Test find_signed/! on Relation
Test find_signed/! on Relation

Want to make sure that those methods work on relation and return
expected result when retation has or doesn't have any records.

Those methods are delegated by
https://github.com/rails/rails/blob/7cb451346618811796efce1f8a2bf576b8e4999c/activerecord/lib/active_record/relation/delegation.rb#L21,
https://github.com/rails/rails/blob/7cb451346618811796efce1f8a2bf576b8e4999c/activerecord/lib/active_record/relation/delegation.rb#L95-L114,
https://github.com/rails/rails/blob/7cb451346618811796efce1f8a2bf576b8e4999c/activerecord/lib/active_record/relation/delegation.rb#L56-L78
as I understand.

Related to https://github.com/rails/rails/pull/39313

EmmaB/rails-1,betesh/rails,yawboakye/rails,vipulnsward/rails,BlakeWilliams/rails,georgeclaghorn/rails,joonyou/rails,yahonda/rails,BlakeWilliams/rails,Stellenticket/rails,MSP-Greg/rails,Erol/rails,tjschuck/rails,tjschuck/rails,kmcphillips/rails,kmcphillips/rails,tgxworld/rails,lcreid/rails,rails/rails,EmmaB/rails-1,Edouard-chin/rails,BlakeWilliams/rails,tjschuck/rails,rails/rails,joonyou/rails,kmcphillips/rails,kddeisz/rails,tjschuck/rails,tgxworld/rails,Envek/rails,Stellenticket/rails,yawboakye/rails,esparta/rails,eileencodes/rails,georgeclaghorn/rails,eileencodes/rails,georgeclaghorn/rails,lcreid/rails,yahonda/rails,BlakeWilliams/rails,bogdanvlviv/rails,rails/rails,Edouard-chin/rails,esparta/rails,betesh/rails,Vasfed/rails,yahonda/rails,eileencodes/rails,Erol/rails,vipulnsward/rails,bogdanvlviv/rails,betesh/rails,tgxworld/rails,yawboakye/rails,betesh/rails,Edouard-chin/rails,lcreid/rails,bogdanvlviv/rails,vipulnsward/rails,esparta/rails,kddeisz/rails,Vasfed/rails,esparta/rails,MSP-Greg/rails,MSP-Greg/rails,kmcphillips/rails,Envek/rails,yahonda/rails,bogdanvlviv/rails,MSP-Greg/rails,EmmaB/rails-1,Stellenticket/rails,kddeisz/rails,Erol/rails,vipulnsward/rails,Stellenticket/rails,lcreid/rails,rails/rails,kddeisz/rails,Erol/rails,georgeclaghorn/rails,Vasfed/rails,Envek/rails,Vasfed/rails,Edouard-chin/rails,yawboakye/rails,tgxworld/rails,joonyou/rails,Envek/rails,eileencodes/rails,joonyou/rails