Add support for IORedis.Cluster type in ConnectionOptions for TypeScript

[glensc]

I don't see explicitly said out that the project supports Redis cluster, neither I do see that it's been spelled out it does not work, but I do see that people talk about it, likely in javascript not in typescript that they have not encountered this problem, example #158

error TS2345: Argument of type '{ redis: IORedis.Redis | IORedis.Cluster; }' is not assignable to parameter of type 'ConnectionOptions'.
#15 5.391   Types of property 'redis' are incompatible.
#15 5.391     Type 'Redis | Cluster' is not assignable to type 'Redis | undefined'.
#15 5.391       Type 'Cluster' is missing the following properties from type 'Redis': Promise, duplicate, send_command

this PR adds { redis: IORedis.Redis | IORedis.Cluster; } typing for ConnectionOptions

cc @evantahler

[glensc]

However, if I monitor Redis with resque-web, I get occasionally

CROSSSLOT Keys in request don't hash to the same slot

If I read from the linked issue:

Because on cluster mode, ioredis library can not delete key on different slot at once.

so, as to my knowledge resque-web is not doing any writes just to read status, I'm assuming it's something node-resque doing.

So the problem in #158 is back?

x-ref:

• Cluster: CROSSSLOT Keys in request don't hash to the same slot redis/ioredis#101

[evantahler]

I think the changes you have here are ready for review - they look good to me!

I can't comment how the Ruby project (resque-web) works, or it's support for redis-cluster. If you are seeing that error with node-resque, a stack trace would be very helpful!

[glensc]

I'll try to report to resque-web the problem first, but as I understand the problem comes the way things are written, but resque-web overview page should not "write" anything.

changed ready to review now, pipelines pass

[glensc]

But maybe it is better to introduce a new type, RedisConnection?

[glensc]

x-ref:

• Redis::CommandError - CROSSSLOT Keys in request don't hash to the same slot resque/resque-web#154

it includes also a trace

[glensc]

@evantahler some feedback on resque-web:

• Redis::CommandError - CROSSSLOT Keys in request don't hash to the same slot resque/resque-web#154 (comment)

It seems like the requested keys (worker ids) requested in the command aren't coming from a single node.