CQS: selenium spec for canvas integration

Added a selenium spec that visits the statistics_cqs page and verifies
that the client app has loaded and mounted successfully.

Closes CNVS-15363

Change-Id: I4a87b5af78343d51ef8e4c0b1e30065eff9e7d6b
Reviewed-on: https://gerrit.instructure.com/40775
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Derek DeVries <ddevries@instructure.com>
QA-Review: Derek DeVries <ddevries@instructure.com>
Product-Review: Ahmad Amireh <ahmad@instructure.com>

client_apps/canvas_quiz_statistics/src/js/models/quiz_statistics.js

@@ -33,6 +33,7 @@ define(function(require) {
 
   parseQuestion = function(participantCount, question) {
     var attrs = pickAndNormalize(question, K.QUESTION_STATISTICS_ATTRS);
+    var correctAnswerPointBiserials;
 
     wrap(attrs.answers).forEach(decorateAnswer.bind(null, participantCount));
     wrap(attrs.answerSets).forEach(decorateAnswerSet.bind(null, participantCount));
@@ -42,9 +43,11 @@ define(function(require) {
         return pickAndNormalize(pointBiserial, K.POINT_BISERIAL_ATTRS);
       });
 
-      attrs.discriminationIndex = findWhere(attrs.pointBiserials, {
+      correctAnswerPointBiserials = findWhere(attrs.pointBiserials, {
         correct: true
-      }).pointBiserial;
+      }) || {};
+
+      attrs.discriminationIndex = correctAnswerPointBiserials.pointBiserial;
     }
 
     return attrs;

spec/selenium/canvas_quiz_statistics_spec.rb

@@ -0,0 +1,37 @@
+require File.expand_path(File.dirname(__FILE__) + '/helpers/quizzes_common')
+
+describe "canvas quiz statistics" do
+  include_examples "quizzes selenium tests"
+
+  before do
+    quiz_with_graded_submission([
+      {:question_data => {:name => 'question 1', :points_possible => 1, 'question_type' => 'true_false_question'}},
+      {:question_data => {:name => 'question 2', :points_possible => 1, 'question_type' => 'true_false_question'}}
+    ])
+
+    course_with_teacher_logged_in(:active_all => true, :course => @course)
+  end
+
+  it 'should mount' do
+    get "/courses/#{@course.id}/quizzes/#{@quiz.id}/statistics_cqs"
+
+    status = driver.execute_script <<-JS
+      var mountStatus = document.body.appendChild(document.createElement('div'));
+
+      require([ 'jquery', 'canvas_quiz_statistics' ], function($, app) {
+        if (app.isMounted()) {
+          $(mountStatus).text('success');
+        } else {
+          $(mountStatus).text('error');
+        }
+      });
+
+      return mountStatus;
+    JS
+
+    wait = Selenium::WebDriver::Wait.new(timeout: 5)
+    wait.until { status.text.present? } # require call is async
+
+    status.text.should match('success')
+  end
+end