TDD

Sunday, December 25th, 2005

About NUnit 2.2.4… Whoops… Make that 2.2.5

I’ve been occupied with other things and not blogging lately. Meanwhile – in fact this is one of the things I’ve been occupied with – NUnit 2.2.4 was released. People tried it and found a few bugs – NUnit 2.2.5 corrects them.

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Tuesday, November 29th, 2005

More on Poetry Magnets

Continuing the exercise of interpreting magnets with words attached to a surface, I’ve published a second installment of the series. In Poetry Magnets: Second Verse I refactor the first solution to take positioning into account.

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Monday, November 21st, 2005

NUnit for .Net 2.0 – Do We Really Need It?

The NUnit 2.2.3 release contains two versions of each download: one built with .Net 1.1, one with .Net 2.0. So, what’s the deal? Do we need separate versions? And which version do you need? I’ll try to explain…

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Friday, November 11th, 2005

Article: Poetry Magnets

In an earlier post, I mentioned that I was working on a problem that was suggested by Bill Wake on the TestDrivenDevelopment mailing list.

The idea is that you have a set of magnets with words on them. People put these on their refrigerators and arrange them to form sentences and even poetry. How could we write a program to take a set of magnet positions and content, producing as output the text that they form? Humans put them together quite readily, even though the alignment is not precise. We could do some algorithm development up front, but I think this is an interesting problem for TDD.

I’m writing up the steps I take to solve it as I go along. Poetry Magnets: First Verse is the first installment.

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Monday, November 7th, 2005

When You Don’t Have a Framework

We forget sometimes how easy it is to write tests – even without a framework. I was sitting in a cafe, working on my new laptop. It’s an Acer Ferrari 4000 that I’m very happy with, but I haven’t completely set it up yet.

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Sunday, October 16th, 2005

User Test Fixtures: How Many? How Long?

There’s a discussion going on right now on the Yahoo TDD list regarding the use of a single instance of the user TestFixture class in NUnit 2.x, as compared to multiple instances in NUnit 1.x and in JUnit before it. A related issue, discussed on the same list a while back, is the question of the lifetime of that single instance. Here’s my take on how the issues relate and how NUnit deals with them.

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Sunday, September 11th, 2005

What’s a Test Worth?

In a discussion about unit-test suites that take too long to run, Ron Jeffries writes

Splitting the tests into slow and fast is a tradeoff, and it’s an easy one. But is it ideal? I think not. I think a better approach might be to split the tests into “likely to provide interesting information” and “unlikely to do so”. Then make the ones that are likely, also fast.

This struck me as an interesting point. If the value of a test is seen as the amount of information it is likely to provide and the cost is – at least in part – the time to run it, then the problem of which tests to keep in that “too slow” test run is quite similar to the value versus cost balancing problem we face in XP when we schedule stories into an iteration.

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