From: Eric Hodel <drbrain@...7.net>
Date: 2007-01-24T11:22:56+09:00
Subject: Re: I don't get rspec

On Jan 23, 2007, at 17:36, Pat Maddox wrote:
> On 1/23/07, Eric Hodel <drbrain@segment7.net> wrote:
>> On Jan 23, 2007, at 16:26, James Edward Gray II wrote:
>> > On Jan 23, 2007, at 6:10 PM, Joe Van Dyk wrote:
>> >> What's wrong with zentest, specifically?
>> >
>> > You will probably understand better by watching the movie, but
>> > zentest encourages you to make a test case for each class and a
>> > test method for each method.
>>
>> Which will match up 1:1 if you factor your code well.
>
> The point is that you shouldn't try to shoehorn your tests into this
> 1:1 approach.

Shoehorning is design smell, so I refactor.  The 1:1 falls out  
because of good design.  Its not something I aim for, its something I  
refactor to.

> You brought up the tutorial as an example of specs that
> match up nicely with the code, but even that ends up with a few
> contexts.  If you just have a StackTest class, you won't get the same
> logical separation.  How many programmers are going to write an
> EmpyStackTest class, a OneItemStackTest class,  a FullStackTest class,
> etc?

BDD and TDD are not 1:1 in this manner, so you've overdesigned your  
unit tests.

Instead, do the simplest thing that works:

require 'rubygems'
require 'test/unit'
require 'test/zentest_assertions'

class TestStack < Test::Unit::TestCase

   def setup
     @s = Stack.new
   end

   def test_empty_eh
     assert @s.empty?
     @s.push 1
     deny @s.empty?
   end

   def test_push
     @s.push 1
     deny @s.empty?
     assert_equal 1, @s.top
   end

   def test_top
     assert_nil @s.top
     @s.push 1
     assert_equal 1, @s.top
   end

end

> As your behavior becomes more complex - by interacting with other
> objects - you need to be able to drill a bit deeper with your
> specifications.  I often have one complete context for an individual
> method.  Not many programmers will create a new test class just to
> spec a method.  And that doesn't mean that this method is too tightly
> coupled to other objects, it just means that you need more
> finely-grained specifications.

This is where I create new methods or new classes on the  
implementation side.  As the number of edgecases increase I pull out  
bits that are resistant to testing by refactoring.  Creating multiple  
test classes to test one implementation class is design smell.

-- 
Eric Hodel - drbrain@segment7.net - http://blog.segment7.net

I LIT YOUR GEM ON FIRE!