Function repeated_assert::that

pub fn that<A, R>(repetitions: usize, delay: Duration, assert: A) -> R
where
    A: Fn() -> R,

Run the provided function assert up to repetitions times with a delay in between tries.

Panics (including failed assertions) will be caught and ignored until the last try is executed.

Examples

Waiting for a file to appear (re-try up to 10 times, wait 50 ms between tries)

repeated_assert::that(10, Duration::from_millis(50), || {
    assert!(Path::new("should_appear_soon.txt").exists());
});

Info

Behind the scene std::panic::set_hook is used to set a custom panic handler. For every iteration but the last, panics are ignored and re-tried after a delay. Only when the last iteration is reached, panics are handled by the panic handler that was registered prior to calling repeated_assert.

The panic handler can only be registerd for the entire process, and it is done on demand the first time repeated_assert is used. repeated_assert works with multiple threads. Each thread is identified by its name, which is automatically set for tests.