Good test coverage (by curling your right bicep)

Most of his comments could almost have been direct quotes from his (excellent) new book Practices of an Agile Developer but one answer about testing really caught my ears. In response to a question about how to know that your writing the right sort of tests in your test driven development, Andy gave the following mnemonic:

Right BICEP

Right - are the results right
B - Boundary conditions
I - Inverse relationships
C - Cross check results (with other sources/methods)
E - Error conditions
P - Performance

I love simple mental tools like that. I'll certainly be mentally checking my right bicep when I write tests from now on. Previously I'd only been checking out my right bicep in the shower after the gym...