has_many :coitems
has_many :merchandise_purchases
has_many :rentable_purchases
+ has_many :bonus_purchases
+ has_many :late_fee_purchases
validates_presence_of :name, :email, :phone, :address
validates_numericality_of :debt
def validate
errors.add(:debt, "should be non-negative") if debt.nil? || debt < 0.00
+ errors.add(:email, "is invalid") unless email =~ /.+@.+\..+/
+ errors.add(:phone, "has invalid format, use XXX-XXX-XXXX") unless phone =~ /^\d{3}-\d{3}-\d{4}$/
end
end