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#![cfg(all(feature = "time", feature = "sync", feature = "io-util"))]
use tokio::time::{self, sleep, Duration};
use tokio_stream::{self, StreamExt};
use tokio_test::*;
use futures::stream;
async fn maybe_sleep(idx: i32) -> i32 {
if idx % 2 == 0 {
sleep(ms(200)).await;
}
idx
}
fn ms(n: u64) -> Duration {
Duration::from_millis(n)
}
#[tokio::test]
async fn basic_usage() {
time::pause();
// Items 2 and 4 time out. If we run the stream until it completes,
// we end up with the following items:
//
// [Ok(1), Err(Elapsed), Ok(2), Ok(3), Err(Elapsed), Ok(4)]
let stream = stream::iter(1..=4).then(maybe_sleep).timeout(ms(100));
let mut stream = task::spawn(stream);
// First item completes immediately
assert_ready_eq!(stream.poll_next(), Some(Ok(1)));
// Second item is delayed 200ms, times out after 100ms
assert_pending!(stream.poll_next());
time::advance(ms(150)).await;
let v = assert_ready!(stream.poll_next());
assert!(v.unwrap().is_err());
assert_pending!(stream.poll_next());
time::advance(ms(100)).await;
assert_ready_eq!(stream.poll_next(), Some(Ok(2)));
// Third item is ready immediately
assert_ready_eq!(stream.poll_next(), Some(Ok(3)));
// Fourth item is delayed 200ms, times out after 100ms
assert_pending!(stream.poll_next());
time::advance(ms(60)).await;
assert_pending!(stream.poll_next()); // nothing ready yet
time::advance(ms(60)).await;
let v = assert_ready!(stream.poll_next());
assert!(v.unwrap().is_err()); // timeout!
time::advance(ms(120)).await;
assert_ready_eq!(stream.poll_next(), Some(Ok(4)));
// Done.
assert_ready_eq!(stream.poll_next(), None);
}
#[tokio::test]
async fn return_elapsed_errors_only_once() {
time::pause();
let stream = stream::iter(1..=3).then(maybe_sleep).timeout(ms(50));
let mut stream = task::spawn(stream);
// First item completes immediately
assert_ready_eq!(stream.poll_next(), Some(Ok(1)));
// Second item is delayed 200ms, times out after 50ms. Only one `Elapsed`
// error is returned.
assert_pending!(stream.poll_next());
//
time::advance(ms(51)).await;
let v = assert_ready!(stream.poll_next());
assert!(v.unwrap().is_err()); // timeout!
// deadline elapses again, but no error is returned
time::advance(ms(50)).await;
assert_pending!(stream.poll_next());
time::advance(ms(100)).await;
assert_ready_eq!(stream.poll_next(), Some(Ok(2)));
assert_ready_eq!(stream.poll_next(), Some(Ok(3)));
// Done
assert_ready_eq!(stream.poll_next(), None);
}
#[tokio::test]
async fn no_timeouts() {
let stream = stream::iter(vec![1, 3, 5])
.then(maybe_sleep)
.timeout(ms(100));
let mut stream = task::spawn(stream);
assert_ready_eq!(stream.poll_next(), Some(Ok(1)));
assert_ready_eq!(stream.poll_next(), Some(Ok(3)));
assert_ready_eq!(stream.poll_next(), Some(Ok(5)));
assert_ready_eq!(stream.poll_next(), None);
}