fix importing assignments with no name

test plan:
 * import a course package containing a nameless assignment,
   and choose to remove dates from the imported course.
   You can find such a package here:
   https://hilary.instructure.com/courses/332573/content_migrations
   (download the .imscc linked to on that page)
   Note that you can't easily create a new nameless assignment,
   because CNVS-12938 adds a validator to prevent this
   (the linked course package predates that fix)
 * the nameless assignment should have a generic name
   ("untitled assignment")
 * go to the syllabus page in the new course
 * there should be no due dates there

fixes CNVS-16624

Change-Id: Ib51773024ccaac2241619cd8b1a5a8b54b99f3ce
Reviewed-on: https://gerrit.instructure.com/43791
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: James Williams  <jamesw@instructure.com>
QA-Review: Jahnavi Yetukuri <jyetukuri@instructure.com>
Product-Review: Jeremy Stanley <jeremy@instructure.com>

Author: jstanley0

app/models/importers/assignment_importer.rb

@@ -33,6 +33,7 @@ def self.import_from_migration(hash, context, migration=nil, item=nil, quiz=nil)
       item ||= Assignment.where(context_type: context.class.to_s, context_id: context, migration_id: hash[:migration_id]).first if hash[:migration_id]
       item ||= context.assignments.new #new(:context => context)
       item.title = hash[:title]
+      item.title = I18n.t('untitled assignment') if item.title.blank?
       item.migration_id = hash[:migration_id]
       item.workflow_state = (hash[:workflow_state] || 'published') if item.new_record? || item.deleted?
       if hash[:instructions_in_html] == false

app/models/importers/course_content_importer.rb

@@ -166,23 +166,23 @@ def self.import_content(course, data, params, migration)
             event.lock_at = shift_date(event.lock_at, shift_options)
             event.unlock_at = shift_date(event.unlock_at, shift_options)
             event.peer_reviews_due_at = shift_date(event.peer_reviews_due_at, shift_options)
-            event.save_without_broadcasting!
+            event.save_without_broadcasting
           end
 
           migration.imported_migration_items_by_class(Announcement).each do |event|
             event.delayed_post_at = shift_date(event.delayed_post_at, shift_options)
-            event.save_without_broadcasting!
+            event.save_without_broadcasting
           end
 
           migration.imported_migration_items_by_class(DiscussionTopic).each do |event|
             event.delayed_post_at = shift_date(event.delayed_post_at, shift_options)
-            event.save_without_broadcasting!
+            event.save_without_broadcasting
           end
 
           migration.imported_migration_items_by_class(CalendarEvent).each do |event|
             event.start_at = shift_date(event.start_at, shift_options)
             event.end_at = shift_date(event.end_at, shift_options)
-            event.save_without_broadcasting!
+            event.save_without_broadcasting
           end
 
           migration.imported_migration_items_by_class(Quizzes::Quiz).each do |event|
@@ -192,14 +192,14 @@ def self.import_content(course, data, params, migration)
             event.show_correct_answers_at = shift_date(event.show_correct_answers_at, shift_options)
             event.hide_correct_answers_at = shift_date(event.hide_correct_answers_at, shift_options)
             event.saved_by = :migration
-            event.save!
+            event.save
           end
 
           migration.imported_migration_items_by_class(ContextModule).each do |event|
             event.unlock_at = shift_date(event.unlock_at, shift_options)
             event.start_at = shift_date(event.start_at, shift_options)
             event.end_at = shift_date(event.end_at, shift_options)
-            event.save!
+            event.save
           end
 
           course.set_course_dates_if_blank(shift_options)

spec/models/importers/assignment_importer_spec.rb

@@ -62,5 +62,31 @@
     a = Assignment.where(migration_id: assignment_hash[:migration_id]).first
     expect(a.points_possible).to eq rubric.points_possible
   end
+
+  it "should infer the default name when importing a nameless assignment" do
+    course_model
+    nameless_assignment_hash = {
+        "migration_id" => "ib4834d160d180e2e91572e8b9e3b1bc6",
+        "assignment_group_migration_id" => "i2bc4b8ea8fac88f1899e5e95d76f3004",
+        "grading_standard_migration_id" => nil,
+        "rubric_migration_id" => nil,
+        "rubric_id" => nil,
+        "quiz_migration_id" => nil,
+        "workflow_state" => "published",
+        "title" => "",
+        "grading_type" => "points",
+        "submission_types" => "none",
+        "peer_reviews" => false,
+        "automatic_peer_reviews" => false,
+        "muted" => false,
+        "due_at" => 1401947999000,
+        "peer_reviews_due_at" => 1401947999000,
+        "position" => 6,
+        "peer_review_count" => 0
+    }
+    Importers::AssignmentImporter.import_from_migration(nameless_assignment_hash, @course)
+    assignment = @course.assignments.where(migration_id: 'ib4834d160d180e2e91572e8b9e3b1bc6').first
+    expect(assignment.title).to eq 'untitled assignment'
+  end
 
 end