Proposal: alternative to Redis::BaseObject.expiration_filter

[rossta]

PRs #172 and #173 highlight a weakness in the current implementation supporting expiration options on class macros, notably in Redis::BaseObject.expiration_filter:

redis-objects/lib/redis/base_object.rb

Line 26 in dffb9a0

def expiration_filter(*names)

This approach requires maintainers to register all appropriate methods and theirs aliases with expiration_filter. This is problematic for Redis::Objects which makes heavy use of alias methods in subclasses.

An alternative approach ideally obviates the need for a separate registry, makes it explicit that expiration is supported within the method definition itself, and handles alias methods seamlessly.

I propose replacing the current implementation with the following:

# Redis::BaseObject
def allow_expiration(&block)
  block.call.tap { set_expiration }
end

Subclasses would simply pass the method implementation as a block to allow_expiration:

# Redis::HashKey
def store(field, value)
  allow_expiration do
    redis.hset(key, field, marshal(value, options[:marshal_keys][field]))
  end
end
alias_method :[]=, :store

This PR depends on tests implemented in #172 and #173.

[nateware]

Thanks Ross! Hopefully this fixes a few outstanding bugs as well.

[rossta]

@nateware Thanks for the quick merge and version bump!