From: Alex Young <alex@...>
Date: 2007-06-13T17:03:46+09:00
Subject: Unit testing idiom

Hi all,

It's always bothered me having code and unit tests in different places - 
  keeping unit tests near the code they are testing *has* to be a good 
thing, right?

Given the above, I stumbled on the following idiom:

$ cat testable.rb
module Test; module Unit; class TestCase; end; end; end

module Testable
   def test_case(&block)
     Class.new(Test::Unit::TestCase).module_eval &block
   end
end

$ cat builtin_tests.rb
require 'testable'

class MyWorkingClass
   extend Testable

   def foo(a,b)
     return a+b
   end

   test_case {
     def test_foo_null
       assert_equal 2, MyWorkingClass.new.foo(1,1)
     end
   }
end

if __FILE__ == $0
   puts MyWorkingClass.new.foo(1,1)
end

$ ruby builtin_tests.rb
2
$ testrb builtin_tests.rb
Loaded suite builtin_tests.rb
Started
.
Finished in 0.00095 seconds.

1 tests, 1 assertions, 0 failures, 0 errors
$

Just thought I'd share :-)  Are there any drawbacks to this method that 
I haven't seen yet?

-- 
Alex