# A Member represents the many-to-many relation of Groups to People. At most # one member may exist for each Person-Group combination. class Member < ApplicationRecord # @!attribute is_leader # @return [Boolean] # whether the person is a leader in the group. belongs_to :person belongs_to :group validates :person_id, uniqueness: { scope: :group_id, message: "is already a member of this group" } end