beef up anonymous controller doc

- rspec#421, rspec#427

features/controller_specs/anonymous_controller.feature

@@ -1,143 +1,152 @@
 Feature: anonymous controller
 
   Use the `controller` method to define an anonymous controller derived from
-  ApplicationController, or any other base controller. This is useful for
-  specifying behavior like global error handling.
+  `ApplicationController`. This is useful for specifying behavior like global
+  error handling.
+
+  To specify a different base class, you can pass the class explicitly to the
+  controller method:
+
+      controller(BaseController)
+
+  You can also configure RSpec to use the described class:
+
+      RSpec.configure do |c|
+        c.infer_base_class_for_anonymous_controllers = true
+      end
+
+      describe BaseController do
+        controller { ... }
+        # ^^ creates an anonymous subclass of `BaseController`
 
   Scenario: specify error handling in ApplicationController
     Given a file named "spec/controllers/application_controller_spec.rb" with:
-    """
-    require "spec_helper"
+      """
+      require "spec_helper"
 
-    class ApplicationController < ActionController::Base
-      class AccessDenied < StandardError; end
+      class ApplicationController < ActionController::Base
+        class AccessDenied < StandardError; end
 
-      rescue_from AccessDenied, :with => :access_denied
+        rescue_from AccessDenied, :with => :access_denied
 
-    private
+      private
 
-      def access_denied
-        redirect_to "/401.html"
+        def access_denied
+          redirect_to "/401.html"
+        end
       end
-    end
 
-    describe ApplicationController do
-      controller do
-        def index
-          raise ApplicationController::AccessDenied
+      describe ApplicationController do
+        controller do
+          def index
+            raise ApplicationController::AccessDenied
+          end
         end
-      end
 
-      describe "handling AccessDenied exceptions" do
-        it "redirects to the /401.html page" do
-          get :index
-          response.should redirect_to("/401.html")
+        describe "handling AccessDenied exceptions" do
+          it "redirects to the /401.html page" do
+            get :index
+            response.should redirect_to("/401.html")
+          end
         end
       end
-    end
-    """
+      """
     When I run `rspec spec`
     Then the examples should all pass
 
   Scenario: specify error handling in subclass of ApplicationController
     Given a file named "spec/controllers/application_controller_subclass_spec.rb" with:
-    """
-    require "spec_helper"
+      """
+      require "spec_helper"
 
-    class ApplicationController < ActionController::Base
-      class AccessDenied < StandardError; end
-    end
+      class ApplicationController < ActionController::Base
+        class AccessDenied < StandardError; end
+      end
 
-    class ApplicationControllerSubclass < ApplicationController
+      class ApplicationControllerSubclass < ApplicationController
 
-      rescue_from ApplicationController::AccessDenied, :with => :access_denied
+        rescue_from ApplicationController::AccessDenied, :with => :access_denied
 
       private
 
-      def access_denied
-        redirect_to "/401.html"
+        def access_denied
+          redirect_to "/401.html"
+        end
       end
-    end
 
-    describe ApplicationControllerSubclass do
-      controller(ApplicationControllerSubclass) do
-        def index
-          raise ApplicationController::AccessDenied
+      describe ApplicationControllerSubclass do
+        controller(ApplicationControllerSubclass) do
+          def index
+            raise ApplicationController::AccessDenied
+          end
         end
-      end
 
-      describe "handling AccessDenied exceptions" do
-        it "redirects to the /401.html page" do
-          get :index
-          response.should redirect_to("/401.html")
+        describe "handling AccessDenied exceptions" do
+          it "redirects to the /401.html page" do
+            get :index
+            response.should redirect_to("/401.html")
+          end
         end
       end
-    end
-    """
+      """
     When I run `rspec spec`
     Then the examples should all pass
 
-  Scenario: base class can be inferred
-    Given a file named "spec/support/base_class_is_inferred_config.rb" with:
-    """
-    require "spec_helper"
-
-    RSpec.configure do |c|
-      c.infer_base_class_for_anonymous_controllers = true
-    end
-    """
-    And a file named "spec/controllers/base_class_can_be_inferred_spec.rb" with:
-    """
-    require "spec_helper"
-
-    class ApplicationController < ActionController::Base
-    end
-
-    class ApplicationControllerSubclass < ApplicationController
-    end
-
-    describe ApplicationControllerSubclass do
-      controller do
-        def index
-          render :text => "Hello World"
-        end
+  Scenario: infer base class from the described class
+    Given a file named "spec/controllers/base_class_can_be_inferred_spec.rb" with:
+      """
+      require "spec_helper"
+
+      RSpec.configure do |c|
+        c.infer_base_class_for_anonymous_controllers = true
       end
 
-      it "creates an anonymous controller that inherits from ApplicationControllerSubclass" do
-        controller.should be_a_kind_of(ApplicationControllerSubclass)
+      class ApplicationController < ActionController::Base; end
+
+      class ApplicationControllerSubclass < ApplicationController; end
+
+      describe ApplicationControllerSubclass do
+        controller do
+          def index
+            render :text => "Hello World"
+          end
+        end
+
+        it "creates an anonymous controller derived from ApplicationControllerSubclass" do
+          controller.should be_a_kind_of(ApplicationControllerSubclass)
+        end
       end
-    end
-    """
+      """
     When I run `rspec spec`
     Then the examples should all pass
 
-  Scenario: regression with ApplicationController around_filters
+  Scenario: invoke around filter in base class
     Given a file named "spec/controllers/application_controller_around_filter_spec.rb" with:
-    """
-    require "spec_helper"
+      """
+      require "spec_helper"
 
-    class ApplicationController < ActionController::Base
-      around_filter :some_around_filter
+      class ApplicationController < ActionController::Base
+        around_filter :an_around_filter
 
-      def some_around_filter
-        @callback_invoked = true
-        yield
+        def an_around_filter
+          @callback_invoked = true
+          yield
+        end
       end
-    end
 
-    describe ApplicationController do
-      controller do
-        def index
-          render :nothing => true
+      describe ApplicationController do
+        controller do
+          def index
+            render :nothing => true
+          end
         end
-      end
 
-      it "invokes the callback" do
-        get :index
+        it "invokes the callback" do
+          get :index
 
-        assigns[:callback_invoked].should be_true
+          assigns[:callback_invoked].should be_true
+        end
       end
-    end
-    """
+      """
     When I run `rspec spec`
     Then the examples should all pass