Error messages for exclusion and inclusion

issue#13108.rb

require 'active_model'

class Account
  include ActiveModel::Model

  attr_accessor :subdomain, :subdomain1, :subdomain2, :subdomain3, :size, :size1, :size2, :size3
  validates :subdomain, exclusion: { in: %w(www us ca jp) }
  validates :subdomain1, exclusion: { in: %w(www us ca jp), message: "is reserverd" }
  validates :subdomain2, exclusion: { in: %w(www us ca jp), message: "%{value} is reserverd" }
  validates :subdomain3, exclusion: { in: %w(www us ca jp), message: "Subdomain %{value} is reserverd" }

  validates :size, inclusion: { in: %w(small medium large) }
  validates :size1, inclusion: { in: %w(small medium large), message: "is not included in the list" }
  validates :size2, inclusion: { in: %w(small medium large), message: "%{value} is not included in the list" }
  validates :size3, inclusion: { in: %w(small medium large), message: "Size %{value} is not included in the list" }
end  

a = Account.new
a.subdomain = 'www'
a.subdomain1 = 'www'
a.subdomain2 = 'www'
a.subdomain3 = 'www'

a.size = 'very large'
a.size1 = 'very large'
a.size2 = 'very large'
a.size3 = 'very large'

a.valid?

puts 'Using only `errors.messages`'
puts a.errors.messages.each { |key, value| puts "#{ key } : #{ value }" }

puts 'Using `errors.full_messages'
a.errors.full_messages

# => Output:

# => Using only `errors.messages`
# => subdomain : ["is reserverd"]
# => subdomain1 : ["is reserverd"]
# => subdomain2 : ["www is reserverd"]
# => subdomain3 : ["Subdomain www is reserverd"]
# => size : ["is not included in the list"]
# => size1 : ["is not included in the list"]
# => size2 : ["very large is not included in the list"]
# => size3 : ["Size very large is not included in the list"]


# => Using `errors.full_messages`
# => Subdomain is reserverd
# => Subdomain1 is reserverd
# => Subdomain2 www is reserverd
# => Subdomain3 Subdomain www is reserverd
# => Size is not included in the list
# => Size1 is not included in the list
# => Size2 very large is not included in the list
# => Size3 Size very large is not included in the list