From: James Mead <jamesmead44@...>
Date: 2006-12-05T23:10:59+09:00
Subject: Re: TDD/unit testing question

On 05/12/06, Peter Szinek <peter@rubyrailways.com> wrote:
> 1) Am I doing something wrong? (i.e. that I spend so much time with
> rewriting/modifying/updating the tests? or is this normal)
> 2) Are there some tools/methods/ideas to speed things up? Or this is
> just good so?
> 3) Maybe I am just too new to these techniques and a skilled TDDist
> marches much faster?

It's difficult to give specific comments without actually seeing the
codebase and tests, but here are some ideas that might help...

- Don't make a big change to the code and then go through fixing loads
of broken tests. This is always disheartening and makes you feel like
you are spending a lot of time fixing tests. Instead break the big
change down into smaller steps - make a small change to the tests and
then fix the code. You should be alternating back and forth between
test and code frequently. Don't get too far away from a green bar i.e.
try to have as few broken tests as possible at any one time.

- If you find that making a change to a single class is breaking loads
of seemingly unrelated tests, this is probably an indication that too
much code is being covered by each test. It may also indicate a high
level of coupling in your design. Try to keep your unit tests as
fine-grained as possible and ensure they really are black-box tests
i.e. not coupled to the implementation. Using Mock Objects in your
unit tests is a very useful technique to keep the tests as focussed as
possible. If you need to write coarser-grained tests, try to write
them against a relatively stable interface. e.g. the public API you
will expose.

-- 
James.
http://blog.floehopper.org
http://mocha.rubyforge.org - Mock Objects for Ruby