In Django (on Google App Engine), should I call main.py when running Unit Tests?

Question

I have a Django application on the Google App Engine, and I would like to start writing unit tests. But I am not sure how to set-up my tests.

When I run my tests, I get the following error:

EnvironmentError: Environment variable DJANGO_SETTINGS_MODULE is undefined.
ERROR: Module: tests could not be imported.

This seems pretty straight forward - my django settings have not been initialized. Setup of th django environment on Google App Engine happens in main.py (specified in app.yaml), but this does obviously not get called for unit tests. Should my unit tests start by calling main() in main.py? I am not sure.

Answer 1

You should probably just export the environment variable in the main entry point into your tests. Depending on your setup, you can probably just do that by importing your main.py file, but it's probably just as easy to add the os.environ['DJANGO_SETTINGS_MODULE'] line to the file you use to run your tests.

This might be a little hard depending on how you've got your tests set up. Are you using a testrunner like nose or Django's test suite tools?

Answer 2

My ultimate solution to this issue was to add the os.environ['DJANGO_SETTINGS_MODULE'] line IMMEDIATELY before using the only real Django function I use, template.render_to_string().

I kept having issues with it getting unset when I had it in the header of a given .py, so I realized just setting it each time would insure it'll always be right.

What a frustrating problem. I really wish there was a simple setting somewhere (perhaps in app.yaml) that would pick the Django version, and set this variable right.

Oh well.