Unit tests as documentation

I share this ideal, but also have to gripe that "descriptive test name" is where this falls apart, every single time.

Getting all your teammates to quit giving all their tests names like "testTheThing" is darn near impossible. It's socially painful to be the one constantly nagging people about names, but it really does take constant nagging to keep the quality high. As soon as the nagging stops, someone invariably starts cutting corners on the test names, and after that everyone who isn't a pedantic weenie about these things will start to follow suit.

Which is honestly the sensible, well-adjusted decision. I'm the pedantic weenie on my team, and even I have to agree that I'd rather my team have a frustrating test suite than frustrating social dynamics.

Personally - and this absolutely echoes the article's last point - I've been increasingly moving toward Donald Knuth's literate style of programming. It helps me organize my thoughts even better than TDD does, and it's earned me far more compliments about the readability of my code than a squeaky-clean test suite ever does. So much so that I'm beginning to hold hope that if you can build enough team mass around working that way it might even develop into a stable equilibrium point as people start to see how it really does make the job more enjoyable.

Hah, I swing the other way! If module foo had a function bar then my test is in module test_foo and the test is called test_bar.

Nine times out of ten this is the only test, which is mostly there to ensure the code gets exercised in a sensible way and returns a thing, and ideally to document and enforce the contract of the function.

What I absolutely agree with you on is that being able to describe this contract alongside the function itself is far more preferable. It’s not quite literate programming but tools like Python’s doctest offer a close approximation to interleaving discourse with machine readable implementation:

  def double(n: int) -> int:
    “””Increase by 100%

    >>> double(7)
    14
    “””
    return 2 * n