Add warp support (#46)

* add tracing, add tests, default to empty string

2 files changed, 93 insertions, 0 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 4604859..4df1d00 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -159,6 +159,20 @@
 //! ```
 //!
 //! Support for `actix-web 2.0.0` is available via the `actix2` feature.
+//!
+//! ## Use with `warp` filters
+//!
+//! The `warp` feature enables the use of `serde_qs::warp::query()`, which
+//! is a substitute for the `warp::query::query()` filter and can be used like this:
+//!
+//! ```ignore
+//! serde_qs::warp::query(Config::default())
+//!     .and_then(|info| async move {
+//!         Ok::<_, Rejection>(format!("Welcome {}!", info.username))
+//!     })
+//!     .recover(serde_qs::warp::recover_fn);
+//! ```
+//!
 
 #[macro_use]
 extern crate serde;
@@ -168,6 +182,8 @@ pub mod actix;
 mod de;
 mod error;
 mod ser;
+#[cfg(feature = "warp")]
+pub mod warp;
 
 #[doc(inline)]
 pub use de::Config;
diff --git a/src/warp.rs b/src/warp.rs
new file mode 100644
index 0000000..93bf3e2
--- /dev/null
+++ b/src/warp.rs
@@ -0,0 +1,77 @@
+//! Functionality for using `serde_qs` with `warp`.
+//!
+//! Enable with the `warp` feature.
+
+extern crate warp_framework as warp;
+
+use crate::{de::Config as QsConfig, error};
+use serde::de;
+use std::sync::Arc;
+use warp::{http::StatusCode, reject::Reject, Filter, Rejection, Reply};
+
+impl Reject for error::Error {}
+
+/// Extract typed information from from the request's query.
+///
+/// ## Example
+///
+/// ```rust
+/// # extern crate warp_framework as warp;
+/// # #[macro_use] extern crate serde_derive;
+/// use warp::Filter;
+/// use serde_qs::Config;
+///
+/// #[derive(Deserialize)]
+/// pub struct UsersFilter {
+///    id: Vec<u64>,
+/// }
+///
+/// fn main() {
+///     let filter = serde_qs::warp::query(Config::default())
+///         .and_then(|info: UsersFilter| async move {
+///             Ok::<_, warp::Rejection>(
+///                 info.id.iter().map(|i| i.to_string()).collect::<Vec<String>>().join(", ")
+///             )
+///         })
+///         .recover(serde_qs::warp::recover_fn);
+/// }
+/// ```
+pub fn query<T>(config: QsConfig) -> impl Filter<Extract = (T,), Error = Rejection> + Clone
+where
+    T: de::DeserializeOwned + Send + 'static,
+{
+    let config = Arc::new(config);
+
+    warp::query::raw()
+        .or_else(|_| async {
+            tracing::debug!("route was called without a query string, defaulting to empty");
+
+            Ok::<_, Rejection>((String::new(),))
+        })
+        .and_then(move |query: String| {
+            let config = Arc::clone(&config);
+
+            async move {
+                config.deserialize_str(query.as_str()).map_err(|err| {
+                    tracing::debug!("failed to decode query string '{}': {:?}", query, err);
+
+                    Rejection::from(err)
+                })
+            }
+        })
+}
+
+/// Use this as the function for a `.recover()` after assembled filter
+///
+/// This is not strictly required but changes the response from a
+/// "500 Internal Server Error" to a "400 Bad Request"
+pub async fn recover_fn(rejection: Rejection) -> Result<impl Reply, Rejection> {
+    if let Some(err) = rejection.find::<error::Error>() {
+        Ok(warp::reply::with_status(
+            err.to_string(),
+            StatusCode::BAD_REQUEST,
+        ))
+    } else {
+        Err(rejection)
+    }
+}