Hide summary for unanswered questions

* Allow users to skip questions
* Hide summary for questions the user hasn't answered yet
* Introduces smell Divergent Change
* Staging for refactoring Extract Decorator

example_app/app/controllers/summaries_controller.rb

@@ -1,7 +1,7 @@
 class SummariesController < ApplicationController
   def show
     @survey = Survey.find(params[:survey_id])
-    @summaries = @survey.summaries_using(summarizer)
+    @summaries = @survey.summaries_using(summarizer, constraints)
   end
 
   private
@@ -13,4 +13,16 @@ def summarizer
   def summarizer_class
     "Summarizer::#{params[:id].classify}".constantize
   end
+
+  def constraints
+    if include_unanswered?
+      {}
+    else
+      { answered_by: current_user }
+    end
+  end
+
+  def include_unanswered?
+    params[:unanswered]
+  end
 end

example_app/app/models/answer.rb

@@ -4,8 +4,6 @@ class Answer < ActiveRecord::Base
   belongs_to :completion
   belongs_to :question
 
-  validates :text, presence: true
-
   def self.for_user(user)
     joins(:completion).where(completions: { user_id: user.id }).last_or_null
   end

example_app/app/models/question.rb

@@ -20,6 +20,14 @@ class Question < ActiveRecord::Base
   delegate :breakdown, :score, to: :submittable
   delegate :title, to: :survey, prefix: true
 
+  def answered_by?(user)
+    answers.
+      joins(:completion).
+      where(completions: { user_id: user }).
+      where("answers.text <> ''").
+      exists?
+  end
+
   def most_recent_answer_text
     answers.most_recent.text
   end

example_app/app/models/survey.rb

@@ -1,4 +1,6 @@
 class Survey < ActiveRecord::Base
+  NO_ANSWER = "You haven't answered this question".freeze
+
   include ActiveModel::ForbiddenAttributesProtection
 
   validates_presence_of :title
@@ -7,9 +9,13 @@ class Survey < ActiveRecord::Base
   has_many :completions
   has_many :questions
 
-  def summaries_using(summarizer)
+  def summaries_using(summarizer, options = {})
     questions.map do |question|
-      question.summary_using(summarizer)
+      if !options[:answered_by] || question.answered_by?(options[:answered_by])
+        question.summary_using(summarizer)
+      else
+        Summary.new(question.title, NO_ANSWER)
+      end
     end
   end
 end

example_app/app/views/summaries/show.html.erb

@@ -1,5 +1,7 @@
 <%= render 'nav', survey: @survey %>
 
+<%= link_to "Show questions I haven't answered", unanswered: true %>
+
 <ol class="summary">
   <%= render partial: 'summaries/summary', collection: @summaries %>
 </ol>

example_app/spec/features/user_views_survey_summary_spec.rb

@@ -34,6 +34,28 @@
     summary_for_question('Name?').should eq('Billy')
   end
 
+  scenario 'only view questions which you have answered' do
+    maker = SurveyMaker.new
+    maker.open_question 'Name?'
+    maker.open_question 'Favorite color?'
+    survey = maker.survey
+    taker = SurveyTaker.new(survey)
+    sign_in
+    taker.complete 'Brian', ''
+    as_another_user { taker.complete 'Billy', 'Red' }
+
+    view_summary survey, 'Most Recent'
+
+    summary_for_question('Name?').should eq('Billy')
+    summary_for_question('Favorite color?').
+      should eq("You haven't answered this question")
+
+    show_unanswered_questions
+
+    summary_for_question('Favorite color?').
+      should eq('Red')
+  end
+
   scenario 'view your answers' do
     maker = SurveyMaker.new
     maker.open_question 'Name?'
@@ -57,10 +79,15 @@
     as_another_user { taker.complete 'Billy' }
 
     view_summary survey, 'Your Answers'
+    show_unanswered_questions
 
     summary_for_question('Name?').should eq('No response')
   end
 
+  def show_unanswered_questions
+    click_on "Show questions I haven't answered"
+  end
+
   def view_summary(survey, type)
     visit survey_path(survey)
     click_link type

example_app/spec/models/answer_spec.rb

@@ -3,8 +3,6 @@
 describe Answer do
   it { should belong_to(:completion) }
   it { should belong_to(:question) }
-
-  it { should validate_presence_of(:text) }
 end
 
 describe Answer, '.for_user' do

example_app/spec/models/question_spec.rb

@@ -16,6 +16,30 @@
   it { should have_many(:answers) }
 end
 
+describe Question, '#answered_by?' do
+  it 'returns true for a user with an answer' do
+    user = create(:user)
+    question = create(:question)
+    AnswerCreator.new(question.survey, user: user).answer(question)
+
+    question.should be_answered_by(user)
+  end
+
+  it 'returns false for a user without an answer' do
+    user = create(:user)
+    other_user = create(:user)
+    survey = create(:survey)
+    question = create(:question, survey: survey)
+    other_question = create(:question, survey: survey)
+    creator = AnswerCreator.new(survey, user: user)
+    creator.answer(question, '')
+    creator.answer(other_question, 'hello')
+    AnswerCreator.new(survey, user: other_user).answer(question)
+
+    question.should_not be_answered_by(user)
+  end
+end
+
 describe Question, '#build_submittable' do
   it 'builds a submittable with the given type and attributes' do
     expected_value = 1.day.ago

example_app/spec/models/survey_spec.rb

@@ -11,7 +11,7 @@
   it 'applies the given summarizer to each question' do
     questions = [build_stubbed(:question), build_stubbed(:question)]
     survey = build_stubbed(:survey, questions: questions)
-    summarizer = stub('summarizer', summarize: 'result')
+    summarizer = stub_summarizer
 
     result = survey.summaries_using(summarizer)
 
@@ -20,6 +20,36 @@
     result.map(&:value).should == %w(result result)
   end
 
+  it 'applies the given summarizer to each question answered by the user' do
+    user = build_stubbed(:user)
+    answered_question = stub_question(user: user, answered: true)
+    unanswered_question = stub_question(user: user, answered: false)
+    questions = [answered_question, unanswered_question]
+    questions.stubs(:answered_by).with(user).returns(questions)
+    survey = build_stubbed(:survey, questions: questions)
+    summarizer = stub_summarizer
+
+    result = survey.summaries_using(summarizer, answered_by: user)
+
+    should_summarize_questions [answered_question], summarizer
+    result.map(&:title).should eq questions.map(&:title)
+    result.map(&:value).
+      should eq ['result', "You haven't answered this question"]
+  end
+
+  def stub_question(arguments)
+    build_stubbed(:question).tap do |question|
+      question.
+        stubs(:answered_by?).
+        with(arguments[:user]).
+        returns(arguments[:answered])
+    end
+  end
+
+  def stub_summarizer
+    stub('summarizer', summarize: 'result')
+  end
+
   def should_summarize_questions(questions, summarizer)
     questions.each do |question|
       summarizer.should have_received(:summarize).with(question)

example_app/spec/support/answer_creator.rb

@@ -6,7 +6,7 @@ def initialize(survey, options = {})
     @completion = create(:completion, options.merge(survey: @survey))
   end
 
-  def answer(question, answer_text)
+  def answer(question, answer_text = 'hello')
     create(
       :answer,
       question: question,