Black 23 enforces some slightly more specific rules about empty line
counts and redundant parenthesis removal, but the result is still
compatible with Black 22.
(This does not actually upgrade our Python environment to Black 23
yet.)
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Replaced unique_together with UniqueConstraint in models that
covered nullable fields as in unique_together database indexes
don't work where subgroup=None. So added conditional unique
index handling invalid duplicate Count data.
Added 0015_clear_duplicate_counts migration to handle existing
data that violates the constraints.
Also corrected a test case in test_counts.py which didn't clear its
state properly and thus was accidentally taking advantage of this
database schema bug.
Anders Kaseorg
arpit551