Comments on: Creative constraints

By: dave

dave — Fri, 18 Jan 2008 19:43:23 +0000

I find unit tests useful for making complicated code simpler to play with. I think it’s all about levels of ambiguity with the purpose of the code you’re writing. Some code is written to get a job done, some code is written as a creative exploratory act. There isn’t a fine line between these roles, and sometimes (most times unless you have a good spec) code moves from exploratory to a purposeful state as time progresses. In this context I slot in unit tests when code becomes more purposeful, and it helps to solidify things in my mind. I don’t go back and modify the tests much, but they go off when you’ve changed something which causes an assumption you’ve made to be false in dependent code. I don’t use them much though – it’s quite a new thing for me in this sort of code.

By: alex dante

alex dante — Fri, 18 Jan 2008 00:31:05 +0000

“So you’re saying (and demonstrating) that it’s possible to both follow your imagination and write unit tests?”

Yes. I use my imagination, I write a little unit test, I write some code, then I run the test to ensure it does _exactly what I wanted_. Even better, I can ensure that my imagination hasn’t _broken everything else_.

But this is when I’m _developing_. Writing ephemeral code for live purposes is _not_ that.

By: Alex

Alex — Tue, 15 Jan 2008 22:45:39 +0000

Wow, OK… So you’re saying (and demonstrating) that it’s possible to both follow your imagination and write unit tests? In that case, how often do you find yourself going back and modifying/deleting old tests?

By: dave

dave — Tue, 15 Jan 2008 15:36:25 +0000

There is nothing wrong with unit tests – it’s just using them appropriately. I use them, not just in code where the needs are obvious, but in exploratory and artistic code as well.

The act of writing of tests can help you understand what you are doing. The key is to write them as you go along, and keep them running all the time. They may not be the most interesting things, but they do make code more flexible, as you have more confidence in changing things later on.

For example of my use of them, see test-lowlevel-graph and test-daisy-graph in: http://www.pawfal.org/flotsam/daisy/daisy.scm

By: dave

dave — Tue, 15 Jan 2008 14:44:24 +0000

A very interesting set of articles. I seem to spend a lot of time trying to convince people programming is a creative business. It’s interesting that fields such as architecture seem to be close, yet are treated so differently.

This confusion has it’s upside – it’s made a lot of money for people who sell books on managing programmers.

By: Alex

Alex — Tue, 15 Jan 2008 14:41:11 +0000

The audience is indeed a feedback mechanism, but both an immediate and informal one -- so very different from unit tests. Also I'd be very surprised if most programmers used unit tests. Unit tests introduce nothing but needless tedium outside of very particular situations. Both here and in your blog post, you are arguing against a straw man. Nowhere have I claimed that feedback isn't important in programming, constraints aren't important to creativity, or that programming is about construction rather than creativity.

By: ocean

ocean — Tue, 15 Jan 2008 14:15:53 +0000

I imagine your audience in that situation would act as the same strong feedback mechanism that unit tests provide to most programmers. In the most general terms, I think it’s important to acknowledge the importance of feedback in programming otherwise you start to fall into something like bikeshed thinking.