Add studentReporting to DiscussionTopicPermissionsType

refs VICE-2174
flag=discussions_reporting

Test Plan:
 - turn discussion reporting ff on
 - go to http://localhost:3000/graphiql
 - run a query similar to the example below
 > should see studentReporting as true
 - go to the discussions landing page in the course
    you queried against
 - click the settings cog in the top right
 - change student reporting to be false (unchecked)
 - run the query again
 - studentReporting should be false

Example Query: (remember to update the _id for the discussion)
query MyQuery {
  __typename
  legacyNode(_id: "23", type: Discussion) {
    ... on Discussion {
      id
      _id
      title
      permissions {
        studentReporting
      }
    }
  }
}

Change-Id: Ibbbae7e546efdcbc52901a38bcf1e606f3881055
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/276278
Reviewed-by: Omar Soto-Fortuño <omar.soto@instructure.com>
QA-Review: Omar Soto-Fortuño <omar.soto@instructure.com>
Product-Review: Omar Soto-Fortuño <omar.soto@instructure.com>
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>

app/graphql/types/discussion_permissions_type.rb

@@ -37,6 +37,11 @@ module Types
       object[:loader].load(:reply)
     end
 
+    field :student_reporting, Boolean, null: true
+    def student_reporting
+      object[:loader].load(:student_reporting)
+    end
+
     field :update, Boolean, null: true
     def update
       object[:loader].load(:update)

app/models/course.rb

@@ -2632,6 +2632,10 @@ class Course < ActiveRecord::Base
      :homeroom_course, :course_color, :alt_name]
   end
 
+  def student_reporting?
+    !!self.allow_student_discussion_reporting
+  end
+
   def set_course_dates_if_blank(shift_options)
     unless Canvas::Plugin.value_to_boolean(shift_options[:remove_dates])
       self.start_at ||= shift_options[:default_start_at]

app/models/discussion_topic.rb

@@ -1173,6 +1173,9 @@ class DiscussionTopic < ActiveRecord::Base
     given { |user, session| context.respond_to?(:allow_student_forum_attachments) && context.allow_student_forum_attachments && context.grants_any_right?(user, session, :create_forum, :post_to_forum) }
     can :attach
 
+    given { course.student_reporting? }
+    can :student_reporting
+
     given { |user, session| !self.root_topic_id && self.context.grants_all_rights?(user, session, :read_forum, :moderate_forum) && self.available_for?(user) }
     can :update and can :read_as_admin and can :delete and can :create and can :read and can :attach
 

spec/graphql/types/discussion_type_spec.rb

@@ -58,6 +58,10 @@ RSpec.shared_examples "DiscussionType" do
         value: 'readAsAdmin',
         allowed: ->(user) { discussion.grants_right?(user, nil, :read_as_admin) }
       },
+      {
+        value: 'studentReporting',
+        allowed: ->(user) { discussion.course.student_reporting? }
+      },
       {
         value: 'manageContent',
         allowed: ->(user) { discussion.context.grants_right?(user, :manage_content) }

spec/models/discussion_topic_spec.rb

@@ -272,7 +272,7 @@ describe DiscussionTopic do
 
     it "does not grant moderate permissions without read permissions" do
       @course.account.role_overrides.create!(:role => teacher_role, :permission => 'read_forum', :enabled => false)
-      expect(@topic.reload.check_policy(@teacher2)).to eql [:create, :duplicate, :attach]
+      expect(@topic.reload.check_policy(@teacher2)).to eql [:create, :duplicate, :attach, :student_reporting]
     end
 
     it "grants permissions if it not locked" do