The tracking issue for this feature is: #50297

The custom_test_frameworks feature allows the use of #[test_case] and #![test_runner]. Any function, const, or static can be annotated with #[test_case] causing it to be aggregated (like #[test]) and be passed to the test runner determined by the #![test_runner] crate attribute.

# #![allow(unused_variables)]
#![feature(custom_test_frameworks)]
#![test_runner(my_runner)]

#fn main() {
fn my_runner(tests: &[&i32]) {
    for t in tests {
        if **t == 0 {
            println!("PASSED");
        } else {
            println!("FAILED");
        }
    }
}

#[test_case]
const WILL_PASS: i32 = 0;

#[test_case]
const WILL_FAIL: i32 = 4;
#}