only count active quizzes in course stats

fixes CNVS-26308

test plan:
- create 2 quizzes, with questions
- take them both
- delete 1 of them
- go to the course stats page
- only the non-deleted quiz should count
  (for quizzes, questions, and submissions)

Change-Id: Ib6155e1036fce43c81c2ad346b7252e818831114
Reviewed-on: https://gerrit.instructure.com/70822
Tested-by: Jenkins
Reviewed-by: Ryan Taylor <rtaylor@instructure.com>
QA-Review: Michael Hargiss <mhargiss@instructure.com>
Product-Review: Simon Williams <simon@instructure.com>

app/views/courses/statistics.html.erb

@@ -67,13 +67,13 @@
         <td class="indent"><%= inactive_students %></td>
       </tr><tr>
         <td><%= t('quizzes', %{Quizzes}) %></td>
-        <td><%= @context.quizzes.count %></td>
+        <td class="quiz_count"><%= @context.quizzes.active.before(@range_end).count %></td>
       </tr><tr>
         <td class="indent"><%= t('quiz_questions', %{Quiz Questions}) %></td>
-        <td class="indent"><%= @context.quizzes.before(@range_end).map{|q| (q.quiz_data || []).length}.sum %></td>
+        <td class="indent quiz_question_count"><%= @context.quizzes.active.before(@range_end).map{|q| (q.quiz_data || []).length}.sum %></td>
       </tr><tr>
         <td class="indent"><%= t('quiz_submissions', %{Quiz Submissions}) %></td>
-        <td class="indent"><%= Quizzes::QuizSubmission.where(quiz_id: @context.quizzes.before(@range_end)).count %></td>
+        <td class="indent quiz_submission_count"><%= Quizzes::QuizSubmission.where(quiz_id: @context.quizzes.active.before(@range_end)).count %></td>
       </tr>
     </table>
   </div>

spec/views/courses/statistics.html.erb_spec.rb

@@ -0,0 +1,42 @@
+#
+# Copyright (C) 2011-12 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__) + '/../../spec_helper')
+require File.expand_path(File.dirname(__FILE__) + '/../views_helper')
+
+describe "courses/statistics.html.erb" do
+  before do
+    course_with_teacher(:active_all => true)
+    assigns[:range_start] = Date.parse("Jan 1 2000")
+    assigns[:range_end] = 3.days.from_now
+  end
+
+  it "only lists active quiz objects, questions, and submissions" do
+    quiz_with_submission
+    @quiz.destroy
+    quiz_with_submission
+
+    view_context(@course, @user)
+    render
+
+    doc = Nokogiri::HTML.parse(response.body)
+    expect(doc.at_css('.quiz_count').text).to eq "1"
+    expect(doc.at_css('.quiz_question_count').text).to eq "1"
+    expect(doc.at_css('.quiz_submission_count').text).to eq "1"
+  end
+end