this post was submitted on 02 Nov 2023
1406 points (98.5% liked)
Programmer Humor
32415 readers
788 users here now
Post funny things about programming here! (Or just rant about your favourite programming language.)
Rules:
- Posts must be relevant to programming, programmers, or computer science.
- No NSFW content.
- Jokes must be in good taste. No hate speech, bigotry, etc.
founded 5 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Who tests the tests
The Testmen?
I've written some tests that got complex enough that I also wrote tests for the logic within the tests.
We do that for some of the more complex business logic. We wrote libraries, which are used by our tests, and we wrote tests which test the library functions to ensure they provide correct results.
What always worries me is that WE came up with that. It wasn't some higher up, or business unit, or anything. Only because we cared to do our job correctly. If we didn't - nobody would. Nobody is watching the testers (in my experience).
Mutation testing is quite cool. Basically it analyzes you code and makes changes that should break something. For example if you have
if (foo) { ... }it will remove the branch or make the branch run every time. It then runs your tests and sees if anything fails. If the tests don't fail then either you should add another test, or that code was truly dead and should be removed.Of course this has lots of "false positives". For example you may be checking if an allocation succeeded and don't need to test if every possible allocation in your code fails, you trust that you can write
if (!mem) abort()correctly.Right,too much coverage is also a bad thing. It leads to having to work on the silly tests every time you change som implementation detail.
Good tests let the insides of the unit change without breaking, as long as the behave the same to the outside world.
Create tests to test the tests. Create tests to test those. Recurse to infinity
Who tests the tests for the tests
Unfortunately, if anyone, I do.