Add a simple UDP test

tests/udp.rs

@@ -0,0 +1,43 @@
+extern crate futures;
+extern crate futures_mio;
+
+use futures::Future;
+use futures::stream::Stream;
+
+macro_rules! t {
+    ($e:expr) => (match $e {
+        Ok(e) => e,
+        Err(e) => panic!("{} failed with {:?}", stringify!($e), e),
+    })
+}
+
+#[test]
+fn send_messages() {
+    let mut l = t!(futures_mio::Loop::new());
+    let a = l.handle().udp_bind(&"127.0.0.1:0".parse().unwrap());
+    let b = l.handle().udp_bind(&"127.0.0.1:0".parse().unwrap());
+    let (a, b) = t!(l.run(a.join(b)));
+    let a_addr = t!(a.local_addr());
+    let b_addr = t!(b.local_addr());
+
+    let ((ar, a), (br, b)) = t!(l.run(a.into_future().join(b.into_future())));
+    let ar = ar.unwrap();
+    let br = br.unwrap();
+
+    assert!(ar.is_write());
+    assert!(!ar.is_read());
+    assert!(br.is_write());
+    assert!(!br.is_read());
+
+    assert_eq!(t!(a.send_to(b"1234", &b_addr)), 4);
+    let (br, b) = t!(l.run(b.into_future()));
+    let br = br.unwrap();
+
+    assert!(br.is_read());
+
+    let mut buf = [0; 32];
+    let (size, addr) = t!(b.recv_from(&mut buf));
+    assert_eq!(size, 4);
+    assert_eq!(&buf[..4], b"1234");
+    assert_eq!(addr, a_addr);
+}