warn when converting assignment to group assignment

closes CNVS-9187

Test plan:
  * make two assignments (not group assignments)
  * on assignment number one, submit some homework
  * edit the assignment and try to convert it to a group assignment,
    you should see a warning
  * try to convert assignment 2 to a group assignment.  there should be
    no warning

Change-Id: I196cbad54fbcfe6df4bcbc3b71d3175e92a104fb
Reviewed-on: https://gerrit.instructure.com/26955
Reviewed-by: Simon Williams <simon@instructure.com>
QA-Review: Amber Taniuchi <amber@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Cameron Matheson <cameron@instructure.com>

app/coffeescripts/views/assignments/GroupCategorySelector.coffee

@@ -32,6 +32,10 @@ define [
     @optionProperty 'groupCategories'
     @optionProperty 'nested'
 
+    initialize: ->
+      super
+      @startedOutAsGroupAssignment = @parentModel.get('group_category_id')?
+
     showGroupCategoryCreateDialog: =>
       if @$groupCategoryID.val() == 'new'
         # TODO: Yikes, we need to pull the javascript out of manage_groups.js
@@ -47,6 +51,13 @@ define [
 
     toggleGroupCategoryOptions: =>
       @$groupCategoryOptions.toggleAccessibly @$hasGroupCategory.prop('checked')
+
+      @$(".group_submission_warning").toggleAccessibly(
+        !@startedOutAsGroupAssignment and
+        @$hasGroupCategory.prop('checked') and
+        @parentModel.attributes.has_submitted_submissions
+      )
+
       if @$hasGroupCategory.prop('checked') and @groupCategories.length == 0
         @showGroupCategoryCreateDialog()
 

app/controllers/assignments_controller.rb

@@ -370,6 +370,7 @@ class AssignmentsController < ApplicationController
         :ASSIGNMENT_INDEX_URL => polymorphic_url([@context, :assignments]),
       }
       hash[:ASSIGNMENT] = assignment_json(@assignment, @current_user, session, override_dates: false)
+      hash[:ASSIGNMENT][:has_submitted_submissions] = @assignment.has_submitted_submissions?
       hash[:URL_ROOT] = polymorphic_url([:api_v1, @context, :assignments])
       hash[:CANCEL_TO] = @assignment.new_record? ? polymorphic_url([@context, :assignments]) : polymorphic_url([@context, @assignment])
       hash[:CONTEXT_ID] = @context.id

app/controllers/discussion_topics_controller.rb

@@ -283,6 +283,7 @@ class DiscussionTopicsController < ApplicationController
       if @topic.assignment.present?
         hash[:ATTRIBUTES][:assignment][:assignment_overrides] =
           (assignment_overrides_json(@topic.assignment.overrides_visible_to(@current_user)))
+        hash[:ATTRIBUTES][:assignment][:has_student_submissions] = @topic.assignment.has_student_submissions?
       end
 
       categories = @context.respond_to?(:group_categories) ? @context.group_categories : []

app/views/jst/assignments/GroupCategorySelector.handlebars

@@ -9,6 +9,12 @@
   </label>
 </div>
 
+<div class="group_submission_warning alert controls" style="display:none">
+  {{#t "students_already_submitted_warning"}}Prior individual submissions will
+  not be counted as group submissions and will show incorrectly in
+  speedgrader.{{/t}}
+</div>
+
 <div id="group_category_options" style="{{hiddenUnless groupCategoryId}}">
 
   <div class="controls">

spec/coffeescripts/views/assignments/EditViewSpec.coffee

@@ -1,5 +1,6 @@
 define [
   'jquery'
+  'underscore'
   'compiled/collections/SectionCollection'
   'compiled/models/Assignment'
   'compiled/models/DueDateList'
@@ -13,19 +14,22 @@ define [
   'compiled/views/assignments/PeerReviewsSelector'
   'helpers/jquery.simulate'
   'helpers/fakeENV'
-], ($, SectionCollection, Assignment, DueDateList, Section,
+], ($, _, SectionCollection, Assignment, DueDateList, Section,
   AssignmentGroupSelector, DueDateListView, DueDateOverrideView, EditView,
   GradingTypeSelector, GroupCategorySelector, PeerReviewsSelector) ->
 
 
   fixtures = $('#fixtures')
 
-  editView = ->
+  defaultAssignmentOpts =
+    name: 'Test Assignment'
+    assignment_overrides: []
+
+  editView = (assignmentOpts = {}) ->
     $('<form id="content"></form>').appendTo fixtures
 
-    assignment = new Assignment
-      name: 'Test Assignment'
-      assignment_overrides: []
+    assignmentOpts = _.extend {}, assignmentOpts, defaultAssignmentOpts
+    assignment = new Assignment assignmentOpts
 
     sectionList = new SectionCollection [Section.defaultDueDateSection()]
     dueDateList = new DueDateList assignment.get('assignment_overrides'), sectionList, assignment
@@ -101,4 +105,28 @@ define [
     equal view.getFormData()['groupCategoryId'], null
 
     ENV.GROUP_CATEGORIES = null
-    ENV.ASSIGNMENT_GROUPS = null
+    ENV.ASSIGNMENT_GROUPS = null
+
+  test 'shows a warning when dangerously changing group status', ->
+    # bleh
+    window.addGroupCategory = ->
+
+    checkWarning = (view, showsWarning) ->
+      $("#assignment_toggle_advanced_options").click()
+      equal $(".group_submission_warning").is(":visible"), false
+      $("#assignment_has_group_category").click()
+      equal $(".group_submission_warning").is(":visible"), showsWarning
+      $("#assignment_has_group_category").click()
+      equal $(".group_submission_warning").is(":visible"), false
+
+    # should warn here
+    view = editView has_submitted_submissions: true
+    checkWarning view, true
+
+    # don't show the warning if you start out with a group
+    view = editView has_submitted_submissions: true, group_category_id: 1
+    checkWarning view, false
+
+    # don't show the warning if there are no submitted submissions
+    view = editView
+    checkWarning view, false

spec/controllers/assignments_controller_spec.rb

@@ -335,8 +335,10 @@ describe AssignmentsController do
       course_with_teacher_logged_in(:active_all => true)
       course_assignment
       get 'edit', :course_id => @course.id, :id => @assignment.id
-      assigns[:js_env][:ASSIGNMENT].should ==
-        subject.send(:assignment_json,@assignment,assigns[:current_user],session)
+      expected_assignment_json = subject.send(:assignment_json, @assignment,
+        assigns[:current_user], session)
+      expected_assignment_json[:has_submitted_submissions] = @assignment.has_submitted_submissions?
+      assigns[:js_env][:ASSIGNMENT].should == expected_assignment_json
       assigns[:js_env][:ASSIGNMENT_OVERRIDES].should ==
         subject.send(:assignment_overrides_json,
                      @assignment.overrides_visible_to(assigns[:current_user]))