From: Gregory Brown <gregory.t.brown@...>
Date: 2007-05-21T23:49:37+09:00
Subject: Re: Need some help..

On 5/21/07, Disha Tamhane <disha.tamhane@gmail.com> wrote:
> Thanks Gregory.... Guess this will work now...
>
> But just to check.. will it not work if it is not enclosed in a method?
>
> Is there an alternative way?

Usually you will want to structure your code so it is most easily
testable.  For example, if you were using system() because you wanted
to test the output to the screen, you can still test that.

Here's a small example

def hello(out=STDOUT)
  out.puts "Hello World"
end

If you were to call that, just as hello(), it'd print to the screen.

But say you wanted to test it, you could use StringIO.
#------
require "stringio"
require "test/unit"

class HelloTest < Test::Unit::TestCase
  def test_hello
    out = StringIO.new
    hello(out)
    out.rewind
    assert_equal "Hello World\n", out.read
  end
end
#----

In general, this makes your code more well organized and easier to
work with.  If you want to do good testing, it pretty much means
you'll need to structure your code so it can be tested :)