nesting_test.rb

# -*- encoding: utf-8 -*-

def main
  Module.nesting # => []
  c = A::B::C.new
  c.b_method
  c.c_method
end

module A
  Module.nesting # => [A]
  module B
    Module.nesting # => [A::B, A]
    class C
      Module.nesting # => [A::B::C, A::B, A]

      def initialize
        Module.nesting # => [A::B::C, A::B, A]
      end

      def c_method
        Module.nesting # => [A::B::C, A::B, A]
      end

      include B

    end

    def b_method
      Module.nesting # => [A::B, A]
    end
  end
end

case $PROGRAM_NAME
when __FILE__
  main
when /spec[^\/]*$/
  # {spec of the implementation}
end