futures-preview 0.3.0-alpha.16

An implementation of futures and streams featuring zero allocations, composability, and iterator-like interfaces.
Documentation 
use futures::executor::block_on_stream;
use futures::stream;

#[test]
fn panic_in_the_middle_of_the_stream() {
    let stream = stream::iter_ok::<_, bool>(vec![Some(10), None, Some(11)]);

    // panic on second element
    let stream_panicking = stream.map(|o| o.unwrap());
    let mut iter = block_on_stream(stream_panicking.catch_unwind());

    assert_eq!(Ok(10), iter.next().unwrap().ok().unwrap());
    assert!(iter.next().unwrap().is_err());
    assert!(iter.next().is_none());
}

#[test]
fn no_panic() {
    let stream = stream::iter_ok::<_, bool>(vec![10, 11, 12]);

    let mut iter = block_on_stream(stream.catch_unwind());

    assert_eq!(Ok(10), iter.next().unwrap().ok().unwrap());
    assert_eq!(Ok(11), iter.next().unwrap().ok().unwrap());
    assert_eq!(Ok(12), iter.next().unwrap().ok().unwrap());
    assert!(iter.next().is_none());
}