Demonstrate in-file testing option for Ruby

class-inline.rb

# This file demonstrates a quick and dirty means of testing a file.
# Above the ```if __FILE__ == $0``` line is where the "production" code
# is written. Inside the IF block, the "test" code is written.
class Inline
  def to_s
    'Hello'
  end
end

# From Terminal, you can type `ruby class-inline.rb`
#
# The tests below will execute and you will see the tell tail results
# of ruby's test output.
#
# __FILE__ is this file.
# $0 is the file that is running via ruby
#
if __FILE__ == $0
  require 'test/unit'

  class InlineTest < Test::Unit::TestCase
    def test_to_s
      assert 'Hello' == Inline.new.to_s
    end
  end
end