add test for waker

actix-server/src/waker.rs

@@ -90,3 +90,37 @@ pub(crate) fn waker_channel() -> (WakerTx, WakerRx) {
 
     (WakerTx(tx), WakerRx(rx))
 }
+
+#[cfg(test)]
+mod test {
+    use std::task::{Context, Poll};
+
+    use super::*;
+
+    #[test]
+    fn test_waker_channel() {
+        let poll = mio::Poll::new().unwrap();
+
+        let waker = from_registry(poll.registry()).unwrap();
+
+        let cx = &mut Context::from_waker(&waker);
+
+        let (tx, mut rx) = waker_channel();
+
+        assert!(rx.poll_recv(cx).is_pending());
+
+        tx.wake(super::WakerInterest::Stop);
+
+        match rx.poll_recv(cx) {
+            Poll::Ready(Some(WakerInterest::Stop)) => {}
+            _ => panic!("Failed to wake up WakerRx"),
+        }
+
+        drop(tx);
+
+        match rx.poll_recv(cx) {
+            Poll::Ready(None) => {}
+            _ => panic!("Failed to close waker channel"),
+        }
+    }
+}