axum-extra/extract/form: Use serde_path_to_error to report key that…

… failed to parse

axum-extra/Cargo.toml

@@ -23,7 +23,7 @@ cookie-private = ["cookie", "cookie?/private"]
 cookie-signed = ["cookie", "cookie?/signed"]
 cookie-key-expansion = ["cookie", "cookie?/key-expansion"]
 erased-json = ["dep:serde_json", "dep:typed-json"]
-form = ["dep:serde_html_form"]
+form = ["dep:form_urlencoded", "dep:serde_html_form", "dep:serde_path_to_error"]
 json-deserializer = ["dep:serde_json", "dep:serde_path_to_error"]
 json-lines = [
     "dep:serde_json",

axum-extra/src/extract/form.rs

@@ -56,7 +56,9 @@ where
             .await
             .map_err(FormRejection::RawFormRejection)?;
 
-        serde_html_form::from_bytes::<T>(&bytes)
+        let deserializer = serde_html_form::Deserializer::new(form_urlencoded::parse(&bytes));
+
+        serde_path_to_error::deserialize::<_, T>(deserializer)
             .map(Self)
             .map_err(|err| FormRejection::FailedToDeserializeForm(Error::new(err)))
     }
@@ -168,7 +170,7 @@ mod tests {
         assert_eq!(res.status(), StatusCode::BAD_REQUEST);
         assert_eq!(
             res.text().await,
-            "Failed to deserialize form: invalid digit found in string"
+            "Failed to deserialize form: a: invalid digit found in string"
         );
 
         let res = client
@@ -179,7 +181,7 @@ mod tests {
         assert_eq!(res.status(), StatusCode::BAD_REQUEST);
         assert_eq!(
             res.text().await,
-            "Failed to deserialize form: invalid digit found in string"
+            "Failed to deserialize form: a: invalid digit found in string"
         );
     }
 }