Sample
axum 0.8.9: Handle silent breaking changes in axum 0.8 OptionalFromRequest and OptionalFromRequestParts extractors where malformed Path, invalid Json, and tuple arity mismatches reject with 400, 415, 422, or 500 instead of returning None
Verified sample for cargo axum 0.8.9: Handle silent breaking changes in axum 0.8 OptionalFromRequest and OptionalFromRequestParts extractors where malformed…
sha256:f6665f3f04e7d8f13d3608f752ed887269d13145363c702ac891e260d741385e
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MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
rust linux x64 rust rust cargo
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| rust 1 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-16 |
| rust 1 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-18 |
Case
HOW- Goal
- Handle silent breaking changes in axum 0.8 OptionalFromRequest and OptionalFromRequestParts extractors where malformed Path, invalid Json, and tuple arity mismatches reject with 400, 415, 422, or 500 instead of returning None
- Packages
- Symbols
-
- axum::extract::Path
- axum::extract::OptionalFromRequestParts
- axum::extract::OptionalFromRequest
- axum::Json
- axum::Router::route
- tower::ServiceExt::oneshot
- Environment
- rust
- Created
- 2026-08-16T08:12:04Z
Contract
- assert Option<Path<u32>> returns Some(Path(42)) on a route with a valid path parameter
- assert Option<Path<u32>> rejects with 400 Bad Request instead of None when the path parameter in the route fails deserialization
- assert Option<Path<u32>> evaluates to None only when the matched route definition contains zero path parameters
- assert Option<Json<T>> evaluates to None only when the Content-Type header is completely omitted
- assert Option<Json<T>> rejects with 400 Bad Request instead of None when Content-Type is application/json but body has malformed JSON syntax
- assert Option<Json<T>> rejects with 422 Unprocessable Entity instead of None when Content-Type is application/json but body has schema or field type mismatches
- assert Option<Json<T>> rejects with 422 Unprocessable Entity instead of None when Content-Type is application/json but required fields are missing
- assert Option<Json<T>> rejects with 415 Unsupported Media Type instead of None when Content-Type header is non-JSON like text/plain
- assert Option<Json<T>> returns Some(Json(T)) when valid JSON body and Content-Type are provided
- assert a 1-tuple Path<(u32,)> on a 2-parameter route rejects with 500 Internal Server Error for arity mismatch instead of silently extracting the first parameter
- assert a 2-tuple Path<(u32, u32)> on a 2-parameter route extracts both parameters and returns 200 OK
Files
- Cargo.lock
- Cargo.toml
- NOTES.md
- csx.json
- src/lib.rs