Saturday, May 5, 2012

The Testing Circle

This is the pattern I find myself in day after day while practicing TDD or BDD.

Step 1?

Usually I start at the whiteboard. It is the easiest place to start as I sketch out the scenario I want to program, but not always. Sometimes a mockup file (image, html, or xml) is provided and I start at the result, sometimes I’m give a scenario already in English, and sometimes I have to fiddle with the code first to see what’s happening.

No Beginning, No Ending

The great thing about the circle is no matter where a start, the flow should always be there in the end. If it isn’t, I take this as a smell that I am neglecting something. Also, while I wrote the arrows going clockwise (the normal way I view this process) they can equally go in reverse.

Smell 1: No Result –> Whiteboard

If the result does trigger the original image on the whiteboard (usually long erased by the time I revisit the code), then this will be a maintenance problem when I try to remember why the code looks the way it does when it changes.

Smell 2: No Code –> English

If the resulting code doesn’t make the comments so easy that they should be deleted for not adding any value, then my intention (so clear when I’m writing the original code) will not be there when my fellow programmers, or myself even a few days later, what the understand the code later.

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