[lincolnq]

If you're interested in this stuff at all, check out some code.

Example: https://github.com/ImperialCollegeLondon/FLT/blob/main/FLT/M...

Also check out the blueprint, which describes the overall structure of the code:

https://imperialcollegelondon.github.io/FLT/blueprint/

I'm very much an outside observer, but it is super interesting to see what Lean code looks like and how people contribute to it. Great thing is that there's no need for unittests (or, in some sense, the final proof statement is the unittest) :P

[staunton]

Most (larger) Lean projects still have "unit tests". Those might be, e.g., trivial examples and counter examples to some definition, to make sure it isn't vacuous.

[schoen]

That's such a nice way to think about unit tests! (In this context and others.)

[pierrefermat1]

I think the better mapping of unit tests would actually be proofs of lemmas ?