1 files changed, 66 insertions, 0 deletions
diff --git a/third_party/rust/tokio/tests/time_interval.rs b/third_party/rust/tokio/tests/time_interval.rs
new file mode 100644
index 0000000000..1123681f49
--- /dev/null
+++ b/third_party/rust/tokio/tests/time_interval.rs
@@ -0,0 +1,66 @@
+#![warn(rust_2018_idioms)]
+#![cfg(feature = "full")]
+
+use tokio::time::{self, Duration, Instant};
+use tokio_test::{assert_pending, assert_ready_eq, task};
+
+use std::task::Poll;
+
+#[tokio::test]
+#[should_panic]
+async fn interval_zero_duration() {
+    let _ = time::interval_at(Instant::now(), ms(0));
+}
+
+#[tokio::test]
+async fn usage() {
+    time::pause();
+
+    let start = Instant::now();
+
+    // TODO: Skip this
+    time::advance(ms(1)).await;
+
+    let mut i = task::spawn(time::interval_at(start, ms(300)));
+
+    assert_ready_eq!(poll_next(&mut i), start);
+    assert_pending!(poll_next(&mut i));
+
+    time::advance(ms(100)).await;
+    assert_pending!(poll_next(&mut i));
+
+    time::advance(ms(200)).await;
+    assert_ready_eq!(poll_next(&mut i), start + ms(300));
+    assert_pending!(poll_next(&mut i));
+
+    time::advance(ms(400)).await;
+    assert_ready_eq!(poll_next(&mut i), start + ms(600));
+    assert_pending!(poll_next(&mut i));
+
+    time::advance(ms(500)).await;
+    assert_ready_eq!(poll_next(&mut i), start + ms(900));
+    assert_ready_eq!(poll_next(&mut i), start + ms(1200));
+    assert_pending!(poll_next(&mut i));
+}
+
+#[tokio::test]
+async fn usage_stream() {
+    use tokio::stream::StreamExt;
+
+    let start = Instant::now();
+    let mut interval = time::interval(ms(10));
+
+    for _ in 0..3 {
+        interval.next().await.unwrap();
+    }
+
+    assert!(start.elapsed() > ms(20));
+}
+
+fn poll_next(interval: &mut task::Spawn<time::Interval>) -> Poll<Instant> {
+    interval.enter(|cx, mut interval| interval.poll_tick(cx))
+}
+
+fn ms(n: u64) -> Duration {
+    Duration::from_millis(n)
+}