Exploration Through Example

Example-driven development, Agile testing, context-driven testing, Agile programming, Ruby, and other things of interest to Brian Marick

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Wed, 17 Dec 2003

Smooth acceptance testing

Suppose I'm using programmer-style test-first design to create a class. I want four things.

1. I want a first test right at the beginning of the task.

2. Whenever a test passes, I want to reach out and near-instantly have a next test to make pass.

3. I want all these tests to push me in small steps toward a solution. I'm unhappy unless the steps are small.

4. When I'm done, I want the collection of tests to add up to a set that gives me good confidence that the task is truly done, not "done modulo bug fixes".

That's all pretty easy because I'm one person creating both tests and code, plus I know conventional testing.

Now consider acceptance testing, the creation of what I quixotically call customer-facing checked examples. A programmer will want all the same things (plus more conversation with business experts).

This is harder, it seems to me, because more people are involved. Suppose testers are creating these acceptance tests (not by themselves, but taking on the primary role, at least until the roles start blending). They have a tough job. They want to get those first tests out fast. They want to keep pumping them out as needed. They have to be both considerate of the time and attention of the business experts and also careful to keep them in charge. They must create tests of the "right size" to keep the programmers making steady, fast progress, but they also have to end up with a stream of tests that somehow makes sense as a bug-preventing suite at the end of the story.

There must be a real craft to this. It's not like conventional test writing. It's more like sequencing exploratory testing, I think, but still different.

Fortunately, it looks like there's a reasonable chance I'll be helping teams get better at this over the next year, and I still plan to make a point of visiting other teams that have their act together. Mail me if you're on one, or if you have good stories to tell.

## Posted at 16:18 in category /agile [permalink] [top]