Sample

Protect axum routes with stateful middleware using from_fn_with_state, isolate route_layer from 404 fallbacks, and manage bottom-to-top layer execution order

sha256:0add9e86ea54fb151285ed7fff0ac6a073835d84159f6bfc43b6e447f030a7be

PUBLISHED L3_CONTRACT_PASS MIT-0

Case

Goal: Protect axum routes with stateful middleware using from_fn_with_state, isolate route_layer from 404 fallbacks, and manage bottom-to-top layer execution order HOW
Packages: axum 0.8.9 tower 0.5.3 http-body-util 0.1.5 tokio 1.53.1
Environment: rust
Created: 2026-08-16T08:11:01Z

assert route_layer protects routes registered before it, returning 200 with typed Extension and injected headers when authorization token is valid
assert route_layer rejects unauthorized requests with 401 and custom error headers without invoking the route handler
assert route_layer leaves public routes registered after it unprotected, returning 200 without executing the auth middleware or incrementing state call counter
assert an unmatched 404 route on a route_layer router returns 404 Not Found without invoking auth middleware
assert Router::layer wraps the entire router including 404 fallbacks, returning 401 Unauthorized for unmatched paths when authorization is absent
assert an unpopulated Extension extractor fails dynamically at runtime with 500 Internal Server Error when the route is not wrapped by the populating middleware
assert chained layers execute in reverse registration order (bottom-to-top): outer layer runs before inner layer on request, and inner layer runs before outer layer on response
assert sub-router route_layer middleware is isolated to the nested prefix and does not run on parent router routes

rust 1 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · cargo@1 · 2026-08-16 · ed25519:d91480838ac982c9