ActiveModel ActiveRecord generate error message

activemodel_activerecord_generate_error_message

class User                     # class User < ActiveRecord::Base
  include ActiveModel::Model   # 
  
  attr_accessor :name, :age
  
  validates :name, presence:     true
  validates :age,  presence:     true,
                   numericality: { only_integer: true, greater_than: 0 }
end

user = User.new(age: -99)
user.valid? 

# Assuming the current locale is "en"
user.errors.full_messages # => [ "Name can't be blank", "Age must be greater than 0"]

user.errors.generate_message(:name, :blank)                     # => "can't be blank"
user.errors.generate_message(:age,  :greater_than, {count: 0})  # => "must be greater than 0"

user.errors.full_message(:name,     :blank)                     # => "Name can't be blank"
user.errors.full_message(:age,       :greater_than, {count: 0}) # => "Age must be greater than 0"