1 files changed, 24 insertions, 0 deletions
diff --git a/third_party/rust/futures/tests/sink_fanout.rs b/third_party/rust/futures/tests/sink_fanout.rs
new file mode 100644
index 0000000000..e57b2d8c7b
--- /dev/null
+++ b/third_party/rust/futures/tests/sink_fanout.rs
@@ -0,0 +1,24 @@
+use futures::channel::mpsc;
+use futures::executor::block_on;
+use futures::future::join3;
+use futures::sink::SinkExt;
+use futures::stream::{self, StreamExt};
+
+#[test]
+fn it_works() {
+    let (tx1, rx1) = mpsc::channel(1);
+    let (tx2, rx2) = mpsc::channel(2);
+    let tx = tx1.fanout(tx2).sink_map_err(|_| ());
+
+    let src = stream::iter((0..10).map(Ok));
+    let fwd = src.forward(tx);
+
+    let collect_fut1 = rx1.collect::<Vec<_>>();
+    let collect_fut2 = rx2.collect::<Vec<_>>();
+    let (_, vec1, vec2) = block_on(join3(fwd, collect_fut1, collect_fut2));
+
+    let expected = (0..10).collect::<Vec<_>>();
+
+    assert_eq!(vec1, expected);
+    assert_eq!(vec2, expected);
+}