Merge branch 'fix/orphan-notification-settings' into 'master'

Fix orphaned notification settings

Closes #29688

See merge request !10763

changelogs/unreleased/fix-orphan-notification-settings.yml

+---
+title: Removed orphaned notification settings without a namespace
+merge_request:
+author:

db/migrate/20170418103908_delete_orphan_notification_settings.rb

+class DeleteOrphanNotificationSettings < ActiveRecord::Migration
+  DOWNTIME = false
+
+  def up
+    execute("DELETE FROM notification_settings WHERE EXISTS (SELECT true FROM (#{orphan_notification_settings}) AS ns WHERE ns.id = notification_settings.id)")
+  end
+
+  def down
+    # This is a no-op method to make the migration reversible.
+    # If someone is trying to rollback for other reasons, we should not throw an Exception.
+    # raise ActiveRecord::IrreversibleMigration
+  end
+
+  def orphan_notification_settings
+    <<-SQL
+      SELECT notification_settings.id
+      FROM   notification_settings
+             LEFT OUTER JOIN namespaces
+                          ON namespaces.id = notification_settings.source_id
+      WHERE  notification_settings.source_type = 'Namespace'
+             AND namespaces.id IS NULL
+    SQL
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170408033905) do
+ActiveRecord::Schema.define(version: 20170418103908) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"

spec/services/groups/destroy_service_spec.rb

@@ -7,6 +7,7 @@ describe Groups::DestroyService, services: true do
   let!(:group)        { create(:group) }
   let!(:nested_group) { create(:group, parent: group) }
   let!(:project)      { create(:empty_project, namespace: group) }
+  let!(:notification_setting) { create(:notification_setting, source: group)}
   let!(:gitlab_shell) { Gitlab::Shell.new }
   let!(:remove_path)  { group.path + "+#{group.id}+deleted" }
 
@@ -23,6 +24,7 @@ describe Groups::DestroyService, services: true do
       it { expect(Group.unscoped.all).not_to include(group) }
       it { expect(Group.unscoped.all).not_to include(nested_group) }
       it { expect(Project.unscoped.all).not_to include(project) }
+      it { expect(NotificationSetting.unscoped.all).not_to include(notification_setting) }
     end
 
     context 'file system' do