Beautiful Testing

Chapter 16. Peeling the Glass Onion at Socialtext

Matthew Heusser

I don’t understand why we thought this was going to work in the first place.

—James Mathis, 2004

It’s Not Business…It’s Personal

I’ve spent my entire adult life developing, testing, and managing software projects. In those years, I’ve learned a few things about our field:

• Software testing as it is practiced in the field bears very little resemblance to how it is taught in the classroom—or even described at some industry presentations.

• There are multiple perspectives on what good software testing is and how to do it well.

• The previous point means that there are no “best practices”—no single way to view or do testing that will allow you to be successful in all environments—but there are rules of thumb that can guide the learner.^[73]

Beyond that, in business software development, I would add a few things more. First, there is a sharp difference between checking,^[74] which is a sort of clerical, repeatable process to make sure things are fine, and investigating, which is a feedback-driven process.

Checking can be automated, or at least parts of it can. With small, discrete units, it is possible for a programmer to select inputs and compare them to outputs automatically. When we combine those units, we begin to see complexity.

Imagine, for example, a simple calculator program that has a very small memory leak every time we press the Clear button. It might behave fine if we test each operation independently, but when we try to use ...