Function wait_for

nodedb-cluster/tests/common/test_node.rs:392–407

Poll a predicate up to `deadline`, sleeping `step` between attempts. Panics with a descriptive message if the predicate never holds.

(
    desc: &str,
    deadline: Duration,
    step: Duration,
    mut pred: F,
)

/// attempts. Panics with a descriptive message if the predicate
/// never holds.
pub async fn wait_for<F: FnMut() -> bool>(
    desc: &str,
    deadline: Duration,
    step: Duration,
    mut pred: F,
) {
    // no-determinism: test timing observability
    let start = std::time::Instant::now();
    while start.elapsed() < deadline {
        if pred() {
            return;
        }
        tokio::time::sleep(step).await;
    }
    panic!("timed out after {:?} waiting for: {}", deadline, desc);
}