Re: Three Law of TDD - to strictly follow, or not?

Michal,

On 8/28/14 12:03 PM, Michal Svoboda [email protected] 
[testdrivendevelopment] wrote:
> Kaleb Pederson [email protected] [testdrivendevelopment] wrote:
>> When the entire test is written up front (for a new class at least)
>> the test will fail, because a failure to compile is considered a
>> failure. The problem that I have with the approach is that when it
>> "passes", does it pass for the right reason? Or, do we have
>> unnecessary test code? or production code? Did the test ever fail for
>> the expected reason, or did it fail only in the form of a compilation
>> failure?
>
> Hi Kaleb,
>
> I hear what you are saying. But it really goes down to that gut feeling.
> Sometimes I want to see the whole story first, not just "once upon a
> time there was an object". It usually depends on what level of certainty
> I feel over my requirements. The objective is to drive the design with
> the test, not to just write it first.

I write acceptance tests all at once. I write unit tests a bit at a 
time, often starting with the creation of a new object whose definition 
does not yet exist. In this fashion I work inside-out within the bounds 
of outside-in.

> Even if the test is written in a bigger chunk, you can still add in the
> code one bit at a time and see the test fail for various reasons until
> you get (and subsequently fix) the desired one.

With effort, you can. But how does that drive the design?

  - George

-- 
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   * George Dinwiddie *                      http://blog.gdinwiddie.com
   Software Development                    http://www.idiacomputing.com
   Consultant and Coach                    http://www.agilemaryland.org
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Posted by: George Dinwiddie <[email protected]>
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