prevent deleting frozen assignments and their groups on index page

fixes CNVS-7669

test plan:
- enable draft mode
- create a course with frozen assignments
- from the assignments index page only
- verify that "delete" option does not appear under gear wheel for:
 * frozen assignments
 * groups with frozen assignments

Change-Id: I55c7a429efc58d014b3e28d7681bc6a245578d81
Reviewed-on: https://gerrit.instructure.com/24203
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Simon Williams <simon@instructure.com>
Product-Review: Simon Williams <simon@instructure.com>
QA-Review: Simon Williams <simon@instructure.com>

app/coffeescripts/models/AssignmentGroup.coffee

@@ -54,3 +54,7 @@ define [
       assignments = @get('assignments')
       return [] unless assignments?
       assignments.pluck('id')
+
+    hasFrozenAssignments: ->
+      @get('assignments').any (m) ->
+        m.get('frozen')

app/coffeescripts/views/assignments/AssignmentGroupListItemView.coffee

@@ -121,6 +121,7 @@ define [
         showWeight: showWeight
         groupWeight: data.group_weight
         toggleMessage: @messages.toggleMessage
+        hasFrozenAssignments: @model.hasFrozenAssignments? and @model.hasFrozenAssignments()
       })
 
     displayableRules: ->

app/views/jst/assignments/AssignmentGroupListItem.handlebars

@@ -64,14 +64,16 @@
               data-focus-returns-to="ag_{{id}}_manage_link"
             >{{#t "edit"}}Edit{{/t}}</a>
           </li>
-          <li>
-            <a
-              href="#"
-              class="delete_group icon-trash"
-              title='{{#t "title_delete"}}Delete Assignment Group?{{/t}}'
-              data-focus-returns-to="ag_{{id}}_manage_link"
-            >{{#t "delete"}}Delete{{/t}}</a>
-          </li>
+          {{#unless hasFrozenAssignments}}
+            <li>
+              <a
+                href="#"
+                class="delete_group icon-trash"
+                title='{{#t "title_delete"}}Delete Assignment Group?{{/t}}'
+                data-focus-returns-to="ag_{{id}}_manage_link"
+              >{{#t "delete"}}Delete{{/t}}</a>
+            </li>
+          {{/unless}}
         </ul>
       {{/if}}
     </div>

app/views/jst/assignments/AssignmentListItem.handlebars

@@ -88,6 +88,7 @@
             data-focus-returns-to="assign_{{id}}_manage_link"
           >{{#t "edit"}}Edit{{/t}}</a>
         </li>
+        {{#unless frozen }}
         <li role="presentation">
           <a
             href="#"
@@ -98,6 +99,7 @@
             title="{{#t "delete_asssignment_title"}}Delete this assignment{{/t}}"
           >{{#t "delete"}}Delete{{/t}}</a>
         </li>
+        {{/unless}}
       </ul>
     </div>
 

spec/coffeescripts/models/AssignmentGroupSpec.coffee

@@ -1,6 +1,7 @@
 define [
+  'compiled/models/Assignment'
   'compiled/models/AssignmentGroup'
-], (AssignmentGroup) ->
+], (Assignment, AssignmentGroup) ->
 
   module "AssignmentGroup"
 
@@ -39,3 +40,11 @@ define [
   test "#countRules returns false if the group has no rules", ->
     ag = new AssignmentGroup
     strictEqual ag.countRules(), 0
+
+  module "AssignmentGroup#hasFrozenAssignments"
+
+  test "returns true if AssignmentGroup has frozen assignments", ->
+    assignment = new Assignment name: 'cheese'
+    assignment.set 'frozen', [ true ]
+    group = new AssignmentGroup name: 'taco', assignments: [ assignment ]
+    deepEqual group.hasFrozenAssignments(), true

spec/selenium/assignments_spec.rb

@@ -523,13 +523,6 @@ describe "assignments" do
         end
         @asmnt.reload.assignment_group.name.should == "other"
       end
-
-      it "should not allow assignment group to be deleted by teacher if "+
-             "assignment group id frozen" do
-        get "/courses/#{@course.id}/assignments"
-        fj("#group_#{@asmnt.assignment_group_id} .delete_group_link").should be_nil
-        fj("#assignment_#{@asmnt.id} .delete_assignment_link").should be_nil
-      end
     end
 
     context "draft state" do
@@ -672,6 +665,40 @@ describe "assignments" do
         end
       end
 
+      context "frozen assignments" do
+        before do
+          @att_map = {
+              "assignment_group_id" => "true"
+          }
+          PluginSetting.stubs(:settings_for_plugin).returns(@att_map)
+
+          @asmnt = @course.assignments.create!(
+              :name => "frozen",
+              :due_at => Time.now.utc + 2.days,
+              :assignment_group => @course.assignment_groups.create!(:name => "default"),
+              :freeze_on_copy => true
+          )
+          @asmnt.copied = true
+          @asmnt.save!
+
+          @course.assignment_groups.create!(:name => "other")
+        end
+
+        it "should not allow assignment group to be deleted by teacher if assignments are frozen" do
+          get "/courses/#{@course.id}/assignments"
+          fj("#ag_#{@asmnt.assignment_group_id}_manage_link").click
+          wait_for_ajaximations
+          element_exists("div#assignment_group_#{@asmnt.assignment_group_id} a.delete_group").should be_false
+        end
+
+        it "should not allow deleting a frozen assignment from index page" do
+          get "/courses/#{@course.id}/assignments"
+          fj("div#assignment_#{@asmnt.id} a.al-trigger").click
+          wait_for_ajaximations
+          element_exists("div#assignment_#{@asmnt.id} a.delete_assignment:visible").should be_false
+        end
+      end
+
       context 'publishing' do
         before do
           ag = @course.assignment_groups.first