embed poll submissions into poll session

fixes CNVS-13275, CNVS-13297
This commit embeds all submissions when a particular poll session is
requested by authorized users (the creator/teacher of the poll and
relevant poll session.).  It also deletes all submissions and sessions
that belong to a poll when that poll is deleted.

Test plan
Submission embedding
- Create a poll and related poll session
- Create multiple submissions for the poll as students
- As a teacher, you should be able to see the related submissions
  when requesting the poll session via the API

Poll session/submission deletion
- Create a poll and two poll sessions, with two submissions per session
- Delete the poll via the api, it should be deleted successfully

Change-Id: I335f92eb97be095a2ddf6bc730954ed8a14220ef
Reviewed-on: https://gerrit.instructure.com/35456
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Derek DeVries <ddevries@instructure.com>
QA-Review: Caleb Guanzon <cguanzon@instructure.com>
Product-Review: Josh Simpson <jsimpson@instructure.com>

app/controllers/polling/poll_submissions_controller.rb

@@ -26,14 +26,25 @@ module Polling
   #       "required": ["id", "poll_choice"],
   #       "properties": {
   #         "id": {
-  #           "description": "The unique identifier for the account role/user assignment.",
+  #           "description": "The unique identifier for the poll submission.",
   #           "example": 1023,
   #           "type": "integer"
   #         },
   #         "poll_choice_id": {
-  #           "description": "The id of the chosen poll choice for this submission.",
+  #           "description": "The unique identifier of the poll choice chosen for this submission.",
-  #           "example": 55,
+  #           "example": 155,
   #           "type": "integer"
+  #         },
+  #         "user_id": {
+  #           "description": "the unique identifier of the user who submitted this poll submission.",
+  #           "example": 4555,
+  #           "type": "integer"
+  #         },
+  #         "created_at": {
+  #           "description": "The date and time the poll submission was submitted.",
+  #           "example": "2013-11-07T13:16:18Z",
+  #           "type": "string",
+  #           "format": "date-time"
   #         }
   #       }
   #    }

app/models/polling/poll.rb

@@ -22,8 +22,8 @@ module Polling
 
     belongs_to :user
     has_many :poll_choices, class_name: 'Polling::PollChoice', dependent: :destroy
-    has_many :poll_submissions, class_name: 'Polling::PollSubmission'
+    has_many :poll_submissions, class_name: 'Polling::PollSubmission', dependent: :destroy
-    has_many :poll_sessions, class_name: 'Polling::PollSession'
+    has_many :poll_sessions, class_name: 'Polling::PollSession', dependent: :destroy
 
     validates_presence_of :question, :user
     validates_length_of :question, maximum: 255, allow_nil: true

app/models/polling/poll_choice.rb

@@ -21,6 +21,7 @@ module Polling
     attr_accessible :text, :poll, :is_correct
 
     belongs_to :poll, class_name: 'Polling::Poll'
+    has_many :poll_submissions, class_name: 'Polling::PollSubmission', dependent: :destroy
 
     validates_presence_of :poll, :text
     validates_length_of :text, maximum: 255, allow_nil: true

app/serializers/polling/poll_session_serializer.rb

@@ -1,11 +1,16 @@
 module Polling
   class PollSessionSerializer < Canvas::APISerializer
-    root :poll_session
+    attributes :id, :is_published, :has_public_results, :results, :course_id, :course_section_id, :created_at, :poll_id, :poll_submissions
-
-    attributes :id, :is_published, :has_public_results, :results, :course_id, :course_section_id, :created_at
 
     def_delegators :object, :results, :poll
 
+    # has_many relationships with embedded objects doesn't work, so we override it this way
+    def poll_submissions
+      @poll_submissions ||= object.poll_submissions.map do |submission|
+        Polling::PollSubmissionSerializer.new(submission, controller: @controller, scope: @scope, root: false)
+      end
+    end
+
     def filter(keys)
       if poll.grants_right?(current_user, session, :update) || object.has_public_results?
         student_keys + teacher_keys
@@ -17,11 +22,11 @@ module Polling
     private
 
     def teacher_keys
-      [:has_public_results, :results]
+      [:has_public_results, :results, :poll_submissions]
     end
 
     def student_keys
-      [:id, :is_published, :course_id, :course_section_id, :created_at]
+      [:id, :is_published, :course_id, :course_section_id, :created_at, :poll_id]
     end
   end
 end

app/serializers/polling/poll_submission_serializer.rb

@@ -1,7 +1,6 @@
 module Polling
   class PollSubmissionSerializer < Canvas::APISerializer
     root :poll_submission
-
+    attributes :id, :poll_session_id, :poll_choice_id, :user_id, :created_at
-    attributes :id, :poll_choice_id
   end
 end

spec/apis/v1/polling/poll_sessions_api_spec.rb

@@ -95,12 +95,29 @@ describe Polling::PollSessionsController, type: :request do
     context "as a teacher" do
       it "retrieves the poll session specified even if closed" do
         @poll_session.close!
+
+        @user = @teacher
         json = get_show
         poll_json = json['poll_sessions'].first
         poll_json['id'].should == @poll_session.id.to_s
         poll_json['is_published'].should be_false
       end
 
+      it "embeds the associated poll submissions" do
+        choice1 = @poll.poll_choices.create!(text: 'Choice A', is_correct: true)
+        choice2 = @poll.poll_choices.create!(text: 'Choice B', is_correct: false)
+
+        2.times { create_submission(choice1) }
+        1.times { create_submission(choice2) }
+
+        @user = @teacher
+        json = get_show
+        poll_session_json = json['poll_sessions'].first
+
+        poll_session_json.should have_key('poll_submissions')
+        poll_session_json['poll_submissions'].size.should == 3
+      end
+
       it "shows the results of a current poll session" do
         choice1 = @poll.poll_choices.create!(text: 'Choice A', is_correct: true)
         choice2 = @poll.poll_choices.create!(text: 'Choice B', is_correct: false)
@@ -119,6 +136,21 @@ describe Polling::PollSessionsController, type: :request do
     end
 
     context "as a student" do
+      it "doesn't embed the associated poll submissions" do
+        choice1 = @poll.poll_choices.create!(text: 'Choice A', is_correct: true)
+        choice2 = @poll.poll_choices.create!(text: 'Choice B', is_correct: false)
+
+        2.times { create_submission(choice1) }
+        1.times { create_submission(choice2) }
+
+        student = student_in_course(active_user:true).user
+        @user = student
+
+        json = get_show
+
+        json.should_not have_key('poll_submissions')
+      end
+
       context "when has_public_results is false" do
         it "doesn't show the results of a current poll session" do
           choice1 = @poll.poll_choices.create!(text: 'Choice A', is_correct: true)
@@ -342,6 +374,4 @@ describe Polling::PollSessionsController, type: :request do
       end
     end
   end
-
-
 end

spec/apis/v1/polling/polls_api_spec.rb

@@ -170,6 +170,16 @@ describe Polling::PollsController, type: :request do
   describe 'DELETE destroy' do
     before(:each) do
       @poll = @teacher.polls.create!(question: 'An Old Title')
+      @choice = @poll.poll_choices.create!(text: 'Blah')
+      @session = @poll.poll_sessions.create!(course: @course)
+      @session.publish!
+
+      @student = student_in_course(active_user: true).user
+      @submission = @session.poll_submissions.create!(
+        user: @student,
+        poll: @poll,
+        poll_choice: @choice
+      )
     end
 
     def delete_destroy
@@ -183,6 +193,7 @@ describe Polling::PollsController, type: :request do
 
     context "as a teacher" do
       it "deletes a poll successfully" do
+        @user = @teacher
         delete_destroy
 
         response.code.should == '204'
@@ -193,6 +204,7 @@ describe Polling::PollsController, type: :request do
         choice_a = @poll.poll_choices.create!(text: 'choice a')
         choice_b = @poll.poll_choices.create!(text: 'choice b')
 
+        @user = @teacher
         delete_destroy
         response.code.should == '204'
         Polling::PollChoice.find_by_id(choice_a.id).should be_nil