//! Rejections //! //! Part of the power of the [`Filter`](../trait.Filter.html) system is being able to //! reject a request from a filter chain. This allows for filters to be //! combined with `or`, so that if one side of the chain finds that a request //! doesn't fulfill its requirements, the other side can try to process //! the request. //! //! Many of the built-in [`filters`](../filters) will automatically reject //! the request with an appropriate rejection. However, you can also build //! new custom [`Filter`](../trait.Filter.html)s and still want other routes to be //! matchable in the case a predicate doesn't hold. //! //! As a request is processed by a Filter chain, the rejections are accumulated into //! a list contained by the [`Rejection`](struct.Rejection.html) type. Rejections from //! filters can be handled using [`Filter::recover`](../trait.Filter.html#method.recover). //! This is a convenient way to map rejections into a [`Reply`](../reply/trait.Reply.html). //! //! For a more complete example see the //! [Rejection Example](https://github.com/seanmonstar/warp/blob/master/examples/rejections.rs) //! from the repository. //! //! # Example //! //! ``` //! use warp::{reply, Reply, Filter, reject, Rejection, http::StatusCode}; //! //! #[derive(Debug)] //! struct InvalidParameter; //! //! impl reject::Reject for InvalidParameter {} //! //! // Custom rejection handler that maps rejections into responses. //! async fn handle_rejection(err: Rejection) -> Result { //! if err.is_not_found() { //! Ok(reply::with_status("NOT_FOUND", StatusCode::NOT_FOUND)) //! } else if let Some(e) = err.find::() { //! Ok(reply::with_status("BAD_REQUEST", StatusCode::BAD_REQUEST)) //! } else { //! eprintln!("unhandled rejection: {:?}", err); //! Ok(reply::with_status("INTERNAL_SERVER_ERROR", StatusCode::INTERNAL_SERVER_ERROR)) //! } //! } //! //! //! // Filter on `/:id`, but reject with InvalidParameter if the `id` is `0`. //! // Recover from this rejection using a custom rejection handler. //! let route = warp::path::param() //! .and_then(|id: u32| async move { //! if id == 0 { //! Err(warp::reject::custom(InvalidParameter)) //! } else { //! Ok("id is valid") //! } //! }) //! .recover(handle_rejection); //! ``` use std::any::Any; use std::convert::Infallible; use std::error::Error as StdError; use std::fmt; use http::{self, StatusCode}; pub(crate) use self::sealed::{CombineRejection, IsReject}; /// Rejects a request with `404 Not Found`. #[inline] pub fn reject() -> Rejection { loop {} } /// Rejects a request with `404 Not Found`. #[inline] pub fn not_found() -> Rejection { loop {} } #[inline] pub(crate) fn invalid_query() -> Rejection { loop {} } #[inline] pub(crate) fn missing_header(name: &'static str) -> Rejection { loop {} } #[inline] pub(crate) fn invalid_header(name: &'static str) -> Rejection { loop {} } #[inline] pub(crate) fn missing_cookie(name: &'static str) -> Rejection { loop {} } #[inline] pub(crate) fn method_not_allowed() -> Rejection { loop {} } #[inline] pub(crate) fn length_required() -> Rejection { loop {} } #[inline] pub(crate) fn payload_too_large() -> Rejection { loop {} } #[inline] pub(crate) fn unsupported_media_type() -> Rejection { loop {} } /// Rejects a request with a custom cause. /// /// A [`recover`][] filter should convert this `Rejection` into a `Reply`, /// or else this will be returned as a `500 Internal Server Error`. /// /// [`recover`]: ../trait.Filter.html#method.recover pub fn custom(err: T) -> Rejection { loop {} } /// Protect against re-rejecting a rejection. /// /// ```compile_fail /// fn with(r: warp::Rejection) { /// let _wat = warp::reject::custom(r); /// } /// ``` fn __reject_custom_compilefail() {} /// A marker trait to ensure proper types are used for custom rejections. /// /// Can be converted into Rejection. /// /// # Example /// /// ``` /// use warp::{Filter, reject::Reject}; /// /// #[derive(Debug)] /// struct RateLimited; /// /// impl Reject for RateLimited {} /// /// let route = warp::any().and_then(|| async { /// Err::<(), _>(warp::reject::custom(RateLimited)) /// }); /// ``` pub trait Reject: fmt::Debug + Sized + Send + Sync + 'static {} trait Cause: fmt::Debug + Send + Sync + 'static { fn as_any(&self) -> &dyn Any; } impl Cause for T where T: fmt::Debug + Send + Sync + 'static, { fn as_any(&self) -> &dyn Any { loop {} } } impl dyn Cause {} pub(crate) fn known>(err: T) -> Rejection { loop {} } /// Rejection of a request by a [`Filter`](crate::Filter). /// /// See the [`reject`](module@crate::reject) documentation for more. pub struct Rejection { reason: Reason, } enum Reason { NotFound, Other(Box), } enum Rejections { Known(Known), Custom(Box), Combined(Box, Box), } macro_rules! enum_known { ($($(#[$attr:meta])* $var:ident ($ty:path),)+) => { pub (crate) enum Known { $($(#[$attr])* $var ($ty),)+ } impl Known { fn inner_as_any(& self) -> & dyn Any { match * self { $($(#[$attr])* Known::$var (ref t) => t,)+ } } } impl fmt::Debug for Known { fn fmt(& self, f : & mut fmt::Formatter <'_ >) -> fmt::Result { match * self { $($(#[$attr])* Known::$var (ref t) => t.fmt(f),)+ } } } impl fmt::Display for Known { fn fmt(& self, f : & mut fmt::Formatter <'_ >) -> fmt::Result { match * self { $($(#[$attr])* Known::$var (ref t) => t.fmt(f),)+ } } } $(#[doc(hidden)] $(#[$attr])* impl From <$ty > for Known { fn from(ty : $ty) -> Known { Known::$var (ty) } })+ }; } enum_known! { MethodNotAllowed(MethodNotAllowed), InvalidHeader(InvalidHeader), MissingHeader(MissingHeader), MissingCookie(MissingCookie), InvalidQuery(InvalidQuery), LengthRequired(LengthRequired), PayloadTooLarge(PayloadTooLarge), UnsupportedMediaType(UnsupportedMediaType), FileOpenError(crate ::fs::FileOpenError), FilePermissionError(crate ::fs::FilePermissionError), BodyReadError(crate ::body::BodyReadError), BodyDeserializeError(crate ::body::BodyDeserializeError), CorsForbidden(crate ::cors::CorsForbidden), #[cfg(feature = "websocket")] MissingConnectionUpgrade(crate ::ws::MissingConnectionUpgrade), MissingExtension(crate ::ext::MissingExtension), BodyConsumedMultipleTimes(crate ::body::BodyConsumedMultipleTimes), } impl Rejection { /// Searches this `Rejection` for a specific cause. /// /// A `Rejection` will accumulate causes over a `Filter` chain. This method /// can search through them and return the first cause of this type. /// /// # Example /// /// ``` /// #[derive(Debug)] /// struct Nope; /// /// impl warp::reject::Reject for Nope {} /// /// let reject = warp::reject::custom(Nope); /// /// if let Some(nope) = reject.find::() { /// println!("found it: {:?}", nope); /// } /// ``` pub fn find(&self) -> Option<&T> { loop {} } /// Returns true if this Rejection was made via `warp::reject::not_found`. /// /// # Example /// /// ``` /// let rejection = warp::reject(); /// /// assert!(rejection.is_not_found()); /// ``` pub fn is_not_found(&self) -> bool { loop {} } } impl From for Rejection { #[inline] fn from(err: T) -> Rejection { loop {} } } impl From for Rejection { #[inline] fn from(infallible: Infallible) -> Rejection { loop {} } } impl IsReject for Infallible { fn status(&self) -> StatusCode { loop {} } fn into_response(&self) -> crate::reply::Response { loop {} } } impl IsReject for Rejection { fn status(&self) -> StatusCode { loop {} } fn into_response(&self) -> crate::reply::Response { loop {} } } impl fmt::Debug for Rejection { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { loop {} } } impl fmt::Debug for Reason { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { loop {} } } impl Rejections {} unit_error! { #[doc = " Invalid query"] pub InvalidQuery : "Invalid query string" } unit_error! { #[doc = " HTTP method not allowed"] pub MethodNotAllowed : "HTTP method not allowed" } unit_error! { #[doc = " A content-length header is required"] pub LengthRequired : "A content-length header is required" } unit_error! { #[doc = " The request payload is too large"] pub PayloadTooLarge : "The request payload is too large" } unit_error! { #[doc = " The request's content-type is not supported"] pub UnsupportedMediaType : "The request's content-type is not supported" } /// Missing request header #[derive(Debug)] pub struct MissingHeader { name: &'static str, } impl MissingHeader { /// Retrieve the name of the header that was missing pub fn name(&self) -> &str { loop {} } } impl fmt::Display for MissingHeader { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { loop {} } } impl StdError for MissingHeader {} /// Invalid request header #[derive(Debug)] pub struct InvalidHeader { name: &'static str, } impl InvalidHeader { /// Retrieve the name of the header that was invalid pub fn name(&self) -> &str { loop {} } } impl fmt::Display for InvalidHeader { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { loop {} } } impl StdError for InvalidHeader {} /// Missing cookie #[derive(Debug)] pub struct MissingCookie { name: &'static str, } impl MissingCookie { /// Retrieve the name of the cookie that was missing pub fn name(&self) -> &str { loop {} } } impl fmt::Display for MissingCookie { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { loop {} } } impl StdError for MissingCookie {} mod sealed { use super::Rejection; use http::StatusCode; use std::convert::Infallible; use std::fmt; pub trait IsReject: fmt::Debug + Send + Sync { fn status(&self) -> StatusCode; fn into_response(&self) -> crate::reply::Response; } fn _assert_object_safe() { loop {} } pub trait CombineRejection: Send + Sized { /// The type that should be returned when only 1 of the two /// "rejections" occurs. /// /// # For example: /// /// `warp::any().and(warp::path("foo"))` has the following steps: /// /// 1. Since this is `and`, only **one** of the rejections will occur, /// and as soon as it does, it will be returned. /// 2. `warp::any()` rejects with `Never`. So, it will never return `Never`. /// 3. `warp::path()` rejects with `Rejection`. It may return `Rejection`. /// /// Thus, if the above filter rejects, it will definitely be `Rejection`. type One: IsReject + From + From + Into; /// The type that should be returned when both rejections occur, /// and need to be combined. type Combined: IsReject; fn combine(self, other: E) -> Self::Combined; } impl CombineRejection for Rejection { type One = Rejection; type Combined = Rejection; fn combine(self, other: Rejection) -> Self::Combined { loop {} } } impl CombineRejection for Rejection { type One = Rejection; type Combined = Infallible; fn combine(self, other: Infallible) -> Self::Combined { loop {} } } impl CombineRejection for Infallible { type One = Rejection; type Combined = Infallible; fn combine(self, _: Rejection) -> Self::Combined { loop {} } } impl CombineRejection for Infallible { type One = Infallible; type Combined = Infallible; fn combine(self, _: Infallible) -> Self::Combined { loop {} } } } #[cfg(test)] mod tests { use super::*; use http::StatusCode; #[derive(Debug, PartialEq)] struct Left; #[derive(Debug, PartialEq)] struct Right; impl Reject for Left {} impl Reject for Right {} #[test] fn rejection_status() { loop {} } #[tokio::test] async fn combine_rejection_causes_with_some_left_and_none_right() { loop {} } #[tokio::test] async fn combine_rejection_causes_with_none_left_and_some_right() { loop {} } #[tokio::test] async fn unhandled_customs() { loop {} } async fn response_body_string(resp: crate::reply::Response) -> String { loop {} } #[test] fn find_cause() { loop {} } #[test] fn size_of_rejection() { loop {} } #[derive(Debug)] struct X(u32); impl Reject for X {} fn combine_n(n: u32, new_reject: F) -> Rejection where F: Fn(u32) -> R, R: Reject, { loop {} } #[test] fn test_debug() { loop {} } }