1 files changed, 95 insertions, 0 deletions
diff --git a/third_party/rust/crossbeam-channel/tests/never.rs b/third_party/rust/crossbeam-channel/tests/never.rs
new file mode 100644
index 0000000000..f275126f7d
--- /dev/null
+++ b/third_party/rust/crossbeam-channel/tests/never.rs
@@ -0,0 +1,95 @@
+//! Tests for the never channel flavor.
+
+use std::thread;
+use std::time::{Duration, Instant};
+
+use crossbeam_channel::{never, select, tick, unbounded};
+
+fn ms(ms: u64) -> Duration {
+    Duration::from_millis(ms)
+}
+
+#[test]
+fn smoke() {
+    select! {
+        recv(never::<i32>()) -> _ => panic!(),
+        default => {}
+    }
+}
+
+#[test]
+fn optional() {
+    let (s, r) = unbounded::<i32>();
+    s.send(1).unwrap();
+    s.send(2).unwrap();
+
+    let mut r = Some(&r);
+    select! {
+        recv(r.unwrap_or(&never())) -> _ => {}
+        default => panic!(),
+    }
+
+    r = None;
+    select! {
+        recv(r.unwrap_or(&never())) -> _ => panic!(),
+        default => {}
+    }
+}
+
+#[test]
+fn tick_n() {
+    let mut r = tick(ms(100));
+    let mut step = 0;
+
+    loop {
+        select! {
+            recv(r) -> _ => step += 1,
+            default(ms(500)) => break,
+        }
+
+        if step == 10 {
+            r = never();
+        }
+    }
+
+    assert_eq!(step, 10);
+}
+
+#[test]
+fn capacity() {
+    let r = never::<i32>();
+    assert_eq!(r.capacity(), Some(0));
+}
+
+#[test]
+fn len_empty_full() {
+    let r = never::<i32>();
+    assert_eq!(r.len(), 0);
+    assert!(r.is_empty());
+    assert!(r.is_full());
+}
+
+#[test]
+fn try_recv() {
+    let r = never::<i32>();
+    assert!(r.try_recv().is_err());
+
+    thread::sleep(ms(100));
+    assert!(r.try_recv().is_err());
+}
+
+#[test]
+fn recv_timeout() {
+    let start = Instant::now();
+    let r = never::<i32>();
+
+    assert!(r.recv_timeout(ms(100)).is_err());
+    let now = Instant::now();
+    assert!(now - start >= ms(100));
+    assert!(now - start <= ms(150));
+
+    assert!(r.recv_timeout(ms(100)).is_err());
+    let now = Instant::now();
+    assert!(now - start >= ms(200));
+    assert!(now - start <= ms(250));
+}