add submitted/unsubmitted quiz users endpoint to quizzes api

Test plan:
  - As a teacher, create a quiz.
  - Visit the quizzes API using JSONAPI headers. For that quiz,
    "submitted_students" should be null. You should get a URL back to
    the "unsubmitted_students" endpoint, which you can query and find
    the unsubmitted students.
  - As a student submit the quiz. As a different student, don't submit
    the quiz.
  - As a teacher, visit the quiz show endpoint for that quiz again. You
    should have "submitted_students" and "unsubmitted_students" under
    the "links" hash. Query these APIs using those URLs. The students
    returned from the link that looks like "?submitted=true"
  - As a student, you should not see "submitted_students" or
   "unsubmitted_students" under the "links" hash when querying
   the show API in JSONAPI format
  - In non-jsonapi format as any user, you should not see
   "unsubmitted_students" or "submitted_students"

closes CNVS-11687

Change-Id: I7094dfc37b0dde501e5a2c1f12ade983cd2a150a
Reviewed-on: https://gerrit.instructure.com/31223
Reviewed-by: Derek DeVries <ddevries@instructure.com>
QA-Review: Caleb Guanzon <cguanzon@instructure.com>
Product-Review: Stanley Stuart <stanley@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>

app/controllers/quizzes/quiz_submission_users_controller.rb

@@ -0,0 +1,178 @@
+# Copyright (C) 2014 Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+module Quizzes
+  class QuizSubmissionUsersController < ::ApplicationController
+    include Filters::Quizzes
+    before_filter :require_context, :require_quiz
+    # @API List of users who have or haven't submitted for a quiz
+    # @beta
+    #
+    # @argument submitted [Optional, boolean]
+    #   If true, return users who have submitted the quiz. If false, return users
+    #   who have not submitted the quiz. If not present, returns all students for
+    #   the course.
+    #
+    # @returns QuizSubmissionUserList
+    #
+    # @model QuizSubmissionUserList
+    #
+    # {
+    #   "meta": {
+    #     "$ref": "QuizSubmissionUserListMeta",
+    #     "description": "contains meta information (such as pagination) for the list of users"
+    #   },
+    #   "users": {
+    #     "$ref": "User",
+    #     "description": "list of users that match the query"
+    #   }
+    # }
+    #
+    # @model QuizSubmissionUserListMeta
+    #
+    # {
+    #   "pagination": {
+    #     "$ref": "JSONAPIPagination",
+    #     "description": "contains pagination information for the list of users"
+    #   }
+    # }
+    #
+    # @model JSONAPIPagination
+    #
+    # {
+    #   "per_page": {
+    #     "type": "integer",
+    #     "description": "number of results per page",
+    #     "example": 10
+    #   },
+    #   "page": {
+    #     "type": "integer",
+    #     "description": "the current page passed as the ?page= parameter",
+    #     "example": 1
+    #   },
+    #   "template": {
+    #     "type": "string",
+    #     "description": "URL template for building out other paged URLs for this endpoint",
+    #     "example": "https://example.instructure.com/api/v1/courses/1/quizzes/1/submission_users?page={page}"
+    #   },
+    #   "page_count": {
+    #     "type": "integer",
+    #     "description": "number of pages for this collection",
+    #     "example": 10
+    #   },
+    #   "count": {
+    #     "type": "integer",
+    #     "description": "total number of items in this collection",
+    #     "example": 100
+    #   }
+    # }
+    def index
+      return unless user_has_teacher_level_access?
+      @users = if submitted_param?
+        @users = submitted? ? submitted_users : unsubmitted_users
+      else
+        @users = user_finder.all_students
+      end
+
+      @users, meta = Api.jsonapi_paginate(@users, self, index_base_url, page: params[:page])
+      users_json = @users.map { |user| user_json(user, @current_user, session) }
+
+      render json: { meta: meta, users: users_json }
+    end
+
+    # @API Send a message to unsubmitted or submitted users for the quiz
+    # @beta
+    #
+    # @param conversations [QuizUserConversation] - Body and recipients to send the message to.
+    #
+    # @model QuizUserConversation
+    #
+    # {
+    #   "body": {
+    #     "type": "string",
+    #     "description": "message body of the conversation to be created",
+    #     "example": "Please take the quiz."
+    #   },
+    #   "recipients": {
+    #     "type": "string",
+    #     "description": "Who to send the message to. May be either 'submitted' or 'unsubmitted'",
+    #     "example": "submitted"
+    #   },
+    #   "subject": {
+    #     "type": "string",
+    #     "description": "Subject of the new Conversation created",
+    #     "example": "ATTN: Quiz 101 Students"
+    #   }
+    # }
+    def message
+      return unless user_has_teacher_level_access?
+      @conversation = Array(params[:conversations]).first
+      if @conversation
+        send_message
+        render json: { status: t('created', 'created') }, status: :created
+      else
+        render json: [], status: :invalid_request
+      end
+    end
+
+    private
+    def index_base_url
+      if submitted_param?
+        api_v1_course_quiz_submission_users_url(
+          @quiz.context,
+          @quiz,
+          submitted: submitted? ? 'true' : 'false'
+        )
+      else
+        api_v1_course_quiz_submission_users_url(@quiz.context, @quiz)
+      end
+    end
+
+    def submitted_param?
+      params.key?(:submitted)
+    end
+
+    def submitted?
+      ::Canvas::Plugin.value_to_boolean(params[:submitted])
+    end
+
+    def submitted_users
+      user_finder.submitted_students
+    end
+
+    def unsubmitted_users
+      user_finder.unsubmitted_students
+    end
+
+    def user_finder
+      @user_finder ||= Quizzes::QuizUserFinder.new(@quiz, @current_user)
+    end
+
+    def send_message
+      Quizzes::QuizUserMessager.new(
+        conversation: @conversation,
+        root_account_id: @domain_root_account.id,
+        async: true,
+        sender: @current_user,
+        quiz: @quiz
+      ).send
+    end
+
+    def user_has_teacher_level_access?
+      authorized_action(@quiz, @current_user, [:grade, :read_statistics])
+    end
+  end
+end

app/models/quizzes/quiz.rb

@@ -1295,4 +1295,5 @@ class Quizzes::Quiz < ActiveRecord::Base
   def self.reflection_type_name
     'quizzes:quiz'
   end
+
 end

app/models/quizzes/quiz_submission.rb

@@ -784,7 +784,7 @@ class Quizzes::QuizSubmission < ActiveRecord::Base
   }
   scope :for_user_ids, lambda { |user_ids| where(:user_id => user_ids) }
   scope :logged_out, where("temporary_user_code is not null")
-  scope :not_settings_only, where("workflow_state<>'settings_only'")
+  scope :not_settings_only, where("quiz_submissions.workflow_state<>'settings_only'")
   scope :completed, where(:workflow_state => %w(complete pending_review))
 
   has_a_broadcast_policy

app/models/quizzes/quiz_user_finder.rb

@@ -0,0 +1,53 @@
+#
+# Copyright (C) 2014 Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+module Quizzes
+  class QuizUserFinder
+    extend Forwardable
+    attr_reader :quiz, :user
+
+    def_delegators :@quiz, :context, :quiz_submissions
+
+    def initialize(quiz, user)
+      @quiz = quiz
+      @user = user
+    end
+
+    def submitted_students
+      all_students.where(id: non_preview_user_ids)
+    end
+
+    def unsubmitted_students
+      all_students.where('users.id NOT IN (?)', non_preview_user_ids)
+    end
+
+    def all_students
+      context.students_visible_to(user).order_by_sortable_name.group('users.id')
+    end
+
+    def non_preview_quiz_submissions
+      # This could optionally check for temporary_user_code<>NULL, but
+      # that's not indexed and we're checking user_id anyway in the queries above.
+      quiz_submissions.where('quiz_submissions.user_id IS NOT NULL')
+    end
+
+    private
+    def non_preview_user_ids
+      non_preview_quiz_submissions.not_settings_only.select(:user_id)
+    end
+  end
+end

app/models/quizzes/quiz_user_messager.rb

@@ -0,0 +1,81 @@
+
+# Copyright (C) 2014 Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+module Quizzes
+  class QuizUserMessager
+    extend Forwardable
+    attr_reader :sender, :async, :recipient_list, :conversation, :quiz
+    attr_reader :root_account_id, :context_id
+
+    def_delegators :@user_finder,
+      :submitted_students,
+      :all_students,
+      :unsubmitted_students
+
+    def initialize(options)
+      @quiz = options.fetch(:quiz)
+      @sender = options.fetch(:sender)
+      @async = options.fetch(:async, true) ? :async : :sync
+      @conversation = options.fetch(:conversation)
+      @root_account_id = options.fetch(:root_account_id)
+      @context_id = quiz.context_id
+      @user_finder = Quizzes::QuizUserFinder.new(quiz, sender)
+    end
+
+    def send
+      ConversationBatch.generate(
+        message,
+        recipients,
+        async,
+        subject: subject,
+        context_id: context_id,
+        group: false
+      )
+    end
+
+    private
+
+    def message
+      @message ||= (
+        Conversation.build_message(
+          sender,
+          body,
+          root_account_id: root_account_id
+        )
+      )
+    end
+
+    def body
+      conversation[:body]
+    end
+
+    def subject
+      conversation[:subject]
+    end
+
+    def recipients
+      list = conversation.fetch(:recipients, 'all')
+      recipients = case list.to_s
+                   when 'unsubmitted' then unsubmitted_students
+                   when 'submitted' then submitted_students
+                   else all_students
+                   end
+      sender.load_messageable_users(recipients.pluck(:id))
+    end
+  end
+end

app/serializers/quizzes/quiz_serializer.rb

@@ -15,7 +15,8 @@ module Quizzes
                 :hide_correct_answers_at, :all_dates, :can_unpublish, :can_update,
                 :require_lockdown_browser, :require_lockdown_browser_for_results,
                 :require_lockdown_browser_monitor, :lockdown_browser_monitor_data,
-                :speed_grader_url, :permissions, :quiz_reports_url, :quiz_statistics_url
+                :speed_grader_url, :permissions, :quiz_reports_url, :quiz_statistics_url,
+                :message_students_url
 
     def_delegators :@controller,
       :api_v1_course_assignment_group_url,
@@ -23,29 +24,58 @@ module Quizzes
       :api_v1_course_quiz_submission_url,
       :api_v1_course_quiz_submissions_url,
       :api_v1_course_quiz_reports_url,
-      :api_v1_course_quiz_statistics_url
+      :api_v1_course_quiz_statistics_url,
+      :api_v1_course_quiz_submission_users_url,
+      :api_v1_course_quiz_submission_users_message_url
+
+   def_delegators :@object,
+     :context,
+     :submitted_students_visible_to,
+     :unsubmitted_students_visible_to
 
     has_one :assignment_group, embed: :ids, root: :assignment_group
     has_many :quiz_submissions, embed: :ids, root: :quiz_submissions
+    has_many :submitted_students, embed: :ids, root: :submitted_students
+    has_many :unsubmitted_students, embed: :ids, root: :unsubmitted_students
+
+    def submitted_students
+      user_finder.submitted_students
+    end
+
+    def unsubmitted_students
+      user_finder.unsubmitted_students
+    end
+
+    def message_students_url
+      api_v1_course_quiz_submission_users_message_url(context, quiz)
+    end
 
     def speed_grader_url
       return nil unless show_speedgrader?
-      speed_grader_course_gradebook_url(quiz.context, assignment_id: quiz.assignment.id)
+      speed_grader_course_gradebook_url(context, assignment_id: quiz.assignment.id)
     end
 
     def quiz_submissions_url
       if user_may_grade?
-        api_v1_course_quiz_submissions_url(quiz.context, quiz)
+        api_v1_course_quiz_submissions_url(context, quiz)
       else
         quiz_submission = quiz.quiz_submissions.where(user_id: current_user).first
         if quiz_submission
-          api_v1_course_quiz_submission_url(quiz.context, quiz, quiz_submission)
+          api_v1_course_quiz_submission_url(context, quiz, quiz_submission)
         else
           nil
         end
       end
     end
 
+    def unsubmitted_students_url
+      api_v1_course_quiz_submission_users_url(context, quiz, submitted: 'false')
+    end
+
+    def submitted_students_url
+      api_v1_course_quiz_submission_users_url(context, quiz, submitted: true)
+    end
+
     def html_url
       controller.send(:course_quiz_url, context, quiz)
     end
@@ -73,8 +103,9 @@ module Quizzes
       super(keys).select do |key|
         case key
         when :all_dates then include_all_dates?
-        when :access_code, :speed_grader_url then user_may_grade?
+        when :access_code, :speed_grader_url, :message_students_url then user_may_grade?
         when :unpublishable then include_unpublishable?
+        when :submitted_students, :unsubmitted_students then user_may_grade?
         else true
         end
       end
@@ -91,19 +122,18 @@ module Quizzes
     def question_count
       quiz.available_question_count
     end
-    
     def require_lockdown_browser
       quiz.require_lockdown_browser?
     end
-    
+
     def require_lockdown_browser_for_results
       quiz.require_lockdown_browser_for_results?
     end
-    
+
     def require_lockdown_browser_monitor
       quiz.require_lockdown_browser_monitor?
     end
-    
+
     def lockdown_browser_monitor_data
       quiz.lockdown_browser_monitor_data
     end
@@ -126,7 +156,7 @@ module Quizzes
     end
 
     def assignment_group_url
-      api_v1_course_assignment_group_url(quiz.context, quiz.assignment_group.id)
+      api_v1_course_assignment_group_url(context, quiz.assignment_group.id)
     end
 
     def quiz_reports_url
@@ -144,7 +174,7 @@ module Quizzes
     private
 
     def show_speedgrader?
-      quiz.assignment.present? && quiz.published? && quiz.context.allows_speed_grader?
+      quiz.assignment.present? && quiz.published? && context.allows_speed_grader?
     end
 
     def due_dates
@@ -176,5 +206,8 @@ module Quizzes
       quiz.grants_right?(current_user, session, :grade)
     end
 
+    def user_finder
+      @user_finder ||= Quizzes::QuizUserFinder.new(quiz, current_user)
+    end
   end
 end

config/routes.rb

@@ -1330,6 +1330,11 @@ routes.draw do
       post "courses/:course_id/quizzes/:id/reorder", :action => :reorder, :path_name => 'course_quiz_reorder'
     end
 
+    scope(:controller => 'quizzes/quiz_submission_users') do
+      get "courses/:course_id/quizzes/:id/submission_users", :action => :index, :path_name => 'course_quiz_submission_users'
+      post "courses/:course_id/quizzes/:id/submission_users/message", :action => :message, :path_name => 'course_quiz_submission_users_message'
+    end
+
     scope(:controller => 'quizzes/quiz_groups') do
       post "courses/:course_id/quizzes/:quiz_id/groups", :action => :create, :path_name => 'course_quiz_group_create'
       put "courses/:course_id/quizzes/:quiz_id/groups/:id", :action => :update, :path_name => 'course_quiz_group_update'

spec/apis/v1/quizzes/quiz_submission_users_spec.rb

@@ -0,0 +1,127 @@
+# Copyright (C) 2014 Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+require File.expand_path(File.dirname(__FILE__) + '/../../api_spec_helper')
+require File.expand_path(File.dirname(__FILE__) + '/../../../models/quizzes/quiz_user_messager_spec_helper')
+
+describe Quizzes::QuizSubmissionUsersController, type: :request do
+  before do
+    course_with_teacher_logged_in(active_all: true)
+    course_quiz(true)
+  end
+
+  def controller_options(options)
+    options.reverse_merge!({
+       controller: "quizzes/quiz_submission_users",
+       action: "message",
+       format: "json",
+       course_id: @course.id,
+       id: @quiz.id
+    })
+  end
+
+  describe "POST message" do
+    include Quizzes::QuizUserMessagerSpecHelper
+
+    before do
+      @finder = Quizzes::QuizUserFinder.new(@quiz, @teacher)
+      course_with_student(active_all: true, course: @course)
+      @user = @teacher
+    end
+
+    def send_message(target_group)
+      raw_api_call(
+        :post,
+        "/api/v1/courses/#{@course.id}/quizzes/#{@quiz.id}/submission_users/message",
+        controller_options(
+          action: 'message',
+          conversations: [
+            { body: 'Ohi!', recipients: target_group.to_s }
+          ]
+        )
+      )
+      run_jobs
+    end
+
+    it "sends a message to unsubmitted users" do
+      expect { send_message(:unsubmitted) }.to change { recipient_messages(:unsubmitted) }.by 1
+      recipient_messages(:submitted).should == 0
+    end
+
+    it "sends a message to submitted users" do
+      sub = @quiz.generate_submission(@student)
+      sub.mark_completed
+      sub.grade_submission
+      expect { send_message(:submitted) }.to change { recipient_messages(:submitted) }.by 1
+      recipient_messages(:unsubmitted).should == 0
+    end
+  end
+
+  describe "GET submission_users" do
+
+    def get_submitted_users(options={})
+      options = controller_options(options.reverse_merge!(action: 'index'))
+      raw_api_call(
+        :get,
+        "/api/v1/courses/#{@course.id}/quizzes/#{@quiz.id}/submission_users",
+        options,
+        { 'Accept' => 'application/json'}
+      )
+      JSON.parse(response.body) if response.success?
+    end
+
+    it "does not allow students to view information at the endpoint" do
+      course_with_student_logged_in(course: @course, active_all: true)
+      get_submitted_users
+      response.should_not be_success
+    end
+
+    it "allows teachers to see submitted students with ?submitted=true" do
+      course_with_student(active_all: true, course: @course)
+      quiz_with_graded_submission([], course: @course, user: @student)
+      @user = @teacher
+      json = get_submitted_users(submitted: true)
+      response.should be_success
+      json['users'].first['id'].should == @student.id
+    end
+
+    it "allows teachers to see unsubmitted students with ?submitted=false" do
+      course_with_student(active_all: true, course: @course)
+      @student_frd = @student
+      quiz_with_graded_submission([], course: @course, user: @student_frd)
+      course_with_student(active_all: true, course: @course)
+      @user = @teacher
+      json = get_submitted_users(submitted: false)
+      response.should be_success
+      user_ids = json['users'].map { |h| h['id'] }
+      user_ids.should_not include @student_frd.id
+      user_ids.should include @student.id
+    end
+
+    it "allows teachers to see all students for quiz when submitted parameter not passed" do
+      course_with_student(active_all: true, course: @course)
+      @student_frd = @student
+      quiz_with_graded_submission([], course: @course, user: @student_frd)
+      course_with_student(active_all: true, course: @course)
+      @user = @teacher
+      json = get_submitted_users
+      response.should be_success
+      user_ids = json['users'].map { |h| h['id'] }
+      user_ids.should include @student_frd.id
+      user_ids.should include @student.id
+    end
+  end
+end

spec/models/quizzes/quiz_user_finder_spec.rb

@@ -0,0 +1,67 @@
+#
+# Copyright (C) 2014 Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+require 'spec_helper'
+
+describe Quizzes::QuizUserFinder do
+
+  before do
+    course_with_teacher_logged_in(course: @course, active_all: true)
+    course_quiz(true)
+    course_with_student(active_all: true, course: @course)
+    @submitted_student = @student
+    course_with_student(active_all: true, course: @course)
+    @unsubmitted_student = @student
+    sub = @quiz.generate_submission(@submitted_student)
+    sub.mark_completed
+    sub.grade_submission
+    @finder = Quizzes::QuizUserFinder.new(@quiz, @teacher)
+  end
+
+  def students
+    [ @unsubmitted_student, @submitted_student ]
+  end
+
+  it "(#all_students) finds all students" do
+    @finder.all_students.should =~ students
+  end
+
+  it "(#unsubmitted_students) finds unsubmitted students" do
+    @finder.unsubmitted_students.should == [ @unsubmitted_student ]
+  end
+
+  it "(#submitted_student) finds submitted students" do
+    @finder.submitted_students.should == [ @submitted_student ]
+  end
+
+  it "doesn't find submissions from teachers for preview submissions" do
+    sub = @quiz.generate_submission(@teacher, preview=true)
+    sub.grade_submission
+    sub.save!
+    @finder.submitted_students.should_not include @teacher
+    @finder.unsubmitted_students.should_not include @teacher
+    @finder.unsubmitted_students.should_not be_empty
+    @finder.all_students.should_not include @teacher
+  end
+
+  it "doesn't duplicate the same user found in multiple sections" do
+    add_section('The Mother We Share')
+    student_in_section(@course_section, user: @submitted_student)
+    @finder.all_students.should =~ students
+  end
+
+end

spec/models/quizzes/quiz_user_messager_spec.rb

@@ -0,0 +1,53 @@
+# Copyright (C) 2014 Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+require 'spec_helper'
+require File.expand_path(File.dirname(__FILE__) + "/quiz_user_messager_spec_helper.rb")
+
+describe Quizzes::QuizUserMessager do
+  include Quizzes::QuizUserMessagerSpecHelper
+
+  before do
+    course_with_teacher_logged_in(active_all: true)
+    course_quiz(true)
+    course_with_student(active_all: true, course: @course)
+    @unsubmitted = @student
+    course_with_student(active_all: true, course: @course)
+    @submitted = @student
+    submission = @quiz.generate_submission(@submitted)
+    submission.mark_completed
+    submission.grade_submission
+    @finder = Quizzes::QuizUserFinder.new(@quiz, @teacher)
+  end
+
+  describe "#send" do
+
+    it "sends to all students" do
+      expect { send_message }.to change { recipient_messages('all') }.by 2
+    end
+
+    it "can send to either submitted or unsubmitted students" do
+      expect {
+        send_message('submitted')
+      }.to change { recipient_messages('submitted') }.by 1
+
+      expect {
+        send_message('unsubmitted')
+      }.to change { recipient_messages('unsubmitted') }.by 1
+    end
+  end
+end

spec/models/quizzes/quiz_user_messager_spec_helper.rb

@@ -0,0 +1,45 @@
+# Copyright (C) 2014 Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+module Quizzes
+  module QuizUserMessagerSpecHelper
+
+    def conversation(recipients)
+      {
+        subject: "Do you want ants?",
+        body: "Because that's how you get ants",
+        recipients: recipients
+      }
+    end
+
+    def send_message(recipients='all')
+      options = {
+        quiz: @quiz,
+        sender: @teacher,
+        conversation: conversation(recipients),
+        root_account_id: Account.default.id
+      }
+      Quizzes::QuizUserMessager.new(options).send
+      run_jobs
+    end
+
+    def recipient_messages(target_group)
+      recipients = @finder.send("#{target_group}_students")
+      recipients.map(&:all_conversations).map(&:size).reduce(:+) || 0
+    end
+
+  end
+end

spec/serializers/quizzes/quiz_serializer_spec.rb

@@ -1,6 +1,15 @@
 require 'spec_helper'
 
 describe Quizzes::QuizSerializer do
+
+  def quiz_serializer(options={})
+    options.reverse_merge!({
+      controller: controller,
+      scope: @user,
+      session: @session
+    })
+    Quizzes::QuizSerializer.new(@quiz, options)
+  end
   let(:quiz) { @quiz }
   let(:context ) { @context }
   let(:serializer) { @serializer }
@@ -24,10 +33,7 @@ describe Quizzes::QuizSerializer do
     controller.stubs(:session).returns session
     controller.stubs(:context).returns context
     @quiz.stubs(:grants_right?).at_least_once.returns true
-    @serializer = Quizzes::QuizSerializer.new(@quiz,
-                                     controller: controller,
-                                     scope: @user,
-                                     session: @session)
+    @serializer = quiz_serializer
     @json = @serializer.as_json[:quiz]
   end
 
@@ -95,6 +101,15 @@ describe Quizzes::QuizSerializer do
     serializer.as_json[:quiz][:question_count].should == 5
   end
 
+  it "sends the message_students_url when user can grade" do
+    quiz.expects(:grants_right?).at_least_once.returns true
+    serializer.as_json[:quiz][:message_students_url].should ==
+      controller.send(:api_v1_course_quiz_submission_users_message_url, quiz, quiz.context)
+
+    quiz.expects(:grants_right?).at_least_once.returns false
+    serializer.as_json[:quiz].should_not have_key :message_students_url
+  end
+
   describe "id" do
 
     it "stringifys when stringify_json_ids? is true" do
@@ -116,8 +131,7 @@ describe Quizzes::QuizSerializer do
       quiz.expects(:locked_for?).
         with(@user, check_policies: true, context: @context).
         returns({due_at: true})
-      json = Quizzes::QuizSerializer.new(quiz, scope: @user, controller: controller).
-        as_json[:quiz]
+      json = quiz_serializer.as_json[:quiz]
       json.should have_key :lock_info
       json.should have_key :lock_explanation
       json[:locked_for_user].should == true
@@ -125,8 +139,7 @@ describe Quizzes::QuizSerializer do
       quiz.expects(:locked_for?).
         with(@user, check_policies: true, context: @context).
         returns false
-      json = Quizzes::QuizSerializer.new(quiz, scope: @user, controller: controller).
-        as_json[:quiz]
+      json = quiz_serializer.as_json[:quiz]
       json.should_not have_key :lock_info
       json.should_not have_key :lock_explanation
       json[:locked_for_user].should == false
@@ -184,9 +197,7 @@ describe Quizzes::QuizSerializer do
       it "sends the url for all submissions when user may grade" do
         course_with_teacher_logged_in(active_all: true)
         quiz_with_graded_submission([], course: @course)
-        serializer = Quizzes::QuizSerializer.new(@quiz,
-                                        controller: controller,
-                                        scope: @teacher)
+        serializer = quiz_serializer(scope: @teacher)
         serializer.as_json[:quiz]['links']['quiz_submissions'].should ==
           controller.send(:api_v1_course_quiz_submissions_url, @quiz.context.id, @quiz.id)
       end
@@ -194,22 +205,17 @@ describe Quizzes::QuizSerializer do
       it "sends the url to a student's submission for students" do
         course_with_student_logged_in(active_all: true)
         quiz_with_graded_submission([], user: @student, course: @course)
-        serializer = Quizzes::QuizSerializer.new(@quiz,
-                                        controller: controller,
-                                        scope: @student)
+        serializer = quiz_serializer(scope: @student)
         serializer.as_json[:quiz]['links']['quiz_submissions'].should ==
           controller.send(:api_v1_course_quiz_submission_url,
                           @quiz.context.id,
                           @quiz.id,
                           @quiz.quiz_submissions.where(user_id: @student).first.id)
-
       end
 
       it "sends nil if user can't grade and doesn't have a submission" do
         course_with_student_logged_in(active_all: true)
-        serializer = Quizzes::QuizSerializer.new(@quiz,
-                                        controller: controller,
-                                        scope: @student)
+        serializer = quiz_serializer(scope: @student)
         serializer.as_json[:quiz]['links']['quiz_submissions'].should be_nil
       end
     end
@@ -243,6 +249,51 @@ describe Quizzes::QuizSerializer do
           controller.send(:api_v1_course_quiz_statistics_url, 3, quiz.id)
       end
     end
+
+    describe "submitted_students" do
+
+      it "sends nil if user can't grade" do
+        course_with_student_logged_in(active_all: true)
+        @quiz.unstub(:grants_right?)
+        serializer = quiz_serializer(scope: @student)
+        serializer.as_json[:quiz]['links'].should_not have_key 'unsubmitted_students'
+      end
+
+      it "sends a url if there are submissions and user can grade" do
+        course_with_teacher_logged_in(active_all: true)
+        course_with_student_logged_in(active_all: true, course: @course)
+        quiz_with_graded_submission([], user: @student, course: @course)
+        serializer = quiz_serializer(scope: @teacher)
+        serializer.as_json[:quiz]['links']['submitted_students'].
+          should == controller.send(:api_v1_course_quiz_submission_users_url,
+                                    @quiz.context,
+                                    @quiz,
+                                    submitted: true)
+      end
+    end
+
+    describe "unsubmitted_students" do
+
+      it "sends nil if user can't grade" do
+        @quiz.unstub(:grants_right?)
+        course_with_student_logged_in(active_all: true)
+        serializer = quiz_serializer(scope: @student)
+        serializer.as_json[:quiz]['links'].should_not have_key 'unsubmitted_students'
+      end
+
+      it "sends a url if there are submissions and user can grade" do
+        course_with_teacher_logged_in(active_all: true)
+        course_with_student_logged_in(active_all: true, course: @course)
+        course_with_student_logged_in(active_all: true, course: @course)
+        quiz_with_graded_submission([], user: @student, course: @course)
+        serializer = quiz_serializer(scope: @teacher)
+        serializer.as_json[:quiz]['links']['unsubmitted_students'].
+          should == controller.send(:api_v1_course_quiz_submission_users_url,
+                                    @quiz.context,
+                                    @quiz,
+                                    submitted: 'false')
+      end
+    end
   end
 
   describe "permissions" do

spec/spec_helper.rb

@@ -638,12 +638,12 @@ end
   end
 
   def student_in_section(section, opts={})
-    user
-    enrollment = section.course.enroll_user(@user, 'StudentEnrollment', :section => section)
-    @user.save!
+    student = opts.fetch(:user) { user }
+    enrollment = section.course.enroll_user(student, 'StudentEnrollment', :section => section)
+    student.save!
     enrollment.workflow_state = 'active'
     enrollment.save!
-    @user
+    student
   end
 
   def teacher_in_course(opts={})