After lots of great work by Trey Hunner on the draft implementation (and
review from Tim Graham, Aymeric Augustin, Tomasz Paczkowski, and James
Da Costa), I think DEP 3 is ready for acceptance.
The latest draft of the DEP is here:
https://github.com/django/deps/blob/master/draft/0003-javascript-tests.rst#reference-implementation
The draft implementation is broken into two pull requests, which are
nearing merge-readiness: https://github.com/django/django/pull/4573 and
https://github.com/django/django/pull/4577
Review of both the DEP and the pull requests welcome! Barring feedback
that reveals a major problem with the DEP, I plan to submit it to the
technical board for acceptance within the next couple days.