A Cynical Introduction To Testing¶

Don’t Feel Bad¶

You might feel bad that you write fewer tests than you “should”.
“Testing is the dental floss of development” – Ned Batchelder
Don’t get mad, get even.

All Code Is Terrible¶

All code is terrible.
There is no shame in writing terrible code.
There is only shame in having more code than is strictly necessary for a purpose.
It’s costly for both the originator and a future reader.

How Do I Avoid Shame?¶

Test everything.
It’s an entirely mechanical process. Use no judgment.
Accept that it will make you “slower”.
Requiring healthy test coverage of your code tends to mean you write less domain code. This is a good thing.

I Mean Everything¶

Wrap your brain around it, roll it around on the tongue: everything.
No function too small.
Code that is proven to work repeatably is beautiful. Even terrible code.
Not unusual to have 2X more test code than “real” code in a given project.

Proving It Works Isn’t The Goal¶

“It’s silly to prove that a function that does “return 1+1” always returns 2.”

Not the only goal. It’s at best a distant third reason.
The first and second goals are:
- detect regressions caused by future maintenance (“return 1+2”).
- use testing as a thinking tool for improving code in real time.

But It Makes Me Slower¶

Yup. This is on purpose.
I’m not a superstar developer. You aren’t either. None of us are.
Writing tests for everything might make you go slower “in the small” but the organization as a whole will go faster.

Don’t Be Afraid To Throw It Away¶

I use testing as a way to think about code. I write something terrible quickly, then I start to write some tests for it. The act of writing tests reveals how terrible it is, and I throw some of it out, and write something better. Rinse, lather, repeat until code is good.
TDD? Not so much me. If it works for you sure.