1 files changed, 60 insertions, 0 deletions
diff --git a/third_party/rust/futures/tests/io_lines.rs b/third_party/rust/futures/tests/io_lines.rs
new file mode 100644
index 0000000000..5ce01a6945
--- /dev/null
+++ b/third_party/rust/futures/tests/io_lines.rs
@@ -0,0 +1,60 @@
+use futures::executor::block_on;
+use futures::future::{Future, FutureExt};
+use futures::io::{AsyncBufReadExt, Cursor};
+use futures::stream::{self, StreamExt, TryStreamExt};
+use futures::task::Poll;
+use futures_test::io::AsyncReadTestExt;
+use futures_test::task::noop_context;
+
+fn run<F: Future + Unpin>(mut f: F) -> F::Output {
+    let mut cx = noop_context();
+    loop {
+        if let Poll::Ready(x) = f.poll_unpin(&mut cx) {
+            return x;
+        }
+    }
+}
+
+macro_rules! block_on_next {
+    ($expr:expr) => {
+        block_on($expr.next()).unwrap().unwrap()
+    };
+}
+
+macro_rules! run_next {
+    ($expr:expr) => {
+        run($expr.next()).unwrap().unwrap()
+    };
+}
+
+#[test]
+fn lines() {
+    let buf = Cursor::new(&b"12\r"[..]);
+    let mut s = buf.lines();
+    assert_eq!(block_on_next!(s), "12\r".to_string());
+    assert!(block_on(s.next()).is_none());
+
+    let buf = Cursor::new(&b"12\r\n\n"[..]);
+    let mut s = buf.lines();
+    assert_eq!(block_on_next!(s), "12".to_string());
+    assert_eq!(block_on_next!(s), "".to_string());
+    assert!(block_on(s.next()).is_none());
+}
+
+#[test]
+fn maybe_pending() {
+    let buf =
+        stream::iter(vec![&b"12"[..], &b"\r"[..]]).map(Ok).into_async_read().interleave_pending();
+    let mut s = buf.lines();
+    assert_eq!(run_next!(s), "12\r".to_string());
+    assert!(run(s.next()).is_none());
+
+    let buf = stream::iter(vec![&b"12"[..], &b"\r\n"[..], &b"\n"[..]])
+        .map(Ok)
+        .into_async_read()
+        .interleave_pending();
+    let mut s = buf.lines();
+    assert_eq!(run_next!(s), "12".to_string());
+    assert_eq!(run_next!(s), "".to_string());
+    assert!(run(s.next()).is_none());
+}