module Directive

NOTE: This is still a pre-release feature! Use at your own risk - it may change before being released.

A utility for creating read-only gem configuration singletons.

Usage:

# In your gem:
module SomeGem
  module Configuration
    extend Directive

    configuration_options do
      option :some_config_option
      option :some_option_with_a_default, default: "I probably know what's best"

      nested :whats_behind do
        option :door_one, default: "It's a goat"
        option :door_two, default: "Another goat"
        option :door_three, default: "It's a car!"
      end
    end
  end
end

# Then, in the application using the gem:
SomeGem::Configuration.configure do |config|
  config.some_config_option = 12345
  config.some_option_with_a_default = "Nope, you really don't"

  config.whats_behind do |nested|
    nested.door_one = "It's a boat!"
    nested.door_three = "The teletubbies on repeat 😱"
  end
end

# Then, back in your gem code:
puts Configuration.config.some_config_option
=> 12345
puts Configuration.config.whats_behind.door_one
=> "It's a boat!"

# Or, if you want to select dynamically:
doors = %i[door_one door_two door_three]
Configuration.config.config_eval(whats_behind, doors.sample).read
=> "The teletubbies on repeat 😱"