v4: EXISTS should resolve to number instead of boolean

[OxleyS]

The raw Redis EXISTS command returns the number of keys, out of the ones passed, that exist in the database. The v4 implementation of client.exists(), however, returns a Promise<boolean>, only returning true if all the passed keys exist.

While I understand making it boolean improves the ergonomics in many cases, this shuts out the possibility of using the command to see if any key of a list exists. (As an aside, it's also a breaking change that should have been mentioned in the migration guide.) It should probably be made to return a number again.

[leibale]

@OxleyS until we'll release the fix you can use:

const reply = await client.sendCommand(['EXISTS', 'key']);

[akelmj]

Not working , return undefined

const reply = await client.sendCommand(['EXISTS', 'category:111']);

and from redisinsight: