An example refinement method like `IO.pipe`'s block form but with no buffering.

sync_pipe.rb

class IO
  module UnbufferedPipe
    refine IO.superclass do
      def unbuffered_pipe(*, **)
        IO.pipe(*, **) do |read_io, write_io|
          read_io.sync = true
          write_io.sync = true

          yield read_io, write_io
        end
      end
    end
  end
end

##
# Usage example
using IO::UnbufferedPipe

IO.unbuffered_pipe do |read_io, write_io|
  write_io << "hola\n"
  read_io.gets
end
#=> "hola\n"