How to test 404 NOT FOUND with django testing framework?

Try

response = self.client.get('/something/really/weird/') # note the '/' before something

127.0.0.1:8000/something/really/weird/ is /something/really/weird/ in path relative to root, not

• something/really/weird
• something/really/weird/
• /something/really/weird

The problem is that your ViewFor404 class returns a 200 status code. Look at Django's TemplateView definition:

class TemplateView(TemplateResponseMixin, View):    """    A view that renders a template.    """    def get_context_data(self, **kwargs):        return {            'params': kwargs        }    def get(self, request, *args, **kwargs):        context = self.get_context_data(**kwargs)        return self.render_to_response(context)

so all your class does is a render_to_response, which generates a '200' response.

If you need to override the 404 handler, you should do something more like this in the view:

return HttpResponseNotFound('<h1>Page not found</h1>')

(I don't know the equivalent in class-based views)

Or better yet, can you avoid customizing the View? To customize the 404 display, you can just create a 404.html template (in your site's templates/ directory), and it will be picked up by Django's error viewer.