Find first that matches block

first_with.rb

module QueryingWithBlock
  def first_with(&block)
    find_each do |record|
      return record if block.call(record)
    end
  end
end

# ActiveRecord::Relation includes QueryingWithBlock
ActiveRecord::Relation.class_eval do
  include QueryingWithBlock
end

# delegates in metaclass of anyone ActiveRecord::Base
# because delegate goes to any instance of the surrounding class
# the surrounding class is the metaclass which ActiveRecord::Base is an instance of...
# can also be achieved through extend 
class << ActiveRecord::Base
  delegate :first_with, :to => :scoped
end

User.first_with(&->(u){ u.name == 'John' })