fix Turnitin showing on assignents in non-Turninit course

fixes CNVS-26295

test plan:
- enable Turnitin on an account
(gollum.instructure.com/OtherServiceTestAccounts#Turnitin)
- toggle an assignment to have Turnitin enabled and choose
  a submission type.
- the assignment show page should show Turnitin as active
- make the assignment "no submission"
- the assignment show page should not show Turnitin
  as active
- re-select a submission type for the assignment so
  the Turnitin text appears again
- disable Turnitin on the account
- the assignment show page should not show Turnitin
  as active

Change-Id: Iac174e52831ddc5e565acfd3d294189f6f4cefd1
Reviewed-on: https://gerrit.instructure.com/71626
Reviewed-by: John Corrigan <jcorrigan@instructure.com>
Tested-by: Jenkins
QA-Review: Michael Hargiss <mhargiss@instructure.com>
Product-Review: Jason Sparks <jsparks@instructure.com>

app/helpers/assignments_helper.rb

@@ -75,4 +75,9 @@ module AssignmentsHelper
       @user.try_rescue(:short_name)
     end
   end
+
+  def turnitin_active?
+    @assignment.turnitin_enabled? && @context.turnitin_enabled? &&
+    !@assignment.submission_types.include?("none")
+  end
 end

app/views/assignments/show.html.erb

@@ -96,7 +96,7 @@
         <span class='value'><%= @assignment.points_possible || t(:no_points, 'None') %></span>
       </li>
       <% if @assignment.expects_submission? || @assignment.expects_external_submission? %>
-        <% turnitin_text = @assignment.turnitin_enabled? ? ' ' + t(:turnitin_enabled_short, '(Turnitin enabled)') : '' %>
+        <% turnitin_text = turnitin_active? ? ' ' + t(:turnitin_enabled_short, '(Turnitin enabled)') : '' %>
         <li>
           <span class='title'><%= t :submitting, 'Submitting' %></span>
           <span class='value'><%= @assignment.readable_submission_types + turnitin_text %></span>
@@ -149,7 +149,7 @@
             </div>
           </div>
         <% end -%>
-        <% if @assignment.turnitin_enabled %>
+        <% if turnitin_active? %>
           <div class="control-group">
             <div class="control-label"><%= t :turnitin, 'Turnitin' %></div>
             <div class="controls">

spec/helpers/assignments_helper_spec.rb

@@ -41,4 +41,42 @@ describe AssignmentsHelper do
       expect(assignment_publishing_enabled?(@assignment, @teacher)).to be_truthy
     end
   end
+
+  describe "#turnitin active?" do
+    before(:once) do
+      course_with_teacher(active_all: true)
+      student_in_course(active_all: true)
+      assignment_model(course: @course)
+      @assignment.turnitin_enabled = true
+      @context = @assignment.context
+      @assignment.update_attributes!({
+        submission_types: ["online_url"]
+      })
+      @context.account.update_attributes!({
+        turnitin_settings: {:originality_report_visibility => 'after_grading'},
+        turnitin_account_id: 12345,
+        turnitin_shared_secret: "the same combination on my luggage"
+      })
+    end
+
+    it "returns true if turnitin is active on the assignment and account" do
+      expect(turnitin_active?).to be_truthy
+    end
+
+    it "returns false if the assignment does not require submissions" do
+      @assignment.update_attributes!({
+        submission_types: ["none"]
+      })
+      expect(turnitin_active?).to be_falsey
+    end
+
+    it "returns false if turnitin is disabled on the account level" do
+      @context.account.update_attributes!({
+        turnitin_settings: nil,
+        turnitin_account_id: nil,
+        turnitin_shared_secret: nil
+      })
+      expect(turnitin_active?).to be_falsey
+    end
+  end
 end