diff options
Diffstat (limited to 'tests/stream.rs')
-rw-r--r-- | tests/stream.rs | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/tests/stream.rs b/tests/stream.rs index 71ec654..5cde458 100644 --- a/tests/stream.rs +++ b/tests/stream.rs @@ -1,5 +1,9 @@ +use std::cell::Cell; use std::iter; +use std::pin::Pin; +use std::rc::Rc; use std::sync::Arc; +use std::task::Context; use futures::channel::mpsc; use futures::executor::block_on; @@ -9,6 +13,7 @@ use futures::sink::SinkExt; use futures::stream::{self, StreamExt}; use futures::task::Poll; use futures::{ready, FutureExt}; +use futures_core::Stream; use futures_test::task::noop_context; #[test] @@ -419,3 +424,40 @@ fn ready_chunks() { assert_eq!(s.next().await.unwrap(), vec![4]); }); } + +struct SlowStream { + times_should_poll: usize, + times_polled: Rc<Cell<usize>>, +} +impl Stream for SlowStream { + type Item = usize; + + fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> { + self.times_polled.set(self.times_polled.get() + 1); + if self.times_polled.get() % 2 == 0 { + cx.waker().wake_by_ref(); + return Poll::Pending; + } + if self.times_polled.get() >= self.times_should_poll { + return Poll::Ready(None); + } + Poll::Ready(Some(self.times_polled.get())) + } +} + +#[test] +fn select_with_strategy_doesnt_terminate_early() { + for side in [stream::PollNext::Left, stream::PollNext::Right] { + let times_should_poll = 10; + let count = Rc::new(Cell::new(0)); + let b = stream::iter([10, 20]); + + let mut selected = stream::select_with_strategy( + SlowStream { times_should_poll, times_polled: count.clone() }, + b, + |_: &mut ()| side, + ); + block_on(async move { while selected.next().await.is_some() {} }); + assert_eq!(count.get(), times_should_poll + 1); + } +} |