Add none filter

src/filters/mod.rs

@@ -18,6 +18,7 @@ pub mod log;
 pub mod method;
 #[cfg(feature = "multipart")]
 pub mod multipart;
+pub mod none;
 pub mod path;
 pub mod query;
 pub mod reply;

src/filters/none.rs

@@ -0,0 +1,41 @@
+//! A filter that matches no route.
+use futures::future;
+
+use crate::filter::{filter_fn, Filter};
+use crate::reject::{self, Rejection};
+
+/// A filter that matches no route.
+///
+/// This can be useful to help with styling.
+///
+/// # Example
+///
+/// ```
+/// use warp::Filter;
+///
+/// let route_1 = warp::path!("something").map(|| "Hello, world!".to_string());
+/// let route_2 = warp::path!("something2").map(|| "Hello, world again!".to_string());
+/// let route_3 = warp::path!("something3").map(|| "Hello, world again again!".to_string());
+///
+/// let routes = warp::none()
+///     .or(route_1)
+///     .or(route_2)
+///     .or(route_3);
+/// ```
+///
+/// looks nicer than the following because the routes are lined up
+/// ```
+/// use warp::Filter;
+///
+/// let route_1 = warp::path!("something").map(|| "Hello, world!".to_string());
+/// let route_2 = warp::path!("something2").map(|| "Hello, world again!".to_string());
+/// let route_3 = warp::path!("something3").map(|| "Hello, world again again!".to_string());
+///
+/// let routes = route_1
+///     .or(route_2)
+///     .or(route_3);
+/// ```
+pub fn none() -> impl Filter<Extract = (), Error = Rejection> + Copy {
+    // always reject with not found
+    filter_fn(|_route| future::ready(Err(reject::not_found())))
+}

src/lib.rs

@@ -137,6 +137,8 @@ pub use self::filters::{
     // log() function
     log::log,
     method::{delete, get, head, method, options, patch, post, put},
+    // none() function
+    none::none,
     path,
     // path() function and macro
     path::path,

tests/none.rs

@@ -0,0 +1,26 @@
+#![deny(warnings)]
+use warp::Filter;
+
+#[tokio::test]
+async fn none_is_not_found() {
+    let filter = warp::none();
+
+    // none should return not found for request
+    let req = warp::test::request();
+    assert!(req.filter(&filter).await.unwrap_err().is_not_found());
+}
+
+#[tokio::test]
+async fn none_can_be_chained() {
+    let req = warp::test::request();
+    let filter = warp::none();
+
+    // should not match anything
+    assert!(!req.matches(&filter).await);
+
+    let req = warp::test::request();
+    let filter = filter.or(warp::get().map(warp::reply));
+
+    // this should now match because we chained the get with 'or'
+    assert!(req.matches(&filter).await);
+}