display gradebook history properly. fixes #6051

changes to a grade were appearing in grade history only
on the date of the first grade. grade changes now display
once on each day that they occur.

Change-Id: I66e84a23f28757e3433e2bcbbe437a9a6ff046d8
Reviewed-on: https://gerrit.instructure.com/6373
Reviewed-by: Ryan Shaw <ryan@instructure.com>
Tested-by: Hudson <hudson@instructure.com>

app/models/assignment.rb

@@ -833,6 +833,7 @@ class Assignment < ActiveRecord::Base
         submission_updated = true if submission.changed?
         submission.workflow_state = "graded" if submission.score_changed? || submission.grade_matches_current_submission
         submission.group = group
+        submission.graded_at = Time.now if did_grade
         previously_graded ? submission.with_versioning(:explicit => true) { submission.save! } : submission.save!
         tags.each do |tag|
           tag.create_outcome_result(student, self, submission)

lib/submission_list.rb

@@ -234,7 +234,7 @@ class SubmissionList
         # Also don't add it to the list.  Just pass the list to the next
         # iteration of the block. 
         next(l) unless h[:score]
-        
+
         # If the submission is different (not null for the first one, or just
         # different than the last one), set the previous_grade to nil (this is
         # the first version that changes a grade), set the new_grade to this
@@ -255,7 +255,7 @@ class SubmissionList
         # Remove the old submission so that it doesn't show up twice in the
         # grade history.
         elsif prior_score != h[:score]
-          l.pop
+          l.pop if prior_graded_at.to_date == h[:graded_at].to_date && prior_grader == h[:grader]
           h[:previous_grade] = prior_grade
           h[:previous_graded_at] = prior_graded_at
           h[:previous_grader] = prior_grader

spec/lib/submission_list_spec.rb

@@ -73,6 +73,16 @@ describe SubmissionList do
         end
       end
     end
+
+    it "should only keep one diff per grader per day" do
+      SubmissionList.days(@course).each do |day|
+        day.graders.each do |grader|
+          grader.assignments.each do |assignment|
+            assignment.submissions.length.should eql assignment.submissions.map(&:student_name).uniq.length
+          end
+        end
+      end
+    end
     
     it "should be able to loop on assignments" do
       available_keys = [:submission_count, :name, :submissions, :assignment_id]
@@ -207,10 +217,13 @@ def interesting_submission_data(opts={})
   opts[:submission] ||= {}
   
   @grader = user_model({:name => 'some_grader'}.merge(opts[:grader]))
+  @grader2 = user_model({:name => 'another_grader'}.merge(opts[:grader]))
   @student = factory_with_protected_attributes(User, {:name => "some student", :workflow_state => "registered"}.merge(opts[:user]))
   @course = factory_with_protected_attributes(Course, {:name => "some course", :workflow_state => "available"}.merge(opts[:course]))
-  e = @course.enroll_teacher(@grader)
-  e.accept
+  [@grader, @grader2].each do |grader|
+    e = @course.enroll_teacher(grader)
+    e.accept
+  end
   @course.enroll_student(@student)
   @assignment = @course.assignments.new({
     :title => "some assignment", 
@@ -220,7 +233,7 @@ def interesting_submission_data(opts={})
   @assignment.save!
   @assignment.grade_student(@student, {:grade => 1.5, :grader => @grader}.merge(opts[:submission]))
   @assignment.grade_student(@student, {:grade => 3, :grader => @grader}.merge(opts[:submission]))
-  @assignment.grade_student(@student, {:grade => 5, :grader => @grader}.merge(opts[:submission]))
+  @assignment.grade_student(@student, {:grade => 5, :grader => @grader2}.merge(opts[:submission]))
   @student = user_model(:name => 'another student')
   @course.enroll_student(@student)
   @assignment.reload

spec/models/assignment_spec.rb

@@ -53,6 +53,18 @@ describe Assignment do
     @submission.versions.length.should eql(1)
   end
 
+  it "should update a submission's graded_at when grading it" do
+    setup_assignment_with_homework
+    @assignment.grade_student(@user, :grade => 1)
+    @submission = @assignment.submissions.first
+    original_graded_at = @submission.graded_at
+    new_time = Time.now + 1.hour
+    Time.stub!(:now).and_return(new_time)
+    @assignment.grade_student(@user, :grade => 2)
+    @submission.reload
+    @submission.graded_at.should_not eql original_graded_at
+  end
+
   it "should update needs_grading_count when submissions transition state" do
     setup_assignment_with_homework
     @assignment.needs_grading_count.should eql(1)