add feature 422 and update version to 0.4.0

.gitignore

@@ -1,3 +1,4 @@
 /target
 /Cargo.lock
 /.idea
+/lcov.info

Cargo.toml

@@ -44,3 +44,4 @@ json = ["axum/json"]
 form = ["axum/form"]
 query = ["axum/query"]
 into_json = ["serde_json"]
+422 = []

README.md

@@ -44,8 +44,11 @@ pub async fn get_page_by_json(
 }
 ```
 
+When validation errors occur, the extractor will automatically return 400 with validation errors as the HTTP message body.
+
 For more usage examples, please refer to the `basic.rs` and `custom.rs` files in the `tests` directory.
 
 ## Features
 
+`422`: Use `422 Unprocessable Entity` instead of `400 Bad Request` as the status code when validation fails.
 `into_json`: When this feature is enabled, validation errors will be serialized into JSON format and returned as the HTTP body.

src/lib.rs

@@ -16,6 +16,13 @@ use axum::http::{Request, StatusCode};
 use axum::response::{IntoResponse, Response};
 use validator::{Validate, ValidationErrors};
 
+/// Http status code returned when there are validation errors.
+#[cfg(feature = "422")]
+pub const VALIDATION_ERROR_STATUS: StatusCode = StatusCode::UNPROCESSABLE_ENTITY;
+/// Http status code returned when there are validation errors.
+#[cfg(not(feature = "422"))]
+pub const VALIDATION_ERROR_STATUS: StatusCode = StatusCode::BAD_REQUEST;
+
 /// Valid entity extractor
 #[derive(Debug, Clone, Copy, Default)]
 pub struct Valid<T>(pub T);
@@ -41,14 +48,14 @@ impl<E: IntoResponse> IntoResponse for ValidRejection<E> {
             ValidRejection::Valid(validate_error) => {
                 #[cfg(feature = "into_json")]
                 match serde_json::to_string(&validate_error) {
-                    Ok(json) => (StatusCode::BAD_REQUEST, json),
+                    Ok(json) => (VALIDATION_ERROR_STATUS, json),
                     Err(error) => (
                         StatusCode::INTERNAL_SERVER_ERROR,
                         format!("Failed to serialize validation error into JSON ({validate_error}): {error}"),
                     ),
                 }
                 #[cfg(not(feature = "into_json"))]
-                (StatusCode::BAD_REQUEST, validate_error.to_string())
+                (VALIDATION_ERROR_STATUS, validate_error.to_string())
             }.into_response(),
             ValidRejection::Inner(json_error) => json_error.into_response(),
         }

tarpaulin.toml

@@ -2,3 +2,9 @@
 
 [feature_into_json]
 features = "into_json"
+
+[feature_422]
+features = "422"
+
+[feature_422_into_json]
+features = "422 into_json"

tests/basic.rs

@@ -9,7 +9,7 @@ use axum::extract::{Path, Query};
 use axum::http::StatusCode;
 use axum::routing::{get, post};
 use axum::{Form, Json, Router};
-use axum_valid::Valid;
+use axum_valid::{Valid, VALIDATION_ERROR_STATUS};
 use serde::{Deserialize, Serialize};
 use serde_json::json;
 use std::net::SocketAddr;
@@ -76,7 +76,7 @@ async fn main() -> anyhow::Result<()> {
         ))
         .send()
         .await?;
-    assert_eq!(invalid_path_response.status(), StatusCode::BAD_REQUEST);
+    assert_eq!(invalid_path_response.status(), VALIDATION_ERROR_STATUS);
     #[cfg(feature = "into_json")]
     assert!(invalid_path_response
         .json::<serde_json::Value>()
@@ -105,7 +105,7 @@ async fn main() -> anyhow::Result<()> {
         .query(&invalid_parameters)
         .send()
         .await?;
-    assert_eq!(invalid_query_response.status(), StatusCode::BAD_REQUEST);
+    assert_eq!(invalid_query_response.status(), VALIDATION_ERROR_STATUS);
     #[cfg(feature = "into_json")]
     assert!(invalid_query_response
         .json::<serde_json::Value>()
@@ -137,7 +137,7 @@ async fn main() -> anyhow::Result<()> {
         .form(&invalid_parameters)
         .send()
         .await?;
-    assert_eq!(invalid_form_response.status(), StatusCode::BAD_REQUEST);
+    assert_eq!(invalid_form_response.status(), VALIDATION_ERROR_STATUS);
     #[cfg(feature = "into_json")]
     assert!(invalid_form_response
         .json::<serde_json::Value>()
@@ -169,7 +169,7 @@ async fn main() -> anyhow::Result<()> {
         .json(&invalid_parameters)
         .send()
         .await?;
-    assert_eq!(invalid_json_response.status(), StatusCode::BAD_REQUEST);
+    assert_eq!(invalid_json_response.status(), VALIDATION_ERROR_STATUS);
     #[cfg(feature = "into_json")]
     assert!(invalid_json_response
         .json::<serde_json::Value>()

tests/custom.rs

@@ -6,7 +6,7 @@ use axum::http::request::Parts;
 use axum::response::{IntoResponse, Response};
 use axum::routing::get;
 use axum::Router;
-use axum_valid::{HasValidate, Valid, ValidRejection};
+use axum_valid::{HasValidate, Valid, ValidRejection, VALIDATION_ERROR_STATUS};
 use hyper::StatusCode;
 use serde::{Deserialize, Serialize};
 use std::net::SocketAddr;
@@ -122,7 +122,7 @@ async fn main() -> anyhow::Result<()> {
         .header(MY_DATA_HEADER, serde_json::to_string(&invalid_my_data)?)
         .send()
         .await?;
-    assert_eq!(invalid_my_data_response.status(), StatusCode::BAD_REQUEST);
+    assert_eq!(invalid_my_data_response.status(), VALIDATION_ERROR_STATUS);
     #[cfg(feature = "into_json")]
     assert!(invalid_my_data_response
         .json::<serde_json::Value>()