updated test.

src/queue.rs

@@ -38,9 +38,16 @@ mod messages {
 
     #[test]
     fn from_sender() {
-        let (tx, _) = channel();
+        let (tx, rx) = channel();
         match tx.into() {
-            Message::Register(_) => {}
+            Message::Register(result) => {
+                let (req, _) = empty_request();
+                result.send(req.into()).unwrap();
+                match rx.recv().unwrap() {
+                    Message::Req(_) => {}
+                    _ => unreachable!("should have been a request"),
+                }
+            }
             _ => unreachable!("should have been a register"),
         }
     }