Comments on: Unit Tests are Free in TDD http://blog.coryfoy.com/2006/01/unit-tests-are-free-in-tdd/ It's all about delivering Wed, 08 Feb 2012 16:42:53 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: William http://blog.coryfoy.com/2006/01/unit-tests-are-free-in-tdd/comment-page-1/#comment-492 William Thu, 19 Oct 2006 11:41:00 +0000 http://blog.cornetdesign.com/?p=312#comment-492 I agree that the anonymous commenter has a point. The larger a code base is, the more work something takes, and 70 kloc of code+tests may not be directly comparable to 70 kloc of pure production code.<br /><br />On the other hand, I think my point still stands: people generally think that TDD and pair programming will slow you down, but even counting only the production code, we were at or better than the top end of the metrics.<br /><br />And I should mention that this went along with fantastic bug statistics. I think this system had a total of two bugs in production since launch. So code debt is probably, as you'd expect, much lower for a well-tested system. I agree that the anonymous commenter has a point. The larger a code base is, the more work something takes, and 70 kloc of code+tests may not be directly comparable to 70 kloc of pure production code.

On the other hand, I think my point still stands: people generally think that TDD and pair programming will slow you down, but even counting only the production code, we were at or better than the top end of the metrics.

And I should mention that this went along with fantastic bug statistics. I think this system had a total of two bugs in production since launch. So code debt is probably, as you’d expect, much lower for a well-tested system.

]]> By: Cory Foy http://blog.coryfoy.com/2006/01/unit-tests-are-free-in-tdd/comment-page-1/#comment-493 Cory Foy Tue, 31 Jan 2006 08:44:00 +0000 http://blog.cornetdesign.com/?p=312#comment-493 (To Anonymous):<br /><br />I'm not sure if I would call it bogus. After all, he met the timeline based on his code without tests based on the Rapid Development book. But in reality he had written twice the amount of code.<br /><br />Also, because he has those tests, he can now make changes, refactor, and add features with a lot more confidence then if he didn't have them. Or, at least that has been my experience. I'd love to hear if you have had a different experience. (To Anonymous):

I’m not sure if I would call it bogus. After all, he met the timeline based on his code without tests based on the Rapid Development book. But in reality he had written twice the amount of code.

Also, because he has those tests, he can now make changes, refactor, and add features with a lot more confidence then if he didn’t have them. Or, at least that has been my experience. I’d love to hear if you have had a different experience.

]]> By: Kent Johnson http://blog.coryfoy.com/2006/01/unit-tests-are-free-in-tdd/comment-page-1/#comment-494 Kent Johnson Sun, 29 Jan 2006 22:54:00 +0000 http://blog.cornetdesign.com/?p=312#comment-494 My personal experience has convinced me that writing unit tests actually makes the project go <b>faster</b>. This is because unit tests enable refactoring, which promotes clean, appropriate design and good design lets the project develop quickly. I've written more here:<br />http://www.pycs.net/users/0000323/weblog/2005/08/21.html#P73 My personal experience has convinced me that writing unit tests actually makes the project go faster. This is because unit tests enable refactoring, which promotes clean, appropriate design and good design lets the project develop quickly. I’ve written more here:
http://www.pycs.net/users/0000323/weblog/2005/08/21.html#P73

]]> By: Anonymous http://blog.coryfoy.com/2006/01/unit-tests-are-free-in-tdd/comment-page-1/#comment-495 Anonymous Sat, 28 Jan 2006 22:19:00 +0000 http://blog.cornetdesign.com/?p=312#comment-495 As much as I like the idea of TDD, this is a pretty bogus comparison. There's a big difference between 35k lines of unit tests, which by definition are only coupled to a small part of the functional program, and 35k lines which actually extend the program's functionality over the existing 35k lines of functional code. McConnell is clearly talking about the second case, which is bound to involve many, many more complex interactions than the "35k lines of unit tests" case. As much as I like the idea of TDD, this is a pretty bogus comparison. There’s a big difference between 35k lines of unit tests, which by definition are only coupled to a small part of the functional program, and 35k lines which actually extend the program’s functionality over the existing 35k lines of functional code. McConnell is clearly talking about the second case, which is bound to involve many, many more complex interactions than the “35k lines of unit tests” case.

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