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use futures::channel::oneshot;
use futures::executor::{block_on, block_on_stream};
use futures::future::{self, join, Future, FutureExt, TryFutureExt};
use futures::stream::{FuturesOrdered, StreamExt};
use futures::task::Poll;
use futures_test::task::noop_context;
use std::any::Any;
#[test]
fn works_1() {
let (a_tx, a_rx) = oneshot::channel::<i32>();
let (b_tx, b_rx) = oneshot::channel::<i32>();
let (c_tx, c_rx) = oneshot::channel::<i32>();
let mut stream = vec![a_rx, b_rx, c_rx].into_iter().collect::<FuturesOrdered<_>>();
b_tx.send(99).unwrap();
assert!(stream.poll_next_unpin(&mut noop_context()).is_pending());
a_tx.send(33).unwrap();
c_tx.send(33).unwrap();
let mut iter = block_on_stream(stream);
assert_eq!(Some(Ok(33)), iter.next());
assert_eq!(Some(Ok(99)), iter.next());
assert_eq!(Some(Ok(33)), iter.next());
assert_eq!(None, iter.next());
}
#[test]
fn works_2() {
let (a_tx, a_rx) = oneshot::channel::<i32>();
let (b_tx, b_rx) = oneshot::channel::<i32>();
let (c_tx, c_rx) = oneshot::channel::<i32>();
let mut stream = vec![a_rx.boxed(), join(b_rx, c_rx).map(|(a, b)| Ok(a? + b?)).boxed()]
.into_iter()
.collect::<FuturesOrdered<_>>();
let mut cx = noop_context();
a_tx.send(33).unwrap();
b_tx.send(33).unwrap();
assert!(stream.poll_next_unpin(&mut cx).is_ready());
assert!(stream.poll_next_unpin(&mut cx).is_pending());
c_tx.send(33).unwrap();
assert!(stream.poll_next_unpin(&mut cx).is_ready());
}
#[test]
fn test_push_front() {
let (a_tx, a_rx) = oneshot::channel::<i32>();
let (b_tx, b_rx) = oneshot::channel::<i32>();
let (c_tx, c_rx) = oneshot::channel::<i32>();
let (d_tx, d_rx) = oneshot::channel::<i32>();
let mut stream = FuturesOrdered::new();
let mut cx = noop_context();
stream.push_back(a_rx);
stream.push_back(b_rx);
stream.push_back(c_rx);
a_tx.send(1).unwrap();
b_tx.send(2).unwrap();
c_tx.send(3).unwrap();
// 1 and 2 should be received in order
assert_eq!(Poll::Ready(Some(Ok(1))), stream.poll_next_unpin(&mut cx));
assert_eq!(Poll::Ready(Some(Ok(2))), stream.poll_next_unpin(&mut cx));
stream.push_front(d_rx);
d_tx.send(4).unwrap();
// we pushed `d_rx` to the front and sent 4, so we should recieve 4 next
// and then 3 after it
assert_eq!(Poll::Ready(Some(Ok(4))), stream.poll_next_unpin(&mut cx));
assert_eq!(Poll::Ready(Some(Ok(3))), stream.poll_next_unpin(&mut cx));
}
#[test]
fn test_push_back() {
let (a_tx, a_rx) = oneshot::channel::<i32>();
let (b_tx, b_rx) = oneshot::channel::<i32>();
let (c_tx, c_rx) = oneshot::channel::<i32>();
let (d_tx, d_rx) = oneshot::channel::<i32>();
let mut stream = FuturesOrdered::new();
let mut cx = noop_context();
stream.push_back(a_rx);
stream.push_back(b_rx);
stream.push_back(c_rx);
a_tx.send(1).unwrap();
b_tx.send(2).unwrap();
c_tx.send(3).unwrap();
// All results should be received in order
assert_eq!(Poll::Ready(Some(Ok(1))), stream.poll_next_unpin(&mut cx));
assert_eq!(Poll::Ready(Some(Ok(2))), stream.poll_next_unpin(&mut cx));
stream.push_back(d_rx);
d_tx.send(4).unwrap();
assert_eq!(Poll::Ready(Some(Ok(3))), stream.poll_next_unpin(&mut cx));
assert_eq!(Poll::Ready(Some(Ok(4))), stream.poll_next_unpin(&mut cx));
}
#[test]
fn from_iterator() {
let stream = vec![future::ready::<i32>(1), future::ready::<i32>(2), future::ready::<i32>(3)]
.into_iter()
.collect::<FuturesOrdered<_>>();
assert_eq!(stream.len(), 3);
assert_eq!(block_on(stream.collect::<Vec<_>>()), vec![1, 2, 3]);
}
#[test]
fn queue_never_unblocked() {
let (_a_tx, a_rx) = oneshot::channel::<Box<dyn Any + Send>>();
let (b_tx, b_rx) = oneshot::channel::<Box<dyn Any + Send>>();
let (c_tx, c_rx) = oneshot::channel::<Box<dyn Any + Send>>();
let mut stream = vec![
Box::new(a_rx) as Box<dyn Future<Output = _> + Unpin>,
Box::new(
future::try_select(b_rx, c_rx)
.map_err(|e| e.factor_first().0)
.and_then(|e| future::ok(Box::new(e) as Box<dyn Any + Send>)),
) as _,
]
.into_iter()
.collect::<FuturesOrdered<_>>();
let cx = &mut noop_context();
for _ in 0..10 {
assert!(stream.poll_next_unpin(cx).is_pending());
}
b_tx.send(Box::new(())).unwrap();
assert!(stream.poll_next_unpin(cx).is_pending());
c_tx.send(Box::new(())).unwrap();
assert!(stream.poll_next_unpin(cx).is_pending());
assert!(stream.poll_next_unpin(cx).is_pending());
}
#[test]
fn test_push_front_negative() {
let (a_tx, a_rx) = oneshot::channel::<i32>();
let (b_tx, b_rx) = oneshot::channel::<i32>();
let (c_tx, c_rx) = oneshot::channel::<i32>();
let mut stream = FuturesOrdered::new();
let mut cx = noop_context();
stream.push_front(a_rx);
stream.push_front(b_rx);
stream.push_front(c_rx);
a_tx.send(1).unwrap();
b_tx.send(2).unwrap();
c_tx.send(3).unwrap();
// These should all be recieved in reverse order
assert_eq!(Poll::Ready(Some(Ok(3))), stream.poll_next_unpin(&mut cx));
assert_eq!(Poll::Ready(Some(Ok(2))), stream.poll_next_unpin(&mut cx));
assert_eq!(Poll::Ready(Some(Ok(1))), stream.poll_next_unpin(&mut cx));
}