ruby on rails - How can I create unique strings (with no numbers) with factory girl?

Or is an external gem necessary to generate random and unique usernames maybe?

Here's my current factory:

factory :user_4 do
    sequence(:id) { |n| n }
    sequence(:first_name) { |n| "Gemini" + n.to_s }
    sequence(:last_name) { |n| "Pollux" + n.to_s }
    sequence(:profile_name) { |n| "GeminiPollux" + n.to_s  }
    sequence(:email) { |n| "geminipollus" + n.to_s + "@hotmail.co.uk" }
end

Using the sequence method works for the id, profile_name and email, but my REGEX validations mean that the first name and last name are automatically invalid, because they have a digit in them. Nothing to do with the uniqueness.

So how should I create these unique names?

Answer

There are infinite possible solutions to generate a random string without relying on third party gems.

Here's one

('a'..'z').to_a.shuffle.join
# => "sugrjtyoiqlbxkzcfnawdhpevm"

Example

factory :user_4 do
  sequence(:id) { |n| n }
  first_name { "Gemini" + random_name }
  # ...

end

def random_name
  ('a'..'z').to_a.shuffle.join
end

If the random factor is too low, you can increase the complexity.