async-time-mock-smol

Asynchronous time mocking for the smol runtime based on async-time-mock-core, inspired by the approach described in Mocking Time In Async Rust.

NOTE: This library is still in it's infancy, the API is still likely to change (read: improve). Please leave your feedback and suggestions on GitHub.

ALSO NOTE: This currently implements an API that looks more like from the tokio runtime instead of smol's Timer API. This might change in the future.

Cargo features

• mock: Enable the mock clock. If you only enable this in tests, this library turns into a thin wrapper around async-std's time functions.
• stream: Implement futures_core::stream::Stream for Interval

Example

```rust use asynctimemock_smol::MockableClock; use std::{ sync::atomic::{AtomicBool, Ordering}, time::Duration, };

static HAS_SLEPT: AtomicBool = AtomicBool::new(false);

async fn sleep(clock: MockableClock) { // Sleep is either mocked or a real smol::Timer::setafter, depending on which variant of MockableClock you pass in. let _guard = clock.sleep(Duration::fromsecs(3600)).await; // Dropping this guard signifies that all the effects of the timer have finished. // This allows test code to wait until the condition to assert for has happened.

println!("Slept for an hour");
HAS_SLEPT.store(true, Ordering::SeqCst);

}

fn main() { smol::block_on( async { let (clock, controller) = MockableClock::mock(); // In production, you can use MockableClock::Real instead

        smol::spawn(sleep(clock)).detach();

        controller.advance_time(Duration::from_secs(600)).await;
        assert!(!HAS_SLEPT.load(Ordering::SeqCst), "Timer won't trigger after just 10 minutes.");

        // advance_time will first trigger the sleep in the task above and then wait until the `_guard` was dropped.
        // This ensures that the task had enough time to actually set `HAS_SLEPT` to `true`.
        controller.advance_time(Duration::from_secs(3000)).await;
        assert!(HAS_SLEPT.load(Ordering::SeqCst), "Timer has triggered after 1 hour.")
    }
);

} ```