allow students to see answers after final attempt

fixes CNVS-19091

test plan:
  - make a quiz where correct answers are visible
    after a final attempt and give them two attempts
    - include some questions that require manual
      grading and some that do not
  - as a student submit two attempts
  - note that you do NOT get an error saying
    'Answers will be shown after your last attempt'
    once you have submitted your second attempt

Change-Id: I4ed1c7c775ef730afb963ed1d15f844e2244602f
Reviewed-on: https://gerrit.instructure.com/55480
Tested-by: Jenkins
Reviewed-by: Brian Finney <bfinney@instructure.com>
QA-Review: Michael Hargiss <mhargiss@instructure.com>
Product-Review: Hilary Scharton <hilary@instructure.com>

app/helpers/quizzes_helper.rb

@@ -122,8 +122,10 @@ module QuizzesHelper
     end
   end
 
-  def render_correct_answer_protection(quiz)
-    return I18n.t('Answers will be shown after your last attempt') if quiz.show_correct_answers_last_attempt
+  def render_correct_answer_protection(quiz, submission)
+    if quiz.show_correct_answers_last_attempt && !submission.last_attempt_completed?
+      return I18n.t('Answers will be shown after your last attempt')
+    end
     show_at = quiz.show_correct_answers_at
     hide_at = quiz.hide_correct_answers_at
     now = Time.now

app/models/quizzes/quiz.rb

@@ -352,8 +352,9 @@ class Quizzes::Quiz < ActiveRecord::Base
 
     return false unless self.show_correct_answers
 
-    if user.present? && self.show_correct_answers_last_attempt && quiz_submission = user.quiz_submissions.where(quiz_id: self.id).first
-      return quiz_submission.attempts_left == 0 && quiz_submission.complete?
+    quiz_submission = user.present? && user.quiz_submissions.where(quiz_id: self.id).first
+    if self.show_correct_answers_last_attempt && quiz_submission
+      return quiz_submission.attempts_left == 0 && quiz_submission.completed?
     end
 
     # If we're showing the results only one time, and are letting students

app/models/quizzes/quiz_submission.rb

@@ -229,12 +229,16 @@ class Quizzes::QuizSubmission < ActiveRecord::Base
       # prevents the student from starting to take the quiz for the last
       # time, then opening a new tab and looking at the results from
       # a prior attempt)
-      !quiz.allowed_attempts || quiz.allowed_attempts < 1 || attempt > quiz.allowed_attempts || (completed? && attempt == quiz.allowed_attempts)
+      !quiz.allowed_attempts || quiz.allowed_attempts < 1 || attempt > quiz.allowed_attempts || last_attempt_completed?
     else
       true
     end
   end
 
+  def last_attempt_completed?
+    completed? && quiz.allowed_attempts && attempt >= quiz.allowed_attempts
+  end
+
   def self.needs_grading
      resp = where("(
          quiz_submissions.workflow_state = 'untaken'

app/views/quizzes/quizzes/_quiz_submission.html.erb

@@ -5,8 +5,8 @@
 
 <% if correct_answers_protected? %>
   <div class="alert">
-    <i class="icon-warning" aria-label="<%= render_correct_answer_protection(@quiz) %>"></i>
-    <span><%= render_correct_answer_protection(@quiz) %></span>
+    <i class="icon-warning" aria-label="<%= render_correct_answer_protection(@quiz, (@current_submission || @submission)) %>"></i>
+    <span><%= render_correct_answer_protection(@quiz, (@current_submission || @submission)) %></span>
   </div>
 <% end %>
 

spec/helpers/quizzes_helper_spec.rb

@@ -398,8 +398,9 @@ describe QuizzesHelper do
       quiz = stub({
         show_correct_answers_last_attempt: true,
       })
+      quiz_submission = stub(last_attempt_completed?: false)
 
-      message = render_correct_answer_protection(quiz)
+      message = render_correct_answer_protection(quiz, quiz_submission)
       expect(message).to match /last attempt/
     end
     it 'should provide a useful message when "no"' do
@@ -409,8 +410,9 @@ describe QuizzesHelper do
         show_correct_answers_at: nil,
         hide_correct_answers_at: nil
       })
+      quiz_submission = stub(last_attempt_completed?: false)
 
-      message = render_correct_answer_protection(quiz)
+      message = render_correct_answer_protection(quiz, quiz_submission)
       expect(message).to match /are hidden/
     end
 
@@ -421,8 +423,9 @@ describe QuizzesHelper do
         show_correct_answers_at: nil,
         hide_correct_answers_at: nil
       })
+      quiz_submission = stub(last_attempt_completed?: false)
 
-      message = render_correct_answer_protection(quiz)
+      message = render_correct_answer_protection(quiz, quiz_submission)
       expect(message).to eq nil
     end
 
@@ -433,8 +436,9 @@ describe QuizzesHelper do
         show_correct_answers_at: 1.day.from_now,
         hide_correct_answers_at: nil
       })
+      quiz_submission = stub(last_attempt_completed?: false)
 
-      message = render_correct_answer_protection(quiz)
+      message = render_correct_answer_protection(quiz, quiz_submission)
       expect(message).to match /will be available/
     end
 
@@ -445,8 +449,9 @@ describe QuizzesHelper do
         show_correct_answers_at: nil,
         hide_correct_answers_at: 1.day.from_now
       })
+      quiz_submission = stub(last_attempt_completed?: false)
 
-      message = render_correct_answer_protection(quiz)
+      message = render_correct_answer_protection(quiz, quiz_submission)
       expect(message).to match /are available until/
     end
   end