Question

Below is the code that I am using:

This is my app/models file:

class One < ActiveRecord::Base
  attr_accessible :name, :surname      
end

class Two < ActiveRecord::Base  
  attr_accessible :name, :one_surname

  # generate a list of one's surnames
  def self.LIST_SURNAMES
    list  = Array.new
    arr   = One.all
    arr.each {|one| list << one.surname}

    return list
  end

  validates :one_surname, :inclusion => self.LIST_SURNAMES()
end

This is my /spec/models file:

FactoryGirl.define do
  factory :two do
    name "two_name"
  end

  factory :one do
    name "one_name"
    surname "one_surname"
  end    
end

describe Two do
  it 'should be created' do
    @one = FactoryGirl.create(:one)

    puts "One.last.surname = #{One.last.surname}"
    puts "Two.LIST_SURNAMES = #{Two.LIST_SURNAMES}"

    @two = FactoryGirl.build(:two, :one_surname => Two.LIST_SURNAMES[0])

    @two.save!
  end
end 

However, my test fails. And I’m entirely unsure of why this is. Any thoughts?

This is the RSpec output:

One.last.surname  = one_surname
Two.LIST_SURNAMES = ["one_surname"]

Further, I am getting this failure:

  1) Two should be created
     Failure/Error: @two.save!
     ActiveRecord::RecordInvalid:
       Validation failed: One surname is not included in the list
 # ./category_spec.rb:29:in `block (2 levels) in <top (required)>'

Answer 1

It’s executing the Two.LIST_SURNAMES at interpretation time, not runtime. So if you want it to get the LIST_SURNAMES at runtime, you’ll need to use a proc

validates :one_surname, :inclusion => {:in => proc {self.LIST_SURNAMES()}}

The rest is optional, but here’s some cleaned code:

class Two < ActiveRecord::Base
  attr_accessible :name, :one_surname

  validates :one_surname, :inclusion => {in: proc{One.pluck(:surname)}}                                              
end

I replaced the LIST_SURNAMES method with One.pluck(:surname) which does the same thing. Also: LIST_SURNAMES, if you keep it, should be def self.list_surnames since it is not a constant.