stream_select_all.rs

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use futures::channel::mpsc;

use futures::executor::{block_on, block_on_stream};

use futures::future::{self, FutureExt};

use futures::stream::{self, select_all, FusedStream, SelectAll, StreamExt};

use futures::task::Poll;

use futures_test::task::noop_context;

#[test]

fn is_terminated() {

    let mut cx = noop_context();

    let mut tasks = SelectAll::new();

    assert_eq!(tasks.is_terminated(), false);

    assert_eq!(tasks.poll_next_unpin(&mut cx), Poll::Ready(None));

    assert_eq!(tasks.is_terminated(), true);

    // Test that the sentinel value doesn't leak

    assert_eq!(tasks.is_empty(), true);

    assert_eq!(tasks.len(), 0);

    tasks.push(future::ready(1).into_stream());

    assert_eq!(tasks.is_empty(), false);

    assert_eq!(tasks.len(), 1);

    assert_eq!(tasks.is_terminated(), false);

    assert_eq!(tasks.poll_next_unpin(&mut cx), Poll::Ready(Some(1)));

    assert_eq!(tasks.is_terminated(), false);

    assert_eq!(tasks.poll_next_unpin(&mut cx), Poll::Ready(None));

    assert_eq!(tasks.is_terminated(), true);

#[test]

fn issue_1626() {

    let a = stream::iter(0..=2);

    let b = stream::iter(10..=14);

    let mut s = block_on_stream(stream::select_all(vec![a, b]));

    assert_eq!(s.next(), Some(0));

    assert_eq!(s.next(), Some(10));

    assert_eq!(s.next(), Some(1));

    assert_eq!(s.next(), Some(11));

    assert_eq!(s.next(), Some(2));

    assert_eq!(s.next(), Some(12));

    assert_eq!(s.next(), Some(13));

    assert_eq!(s.next(), Some(14));

    assert_eq!(s.next(), None);

#[test]

fn works_1() {

    let (a_tx, a_rx) = mpsc::unbounded::<u32>();

    let (b_tx, b_rx) = mpsc::unbounded::<u32>();

    let (c_tx, c_rx) = mpsc::unbounded::<u32>();

    let streams = vec![a_rx, b_rx, c_rx];

    let mut stream = block_on_stream(select_all(streams));

    b_tx.unbounded_send(99).unwrap();

    a_tx.unbounded_send(33).unwrap();

    assert_eq!(Some(33), stream.next());

    assert_eq!(Some(99), stream.next());

    b_tx.unbounded_send(99).unwrap();

    a_tx.unbounded_send(33).unwrap();

    assert_eq!(Some(33), stream.next());

    assert_eq!(Some(99), stream.next());

    c_tx.unbounded_send(42).unwrap();

    assert_eq!(Some(42), stream.next());

    a_tx.unbounded_send(43).unwrap();

    assert_eq!(Some(43), stream.next());

    drop((a_tx, b_tx, c_tx));

    assert_eq!(None, stream.next());

#[test]

fn clear() {

    let mut tasks =

        select_all(vec![stream::iter(vec![1].into_iter()), stream::iter(vec![2].into_iter())]);

    assert_eq!(block_on(tasks.next()), Some(1));

    assert!(!tasks.is_empty());

    tasks.clear();

    assert!(tasks.is_empty());

    tasks.push(stream::iter(vec![3].into_iter()));

    assert!(!tasks.is_empty());

    tasks.clear();

    assert!(tasks.is_empty());

    assert_eq!(block_on(tasks.next()), None);

    assert!(tasks.is_terminated());

    tasks.clear();

    assert!(!tasks.is_terminated());

#[test]

fn iter_mut() {

    let mut stream =

        vec![stream::pending::<()>(), stream::pending::<()>(), stream::pending::<()>()]

            .into_iter()

            .collect::<SelectAll<_>>();

    let mut iter = stream.iter_mut();

    assert_eq!(iter.len(), 3);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 2);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 1);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 0);

    assert!(iter.next().is_none());

    let mut stream = vec![stream::iter(vec![]), stream::iter(vec![1]), stream::iter(vec![2])]

        .into_iter()

        .collect::<SelectAll<_>>();

    assert_eq!(stream.len(), 3);

    assert_eq!(block_on(stream.next()), Some(1));

    assert_eq!(stream.len(), 2);

    let mut iter = stream.iter_mut();

    assert_eq!(iter.len(), 2);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 1);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 0);

    assert!(iter.next().is_none());

    assert_eq!(block_on(stream.next()), Some(2));

    assert_eq!(stream.len(), 2);

    assert_eq!(block_on(stream.next()), None);

    let mut iter = stream.iter_mut();

    assert_eq!(iter.len(), 0);

    assert!(iter.next().is_none());

#[test]

fn iter() {

    let stream = vec![stream::pending::<()>(), stream::pending::<()>(), stream::pending::<()>()]

        .into_iter()

        .collect::<SelectAll<_>>();

    let mut iter = stream.iter();

    assert_eq!(iter.len(), 3);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 2);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 1);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 0);

    assert!(iter.next().is_none());

    let mut stream = vec![stream::iter(vec![]), stream::iter(vec![1]), stream::iter(vec![2])]

        .into_iter()

        .collect::<SelectAll<_>>();

    assert_eq!(stream.len(), 3);

    assert_eq!(block_on(stream.next()), Some(1));

    assert_eq!(stream.len(), 2);

    let mut iter = stream.iter();

    assert_eq!(iter.len(), 2);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 1);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 0);

    assert!(iter.next().is_none());

    assert_eq!(block_on(stream.next()), Some(2));

    assert_eq!(stream.len(), 2);

    assert_eq!(block_on(stream.next()), None);

    let mut iter = stream.iter();

    assert_eq!(iter.len(), 0);

    assert!(iter.next().is_none());

#[test]

fn into_iter() {

    let stream = vec![stream::pending::<()>(), stream::pending::<()>(), stream::pending::<()>()]

        .into_iter()

        .collect::<SelectAll<_>>();

    let mut iter = stream.into_iter();

    assert_eq!(iter.len(), 3);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 2);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 1);

    assert!(iter.next().is_some());

    assert_eq!(iter.len(), 0);

    assert!(iter.next().is_none());