use tokio::stream::{self, Stream, StreamExt};
use tokio::sync::mpsc;
use tokio_test::task;
use tokio_test::{assert_pending, assert_ready};
#[tokio::test]
async fn merge_sync_streams() {
let mut s = stream::iter(vec![0, 2, 4, 6]).merge(stream::iter(vec![1, 3, 5]));
for i in 0..7 {
let rem = 7 - i;
assert_eq!(s.size_hint(), (rem, Some(rem)));
assert_eq!(Some(i), s.next().await);
}
assert!(s.next().await.is_none());
}
#[tokio::test]
async fn merge_async_streams() {
let (tx1, rx1) = mpsc::unbounded_channel();
let (tx2, rx2) = mpsc::unbounded_channel();
let mut rx = task::spawn(rx1.merge(rx2));
assert_eq!(rx.size_hint(), (0, None));
assert_pending!(rx.poll_next());
tx1.send(1).unwrap();
assert!(rx.is_woken());
assert_eq!(Some(1), assert_ready!(rx.poll_next()));
assert_pending!(rx.poll_next());
tx2.send(2).unwrap();
assert!(rx.is_woken());
assert_eq!(Some(2), assert_ready!(rx.poll_next()));
assert_pending!(rx.poll_next());
drop(tx1);
assert!(rx.is_woken());
assert_pending!(rx.poll_next());
tx2.send(3).unwrap();
assert!(rx.is_woken());
assert_eq!(Some(3), assert_ready!(rx.poll_next()));
assert_pending!(rx.poll_next());
drop(tx2);
assert!(rx.is_woken());
assert_eq!(None, assert_ready!(rx.poll_next()));
}