Django's APPEND_SLASH setting does not work with static, why? - django

Question

Django's 4.1.1 APPEND_SLASH setting automatically appends a slash / until I add static roots, i.e. urlpatterns += static(settings.STATIC_URL, document_root=settings.STATIC_ROOT).
For example, this works with http://127.0.0.1:8000/admin and http://127.0.0.1:8000/admin/
urlpatterns = [
path('', home),
path('admin/', admin.site.urls),
]
However, adding my static roots and the setting no longer takes effect:
urlpatterns = [
path('', home),
path('admin/', admin.site.urls),
]
urlpatterns += static(settings.STATIC_URL, document_root=settings.STATIC_ROOT)
urlpatterns += static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)
Why? Is this a bug? How is urlpatterns += static etc impacting Django's setting?

Answer 1

When you append static to your URLconf, it takes all URLs that do not match existing URL patterns and attempts to serve them through the view django.views.static.serve, which does not respect settings.APPEND_SLASH.
This should only be a problem in development, as you'll be serving static files through nginx/apache/whatever in production, but this is a good opportunity for you to sanitize all of your URLs in templates, etc. to include trailing slashes (hint: use the {% url %} template tag). You won't be able to do much about users typing URLs directly without the trailing slash, but again, this is only in development.
You can also use Whitenoise in development to get around this (http://whitenoise.evans.io/en/stable/django.html).