new_contents: import StringIO
  
  from django.core.management import call_command
  from django.test import TestCase
  
  
  class CommandsTestCase(TestCase):
      def test_no_missing_migrations(self):
  
          result = StringIO.StringIO()
          call_command('makemigrations', dry_run=True, stdout=result)
          result_string = result.getvalue()
          self.assertEqual(result_string, 'No changes detected\n')
  
subject: Add a test for missing migrations