Extract Decorator Step Six

* Flip composition

Author: jferris

example_app/app/models/survey.rb

@@ -9,8 +9,8 @@ class Survey < ActiveRecord::Base
 
   def summaries_using(summarizer, options = {})
     questions.map do |question|
-      UnansweredQuestionHider.new(summarizer, options[:answered_by]).
-        summarize(question)
+      hider = UnansweredQuestionHider.new(summarizer, options[:answered_by])
+      question.summary_using(hider)
     end
   end
 end

example_app/app/models/unanswered_question_hider.rb

@@ -10,14 +10,14 @@ def summarize(question)
     if hide_unanswered_question?(question)
       hide_answer_to_question(question)
     else
-      question.summary_using(@summarizer)
+      @summarizer.summarize(question)
     end
   end
 
   private
 
   def hide_answer_to_question(question)
-    Summary.new(question.title, NO_ANSWER)
+    NO_ANSWER
   end
 
   def hide_unanswered_question?(question)

example_app/spec/models/unanswered_question_hider_spec.rb

@@ -9,36 +9,33 @@
 
     result = hider.summarize(question)
 
-    result.title.should eq question.title
-    result.value.should eq UnansweredQuestionHider::NO_ANSWER
+    result.should eq UnansweredQuestionHider::NO_ANSWER
   end
 
   it 'delegates to the summarizer given a user with an answer' do
-    summary = stub('summary')
     user = build_stubbed(:user)
     question = stub_answered_question(user, true)
-    summarizer = stub_summarizer(question, summary)
+    summarizer = stub_summarizer(question, 'value')
     hider = UnansweredQuestionHider.new(summarizer, user)
 
     result = hider.summarize(question)
 
-    result.should eq summary
+    result.should eq 'value'
   end
 
   it 'delegates to the summarizer without a user' do
-    summary = stub('summary')
     question = build_stubbed(:question)
-    summarizer = stub_summarizer(question, summary)
+    summarizer = stub_summarizer(question, 'value')
     hider = UnansweredQuestionHider.new(summarizer, nil)
 
     result = hider.summarize(question)
 
-    result.should eq summary
+    result.should eq 'value'
   end
 
-  def stub_summarizer(question, summary)
+  def stub_summarizer(question, value)
     stub('summarizer').tap do |summarizer|
-      question.stubs(:summary_using).with(summarizer).returns(summary)
+      summarizer.stubs(:summarize).with(question).returns(value)
     end
   end