source_location_demo.rb

module Configurable
  def is_a
    wrapper(true)
  end

  def is_not_a
    wrapper(false)
  end

  private
  
  def wrapper(wrapper_type)
    wrapper_type ? positive_wrapper : negative_wrapper
  end

  def positive_wrapper
    @positive_wrapper ||= HumanWrapper.new(self, true)
  end

  def negative_wrapper
    @negative_wrapper ||= HumanWrapper.new(self, false)
  end

  class HumanWrapper
    attr_accessor :base, :wrapper_type
    def initialize(base, wrapper_type)
      @base = base
      @wrapper_type = wrapper_type
    end
  
    def method_missing(method_name)
      result = wrapper_type
      base.instance_eval do
        define_singleton_method("#{ method_name}?") do 
          result
        end
      end
    end
  end
end

class Human
  include Configurable
end


john = Human.new
#<Human:0x00007f8f91091488> 

john.is_a.developer
#=> :developer?
john.developer?
#=> true

john.is_not_a.financial_adviser
#=> :financial_adviser?
john.financial_adviser?
#=> false

john.method(:developer?).source_location
#=> ['source_location_demo.rb', 34]

john.method(:financial_adviser?).source_location
#=> ['source_location_demo.rb', 34]

john.method(:developer?).source.owner
#=> #<Class:#<Human:0x00007f8f91091488>>
# Because #developer? is a singleton method.