Add OutOfMemoryError as a subclass of CommandError

That error is a bit unique as it's a "server error" contrary
to most command errors. So it's useful to treat it differently.

Author: byroot

CHANGELOG.md

@@ -1,5 +1,7 @@
 # Unreleased
 
+- Add `OutOfMemoryError` as a subclass of `CommandError`
+
 # 5.0.2
 
 - Fix `Redis#close` to properly reset the fork protection check.

lib/redis/client.rb

@@ -17,6 +17,10 @@ class Client < ::RedisClient
       RedisClient::ProtocolError => Redis::ProtocolError,
     }
 
+    if defined?(RedisClient::OutOfMemoryError)
+      ERROR_MAPPING[RedisClient::OutOfMemoryError] = Redis::OutOfMemoryError
+    end
+
     class << self
       def config(**kwargs)
         super(protocol: 2, **kwargs)

lib/redis/errors.rb

@@ -29,6 +29,9 @@ class WrongTypeError < CommandError
   class ReadOnlyError < CommandError
   end
 
+  class OutOfMemoryError < CommandError
+  end
+
   # Base error for connection related errors.
   class BaseConnectionError < BaseError
   end