Re: [Suggestion] GNUstep-test for quality control (WAS: Re: deferreddeallocation)

[Chris Hanson]

On Wednesday, October 15, 2003, at 01:58  PM, Stefan Urbanek wrote:
> I think, that if at least half of the effort devoted to writing test 
> suites (i am not against them) is also devoted to make gnustep more 
> attractive, it can also help to remove bugs and have a quality 
> controll.

Actually, "the effort devoted to writing test suites" should be spent 
in *advance* of the features those suites test.  This is called 
Test-Driven Development.

When implementing a feature, you first write a simple test case for one 
aspect of that feature.  Build, the test suite runs including your new 
test case, it fails because you haven't implemented the code to make it 
pass.  Implement the code to make the test pass.  Build, the test suite 
runs including your new test, it passes.  Now refactor -- remove 
duplication from the entire codebase including your new code.  Build 
again, the test suite should still pass.

Then do it again, and again, and again, until you've fully implemented 
the feature.  Write a test, make it pass, refactor.  Write a test, make 
it pass, refactor.

Then move on to the next feature.  Write a test, make it pass, refactor.

This is the core of a talk Robert C. "Uncle Bob" Martin of Object 
Mentor gives: *Testing is about specification, not verification.*  In 
other words, the tests specify the functionality you're looking for -- 
both with success cases and failure cases -- they don't verify that 
things you've already written work.

And here's the benefit: Since you're eliminating most debugging by 
doing this, you're actually going *faster* than you would be without 
doing tests first.

  -- Chris

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Chris Hanson, bDistributed.com, Inc.  |  Email: cmh@bDistributed.com
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