display late message on DA in speedgrader

The model logic of QuizSubmission#late? now accounts for
differentiated assignments. This bubbles up to a fix for
the view.

fixes CNVS-24099

Test plan:
 1. As a teacher in a course with 2 or more students,
    Create a quiz.
 2. Assign the quiz to a student with a due date in the
    past.
 3. As that student, take the quiz.
 4. Go to speedgrader and verify the quiz is late.

Change-Id: If95846dfdccda2684e33334c20a27da4172d0d20
Reviewed-on: https://gerrit.instructure.com/67263
Tested-by: Jenkins
Reviewed-by: Derek Bender <djbender@instructure.com>
Reviewed-by: Spencer Olson <solson@instructure.com>
QA-Review: Jason Carter <jcarter@instructure.com>
Product-Review: Christi Wruck

app/models/quizzes/quiz_submission.rb

@@ -850,11 +850,17 @@ class Quizzes::QuizSubmission < ActiveRecord::Base
     fixer.run!(self)
   end
 
+  def due_at
+    return quiz.due_at if submission.blank?
+
+    quiz.overridden_for(submission.user).due_at
+  end
+
   # TODO: Extract? conceptually similar to Submission::Tardiness#late?
   def late?
     return false if finished_at.blank?
-    return false if quiz.due_at.blank?
+    return false if due_at.blank?
 
-    finished_at > quiz.due_at
+    finished_at > due_at
   end
 end

spec/models/quizzes/quiz_submission_spec.rb

@@ -643,7 +643,7 @@ describe Quizzes::QuizSubmission do
       })
       expect(@quiz_submission.submission.workflow_state).to eql 'graded'
     end
-    
+
     it "should mark a submission complete if all essay questions have been graded, even if a text_only_question is present" do
       quiz_with_graded_submission([{:question_data => {:name => 'question 1', :points_possible => 1, 'question_type' => 'essay_question'}},
                                    {:question_data => {:name => 'question 2', :points_possible => 1, 'question_type' => 'text_only_question'}}]) do
@@ -1559,48 +1559,87 @@ describe Quizzes::QuizSubmission do
     end
   end
 
-  describe "Tardiness" do
-    let(:course)      { Course.create! }
-    let(:now)         { Time.zone.now }
-    let(:quiz)        { course.quizzes.create! due_at: 3.days.ago(now) }
-    let(:submission)  { quiz.quiz_submissions.create! }
+  describe "#late?" do
+    let(:course)          { Course.create! }
+    let(:now)             { Time.zone.now }
+    let(:quiz)            { course.quizzes.create! due_at: 3.days.ago(now) }
+
+    context "for quizzes with a due date" do
+      let(:quiz_submission) { quiz.quiz_submissions.create! }
 
-    describe "#late?" do
       it "is not late when on turned in before the due date" do
-        submission.finished_at = 4.days.ago(now)
-        submission.save
+        quiz_submission.finished_at = 4.days.ago(now)
+        quiz_submission.save
 
-        expect(submission.late?).to eq false
+        expect(quiz_submission.late?).to eq false
       end
 
       it "is not late when on turned in exactly at the due date" do
-        submission.finished_at = 3.days.ago(now)
-        submission.save
+        quiz_submission.finished_at = 3.days.ago(now)
+        quiz_submission.save
 
-        expect(submission.late?).to eq false
+        expect(quiz_submission.late?).to eq false
+      end
+
+      it "is late when turned in after the due date" do
+        quiz_submission.finished_at = 2.days.ago(now)
+        quiz_submission.save
+
+        expect(quiz_submission.late?).to eq true
       end
 
       it "is not late when unfinished" do
-        expect(submission.late?).to eq false
+        expect(quiz_submission.late?).to eq false
+      end
+    end
+
+    context "for quizzes without a due date" do
+      let(:quiz) { course.quizzes.create! }
+      let(:quiz_submission) do
+        quiz.quiz_submissions.create! do |qs|
+          qs.finished_at = 3.days.ago(now)
+        end
       end
 
       it "is not late when the quiz has no due date" do
-        quiz_two                    = course.quizzes.create!
-        submission_two              = quiz_two.quiz_submissions.create!
-        submission_two.finished_at  = 3.days.ago(now)
-        submission_two.save
-        expect(submission_two.late?).to eq false
+        expect(quiz_submission.late?).to eq false
+      end
+    end
+
+    context "for quizzes with overridden due dates for some students" do
+      let(:quiz_submission) do
+        quiz.quiz_submissions.create! do |qs|
+          qs.user = student
+          qs.finished_at = 1.week.ago(now)
+        end
       end
 
-      it "is late when on turned in after the due date" do
-        submission.finished_at = 2.days.ago(now)
-        submission.save
+      let(:student) { User.create! }
 
-        expect(submission.late?).to eq true
+      let!(:enroll_student) do
+        course.enroll_user student, 'StudentEnrollment'
+      end
+
+      let!(:override_students_quiz) do
+        assignment_override = quiz.assignment_overrides.create! do |override|
+          override.due_at = 3.weeks.ago(now)
+          override.due_at_overridden = true
+        end
+
+        assignment_override.assignment_override_students.create! do |aos|
+          aos.quiz = quiz
+          aos.user = student
+        end
+      end
+
+      it "is late when it's overridden due date is before the submission" do
+        submission = stub("blank?" => false, "user" => student)
+        quiz_submission.stubs(:submission).returns(submission)
+        expect(quiz_submission.late?).to eq true
       end
     end
   end
-  
+
   describe '#excused?' do
     let(:submission) do
       s=Submission.new