namespace_example.rb

# pipe/base.rb
module Pipe
  class Base
    def flow
    end
  end
end

# pipe/email_pipe.rb
require 'pipe/base'

module Pipe
  class EmailPipe < Base
    # additional methods
  end
end

# pipe/sms_pipe.rb
require 'pipe/base'

module Pipe
  class SmsPipe < Base
    # additional methods
  end
end

# pipe.rb

require 'pipe/email_pipe'
require 'pipe/sms_pipe'

# spec/pipe/email_pipe_spec.rb

require 'pipe/email'

include Pipe

decribe EmailPipe do

  it "should do stuff" do
  end
end