#[test]s on non top-level functions.

[WildCryptoFox]

It would be nice if we could implement test cases directly on a type that they test. This is especially useful when generating code (and test cases) with macros.

In the example below, the expected result would be Unit::my_important_test when testing.

struct Unit;

impl Unit {
    #[test]
    fn my_important_test() { /* ... */ }
}

Alternatively one can just create a non_camel_case module sharing the same identifier as the struct. But this looks off for that exact reason. And abuses the bug as reported in #29185.

#[cfg(test)] #[allow(non_camel_case)]
mod Unit {
    #[test]
    fn my_important_test() { /* ... */ }
}

[steveklabnik]

Triage: no change.

[steveklabnik]

Triage: no change. Given that this was filed in 2015, with zero additional comments, I'm going to close this. We have some work underway for more flexible test runners; they may or may not implement this feature, but it doesn't appear like this is something broadly desired nor going to be implemented any time soon.