tari_test_utils 5.3.0-pre.9

// Copyright 2019 The Tari Project
//
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mod async_assert_eventually;

/// Creates a test counter future Context.
///
/// ## Usage
/// ```edition2018
/// # use futures::future::{self, FutureExt};
/// # use tari_test_utils::counter_context;
///
/// {
///     let mut my_fut = future::ready(());
///     counter_context!(cx); // cx variable in scope
///     assert!(my_fut.poll_unpin(&mut cx).is_ready());
/// }
///
/// {
///     let mut my_fut = future::ready(());
///     counter_context!(cx, counter); // cx and counter variables in scope
///     assert!(my_fut.poll_unpin(&mut cx).is_ready());
///     assert_eq!(counter.get(), 0); // `poll` didn't call the waker
/// }
/// ```
#[macro_export]
macro_rules! counter_context {
    ($n:ident, $c:ident) => {
        use futures_test::task::new_count_waker;
        let (waker, $c) = new_count_waker();
        let mut $n = futures::task::Context::from_waker(&waker);
    };
    ($n:ident) => {
        use futures_test::task::new_count_waker;
        let (waker, _) = new_count_waker();
        let mut $n = futures::task::Context::from_waker(&waker);
    };
}

/// Creates a test counter future Context.
///
/// ## Usage
/// ```edition2018
/// # use futures::future::{self, FutureExt};
/// # use tari_test_utils::panic_context;
///
/// let mut my_fut = future::ready(());
/// panic_context!(cx); // cx variable in scope
/// assert!(my_fut.poll_unpin(&mut cx).is_ready());
/// ```
#[macro_export]
macro_rules! panic_context {
    ($n:ident) => {
        use futures_test::task::panic_waker;
        let waker = panic_waker();
        let mut $n = futures::task::Context::from_waker(&waker);
    };
}

#[cfg(test)]
mod test {
    use std::task::Poll;

    use futures::{
        future::{self, FutureExt},
        task::Context,
    };

    #[test]
    fn counter_context() {
        {
            let mut my_fut = future::ready(());
            counter_context!(cx); // cx variable in scope
            assert!(my_fut.poll_unpin(&mut cx).is_ready());
        }

        {
            let mut my_fut = future::ready(());
            counter_context!(cx, counter); // cx and counter variables in scope
            assert!(my_fut.poll_unpin(&mut cx).is_ready());
            assert_eq!(counter.get(), 0); // `poll` didn't call the waker
        }
    }

    #[test]
    #[should_panic]
    fn panic_context() {
        let mut my_fut = future::poll_fn::<(), _>(|cx: &mut Context<'_>| {
            cx.waker().wake_by_ref();
            Poll::Pending
        });
        panic_context!(cx);

        let _ = my_fut.poll_unpin(&mut cx);
    }
}