Fix failing tests

The initial error was during compile time because of passing None for
the request `data` parameter. The docs were updated to reflect that
`None` must be parameterized like `None::<u8>`.

Having resolved that, there was a runtime error for the tests where one
of them would fail because the specified port was already used.
Presumably the tests run in parallel. The StackListener type was updated
to take a `port: u16` argument which it will attempt to listen on. This
isn't an ideal solution, and another issue will be filed to address it.

Resolves #1.

src/lib.rs

@@ -93,6 +93,8 @@ impl ::std::fmt::Display for Error {
 /// `rustc_serialize::Encodable`, and the result type must implement `rustc_serialize::Decodable`.
 /// This can usually be achieved with `#[derive(RustcEncodable)]` and `#[derive(RustcDecodable)]`.
 ///
+/// **Note:** If not providing data, you must provide a parameterized `None` such as `None::<u8>`.
+///
 /// # Example
 ///
 /// ```no_run

tests/lib.rs

@@ -38,21 +38,23 @@ struct ResponseData {
     pong: bool
 }
 
-const HOST: &'static str = "0.0.0.0:12345";
-fn url(frag: &str) -> String {
-    format!("http://{}{}", HOST, frag)
-}
-
 struct StackListener {
-    server: ::hyper::server::Listening
+    server: ::hyper::server::Listening,
+    host: String,
 }
 
 impl StackListener {
-    pub fn new() -> StackListener {
+    pub fn new(port: u16) -> StackListener {
+        let host = format!("0.0.0.0:{}", port);
         StackListener {
-            server: PingServer::build().listen_with(HOST, 1, Protocol::Http).unwrap()
+            server: PingServer::build().listen_with(&host[..], 1, Protocol::Http).unwrap(),
+            host: host
         }
     }
+
+    pub fn url(&self, path: &str) -> String {
+        format!("http://{}{}", self.host, path)
+    }
 }
 
 impl Drop for StackListener {
@@ -63,22 +65,22 @@ impl Drop for StackListener {
 
 #[test]
 #[allow(unused_variables)]
-fn ping_pong() {
-    let server = StackListener::new();
+fn with_data() {
+    let server = StackListener::new(40918);
 
     let req = RequestData { ping: true };
 
     // When this fails, the error I get it "called Option::unwrap() on a None value" which is not
     // helpful for resolving what the problem is.
-    let res: ResponseData = request(Method::Post, &(url("/ping"))[..], Some(req)).unwrap().unwrap();
+    let url = server.url("/ping");
+    let res: ResponseData = request(Method::Post, &url[..], Some(req)).unwrap().unwrap();
 }
 
 #[test]
 #[allow(unused_variables)]
-fn ping_pong_none_data() {
-    let server = StackListener::new();
+fn none_data() {
+    let server = StackListener::new(40919);
 
-    // When this fails, the error I get it "called Option::unwrap() on a None value" which is not
-    // helpful for resolving what the problem is.
-    let res: ResponseData = request(Method::Post, &(url("/ping"))[..], None).unwrap().unwrap();
+    let url = server.url("/ping");
+    let res: ResponseData = request(Method::Post, &url[..], None::<u8>).unwrap().unwrap();
 }