custom_test_frameworks - The Rust Unstable Book

# `custom_test_frameworks`

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)]
    #![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;
    }