Django test client does not handle exceptions?

Question

I've the need to write some tests for custom handler404 and handler500 in Django, using django test dummy client. The first is easy to test while I have problems with the second.

Basically, problem is that Django test client does not catch the exception and does not route to the proper handler. This is a problem because we need to test that the right custom handler and template are used.

We have a simple middleware class to simulate exceptions for tests:

  class HTTPStatusCodeMiddleware(object):
    def process_view(self, request, *args):
        if 'cookie_500_error' in request.COOKIES:
            raise Exception('Test exception')

Code above works fine for manual testing in browser.

Now, tests are:

  def test_404_template(self):                                                 
      c = Client()                                                             
      url = '/not_existing.html'                                               
      response = c.get(url)                                                    
      self.assertEqual(response.status_code, 404)  # success                  
      self.assertTemplateUsed(response, 'custom/404.html')  # success   

  def test_500_template(self):                                                 
      c = Client()                                                             
      c.cookies['cookie_500_error'] = '1'                                  
      response = c.get('/')  # here middleware raises exception!!!
      self.assertEqual(response.status_code, 500)
      self.assertTemplateUsed(response, 'custom/500.html')

Any idea? I don't have the option to use selenium. Thanks!

Answer 1

Django test client handles only some exceptions (see the docs). All the others are visible in the test and you can test them ;)