1 files changed, 22 insertions, 0 deletions
diff --git a/third_party/rust/futures/tests/recurse.rs b/third_party/rust/futures/tests/recurse.rs
new file mode 100644
index 0000000000..2920a41a59
--- /dev/null
+++ b/third_party/rust/futures/tests/recurse.rs
@@ -0,0 +1,22 @@
+use futures::executor::block_on;
+use futures::future::{self, FutureExt, BoxFuture};
+use std::sync::mpsc;
+use std::thread;
+
+#[test]
+fn lots() {
+    fn do_it(input: (i32, i32)) -> BoxFuture<'static, i32> {
+        let (n, x) = input;
+        if n == 0 {
+            future::ready(x).boxed()
+        } else {
+            future::ready((n - 1, x + n)).then(do_it).boxed()
+        }
+    }
+
+    let (tx, rx) = mpsc::channel();
+    thread::spawn(|| {
+        block_on(do_it((1_000, 0)).map(move |x| tx.send(x).unwrap()))
+    });
+    assert_eq!(500_500, rx.recv().unwrap());
+}