Extend custom rejection examples (#1276)

* examples: Created new `error-handling` example * examples(error-handling): Add error codes and responses * examples(error-handling): `custom_extractor` * examples(error-handling): `derive_from_request` * examples(error-handling): Using POST instead of GET * examples(error-handling): Using `thiserror` for `derive_from_request` * examples(error-handling): Using `snake-case` for routes * revert(error-handling): Use `From` impl instead of `thiserror` refs: 3533d96215 * examples(error-handling): Removed chrono * examples: merged `error-handling` and `customize-extractor-error` * examples(customize-extractor-error): Improved error codes * examples(customize-extractor-error): rustfmt * examples(customize-extractor-error): Removed `matched-path` feature Co-authored-by: David Pedersen <[email protected]> * examples(customize-extractor-error): added `publish=false` to `Cargo.toml` Co-authored-by: David Pedersen <[email protected]> * examples(customize-extractor-error): Fix env filter * examples(customize-extractor-error): Added README * examples(customize-extractor-error): Added `with_rejection` comments * examples(customize-extractor-error): Added `custom_extractor` comments * examples(customize-extractor-error):Typo on `with_rejection` * examples(customize-extractor-error): Added `boilerplate` con to `custom_extractor` * examples(customize-extractor-error): Added `derive_from_request` comments * examples(customize-extractor-error): typo impossible * examples(customize-extractor-error): typos * examples(customize-extractor-error): replaced `extensions` with `extract` * examples(customize-extractor-error): typo `from` Co-authored-by: David Pedersen <[email protected]> Co-authored-by: David Pedersen <[email protected]>
2026-09-03 00:00:07 +02:00 · 2022-08-19 13:11:03 +00:00
parent 18dd830b84
commit 789f51ba1a
6 changed files with 219 additions and 74 deletions
@@ -0,0 +1,57 @@
+//! Uses `axum_extra::extract::WithRejection` to transform one rejection into
+//! another
+//!
+//! + Easy learning curve: `WithRejection` acts as a wrapper for another
+//!   already existing extractor. You only need to provide a `From` impl
+//!   between the original rejection type and the target rejection. Crates like
+//!   `thiserror` can provide such conversion using derive macros. See
+//!   [`thiserror`]
+//! - Verbose types: types become much larger, which makes them difficult to
+//!   read. Current limitations on type aliasing makes impossible to destructure
+//!   a type alias. See [#1116]
+//!   
+//! [`thiserror`]: https://crates.io/crates/thiserror
+//! [#1116]: https://github.com/tokio-rs/axum/issues/1116#issuecomment-1186197684
+
+use axum::{extract::rejection::JsonRejection, http::StatusCode, response::IntoResponse, Json};
+use axum_extra::extract::WithRejection;
+use serde_json::{json, Value};
+use thiserror::Error;
+
+pub async fn handler(
+    // `WitRejection` will extract `Json<Value>` from the request. If it fails,
+    // `JsonRejection` will be transform into `ApiError` and returned as response
+    // to the client.
+    //
+    // The second constructor argument is not meaningful and can be safely ignored
+    WithRejection(Json(value), _): WithRejection<Json<Value>, ApiError>,
+) -> impl IntoResponse {
+    Json(dbg!(value))
+}
+
+// We derive `thiserror::Error`
+#[derive(Debug, Error)]
+pub enum ApiError {
+    // The `#[from]` attribute generates `From<JsonRejection> for ApiError`
+    // implementation. See `thiserror` docs for more information
+    #[error(transparent)]
+    JsonExtractorRejection(#[from] JsonRejection),
+}
+// We implement `IntoResponse` so ApiError can be used as a response
+impl IntoResponse for ApiError {
+    fn into_response(self) -> axum::response::Response {
+        let payload = json!({
+            "message": self.to_string(),
+            "origin": "with_rejection"
+        });
+        let code = match self {
+            ApiError::JsonExtractorRejection(x) => match x {
+                JsonRejection::JsonDataError(_) => StatusCode::UNPROCESSABLE_ENTITY,
+                JsonRejection::JsonSyntaxError(_) => StatusCode::BAD_REQUEST,
+                JsonRejection::MissingJsonContentType(_) => StatusCode::UNSUPPORTED_MEDIA_TYPE,
+                _ => StatusCode::INTERNAL_SERVER_ERROR,
+            },
+        };
+        (code, Json(payload)).into_response()
+    }
+}