Add test to verify enum in query

Docs are updated to show example of how to use enum.
Closes  #371

src/extractor.rs

@@ -139,15 +139,24 @@ impl<T: fmt::Display> fmt::Display for Path<T> {
 /// #[macro_use] extern crate serde_derive;
 /// use actix_web::{App, Query, http};
 ///
-/// #[derive(Deserialize)]
+///
-/// struct Info {
+///#[derive(Debug, Deserialize)]
-///     username: String,
+///pub enum ResponseType {
-/// }
+///    Token,
+///    Code
+///}
+///
+///#[derive(Deserialize)]
+///pub struct AuthRequest {
+///    id: u64,
+///    response_type: ResponseType,
+///}
 ///
 /// // use `with` extractor for query info
 /// // this handler get called only if request's query contains `username` field
-/// fn index(info: Query<Info>) -> String {
+/// // The correct request for this handler would be `/index.html?id=64&response_type=Code"`
-///     format!("Welcome {}!", info.username)
+/// fn index(info: Query<AuthRequest>) -> String {
+///     format!("Authorization request for client with id={} and type={:?}!", info.id, info.response_type)
 /// }
 ///
 /// fn main() {

tests/test_handlers.rs

@@ -91,6 +91,48 @@ fn test_query_extractor() {
     assert_eq!(response.status(), StatusCode::BAD_REQUEST);
 }
 
+#[derive(Deserialize, Debug)]
+pub enum ResponseType {
+    Token,
+    Code
+}
+
+#[derive(Debug, Deserialize)]
+pub struct AuthRequest {
+    id: u64,
+    response_type: ResponseType,
+}
+
+#[test]
+fn test_query_enum_extractor() {
+    let mut srv = test::TestServer::new(|app| {
+        app.resource("/index.html", |r| {
+            r.with(|p: Query<AuthRequest>| format!("{:?}", p.into_inner()))
+        });
+    });
+
+    // client request
+    let request = srv
+        .get()
+        .uri(srv.url("/index.html?id=64&response_type=Code"))
+        .finish()
+        .unwrap();
+    let response = srv.execute(request.send()).unwrap();
+    assert!(response.status().is_success());
+
+    // read response
+    let bytes = srv.execute(response.body()).unwrap();
+    assert_eq!(bytes, Bytes::from_static(b"AuthRequest { id: 64, response_type: Code }"));
+
+    let request = srv.get().uri(srv.url("/index.html?id=64&response_type=Co")).finish().unwrap();
+    let response = srv.execute(request.send()).unwrap();
+    assert_eq!(response.status(), StatusCode::BAD_REQUEST);
+
+    let request = srv.get().uri(srv.url("/index.html?response_type=Code")).finish().unwrap();
+    let response = srv.execute(request.send()).unwrap();
+    assert_eq!(response.status(), StatusCode::BAD_REQUEST);
+}
+
 #[test]
 fn test_async_extractor_async() {
     let mut srv = test::TestServer::new(|app| {