Rails.application#env_config is now public API. [Closes #1924]

railties/lib/rails/application.rb

@@ -106,6 +106,15 @@ module Rails
       self
     end
 
+    # Rails.application.env_config stores some of the Rails initial environment parameters.
+    # Currently stores:
+    #
+    #   * action_dispatch.parameter_filter" => config.filter_parameters,
+    #   * action_dispatch.secret_token"     => config.secret_token,
+    #   * action_dispatch.show_exceptions"  => config.action_dispatch.show_exceptions
+    #
+    # These parameters will be used by middlewares and engines to configure themselves.
+    #
     def env_config
       @env_config ||= super.merge({
         "action_dispatch.parameter_filter" => config.filter_parameters,

railties/test/application/configuration_test.rb

@@ -516,5 +516,14 @@ module ApplicationTests
       get "/", { :format => :xml }, "HTTP_ACCEPT" => "application/xml"
       assert_equal 'XML', last_response.body
     end
+
+    test "Rails.application#env_config exists and include some existing parameters" do
+      make_basic_app
+
+      assert_respond_to app, :env_config
+      assert_equal      app.env_config['action_dispatch.parameter_filter'], app.config.filter_parameters
+      assert_equal      app.env_config['action_dispatch.secret_token'],     app.config.secret_token
+      assert_equal      app.env_config['action_dispatch.show_exceptions'],  app.config.action_dispatch.show_exceptions
+    end
   end
 end