Use a factory's sequence to generate unique phone numbers

Question

I'm new to TDD, RSpec and factories, and trying to understand how to test that each User's phone number attribute is unique. To do so, I'm trying to use a sequence in my User factory. I'm not having much luck with the following:

FactoryGirl.define do
  factory :user do
    number = 123456789
    sequence(:phone_number) {|n| (number + n).to_s }
  end
end

Any thoughts on the best way to accomplish this? Also, what kind of test would make sense for something like this where ultimately I would want to add the following validation to the user model to make such a test pass?

validates :phone_number, :uniqueness => true

Thanks!

Answer 1

Try using a lambda with a random 10 digit number:

phone_number { rand(10**9..10**10) } 

Answer 2

Try this:

FactoryGirl.define do
  sequence :phone_number do |n|
     "123456789#{n}"
  end

  factory :user do
    phone_number
  end
end

and in order to test your validation use this in your user_spec

it { should validate_uniqueness_of(:phone_number) }

Answer 3

To complete @westonplatter answer, in order to start at 0 000 000 000, you can use String#rjust:

FactoryGirl.define do
  factory :user do
    sequence(:phone_number) {|n| n.to_s.rjust(10, '0') }
  end
end

Example:

> 10.times { |n| puts n.to_s.rjust(10, '0') }
0000000000
0000000001
0000000002
0000000003
0000000004
0000000005
0000000006
0000000007
0000000008
0000000009

Answer 4

While the random solution works, you have a small chance of not getting a unique number. I think you should leverage the FactoryGirl sequence.

We can start at, 1,000,000,000 (100-000-000) and increment up. Note: This only gives you 98,999,999,999 unqiue phone numbers, which should be sufficient. If not, you have other issues.

FactoryGirl.define do
  sequence :phone_number do |n|
    num = 1*(10**8) + n
    num.to_s
  end

  factory :user do
    phone_number
  end
end