Unable to instantiate RedisCluster according to pyright

[trajano]

I got the following error on pyright

 error: Cannot instantiate abstract class "RedisCluster"
    "CommandsProtocol.connection_pool" is not implemented (reportAbstractUsage)

When doing

return RedisCluster(startup_nodes=startup_nodes,  protocol=3)

[vladvildanov]

@trajano Hi! Which version of client are you using? Could you please double check that class that you're instantiating is a correct one:

from redis.cluster import RedisCluster

[trajano]

I'm using the asyncio one

from redis.asyncio import Redis
from redis.asyncio.cluster import ClusterNode, RedisCluster

[vladvildanov]

Which client version are you using? RedisCluster client was never marked as an abstract class, could you please double check if the instance you're creating is actually redis-py RedisCluster? Could you please also try it with latest version of redis-py?

[trajano]

The pyproject.yaml says "redis>=5.2.1", https://pypi.org/project/redis/

from redis.asyncio import Redis
from redis.asyncio.cluster import ClusterNode, RedisCluster

It's not marked as abstract but pyright deemed it to be abstract because it is missing the implementation of "CommandsProtocol.connection_pool" is not implemented (reportAbstractUsage)

[vladvildanov]

@trajano Yeah, I totally understand from the exception message. CommandsProtocol.connection_pool isn't a method, it's a property. Also, CommandsProtocol extends Python Protocol and this class isn't instantiable at all. I cannot reproduce this behaviour by just instantiate async RedisCluster class on my local. Could you please verify that pyright isn't a source of issue? Also please share more info about your environment, anything that would help me to reproduce the issue

[trajano]

I just added a ticket on pyright, but not sure what the rules are for abstract classes in Python, it's not as strict as in Java.

[trajano]

According to microsoft/pyright#10225 seems like it's an issue with this library.

[vladvildanov]

@trajano Maybe, but if we would have an issue with instantiating RedisCluster object it would be catched by our tests. That's why I'm asking additional information to understand how to reproduce this issue. Anything about your environment would be appreciated

[trajano]

@vladvildanov I don't have any issues of instantiating it at run time.

This is primarily a type validation issue which is done on pyright (and according to microsoft/pyright#10225 (comment) it also applies to MyPy as well. The workaround I am doing is to "ignore" the type error.

[trajano]

From what I can tell to fix this you add

        self._lock: Optional[asyncio.Lock] = None
        # add the following to fix pyright issue
        self.connection_pool: "redis.asyncio.ConnectionPool"

In asyncio/cluster.py line 393

[trajano]

Python is not my primary language, so I am not sure what kind of impact that would have. Though on a side note, it is kind of annoying that the async APIs return both normal and Awaitable when it should only return awaitables.

[aiguofer]

I'm running into the same issue... I'll just # type: ignore for now, which is a shame, but hoping typing gets fixed for async redis!