.
@@ -39,27 +38,27 @@ module Rails
       def paths
         @paths ||= begin
           paths = Rails::Paths::Root.new(@root)
-          paths.app                 "app",                 :eager_load => true, :glob => "*"
-          paths.app.controllers     "app/controllers",     :eager_load => true
-          paths.app.helpers         "app/helpers",         :eager_load => true
-          paths.app.models          "app/models",          :eager_load => true
-          paths.app.mailers         "app/mailers",         :eager_load => true
-          paths.app.views           "app/views"
-          paths.lib                 "lib",                 :load_path => true
-          paths.lib.tasks           "lib/tasks",           :glob => "**/*.rake"
-          paths.config              "config"
-          paths.config.initializers "config/initializers", :glob => "**/*.rb"
-          paths.config.locales      "config/locales",      :glob => "*.{rb,yml}"
-          paths.config.routes       "config/routes.rb"
-          paths.config.environments "config/environments", :glob => "#{Rails.env}.rb"
-          paths.public              "public"
-          paths.public.javascripts  "public/javascripts"
-          paths.public.stylesheets  "public/stylesheets"
-          paths.vendor              "vendor", :load_path => true
-          paths.vendor.plugins      "vendor/plugins"
-          paths.db                  "db"
-          paths.db.migrate          "db/migrate"
-          paths.db.seeds            "db/seeds.rb"
+          paths.add "app",                 :eager_load => true, :glob => "*"
+          paths.add "app/controllers",     :eager_load => true
+          paths.add "app/helpers",         :eager_load => true
+          paths.add "app/models",          :eager_load => true
+          paths.add "app/mailers",         :eager_load => true
+          paths.add "app/views"
+          paths.add "lib",                 :load_path => true
+          paths.add "lib/tasks",           :glob => "**/*.rake"
+          paths.add "config"
+          paths.add "config/environments", :glob => "#{Rails.env}.rb"
+          paths.add "config/initializers", :glob => "**/*.rb"
+          paths.add "config/locales",      :glob => "*.{rb,yml}"
+          paths.add "config/routes",       :with => "config/routes.rb"
+          paths.add "db"
+          paths.add "db/migrate"
+          paths.add "db/seeds",            :with => "db/seeds.rb"
+          paths.add "public"
+          paths.add "public/javascripts"
+          paths.add "public/stylesheets"
+          paths.add "vendor",              :load_path => true
+          paths.add "vendor/plugins"
           paths
         end
       end
diff --git a/railties/lib/rails/engine/railties.rb b/railties/lib/rails/engine/railties.rb
index 389a7602c6..e91bdbf1e5 100644
--- a/railties/lib/rails/engine/railties.rb
+++ b/railties/lib/rails/engine/railties.rb
@@ -15,7 +15,7 @@ module Rails
       def plugins
         @plugins ||= begin
           plugin_names = (@config.plugins || [:all]).map { |p| p.to_sym }
-          Plugin.all(plugin_names, @config.paths.vendor.plugins)
+          Plugin.all(plugin_names, @config.paths["vendor/plugins"].existent)
         end
       end
     end
diff --git a/railties/lib/rails/paths.rb b/railties/lib/rails/paths.rb
index d303212f52..1729e8707e 100644
--- a/railties/lib/rails/paths.rb
+++ b/railties/lib/rails/paths.rb
@@ -2,15 +2,17 @@ require 'set'
 
 module Rails
   module Paths
-    module PathParent
-      attr_reader :children
-
+    module PathParent #:nodoc:
       def method_missing(id, *args)
-        name = id.to_s
+        match = id.to_s.match(/^(.*)=$/)
+        full  = [@current, $1 || id].compact.join("/")
+
+        ActiveSupport::Deprecation.warn 'config.paths.app.controller API is deprecated in ' <<
+          'favor of config.paths["app/controller"] API.'
 
-        if name =~ /^(.*)=$/ || args.any?
-          @children[$1 || name] = Path.new(@root, *args)
-        elsif path = @children[name]
+        if match || args.any?
+          @root[full] = Path.new(@root, full, *args)
+        elsif path = @root[full]
           path
         else
           super
@@ -18,22 +20,72 @@ module Rails
       end
     end
 
-    class Root
+    # This object is an extended hash that behaves as root of the Rails::Paths system.
+    # It allows you to collect information about how you want to structure your application
+    # paths by a Hash like API. It requires you to give a physical path on initialization.
+    #
+    #   root = Root.new
+    #   root.add "app/controllers", :eager_load => true
+    #
+    # The command above creates a new root object and add "app/controllers" as a path.
+    # This means we can get a Path object back like below:
+    #
+    #   path = root["app/controllers"]
+    #   path.eager_load?               #=> true
+    #   path.is_a?(Rails::Paths::Path) #=> true
+    #
+    # The Path object is simply an array and allows you to easily add extra paths:
+    #
+    #   path.is_a?(Array) #=> true
+    #   path.inspect      #=> ["app/controllers"]
+    #
+    #   path << "lib/controllers"
+    #   path.inspect      #=> ["app/controllers", "lib/controllers"]
+    #
+    # Notice that when you add a path using #add, the path object created already
+    # contains te path with the same path value given to #add. In some situations,
+    # you may not want this behavior, so you can give :with as option.
+    #
+    #   root.add "config/routes", :with => "config/routes.rb"
+    #   root["config/routes"].inspect #=> ["config/routes.rb"]
+    #
+    # #add also accepts the following options as argument: eager_load, autoload,
+    # autoload_once and glob.
+    #
+    # Finally, the Path object also provides a few helpers:
+    #
+    #   root = Root.new
+    #   root.path = "/rails"
+    #   root.add "app/controllers"
+    #
+    #   root["app/controllers"].expanded #=> ["/rails/app/controllers"]
+    #   root["app/controllers"].existent #=> ["/rails/app/controllers"]
+    #
+    # Check the Path documentation for more information.
+    class Root < ::Hash
       include PathParent
-
       attr_accessor :path
 
       def initialize(path)
         raise if path.is_a?(Array)
-        @children = {}
+        @current = nil
         @path = path
         @root = self
-        @all_paths = []
+        super()
+      end
+
+      def []=(path, value)
+        value = Path.new(self, path, value) unless value.is_a?(Path)
+        super(path, value)
+      end
+
+      def add(path, options={})
+        with = options[:with] || path
+        self[path] = Path.new(self, path, with, options)
       end
 
       def all_paths
-        @all_paths.uniq!
-        @all_paths
+        values.tap { |v| v.uniq! }
       end
 
       def autoload_once
@@ -52,68 +104,54 @@ module Rails
         filter_by(:load_path?)
       end
 
-      def push(*)
-        raise "Application root can only have one physical path"
-      end
-
-      alias unshift push
-      alias << push
-      alias concat push
-
     protected
 
       def filter_by(constraint)
         all = []
         all_paths.each do |path|
           if path.send(constraint)
-            paths  = path.paths
-            paths -= path.children.values.map { |p| p.send(constraint) ? [] : p.paths }.flatten
+            paths  = path.existent
+            paths -= path.children.map { |p| p.send(constraint) ? [] : p.existent }.flatten
             all.concat(paths)
           end
         end
         all.uniq!
-        all.reject! { |p| !File.exists?(p) }
         all
       end
     end
 
-    class Path
-      include PathParent, Enumerable
+    class Path < Array
+      include PathParent
 
       attr_reader :path
       attr_accessor :glob
 
-      def initialize(root, *paths)
-        options   = paths.last.is_a?(::Hash) ? paths.pop : {}
-        @children = {}
+      def initialize(root, current, *paths)
+        options = paths.last.is_a?(::Hash) ? paths.pop : {}
+        super(paths.flatten)
+
+        @current  = current
         @root     = root
-        @paths    = paths.flatten
         @glob     = options[:glob]
 
         autoload_once! if options[:autoload_once]
         eager_load!    if options[:eager_load]
         autoload!      if options[:autoload]
         load_path!     if options[:load_path]
-
-        @root.all_paths << self
-      end
-
-      def each
-        to_a.each { |p| yield p }
       end
 
-      def push(path)
-        @paths.push path
+      def children
+        keys = @root.keys.select { |k| k.include?(@current) }
+        keys.delete(@current)
+        @root.values_at(*keys.sort)
       end
 
-      alias << push
-
-      def unshift(path)
-        @paths.unshift path
+      def first
+        expanded.first
       end
 
-      def concat(paths)
-        @paths.concat paths
+      def last
+        expanded.last
       end
 
       %w(autoload_once eager_load autoload load_path).each do |m|
@@ -132,20 +170,36 @@ module Rails
         RUBY
       end
 
-      def paths
+      # Expands all paths against the root and return all unique values.
+      def expanded
         raise "You need to set a path root" unless @root.path
+        result = []
 
-        result = @paths.map do |p|
+        each do |p|
           path = File.expand_path(p, @root.path)
-          @glob ? Dir[File.join(path, @glob)] : path
+
+          if @glob
+            result.concat Dir[File.join(path, @glob)]
+          else
+            result << path
+          end
         end
 
-        result.flatten!
         result.uniq!
         result
       end
 
-      alias to_a paths
+      # Returns all expanded paths but only if they exist in the filesystem.
+      def existent
+        expanded.select { |f| File.exists?(f) }
+      end
+
+      def paths
+        ActiveSupport::Deprecation.warn "paths is deprecated. Please call expand instead."
+        expanded
+      end
+
+      alias to_a expanded
     end
   end
 end
\ No newline at end of file
diff --git a/railties/lib/rails/plugin.rb b/railties/lib/rails/plugin.rb
index 5614624673..76fa76598c 100644
--- a/railties/lib/rails/plugin.rb
+++ b/railties/lib/rails/plugin.rb
@@ -62,13 +62,13 @@ module Rails
     end
 
     initializer :handle_lib_autoload, :before => :set_load_path do |app|
-      paths = if app.config.reload_plugins
+      autoload = if app.config.reload_plugins
         config.autoload_paths
       else
         config.autoload_once_paths
       end
 
-      paths.concat config.paths.lib.to_a
+      autoload.concat paths["lib"].existent
     end
 
     initializer :load_init_rb, :before => :load_config_initializers do |app|
diff --git a/railties/lib/rails/tasks/railties.rake b/railties/lib/rails/tasks/railties.rake
index 7cf31f84a0..0c1ee0f17a 100644
--- a/railties/lib/rails/tasks/railties.rake
+++ b/railties/lib/rails/tasks/railties.rake
@@ -2,7 +2,7 @@ namespace :railties do
   desc "Create symlinks to railties public directories in application's public directory."
   task :create_symlinks => :environment do
     paths = Rails.application.config.static_asset_paths.dup
-    app_public_path = Rails.application.config.paths.public.to_a.first
+    app_public_path = Rails.application.paths["public"].first
 
     paths.each do |mount_path, path|
       symlink_path = File.join(app_public_path, mount_path)
diff --git a/railties/test/application/configuration_test.rb b/railties/test/application/configuration_test.rb
index 7403d16cf4..b8d0854286 100644
--- a/railties/test/application/configuration_test.rb
+++ b/railties/test/application/configuration_test.rb
@@ -42,7 +42,7 @@ module ApplicationTests
     test "Rails::Application responds to paths" do
       require "#{app_path}/config/environment"
       assert_respond_to AppTemplate::Application, :paths
-      assert_equal AppTemplate::Application.paths.app.views.to_a, ["#{app_path}/app/views"]
+      assert_equal AppTemplate::Application.paths["app/views"].expanded, ["#{app_path}/app/views"]
     end
 
     test "the application root is set correctly" do
@@ -180,7 +180,7 @@ module ApplicationTests
 
     test "config.paths.public sets Rails.public_path" do
       add_to_config <<-RUBY
-        config.paths.public = "somewhere"
+        config.paths["public"] = "somewhere"
       RUBY
 
       require "#{app_path}/config/application"
diff --git a/railties/test/application/console_test.rb b/railties/test/application/console_test.rb
index 25b4a21902..d4159dd0fd 100644
--- a/railties/test/application/console_test.rb
+++ b/railties/test/application/console_test.rb
@@ -1,7 +1,7 @@
 require 'isolation/abstract_unit'
 
 class ConsoleTest < Test::Unit::TestCase
-  include ActiveSupport::Testing::Isolation
+  include ActiveSupport::Testing::Isolation  
 
   def setup
     build_app
@@ -14,16 +14,15 @@ class ConsoleTest < Test::Unit::TestCase
   end
 
   def test_app_method_should_return_integration_session
+    TestHelpers::Rack.send :remove_method, :app
     load_environment
     console_session = app
-    assert_not_nil console_session
     assert_instance_of ActionDispatch::Integration::Session, console_session
   end
 
   def test_new_session_should_return_integration_session
     load_environment
     session = new_session
-    assert_not_nil session
     assert_instance_of ActionDispatch::Integration::Session, session
   end
 
diff --git a/railties/test/application/generators_test.rb b/railties/test/application/generators_test.rb
index d258625f42..551e966c85 100644
--- a/railties/test/application/generators_test.rb
+++ b/railties/test/application/generators_test.rb
@@ -69,7 +69,7 @@ module ApplicationTests
       assert_equal :rspec, Rails::Generators.options[:rails][:test_framework]
       assert_equal "-w", Rails::Generators.aliases[:rails][:test_framework]
       assert_equal Hash[:shoulda => :test_unit], Rails::Generators.fallbacks
-      assert_equal ["#{app_path}/lib/templates", "some/where"], Rails::Generators.templates_path
+      assert_equal ["some/where"], Rails::Generators.templates_path
     end
 
     test "generators no color on initialization" do
diff --git a/railties/test/application/paths_test.rb b/railties/test/application/paths_test.rb
index c98b11556b..b1ff6e9cb1 100644
--- a/railties/test/application/paths_test.rb
+++ b/railties/test/application/paths_test.rb
@@ -25,7 +25,7 @@ module ApplicationTests
     end
 
     def assert_path(paths, *dir)
-      assert_equal [root(*dir)], paths.paths
+      assert_equal [root(*dir)], paths.expanded
     end
 
     def assert_in_load_path(*path)
@@ -37,20 +37,20 @@ module ApplicationTests
     end
 
     test "booting up Rails yields a valid paths object" do
-      assert_path @paths.app.models, "app", "models"
-      assert_path @paths.app.helpers, "app", "helpers"
-      assert_path @paths.app.views, "app", "views"
-      assert_path @paths.lib, "lib"
-      assert_path @paths.vendor, "vendor"
-      assert_path @paths.vendor.plugins, "vendor", "plugins"
-      assert_path @paths.tmp, "tmp"
-      assert_path @paths.tmp.cache, "tmp", "cache"
-      assert_path @paths.config, "config"
-      assert_path @paths.config.locales, "config", "locales", "en.yml"
-      assert_path @paths.config.environment, "config", "environment.rb"
-      assert_path @paths.config.environments, "config", "environments", "development.rb"
+      assert_path @paths["app/models"],          "app/models"
+      assert_path @paths["app/helpers"],         "app/helpers"
+      assert_path @paths["app/views"],           "app/views"
+      assert_path @paths["lib"],                 "lib"
+      assert_path @paths["vendor"],              "vendor"
+      assert_path @paths["vendor/plugins"],      "vendor/plugins"
+      assert_path @paths["tmp"],                 "tmp"
+      assert_path @paths["tmp/cache"],           "tmp/cache"
+      assert_path @paths["config"],              "config"
+      assert_path @paths["config/locales"],      "config/locales/en.yml"
+      assert_path @paths["config/environment"],  "config/environment.rb"
+      assert_path @paths["config/environments"], "config/environments/development.rb"
 
-      assert_equal root("app", "controllers"), @paths.app.controllers.to_a.first
+      assert_equal root("app", "controllers"), @paths["app/controllers"].expanded.first
     end
 
     test "booting up Rails yields a list of paths that are eager" do
diff --git a/railties/test/paths_test.rb b/railties/test/paths_test.rb
index 80fae8c543..6e4e3446b3 100644
--- a/railties/test/paths_test.rb
+++ b/railties/test/paths_test.rb
@@ -20,234 +20,264 @@ class PathsTest < ActiveSupport::TestCase
 
   test "a paths object initialized with nil can be updated" do
     root = Rails::Paths::Root.new(nil)
-    root.app = "app"
+    root.add "app"
     root.path = "/root"
-    assert_equal ["/root/app"], root.app.to_a
+    assert_equal ["app"], root["app"]
+    assert_equal ["/root/app"], root["app"].to_a
   end
 
   test "creating a root level path" do
-    @root.app = "/foo/bar"
-    assert_equal ["/foo/bar"], @root.app.to_a
+    @root.add "app"
+    assert_equal ["/foo/bar/app"], @root["app"].to_a
+  end
+
+  test "creating a root level path with options" do
+    @root.add "app", :with => "/foo/bar"
+    assert_equal ["/foo/bar"], @root["app"].to_a
   end
 
   test "raises exception if root path never set" do
     root = Rails::Paths::Root.new(nil)
-    root.app = "app"
+    root.add "app"
     assert_raises RuntimeError do
-      root.app.to_a
+      root["app"].to_a
     end
   end
 
-  test "creating a root level path without assignment" do
-    @root.app "/foo/bar"
-    assert_equal ["/foo/bar"], @root.app.to_a
-  end
-
-  test "trying to access a path that does not exist raises NoMethodError" do
-    assert_raises(NoMethodError) { @root.app }
-  end
-
-  test "relative paths are relative to the paths root" do
-    @root.app = "app"
-    assert_equal ["/foo/bar/app"], @root.app.to_a
-  end
-
-  test "relative paths are relative to the paths root without assignment" do
-    @root.app "app"
-    assert_equal ["/foo/bar/app"], @root.app.to_a
-  end
-
   test "creating a child level path" do
-    @root.app        = "/foo/bar"
-    @root.app.models = "/foo/bar/baz"
-    assert_equal ["/foo/bar/baz"], @root.app.models.to_a
+    @root.add "app"
+    @root.add "app/models"
+    assert_equal ["/foo/bar/app/models"], @root["app/models"].to_a
   end
 
-  test "creating a child level path without assignment" do
-    @root.app        = "/foo/bar"
-    @root.app.models   "/foo/bar/baz"
-    assert_equal ["/foo/bar/baz"], @root.app.models.to_a
+  test "creating a child level path with option" do
+    @root.add "app"
+    @root.add "app/models", :with => "/foo/bar/baz"
+    assert_equal ["/foo/bar/baz"], @root["app/models"].to_a
   end
 
   test "child level paths are relative from the root" do
-    @root.app        = "/app"
-    @root.app.models = "baz"
-
-    assert_equal ["/foo/bar/baz"], @root.app.models.to_a
+    @root.add "app"
+    @root.add "app/models", :with => "baz"
+    assert_equal ["/foo/bar/baz"], @root["app/models"].to_a
   end
 
   test "adding multiple physical paths as an array" do
-    @root.app = ["/app", "/app2"]
-    assert_equal ["/app", "/app2"], @root.app.to_a
-  end
-
-  test "adding multiple physical paths as an array without assignment" do
-    @root.app "/app", "/app2"
-    assert_equal ["/app", "/app2"], @root.app.to_a
+    @root.add "app", :with => ["/app", "/app2"]
+    assert_equal ["/app", "/app2"], @root["app"].to_a
   end
 
   test "adding multiple physical paths using #push" do
-    @root.app = "/app"
-    @root.app.push "/app2"
-    assert_equal ["/app", "/app2"], @root.app.to_a
+    @root.add "app"
+    @root["app"].push "app2"
+    assert_equal ["/foo/bar/app", "/foo/bar/app2"], @root["app"].to_a
   end
 
   test "adding multiple physical paths using <<" do
-    @root.app = "/app"
-    @root.app << "/app2"
-    assert_equal ["/app", "/app2"], @root.app.to_a
+    @root.add "app"
+    @root["app"] << "app2"
+    assert_equal ["/foo/bar/app", "/foo/bar/app2"], @root["app"].to_a
   end
 
   test "adding multiple physical paths using concat" do
-    @root.app = "/app"
-    @root.app.concat ["/app2", "/app3"]
-    assert_equal ["/app", "/app2", "/app3"], @root.app.to_a
+    @root.add "app"
+    @root["app"].concat ["app2", "/app3"]
+    assert_equal ["/foo/bar/app", "/foo/bar/app2", "/app3"], @root["app"].to_a
   end
 
   test "adding multiple physical paths using #unshift" do
-    @root.app = "/app"
-    @root.app.unshift "/app2"
-    assert_equal ["/app2", "/app"], @root.app.to_a
+    @root.add "app"
+    @root["app"].unshift "app2"
+    assert_equal ["/foo/bar/app2", "/foo/bar/app"], @root["app"].to_a
   end
 
   test "the root can only have one physical path" do
     assert_raise(RuntimeError) { Rails::Paths::Root.new(["/fiz", "/biz"]) }
-    assert_raise(RuntimeError) { @root.push "/biz"    }
-    assert_raise(RuntimeError) { @root.unshift "/biz" }
-    assert_raise(RuntimeError) { @root.concat ["/biz"]}
-    assert_raise(RuntimeError) { @root << "/biz"      }
   end
 
   test "it is possible to add a path that should be autoloaded only once" do
-    @root.app = "/app"
-    @root.app.autoload_once!
-    assert @root.app.autoload_once?
-    assert @root.autoload_once.include?(@root.app.paths.first)
+    @root.add "app", :with => "/app"
+    @root["app"].autoload_once!
+    assert @root["app"].autoload_once?
+    assert @root.autoload_once.include?(@root["app"].expanded.first)
   end
 
   test "it is possible to remove a path that should be autoloaded only once" do
-    @root.app = "/app"
-    @root.app.autoload_once!
-    assert @root.app.autoload_once?
+    @root["app"] = "/app"
+    @root["app"].autoload_once!
+    assert @root["app"].autoload_once?
 
-    @root.app.skip_autoload_once!
-    assert !@root.app.autoload_once?
-    assert !@root.autoload_once.include?(@root.app.paths.first)
+    @root["app"].skip_autoload_once!
+    assert !@root["app"].autoload_once?
+    assert !@root.autoload_once.include?(@root["app"].expanded.first)
   end
 
   test "it is possible to add a path without assignment and specify it should be loaded only once" do
-    @root.app "/app", :autoload_once => true
-    assert @root.app.autoload_once?
+    @root.add "app", :with => "/app", :autoload_once => true
+    assert @root["app"].autoload_once?
     assert @root.autoload_once.include?("/app")
   end
 
   test "it is possible to add multiple paths without assignment and specify it should be loaded only once" do
-    @root.app "/app", "/app2", :autoload_once => true
-    assert @root.app.autoload_once?
+    @root.add "app", :with => ["/app", "/app2"], :autoload_once => true
+    assert @root["app"].autoload_once?
     assert @root.autoload_once.include?("/app")
     assert @root.autoload_once.include?("/app2")
   end
 
   test "making a path autoload_once more than once only includes it once in @root.load_once" do
-    @root.app = "/app"
-    @root.app.autoload_once!
-    @root.app.autoload_once!
-    assert_equal 1, @root.autoload_once.select {|p| p == @root.app.paths.first }.size
+    @root["app"] = "/app"
+    @root["app"].autoload_once!
+    @root["app"].autoload_once!
+    assert_equal 1, @root.autoload_once.select {|p| p == @root["app"].expanded.first }.size
   end
 
   test "paths added to a load_once path should be added to the autoload_once collection" do
-    @root.app = "/app"
-    @root.app.autoload_once!
-    @root.app << "/app2"
+    @root["app"] = "/app"
+    @root["app"].autoload_once!
+    @root["app"] << "/app2"
     assert_equal 2, @root.autoload_once.size
   end
 
   test "it is possible to mark a path as eager loaded" do
-    @root.app = "/app"
-    @root.app.eager_load!
-    assert @root.app.eager_load?
-    assert @root.eager_load.include?(@root.app.paths.first)
+    @root["app"] = "/app"
+    @root["app"].eager_load!
+    assert @root["app"].eager_load?
+    assert @root.eager_load.include?(@root["app"].to_a.first)
   end
 
   test "it is possible to skip a path from eager loading" do
-    @root.app = "/app"
-    @root.app.eager_load!
-    assert @root.app.eager_load?
+    @root["app"] = "/app"
+    @root["app"].eager_load!
+    assert @root["app"].eager_load?
 
-    @root.app.skip_eager_load!
-    assert !@root.app.eager_load?
-    assert !@root.eager_load.include?(@root.app.paths.first)
+    @root["app"].skip_eager_load!
+    assert !@root["app"].eager_load?
+    assert !@root.eager_load.include?(@root["app"].to_a.first)
   end
 
   test "it is possible to add a path without assignment and mark it as eager" do
-    @root.app "/app", :eager_load => true
-    assert @root.app.eager_load?
+    @root.add "app", :with => "/app", :eager_load => true
+    assert @root["app"].eager_load?
     assert @root.eager_load.include?("/app")
   end
 
   test "it is possible to add multiple paths without assignment and mark them as eager" do
-    @root.app "/app", "/app2", :eager_load => true
-    assert @root.app.eager_load?
+    @root.add "app", :with => ["/app", "/app2"], :eager_load => true
+    assert @root["app"].eager_load?
     assert @root.eager_load.include?("/app")
     assert @root.eager_load.include?("/app2")
   end
 
   test "it is possible to create a path without assignment and mark it both as eager and load once" do
-    @root.app "/app", :eager_load => true, :autoload_once => true
-    assert @root.app.eager_load?
-    assert @root.app.autoload_once?
+    @root.add "app", :with => "/app", :eager_load => true, :autoload_once => true
+    assert @root["app"].eager_load?
+    assert @root["app"].autoload_once?
     assert @root.eager_load.include?("/app")
     assert @root.autoload_once.include?("/app")
   end
 
   test "making a path eager more than once only includes it once in @root.eager_paths" do
-    @root.app = "/app"
-    @root.app.eager_load!
-    @root.app.eager_load!
-    assert_equal 1, @root.eager_load.select {|p| p == @root.app.paths.first }.size
+    @root["app"] = "/app"
+    @root["app"].eager_load!
+    @root["app"].eager_load!
+    assert_equal 1, @root.eager_load.select {|p| p == @root["app"].expanded.first }.size
   end
 
   test "paths added to a eager_load path should be added to the eager_load collection" do
-    @root.app = "/app"
-    @root.app.eager_load!
-    @root.app << "/app2"
+    @root["app"] = "/app"
+    @root["app"].eager_load!
+    @root["app"] << "/app2"
     assert_equal 2, @root.eager_load.size
   end
 
   test "it should be possible to add a path's default glob" do
-    @root.app = "/app"
-    @root.app.glob = "*.rb"
-    assert_equal "*.rb", @root.app.glob
+    @root["app"] = "/app"
+    @root["app"].glob = "*.rb"
+    assert_equal "*.rb", @root["app"].glob
   end
 
   test "it should be possible to override a path's default glob without assignment" do
-    @root.app "/app", :glob => "*.rb"
-    assert_equal "*.rb", @root.app.glob
+    @root.add "app", :with => "/app", :glob => "*.rb"
+    assert_equal "*.rb", @root["app"].glob
   end
 
   test "a path can be added to the load path" do
-    @root.app = "app"
-    @root.app.load_path!
-    @root.app.models = "app/models"
+    @root["app"] = "app"
+    @root["app"].load_path!
+    @root["app/models"] = "app/models"
     assert_equal ["/foo/bar/app"], @root.load_paths
   end
 
   test "a path can be added to the load path on creation" do
-    @root.app "/app", :load_path => true
-    assert @root.app.load_path?
+    @root.add "app", :with => "/app", :load_path => true
+    assert @root["app"].load_path?
     assert_equal ["/app"], @root.load_paths
   end
 
   test "a path can be marked as autoload path" do
-    @root.app = "app"
-    @root.app.autoload!
-    @root.app.models = "app/models"
+    @root["app"] = "app"
+    @root["app"].autoload!
+    @root["app/models"] = "app/models"
     assert_equal ["/foo/bar/app"], @root.autoload_paths
   end
 
   test "a path can be marked as autoload on creation" do
-    @root.app "/app", :autoload => true
-    assert @root.app.autoload?
+    @root.add "app", :with => "/app", :autoload => true
+    assert @root["app"].autoload?
     assert_equal ["/app"], @root.autoload_paths
   end
+
+  # Deprecated API tests
+
+  test "reading a root level path with assignment" do
+    @root.add "app"
+    assert_deprecated do
+      assert_equal ["/foo/bar/app"], @root.app.to_a
+    end
+  end
+
+  test "creating a root level path with assignment" do
+    assert_deprecated do
+      @root.app = "/foo/bar"
+    end
+    assert_equal ["/foo/bar"], @root["app"].to_a
+  end
+
+  test "creating a root level path without assignment" do
+    assert_deprecated do
+      @root.app "/foo/bar"
+    end
+    assert_equal ["/foo/bar"], @root["app"].to_a
+  end
+
+  test "reading a nested level path with assignment" do
+    @root.add "app"
+    @root.add "app/model"
+    assert_deprecated do
+      assert_equal ["/foo/bar/app/model"], @root.app.model.to_a
+    end
+  end
+
+  test "creating a nested level path with assignment" do
+    @root.add "app"
+    assert_deprecated do
+      @root.app.model = "/foo/bar"
+    end
+    assert_equal ["/foo/bar"], @root["app/model"].to_a
+  end
+
+  test "creating a nested level path without assignment" do
+    @root.add "app"
+    assert_deprecated do
+      @root.app.model "/foo/bar"
+    end
+    assert_equal ["/foo/bar"], @root["app/model"].to_a
+  end
+
+  test "trying to access a path that does not exist raises NoMethodError" do
+    assert_deprecated do
+      assert_raises(NoMethodError) { @root.app }
+    end
+  end
 end
diff --git a/railties/test/railties/engine_test.rb b/railties/test/railties/engine_test.rb
index 89262aeaae..5eed4def14 100644
--- a/railties/test/railties/engine_test.rb
+++ b/railties/test/railties/engine_test.rb
@@ -552,11 +552,11 @@ module RailtiesTest
         end
       RUBY
 
-      @plugin.write "app/views/bukkits/posts/new.html.erb", <<-RUBY
+      @plugin.write "app/views/bukkits/posts/new.html.erb", <<-ERB
           <%= form_for(Bukkits::Post.new) do |f| %>
             <%= f.text_field :title %>
           <% end %>
-      RUBY
+      ERB
 
       add_to_config("config.action_dispatch.show_exceptions = false")
 
@@ -593,7 +593,7 @@ module RailtiesTest
           module Bukkits
             class Engine < ::Rails::Engine
               namespace(Bukkits)
-              config.paths.public = "#{File.join(@plugin.path, "alternate_public")}"
+              paths["public"] = "#{File.join(@plugin.path, "alternate_public")}"
             end
           end
         RUBY
@@ -611,7 +611,7 @@ module RailtiesTest
           module Bukkits
             class Engine < ::Rails::Engine
               namespace(Bukkits)
-              config.paths.public = "#{File.join(@plugin.path, "not_existing")}"
+              paths["public"] = "#{File.join(@plugin.path, "not_existing")}"
             end
           end
         RUBY