Single file code example with watcher

something.rb

##
# Single file starter with broken test using only the Ruby standard library.
#
def mymeth(a,b)                                                                                      
  a + b                                                                                              
end                                                                                                  
                                                                                                     
require "minitest/autorun"                                                                           
                                                                                                     
class TheTest < Minitest::Test                                                                       
  def test_mymeth                                                                                    
    assert_equal 3, mymeth(1,2)                                                                      
  end                                                                                                
end

watch_something.sh

##
# Watch for saves and run the code through the Ruby interpreter.
# Uses https://github.com/inotify-tools/inotify-tools/wiki
#
while inotifywait -e close_write something.rb; do clear; ruby something.rb; done