"With practice, that preemptive design feedback becomes internalized in the programmer, granting some of the benefit even when not writing tests."
"Practicing TDD encouraged me to do things in a certain sequence and style: write only a few lines at a time, get a simple example working by hardcoding some data, remove duplication mercilessly. I now do those things whether I test-drive my code or don't. Even so, I tend to prefer to test-drive, most of the time.
I used to stop myself from writing code without test-driving it. I no longer do. As with Liz, with Bob, with others, that comes from my myriad-plus-hours of practice.
I have taught people the first rule in Liz's bullet list for years: when in doubt, write the test. I call this a Novice Rule (Dreyfus Model) and teach it that way: "The Novice Rule is 'if you're not sure, then write the test; you need the practice.'"
At 16:30 Jessica: "I tend to write in a very testable style even when I'm not writing tests. Which saves my butt when I go back and want to add tests later."
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