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Diffstat (limited to '')
-rw-r--r-- | vendor/futures/tests/stream.rs | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/vendor/futures/tests/stream.rs b/vendor/futures/tests/stream.rs new file mode 100644 index 000000000..0d453d175 --- /dev/null +++ b/vendor/futures/tests/stream.rs @@ -0,0 +1,151 @@ +use futures::channel::mpsc; +use futures::executor::block_on; +use futures::future::{self, Future}; +use futures::sink::SinkExt; +use futures::stream::{self, StreamExt}; +use futures::task::Poll; +use futures::FutureExt; +use futures_test::task::noop_context; + +#[test] +fn select() { + fn select_and_compare(a: Vec<u32>, b: Vec<u32>, expected: Vec<u32>) { + let a = stream::iter(a); + let b = stream::iter(b); + let vec = block_on(stream::select(a, b).collect::<Vec<_>>()); + assert_eq!(vec, expected); + } + + select_and_compare(vec![1, 2, 3], vec![4, 5, 6], vec![1, 4, 2, 5, 3, 6]); + select_and_compare(vec![1, 2, 3], vec![4, 5], vec![1, 4, 2, 5, 3]); + select_and_compare(vec![1, 2], vec![4, 5, 6], vec![1, 4, 2, 5, 6]); +} + +#[test] +fn flat_map() { + block_on(async { + let st = + stream::iter(vec![stream::iter(0..=4u8), stream::iter(6..=10), stream::iter(0..=2)]); + + let values: Vec<_> = + st.flat_map(|s| s.filter(|v| futures::future::ready(v % 2 == 0))).collect().await; + + assert_eq!(values, vec![0, 2, 4, 6, 8, 10, 0, 2]); + }); +} + +#[test] +fn scan() { + block_on(async { + let values = stream::iter(vec![1u8, 2, 3, 4, 6, 8, 2]) + .scan(1, |state, e| { + *state += 1; + futures::future::ready(if e < *state { Some(e) } else { None }) + }) + .collect::<Vec<_>>() + .await; + + assert_eq!(values, vec![1u8, 2, 3, 4]); + }); +} + +#[test] +fn take_until() { + fn make_stop_fut(stop_on: u32) -> impl Future<Output = ()> { + let mut i = 0; + future::poll_fn(move |_cx| { + i += 1; + if i <= stop_on { + Poll::Pending + } else { + Poll::Ready(()) + } + }) + } + + block_on(async { + // Verify stopping works: + let stream = stream::iter(1u32..=10); + let stop_fut = make_stop_fut(5); + + let stream = stream.take_until(stop_fut); + let last = stream.fold(0, |_, i| async move { i }).await; + assert_eq!(last, 5); + + // Verify take_future() works: + let stream = stream::iter(1..=10); + let stop_fut = make_stop_fut(5); + + let mut stream = stream.take_until(stop_fut); + + assert_eq!(stream.next().await, Some(1)); + assert_eq!(stream.next().await, Some(2)); + + stream.take_future(); + + let last = stream.fold(0, |_, i| async move { i }).await; + assert_eq!(last, 10); + + // Verify take_future() returns None if stream is stopped: + let stream = stream::iter(1u32..=10); + let stop_fut = make_stop_fut(1); + let mut stream = stream.take_until(stop_fut); + assert_eq!(stream.next().await, Some(1)); + assert_eq!(stream.next().await, None); + assert!(stream.take_future().is_none()); + + // Verify TakeUntil is fused: + let mut i = 0; + let stream = stream::poll_fn(move |_cx| { + i += 1; + match i { + 1 => Poll::Ready(Some(1)), + 2 => Poll::Ready(None), + _ => panic!("TakeUntil not fused"), + } + }); + + let stop_fut = make_stop_fut(1); + let mut stream = stream.take_until(stop_fut); + assert_eq!(stream.next().await, Some(1)); + assert_eq!(stream.next().await, None); + assert_eq!(stream.next().await, None); + }); +} + +#[test] +#[should_panic] +fn chunks_panic_on_cap_zero() { + let (_, rx1) = mpsc::channel::<()>(1); + + let _ = rx1.chunks(0); +} + +#[test] +#[should_panic] +fn ready_chunks_panic_on_cap_zero() { + let (_, rx1) = mpsc::channel::<()>(1); + + let _ = rx1.ready_chunks(0); +} + +#[test] +fn ready_chunks() { + let (mut tx, rx1) = mpsc::channel::<i32>(16); + + let mut s = rx1.ready_chunks(2); + + let mut cx = noop_context(); + assert!(s.next().poll_unpin(&mut cx).is_pending()); + + block_on(async { + tx.send(1).await.unwrap(); + + assert_eq!(s.next().await.unwrap(), vec![1]); + tx.send(2).await.unwrap(); + tx.send(3).await.unwrap(); + tx.send(4).await.unwrap(); + assert_eq!(s.next().await.unwrap(), vec![2, 3]); + assert_eq!(s.next().await.unwrap(), vec![4]); + }); +} |