valid_options

# File activerecord/lib/active_record/associations/builder/has_one.rb, line 9
    def self.valid_options(options)
      valid = super
      valid += [:as, :foreign_type] if options[:as]
      valid += [:ensuring_owner_was] if options[:dependent] == :destroy_async
      valid += [:through, :source, :source_type] if options[:through]
      valid += [:disable_joins] if options[:disable_joins] && options[:through]
      valid
    end