disable multiple_dropdowns_question selects when not editable

fixes CNVS-14719

test plan:
- Create a quiz with a multiple-dropdowns-question.
- Navigate to take the quiz.
- Observe that the dropdowns work as expected.
- Complete the quiz with a student.
- Observe the completed quiz screen.
- Observe that there are no dropdowns in the question text.
- Observe that the selected answers are just treated as plaintext
  when interacted with via VoiceOver, NVDA & JAWS.

Change-Id: I9506f064417eae85c084a15c416974d4f00568ee
Reviewed-on: https://gerrit.instructure.com/70156
Tested-by: Jenkins
Reviewed-by: Matt Berns <mberns@instructure.com>
QA-Review: Michael Hargiss <mhargiss@instructure.com>
Product-Review: Nathan Rogowski <nathan@instructure.com>

app/helpers/quizzes_helper.rb

@@ -451,6 +451,7 @@ module QuizzesHelper
     question = hash_get(options, :question)
     answers  = hash_get(options, :answers)
     answer_list = hash_get(options, :answer_list)
+    editable = hash_get(options, :editable)
     res      = user_content hash_get(question, :question_text)
     index  = 0
     doc = Nokogiri::HTML.fragment(res)
@@ -464,9 +465,18 @@ module QuizzesHelper
         a = hash_get(answers, question_id)
       end
 
-      # If existing answer is one of the options, select it
-      if opt_tag = s.children.css("option[value='#{a}']").first
-        opt_tag["selected"] = "selected"
+      if editable
+        # If existing answer is one of the options, select it
+        if (opt_tag = s.children.css("option[value='#{a}']").first)
+          opt_tag["selected"] = "selected"
+        end
+      else
+        # If existing answer is one of the options, replace it with a span
+        if (opt_tag = s.children.css("option[value='#{a}']").first)
+          s.replace(<<-HTML)
+            <span>#{opt_tag.content}</span>
+          HTML
+        end
       end
     end
     doc.to_s.html_safe

app/views/quizzes/quizzes/_display_question.html.erb

@@ -153,7 +153,9 @@
                variables.each {|var| answer_list << hash_get(user_answer, "answer_id_for_#{var}") }
              end
           %>
-          <%= multiple_dropdowns_question :question => question, :answers => @stored_params, :answer_list => answer_list %>
+          <%= multiple_dropdowns_question({
+            :question => question, :answers => @stored_params, :answer_list => answer_list, :editable => assessing
+          }) %>
         <% else %>
           <%= user_content(hash_get(question, :question_text)) %>
         <% end %>

spec/helpers/quizzes_helper_spec.rb

@@ -253,18 +253,42 @@ describe QuizzesHelper do
     end
 
     it "should select the user's answer" do
-      html = multiple_dropdowns_question(question: { question_text: 'some <select class="question_input" name="question_4"><option value="val">val</option></select>'},
-                                         answer_list: ['val'])
+      html = multiple_dropdowns_question({
+        question: {
+          question_text: 'some <select class="question_input" name="question_4"><option value="val">val</option></select>'
+        },
+        answer_list: ['val'],
+        editable: true
+      })
       expect(html).to eq 'some <select class="question_input" name="question_4"><option value="val" selected>val</option></select>'
       expect(html).to be_html_safe
     end
 
     it "should not blow up if the user's answer isn't there" do
-      html = multiple_dropdowns_question(question: { question_text: 'some <select class="question_input" name="question_4"><option value="other_val">val</option></select>'},
-                                         answer_list: ['val'])
+      html = multiple_dropdowns_question({
+        question: {
+          question_text: 'some <select class="question_input" name="question_4"><option value="other_val">val</option></select>'
+        },
+        answer_list: ['val'],
+        editable: true
+      })
       expect(html).to eq 'some <select class="question_input" name="question_4"><option value="other_val">val</option></select>'
       expect(html).to be_html_safe
     end
+
+    it "should disable select boxes that are not editable" do
+      html_string = multiple_dropdowns_question({
+        question: {
+          question_text: 'some <select class="question_input" name="question_4"><option value="val">val</option></select>'
+        },
+        answer_list: ['val'],
+        editable: false
+      })
+      html = Nokogiri::HTML.fragment(html_string)
+      span_html = html.css('span').first
+      expect(span_html).not_to be_nil
+      expect(html_string).to be_html_safe
+    end
   end
 
   describe "#quiz_edit_text" do