1 files changed, 66 insertions, 0 deletions
diff --git a/third_party/rust/futures-channel/tests/channel.rs b/third_party/rust/futures-channel/tests/channel.rs
new file mode 100644
index 0000000000..5f01a8ef4c
--- /dev/null
+++ b/third_party/rust/futures-channel/tests/channel.rs
@@ -0,0 +1,66 @@
+use futures::channel::mpsc;
+use futures::executor::block_on;
+use futures::future::poll_fn;
+use futures::sink::SinkExt;
+use futures::stream::StreamExt;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::thread;
+
+#[test]
+fn sequence() {
+    let (tx, rx) = mpsc::channel(1);
+
+    let amt = 20;
+    let t = thread::spawn(move || block_on(send_sequence(amt, tx)));
+    let list: Vec<_> = block_on(rx.collect());
+    let mut list = list.into_iter();
+    for i in (1..=amt).rev() {
+        assert_eq!(list.next(), Some(i));
+    }
+    assert_eq!(list.next(), None);
+
+    t.join().unwrap();
+}
+
+async fn send_sequence(n: u32, mut sender: mpsc::Sender<u32>) {
+    for x in 0..n {
+        sender.send(n - x).await.unwrap();
+    }
+}
+
+#[test]
+fn drop_sender() {
+    let (tx, mut rx) = mpsc::channel::<u32>(1);
+    drop(tx);
+    let f = poll_fn(|cx| rx.poll_next_unpin(cx));
+    assert_eq!(block_on(f), None)
+}
+
+#[test]
+fn drop_rx() {
+    let (mut tx, rx) = mpsc::channel::<u32>(1);
+    block_on(tx.send(1)).unwrap();
+    drop(rx);
+    assert!(block_on(tx.send(1)).is_err());
+}
+
+#[test]
+fn drop_order() {
+    static DROPS: AtomicUsize = AtomicUsize::new(0);
+    let (mut tx, rx) = mpsc::channel(1);
+
+    struct A;
+
+    impl Drop for A {
+        fn drop(&mut self) {
+            DROPS.fetch_add(1, Ordering::SeqCst);
+        }
+    }
+
+    block_on(tx.send(A)).unwrap();
+    assert_eq!(DROPS.load(Ordering::SeqCst), 0);
+    drop(rx);
+    assert_eq!(DROPS.load(Ordering::SeqCst), 1);
+    assert!(block_on(tx.send(A)).is_err());
+    assert_eq!(DROPS.load(Ordering::SeqCst), 2);
+}