`FromRequest` derive with `Option<T>` field unexpected semantics

[shikhar]

• I have looked for existing issues (including closed) about this

Bug Report

Version

0.8.8

Platform

25.2.0 Darwin Kernel Version 25.2.0: Tue Nov 18 21:07:05 PST 2025; root:xnu-12377.61.12~1/RELEASE_ARM64_T6020 arm64

Crates

axum-macros

Description

#[derive(FromRequest)]
#[from_request(rejection(MyError))]
pub struct Args {
    #[from_request(via(Path))]
    something: String,
    #[from_request(via(Json))]
    request: Option<T>
}

What I expect: for the optional request field, I get a Some(T) only if a valid JSON body is provided. If it is invalid, it should cause a JsonRejection with the From<JsonRejection> for MyError impl.

What is happening: the expanded version is using FromRequest and .ok() to convert a JsonRejection into None.

What I think should happen: optional field should require the extractor to implement OptionalFromRequest, and use that.