[win311fwg]

> But if you're developing a CRUD app that uses a database, there may be no properties of your app at all that are worth fuzzing.

Surely we have seen enough SQL injection issues over the years to know that, where "uses a database" means using SQL, fuzzing (or formal verification) is a necessity? That only scratches the surface of where fuzzing and property-based testing can be applicable to CRUD apps.

> Effect-free logic is likely to be ~1% of your code base, or less.

Excellent news. Side effects are where property-based testing finds its maximum return on investment. Mutations in any kind of complex system are especially hard to reason about and are easy to get wrong. Property-based testing is great at uncovering the edge cases you failed to consider.

> This is why we keep talking past each other

You keep talking past each other because "CRUD app" or "e-commerce app" is too nebulous. Concretely define exactly what this CRUD app is and then we can all meaningfully zero in on where property-based testing and fuzzing may or may not be useful. As long as you leave everyone to imagine what their own pet CRUD app looks like, you will never find a a shared understanding in which to discuss it.