Django's own tests should always treat both Django deprecation warnings as errors

[Mike Edmunds]

Django's runtests.py treats RemovedAfterNextVersionWarning (currently equivalent to RemovedInDjango70Warning) as an error, in all releases. And in x.0 and x.2 releases, it also treats RemovedInNextVersionWarning as an error.

However, in x.1 releases RemovedInNextVersionWarning is not handled as an error (because there is no RemovedInDjango62Warning, or any x.2 equivalent).

This doesn't matter for most Django tests, which use the concrete RemovedInDjango70Warning, RemovedInDjango71Warning, etc. But it complicates testing Django's own deprecation utilities and assertion helpers, and it makes discussions of them complicated.

Suggestion: change runtests.py to use the generic warnings and treat them both as errors—always, without the need to advance them each release:

# Before:
warnings.simplefilter("error", RemovedInDjango70Warning)

# After
warnings.simplefilter("error", RemovedInNextVersionWarning)
warnings.simplefilter("error", RemovedAfterNextVersionWarning)

(I think this becomes moot if/when we switch to calendar cycle releases.)

[Jacob Walls]

Thanks, I can see how this makes testing the assertions themselves more difficult. (I'll leave Testing Framework as the component in that case.)

(I think this becomes moot if/when we switch to calendar cycle releases.)

Can you expand on that part? I'm assuming that part wouldn't change.

[Mike Edmunds]

Replying to Jacob Walls:

(I think this becomes moot if/when we switch to calendar cycle releases.)

Can you expand on that part? I'm assuming that part wouldn't change.

The ​DEP 20 deprecation policy doesn't have the X.0 special cases that result in RemovedInDjango62Warning not existing, so being omitted from the runtests.py filters. There will always be two concrete RemovedIn warnings defined…

# Django 2028.x:
# RemovedInNextVersionWarning (DeprecationWarning):
warnings.simplefilter("error", RemovedInDjango2029Warning)
# RemovedAfterNextVersionWarning (PendingDeprecationWarning):
warnings.simplefilter("error", RemovedInDjango2030Warning)

[Héctor Castillo]

Hi, I’d like to work on this issue.

[Mike Edmunds]

Welcome Héctor. Please follow ​Django's contributor docs starting with ​"Claiming" tickets.

[Héctor Castillo]

PR submitted: ​​https://github.com/django/django/pull/21216

[Jacob Walls <jacobtylerwalls@…>]

In f8c0a93:

Fixed #37080 -- Filtered by generic deprecation warnings in runtests.py.