tokio/tokio-stream/tests/stream_iter.rs

use tokio_stream as stream;
use tokio_test::task;

use std::iter;

#[tokio::test]
async fn coop() {
    let mut stream = task::spawn(stream::iter(iter::repeat(1)));

    for _ in 0..10_000 {
        if stream.poll_next().is_pending() {
            assert!(stream.is_woken());
            return;
        }
    }

    panic!("did not yield");
}