How do you set DEBUG to True when running a Django test?

I'm currently running some Django tests and it looks that DEBUG=False by default. Is there a way to run a specific test where I can set DEBUG=True at the command line or in code?

For a specific test inside a test case, you can use the override_settings decorator:

from django.test.utils import override_settings
from django.conf import settings
class TestSomething(TestCase):
    @override_settings(DEBUG=True)
    def test_debug(self):
        assert settings.DEBUG

Starting with Django 1.11 you can use --debug-mode to set the DEBUG setting to True prior to running tests.

The accepted answer didn't work for me. I use Selenium for testing, and setting @override_settings(DEBUG=True) makes the test browser always display 404 error on every page. And DEBUG=False does not show exception tracebacks. So I found a workaround.

The idea is to emulate DEBUG=True behaviour, using custom 500 handler and built-in django 500 error handler.

1. Add this to myapp.views:

    import sys
    from django import http
    from django.views.debug import ExceptionReporter
   
    def show_server_error(request):
        """
        500 error handler to show Django default 500 template
        with nice error information and traceback.
        Useful in testing, if you can't set DEBUG=True.
   
        Templates: `500.html`
        Context: sys.exc_info() results
         """
        exc_type, exc_value, exc_traceback = sys.exc_info()
        error = ExceptionReporter(request, exc_type, exc_value, exc_traceback)
        return http.HttpResponseServerError(error.get_traceback_html())
   

2. urls.py:

    from django.conf import settings
   
    if settings.TESTING_MODE:
        # enable this handler only for testing, 
        # so that if DEBUG=False and we're not testing,
        # the default handler is used
        handler500 = 'myapp.views.show_server_error'
   

3. settings.py:

    # detect testing mode
    import sys
    TESTING_MODE = 'test' in sys.argv
   

Now if any of your Selenium tests encounters 500 error, you'll see a nice error page with traceback and everything. If you run a normal non-testing environment, default 500 handler is used.

Inspired by:

• https://stackoverflow.com/questions/12924746/where-in-django-is-the-default-500-traceback-rendered-so-that-i-can-use-it-to-cr
• https://stackoverflow.com/questions/4088253/django-how-to-detect-test-environment

Okay let's say you want to write tests for error testcase for which the urls are :-

urls.py

if settings.DEBUG:
    urlpatterns += [
        url(r'^404/$', page_not_found_view),
        url(r'^500/$', my_custom_error_view),
        url(r'^400/$', bad_request_view),
        url(r'^403/$', permission_denied_view),
    ] 

test_urls.py:-

from django.conf import settings

class ErroCodeUrl(TestCase):

    def setUp(self):
        settings.DEBUG = True

    def test_400_error(self):
        response = self.client.get('/400/')
        self.assertEqual(response.status_code, 500)

Hope you got some idea!

Nothing worked for me except https://stackoverflow.com/a/1118271/5750078 Use Python 3.7

breakpoint() 

method. Works fine on pycharm

You can't see the results of DEBUG=True when running a unit test. The pages don't display anywhere. No browser.

Changing DEBUG has no effect, since the web pages (with the debugging output) are not visible anywhere.

If you want to see a debugging web page related to a failing unit test, then do this.

1. Drop your development database.

2. Rerun syncdb to build an empty development database.

3. Run the various loaddata scripts to rebuild the fixtures for that test in your development database.

4. Run the server and browse the page.

Now you can see the debug output.