custom_faker_provider.md

🛠️ Crafting Custom Faker Providers for Domain-specific Data

Faker allows you to define custom providers to generate domain-specific data. This is ideal when your application requires specialized formats or complex patterns that built-in generators don’t cover. You can create a provider by subclassing Faker::Base, defining methods, and then registering it with Faker::Base.add_provider. Once registered, you can call it like any other Faker generator.

module Faker
  class MyDomain < Base
    flexible :my_domain

    class << self
      def transaction_id
        "TXN-#{rand(1000..9999)}-#{sample(["USD","EUR","JPY"])}"
      end

      def tracking_code
        Array.new(3) { rand(65..90).chr }.join + rand(10**6).to_s.rjust(6, '0')
      end
    end
  end
end

# Register the provider globally
Faker::Base.add_provider(Faker::MyDomain)

# Usage
Faker::MyDomain.transaction_id  #=> "TXN-4823-EUR"
Faker::MyDomain.tracking_code   #=> "QWG042519"