Okay, shall we take a breather from difficult concepts and do something at least a little more concrete and geeky?
And the windswept trees whisper "yessssss, yessssss".
Recall that a microtest is a tiny snippet of test code, run in a separate app, that depends on a tiny snippet of shipping code. It is typically focused in its intent on a single branch or calculation in that shipping code. It is fast to write, to read, to diagnose.
What does a microtest prove?
A microtest proves, for an almost comically small subset of the shipping app, that what the geek said is what the computer heard is what the geek wanted.
That’s all. That’s what a microtest proves.
My goodness gracious, the proof provided by microtests, call it m-proof for short, that m-proof seems kinda, well, not to put too fine a point on it, paltry.
I mean, c’mon, really? That’s all a microtest proves? The geek said X. The computer heard X, the geek wanted X?
Trivial. Baby-ish. Pale. Weak. Minor. Dispensable. Training wheels, hand-rails, tedious, time-wasting.
If that’s where you’re at, then the time is absolutely perfect for you to start to grasp that TDD is a radically different "way of making" than what came before it. It’s not the old way with a new technique slapped on it. It is a genuinely new way.
The movement we’re in is distinguishable from other movements in software by an expansion of focus. The old trade focused almost entirely on the made — the actual product — the movement says the new trade is focused simultaneously on the made, the making, and the maker.
And the value of the m-proof is a hard technical kernal that lies at the very heart of what that movement has learned. To understand that value, one has to keep that triad — made, making, maker — in the foreground.
Does it seem mysterious? The m-proofs seem like little bits of dust at first glance. But a TDD’er will tell you that’s a mistaken assessment. They are actually astonishing little particles of finest gold.
How? How can such a paltry thing actually be worth our time to learn & do?
Well, that’s what i’m about, here, is explaining that mystery. This thread is by way of a long introduction to the main song.
By metaphor, here’s Julia Fordham, singing from the great american songbook, with a very long prelude. I will take a break and start the splainin’- proper after a little geekery on the day job.
I’ll be back soon. Stay tuned?