Automating tests in Django

Updated

At work lately we’ve been writing a bunch of tests for all of the work we’ve been doing. This is generally a good thing (tm). I was getting tired of manually having to write all of the code to test the views inside of my app. So I decide to write a little app that helps me automate the writing of tests.

I wrote a piece of middleware (that should obviously only be used during development!) that shadows the current activity in django into a log file. This log file should then be ready to copy and paste into a doctest for easy testing of your views. This is a little hard to explain, but the code should be pretty self explanitory.

I created a `google code project <http://code.google.com/p/django-testmaker/>`_for it so that people can go ahead and hack on it and make it better. It is pretty rudimentary at current, but it gets the job done.

I think a big win from this approach is that your testing data is much more “real”, since it’s a copy of your session with a real browser. I know writing django tests I sometimes use contrived data because it is a pain to enter it all. This should help improve on that situation.

Here is a video of it in action, this should allow it to make more sense.

Django TestMaker from Eric Holscher on Vimeo.

Writeup

Figured it would be good to writeup the screencast.

Step 1: Get django-testmaker svn checkout http://django-testmaker.googlecode.com/svn/trunk/ django-testmaker-read-only

Make sure the testmaker module is in your PYTHONPATH.

Step 2: Add 'testmaker.middleware.testmaker.TestMakerMiddleware',

to your MIDDLEWARE_CLASSES in your settings file.

Step 3: Run the test server with the middleware installed. ./manage.py runserver

Browse around your site.

Step 4: run tail -f /tmp/testmaker.log

to see your output.

Step 5: Take the output from testmaker.log and put it into a file in PROJECT/tests.py. Make sure that your tests.py contains:

"""
>>> from django.core.management import call_command
>>> call_command('loaddata', 'PATH/TO/PROJECT/fixtures/PROJECT.json', verbosity=0)
>>> from django.test import Client
>>> c = Client()
YOUR TESTS GOES HERE
"""

at the top of your tests.py file.

Step 6: Run the command ./manage.py dumpdata > PROEJCT/fixtures/PROJECT.json

You can have dumpdata just dump the data for a single project if you provide PROJECT as an argument to it. Be warned though, that the tests might break because of it using data from other apps. (Like my example would break because the mine project uses data from my blog app.)

Step 7: ./manage.py test PROJECT

Step 8: PROFIT!!

Update

I added a management command to the project to simply this process a ton. I’ll be making another screencast and blog post (and maybe even some REAL DOCS!) tonight, so stay tuned for that.

This Post

Published 2008-07-23

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