Problems with Django Testing and Selenium

As mentioned in previous posts, I am thrilled with the Django testing infrastructure. Although TestCases are a great start, I have a situation where I really would like to automatically push some buttons on my page. This seemed like a job for Selenium. The Django docs give a nice example, so I thought I would give it a try. Things did not go as expected.

This was related to the way Django (version 1.4) runs tests and the way the staticfiles app works. When tests are run, DEBUG is set by the test runner to False. No problem when running TestCases because the pages are not actually loaded. No static files are needed.

Setup a test using LiveServerTestCase, and now static files are needed. But when DEBUG=False, the staticfiles app leaves serving static files to you. If you have never run DEBUG=False in your development environment, you probably are not setup to serve the static files. Hence you get a flood of HTTP 500 errors.

The solution is on stackoverflow. Here is my code (IS_DEV is a setting indicating the code is running on the development server):

if settings.IS_DEV and ('test' in sys.argv):
    urlpatterns += patterns('',
                            url(r'^%s/(?P.*)$'%settings.STATIC_URL[1:], 'django.views.static.serve', {
                                'document_root': settings.STATIC_ROOT,
                                }),
                            )

urlpatterns += staticfiles_urlpatterns()

When I first implemented this solution, it appeared to not be working because I still got one HTTP 500 error. This was a little difficult to debug because instead of displaying a debug error page, it just generated a server error (because DEBUG=False). I was able to track down the source of that error by turning on the logger. This showed the error was due to a missing favicon.ico file.

Django Collectstatic Gotchas

Overall the Django staticfiles app is great. But I ran into one behavior I did not expect that caused some problems.

As noted in the documentation:

 The default is to look in all locations defined in STATICFILES_DIRS and in the 'static' directory of apps specified by the INSTALLED_APPS setting

and:

Duplicate file names are by default resolved in a similar way to how template resolution works: the file that is first found in one of the specified locations will be used.

To make my apps more modular, I put a static directory in each. Each containing among other things a css folder. Unfortunately for me, I used the same name for some css files in different apps. Thus the first one found made it into collectedstatic and the other one did not. This was not what I was expecting.

To solve the problem, I set

STATICFILES_FINDERS = ( "django.contrib.staticfiles.finders.FileSystemFinder", )

And I added my apps to STATICFILES_DIRS like this:

STATICFILES_DIRS=[('my_django',os.path.join(MY_DJANGO_PATH,'static')),
('app1',os.path.join(MY_DJANGO_PATH,'app1','static')),
('app2',os.path.join(MY_DJANGO_PATH,'app2','static')))

Now collected static made a folder for each app.