Class configuration using method_missing

config_example_method_missing.rb

module Awesome
  @config = {}

  def self.configure
    yield(self)
  end

  def self.method_missing method, *args, &block
    if method.to_s[-1] == '='
      @config[method[0..-2].to_sym] = args.first
    else
      @config[method]
    end
  end
end

Awesome.configure do |a|
  a.magic_number = 3
end

puts Awesome.magic_number
# => 3