fix anonymous peer review checkbox on graded discussion form.

fixes CNVS-19782

The checkbox used to determine whether or not an assignment's peer
reviews should be considered anonymous, which is part of a backbone
view, did not function properly if it was 'nested' (i.e., if the name on
the field should be `assiginment[anonymous_peer_reviews]`, instead of just
`anonymous_peer_reviews`. The `checkbox` helper is already setup to
handle this; we just needed to pass the `nested` value to it, and to
update how we determine whether or not the checkbox should appear
checked, so as to avoid manually setting the checkbox's `name`
attribute.

Additionally, this patch fixes a bug in the
`RubricAssessment#considered_anonymous?` method, which would blow up if
the model did not have a related rubric_association. I've added a
protection to two other methods that would have thrown exceptions in the
absence of a rubric_assocation as well.

Finally, I updated the logic in the SubmissionComment policy
declaration, so that when trying to `:read_author`, a student can always
see the name of a teacher, even if the comment is marked as anonymous.

test plan:
- as a teacher, create a graded discussion topic. When doing say, enable
  peer reviews, and enable anonymous peer reviews.
- as a student, submit an entry for the graded discussion topic.
- as a teacher, assign a peer review to a student for the submission
  above.
- as the reviewer student, submit a review.
- as the reviewed student, navigate to the submission details page
  (/courses/:course_id/assignments/:assignment_id/submissions/:user_id)
  and observe the comment list on the right hand side of the page.
- observe that the name of the reviewer student is not present, and
  instead it says 'Anonymous User'.
- as the teacher, navigate to the same submission page, and observe the
  comment list on the right hand side of the page.
- observe that the name of the reviewer student IS present.
- as the teacher, navigate to the same submission page, and observe the
  comment list on the right hand side of the page
- as the teacher, leave a comment on the submitted assignment.
- as the reviewed student, navigate to the submission details page, and
  observe the comment list on the right hand side of the page.
- observe that the name of the reviewer teacher IS present.

Change-Id: I572dd7fa319cd784e59f00057898fcea5349c899
Reviewed-on: https://gerrit.instructure.com/52099
Tested-by: Jenkins
Reviewed-by: Mike Nomitch <mnomitch@instructure.com>
QA-Review: Adam Stone <astone@instructure.com>
Product-Review: Hilary Scharton <hilary@instructure.com>

app/models/rubric_assessment.rb

@@ -53,7 +53,14 @@ class RubricAssessment < ActiveRecord::Base
 
   def update_outcomes_for_assessment(outcome_ids=[])
     return if outcome_ids.empty?
-    alignments = self.rubric_association.association_object.learning_outcome_alignments.where(learning_outcome_id: outcome_ids)
+    alignments = if self.rubric_association.present?
+      self.rubric_association.association_object.learning_outcome_alignments.where({
+        learning_outcome_id: outcome_ids
+      })
+    else
+      []
+    end
+
     (self.data || []).each do |rating|
       if rating[:learning_outcome_id]
         alignments.each do |alignment|
@@ -125,7 +132,13 @@ class RubricAssessment < ActiveRecord::Base
 
   def update_assessment_requests
     requests = self.assessment_requests
-    requests += self.rubric_association.assessment_requests.where(assessor_id: self.assessor_id, asset_id: self.artifact_id, asset_type: self.artifact_type)
+    if self.rubric_association.present?
+      requests += self.rubric_association.assessment_requests.where({
+        assessor_id: self.assessor_id,
+        asset_id: self.artifact_id,
+        asset_type: self.artifact_type
+      })
+    end
     requests.each { |a|
       a.attributes = {:rubric_assessment => self, :assessor => self.assessor}
       a.complete
@@ -202,6 +215,7 @@ class RubricAssessment < ActiveRecord::Base
   end
 
   def considered_anonymous?
+    return false unless self.rubric_association.present?
     self.rubric_association.association_type == 'Assignment' &&
     self.rubric_association.association_object.anonymous_peer_reviews?
   end

app/models/submission_comment.rb

@@ -103,7 +103,8 @@ class SubmissionComment < ActiveRecord::Base
     given { |user, session|
       !self.anonymous? ||
         self.author == user ||
-        self.submission.assignment.context.grants_right?(user, session, :view_all_grades)
+        self.submission.assignment.context.grants_right?(user, session, :view_all_grades) ||
+        self.submission.assignment.context.grants_right?(self.author, session, :view_all_grades)
     }
     can :read_author
   end

app/views/jst/assignments/PeerReviewsSelector.handlebars

@@ -97,10 +97,11 @@
         </div>
 
         <label class="checkbox" for="anonymous_peer_reviews">
-          {{checkbox "anonymousPeerReviews"
+          {{checkbox "anonymous_peer_reviews"
+          checked=anonymousPeerReviews
           id="anonymous_peer_reviews"
-          name="anonymous_peer_reviews"
           aria-controls="anonymous_peer_reviews"
+          prefix=prefix
           disabled=peerReviewsFrozen}}
           {{#t "labels.anonymous_peer_reviews"}}
             Peer Reviews Appear Anonymously

spec/models/rubric_assessment_spec.rb

@@ -155,5 +155,21 @@ describe RubricAssessment do
         expect(@assessment.grants_right?(@teacher, :read_assessor)).to be_truthy
       end
     end
+
+    describe "#considered_anonymous?" do
+      let_once(:assessment) {
+        RubricAssessment.create!({
+          artifact: @assignment.find_or_create_submission(@student),
+          assessment_type: 'peer_review',
+          assessor: student_in_course(active_all: true).user,
+          rubric: @rubric,
+          user: @student
+        })
+      }
+
+      it "should not blow up without a rubric_association" do
+        expect{assessment.considered_anonymous?}.not_to raise_error
+      end
+    end
   end
 end

spec/models/submission_comment_spec.rb

@@ -193,6 +193,11 @@ This text has a http://www.google.com link in it...
           author: @student2,
           comment: "My peer review comment."
         })
+
+        @teacher_comment = @submission.add_comment({
+          author: @teacher,
+          comment: "My teacher review comment."
+        })
       end
 
       it "should mark submission comment as anonymous" do
@@ -206,6 +211,10 @@ This text has a http://www.google.com link in it...
       it "should allow teacher to see reviewer name" do
         expect(@reviewer_comment.grants_right?(@teacher, :read_author)).to be_truthy
       end
+
+      it "should allow reviewed to see a teacher comment" do
+        expect(@teacher_comment.grants_right?(@student1, :read_author)).to be_truthy
+      end
     end
   end