Redis 3.0 has backwards-incompatible ZADD and others

[jbaum-cmcrc]

Redis 3.0 has backwards-incompatible ZADD, which now takes a mapping rather than *args or even length or **kwargs, as well as other backwards-incompatible changes.

See:

• "3.0.0 Backwards incompatible changes" in the redis-py CHANGES file:
  https://github.com/andymccurdy/redis-py/blob/master/CHANGES

• The zadd function in the redis-py documentation:
  https://redis-py.readthedocs.io/en/latest/#redis.Redis.zadd

[bmerry]

Thanks for the heads-up. I will have to figure out what to do with fakeredis, since I'm sure people will still want to use it with code written against redis 2, and I doubt I will have time to maintain two branches (or even when I'll have time to make all the changes for compatibility with redis-py 3).

[jbaum-cmcrc]

One temporary measure might be to fail in the fakeredis ZADD (and ZINCRBY, MGET, MSET and MSETNX) when the redis-py version is >=3; that will alert users to the problem and avoid the situation where someone upgrades to the latest redis, the tests pass, but the code fails in production.

[bmerry]

Fixed in 1.0rc1, by emulating redis at a level below redis-py rather than emulating all the wrapping added by redis-py.