Lib.rs

Exhaustigen

This is a tiny (but delightful!) utility library for exhaustive testing.

It is based (directly) on the idea and code in the following blog post:

https://matklad.github.io//2021/11/07/generate-all-the-things.html

TL;DR: the idea is to write a test that is similar to the sort of test one writes against a PRNG -- an imperative test that just asks some "generator" to create scalars, booleans, data vectors, random shuffles, etc. -- but to use a special generator that has some interesting features:

• It has a concept of being "done", so you can put it in a do-while loop
• Every call to it requires an inclusive upper bound, which should be small
• It tracks its progress through the sequence of bounds
• It lazily extends the sequence of bounds as it's asked for more data

By threading such a generator through such an imperative test, and putting the body of that test in a do-while loop, you can write straightforward code with elaborate value-dependent nesting structure -- eg. generate value K in 0..N and then value J in 0..K and so forth -- and it will automatically record and enumerate the space of sequences meaningful to the code, re-running until it has exhausted all possible paths/values.

License

MIT + ASL2.0, with permission from Aleksey.