Add support for custom default controller configuration (#788)

* Add configure functionality to allow customizing the default.

* Add configuration module and tests.

* Add documentation to the README.md

* Skip tests that only fail when whole suite is ran.

* Fix the double leaking by re-writing the test that caused the issue.

* Clean up railtie - Exract out method, Remove unnecessary compatibility.

* Add new functionality to the dummy app to increase test coverage.

README.md

@@ -368,6 +368,18 @@ you'll have access to an ArticleDecorator object instead. In your controller you
 can continue to use the `@article` instance variable to manipulate the model -
 for example, `@article.comments.build` to add a new blank comment for a form.
 
+## Configuration
+Draper works out the box well, but also provides a hook for you to configure its 
+default functionality. For example, Draper assumes you have a base `ApplicationController`.
+If your base controller is named something different (e.g. `BaseController`),
+you can tell Draper to use it by adding the following to an initializer:
+
+```ruby
+Draper.configure do |config|
+  config.default_controller = BaseController
+end
+```
+
 ## Testing
 
 Draper supports RSpec, MiniTest::Rails, and Test::Unit, and will add the

lib/draper.rb

@@ -9,6 +9,7 @@ require 'active_support/core_ext/hash/reverse_merge'
 require 'active_support/core_ext/name_error'
 
 require 'draper/version'
+require 'draper/configuration'
 require 'draper/view_helpers'
 require 'draper/delegation'
 require 'draper/automatic_delegation'
@@ -27,6 +28,8 @@ require 'draper/decorates_assigned'
 require 'draper/railtie' if defined?(Rails)
 
 module Draper
+  extend Draper::Configuration
+
   def self.setup_action_controller(base)
     base.class_eval do
       include Draper::ViewContext

lib/draper/configuration.rb

@@ -0,0 +1,15 @@
+module Draper
+  module Configuration
+    def configure
+      yield self
+    end
+
+    def default_controller
+      @@default_controller ||= ApplicationController
+    end
+
+    def default_controller=(controller)
+      @@default_controller = controller
+    end
+  end
+end

lib/draper/railtie.rb

@@ -3,8 +3,6 @@ require 'rails/railtie'
 module ActiveModel
   class Railtie < Rails::Railtie
     generators do |app|
-      app ||= Rails.application # Rails 3.0.x does not yield `app`
-
       Rails::Generators.configure! app.config.generators
       require_relative '../generators/controller_override'
     end
@@ -13,7 +11,6 @@ end
 
 module Draper
   class Railtie < Rails::Railtie
-
     config.after_initialize do |app|
       app.config.paths.add 'app/decorators', eager_load: true
 
@@ -23,19 +20,19 @@ module Draper
       end
     end
 
-    initializer "draper.setup_action_controller" do |app|
+    initializer 'draper.setup_action_controller' do
       ActiveSupport.on_load :action_controller do
         Draper.setup_action_controller self
       end
     end
 
-    initializer "draper.setup_action_mailer" do |app|
+    initializer 'draper.setup_action_mailer' do
       ActiveSupport.on_load :action_mailer do
         Draper.setup_action_mailer self
       end
     end
 
-    initializer "draper.setup_orm" do |app|
+    initializer 'draper.setup_orm' do
       [:active_record, :mongoid].each do |orm|
         ActiveSupport.on_load orm do
           Draper.setup_orm self
@@ -43,26 +40,22 @@ module Draper
       end
     end
 
-    initializer "draper.minitest-rails_integration" do |app|
+    initializer 'draper.minitest-rails_integration' do
       ActiveSupport.on_load :minitest do
-        require "draper/test/minitest_integration"
+        require 'draper/test/minitest_integration'
       end
     end
 
-    console do
+    def initialize_view_context
       require 'action_controller/test_case'
-      ApplicationController.new.view_context
+      Draper.default_controller.new.view_context
       Draper::ViewContext.build
     end
 
-    runner do
-      require 'action_controller/test_case'
-      ApplicationController.new.view_context
-      Draper::ViewContext.build
-    end
+    console { initialize_view_context }
 
-    rake_tasks do
-      Dir[File.join(File.dirname(__FILE__),'tasks/*.rake')].each { |f| load f }
-    end
+    runner { initialize_view_context }
+
+    rake_tasks { Dir[File.join(File.dirname(__FILE__), 'tasks/*.rake')].each { |f| load f } }
   end
 end

lib/draper/view_context/build_strategy.rb

@@ -37,7 +37,8 @@ module Draper
         attr_reader :block
 
         def controller
-          (Draper::ViewContext.controller || ApplicationController.new).tap do |controller|
+          Draper::ViewContext.controller ||= Draper.default_controller.new
+          Draper::ViewContext.controller.tap do |controller|
             controller.request ||= new_test_request controller if defined?(ActionController::TestRequest)
           end
         end

spec/draper/configuration_spec.rb

@@ -0,0 +1,25 @@
+require 'spec_helper'
+
+module Draper
+  RSpec.describe Configuration do
+    it 'yields Draper on configure' do
+      Draper.configure { |config| expect(config).to be Draper }
+    end
+
+    it 'defaults default_controller to ApplicationController' do
+      expect(Draper.default_controller).to be ApplicationController
+    end
+
+    it 'allows customizing default_controller through configure' do
+      default = Draper.default_controller
+
+      Draper.configure do |config|
+        config.default_controller = CustomController
+      end
+
+      expect(Draper.default_controller).to be CustomController
+
+      Draper.default_controller = default
+    end
+  end
+end

spec/draper/view_context/build_strategy_spec.rb

@@ -23,11 +23,10 @@ module Draper
 
       context "when a current controller is not set" do
         it "uses ApplicationController" do
-          view_context = fake_view_context
-          stub_const "ApplicationController", double(new: fake_controller(view_context))
-          strategy = ViewContext::BuildStrategy::Full.new
-
-          expect(strategy.call).to be view_context
+          expect(Draper::ViewContext.controller).to be_nil
+          view_context = ViewContext::BuildStrategy::Full.new.call
+          expect(view_context.controller).to eq Draper::ViewContext.controller
+          expect(view_context.controller).to be_an ApplicationController
         end
       end
 

spec/dummy/app/controllers/application_controller.rb

@@ -1,4 +0,0 @@
-class ApplicationController < ActionController::Base
-  include LocalizedUrls
-  protect_from_forgery
-end

spec/dummy/app/controllers/base_controller.rb

@@ -0,0 +1,4 @@
+class BaseController < ActionController::Base
+  include LocalizedUrls
+  protect_from_forgery
+end

spec/dummy/app/controllers/posts_controller.rb

@@ -1,4 +1,4 @@
-class PostsController < ApplicationController
+class PostsController < BaseController
   decorates_assigned :post
 
   def show

spec/dummy/config/initializers/draper.rb

@@ -0,0 +1,3 @@
+Draper.configure do |config|
+  config.default_controller = BaseController
+end

spec/dummy/spec/decorators/post_decorator_spec.rb

@@ -58,7 +58,7 @@ describe PostDecorator do
     expect(xml).to have_css "post > updated-at", text: "overridden"
   end
 
-  it "uses a test view context from ApplicationController" do
-    expect(Draper::ViewContext.current.controller).to be_an ApplicationController
+  it "uses a test view context from BaseController" do
+    expect(Draper::ViewContext.current.controller).to be_an BaseController
   end
 end

spec/spec_helper.rb

@@ -30,6 +30,9 @@ module Namespaced
   class OtherDecorator < Draper::Decorator; end
 end
 
+ApplicationController = Class.new(ActionController::Base)
+CustomController = Class.new(ActionController::Base)
+
 # After each example, revert changes made to the class
 def protect_class(klass)
   before { stub_const klass.name, Class.new(klass) }